Analysis on influencing factors of abnormal renal function in elderly patients with type 2 diabetes mellitus.

PubMed

Chai, Tao; Zhang, Dawei; Li, Zhongxin

2018-04-12

To investigate the related influencing factors of abnormal renal function in elderly in patients with type 2 diabetes mellitus (T2DM) and their clinical significance. The clinical data of elderly T2DM patients hospitalized in Beijing Luhe Hospital from January 2013 to June2016 were retrospectively analyzed. According to their glomerular filtration rate (GFR) levels, these patients were divided into GFR ≥90 mL/min/1.73m2 group (Group A), GFR =60-90 mL/min/1.73m2 group (Group B), and GFR <60 mL/min/1.73m2 group (Group C, i.e., abnormal renal function group). Clinical and laboratory indicators were compared among each group. A total of 614 elderly T2DM patients were collected and divided into Group A (n=186), Group B (n=280) and Group C (n=148, 24.10%). Among them, patients clinically diagnosed with diabetic nephropathy (DN) accounted for 13.68%, and those complicated with high blood pressure (HBP) accounted for 61.40%. In Group C, DN accounted for only 29.73%. In elderly T2DM patients, HBP course, systolic blood pressure (SBP), diastolic blood pressure (DBP), 2h postprandial blood glucose (2hPBG), serum total cholesterol (TC) and blood uric acid (BUA) were independent influencing factors associated with abnormal renal function, among which HBP had a more significant impact on abnormal renal function. With the increase of blood pressure (BP) level, the extension in the course of DM, the increase in urinary albumin/creatinine (Alb/Cr) and the decrease in GFR, the incidence rate of abnormal renal function was increased. HBP course, SBP, DBP, 2hPBG, TC and BUA are independent risk factors for abnormal renal function in elderly patients with T2DM. Well-controlled BP and blood glucose are protective factors, and a comprehensive treatment targeting to the above influencing factors has important clinical significance in preventing and delaying the occurrence and development of abnormal renal function.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geyskes, G.G.; Oei, H.Y.; Puylaert, C.B.

Radioisotope renography was performed in 21 patients with hypertension and unilateral renal artery stenosis with and without premedication with 25 mg of captopril, and the results were compared with the effect of percutaneous transluminal angioplasty on the blood pressure, assessed 6 weeks after angioplasty. Angioplasty caused a considerable decrease in blood pressure in 15 of the 21 patients. In 12 of these 15 patients, captopril induced changes in the time-activity curves of the affected kidney only, suggesting deterioration of the excretory function of that kidney, while the function of the contralateral kidney remained normal. After angioplasty the asymmetry in themore » time-activity curves diminished despite identical pretreatment with captopril. Such captopril-induced unilateral impairment of the renal function was not seen in the six patients with unilateral renal artery stenosis whose blood pressure did not change after percutaneous transluminal angioplasty or in 13 patients with hypertension and normal renal arteries. The functional impairment of the affected kidneys was characterized by a decrease of /sup 99m/Tc-diethylenetriamine pentaacetic acid uptake and a delay of /sup 131/I-hippurate excretion, while the /sup 131/I-hippurate uptake remained unaffected. These data are in agreement with a reduced glomerular filtration rate and diuresis during preservation of the renal blood flow, changes that can be expected after converting enzyme inhibition in a kidney with low perfusion and an active, renin-mediated autoregulation of the glomerular filtration rate. These data suggest that functional captopril-induced unilateral changes, shown by split renal function studies with noninvasive gamma camera scintigraphy, can be used as a diagnostic test for renovascular hypertension caused by unilateral renal artery stenosis.« less

Renal neural mechanisms in salt-sensitive hypertension.

PubMed

DiBona, G F

1995-01-01

Genetic forms of salt (NaCl)-sensitive hypertension are characterized by increased renal sympathetic nerve activity responses to environmental stimuli. The increases in renal sympathetic nerve activity produce marked changes in renal function with renal vasoconstriction and sodium and water retention which can contribute to the initiation, development and maintenance of hypertension. In genetic forms of NaCl-sensitive hypertension, increased dietary NaCl intake produces alterations in norepinephrine kinetics with decreased concentrations of norepinephrine in regions of the anterior hypothalamus which are critical for the regulation of peripheral sympathetic nerve activity. This local central decrease in tonic alpha 2 adrenoceptor sympathoinhibitory input leads to increased peripheral (renal) sympathetic nerve activity and hypertension. Similarly, with increased dietary NaCl intake, patients with NaCl-sensitive hypertension develop increased arterial pressure, renal vasoconstriction, increased glomerular capillary pressure and increased urinary albumin excretion. Thus, increased dietary NaCl intake can, via central nervous system actions, produce increases in renal sympathetic nerve activity whose renal functional effects contribute to the pathophysiology of hypertension.

Neural regulation of the kidney function in rats with cisplatin induced renal failure

PubMed Central

Goulding, Niamh E.; Johns, Edward J.

2015-01-01

Aim: Chronic kidney disease (CKD) is often associated with a disturbed cardiovascular homeostasis. This investigation explored the role of the renal innervation in mediating deranged baroreflex control of renal sympathetic nerve activity (RSNA) and renal excretory function in cisplatin-induced renal failure. Methods: Rats were either intact or bilaterally renally denervated 4 days prior to receiving cisplatin (5 mg/kg i.p.) and entered a chronic metabolic study for 8 days. At day 8, other groups of rats were prepared for acute measurement of RSNA or renal function with either intact or denervated kidneys. Results: Following the cisplatin challenge, creatinine clearance was 50% lower while fractional sodium excretion and renal cortical and medullary TGF-β1 concentrations were 3–4 fold higher in both intact and renally denervated rats compared to control rats. In cisplatin-treated rats, the maximal gain of the high-pressure baroreflex curve was only 20% that of control rats, but following renal denervation not different from that of renally denervated control rats. Volume expansion reduced RSNA by 50% in control and in cisplatin-treated rats but only following bilateral renal denervation. The volume expansion mediated natriuresis/diuresis was absent in the cisplatin-treated rats but was normalized following renal denervation. Conclusions: Cisplatin-induced renal injury impaired renal function and caused a sympatho-excitation with blunting of high and low pressure baroreflex regulation of RSNA, which was dependent on the renal innervation. It is suggested that in man with CKD there is a dysregulation of the neural control of the kidney mediated by its sensory innervation. PMID:26175693

Renal blood flow dynamics in inbred rat strains provides insight into autoregulation.

PubMed

A Mitrou, Nicholas G; Cupples, William A

2014-01-01

Renal autoregulation maintains stable renal blood flow in the face of constantly fluctuating blood pressure. Autoregulation is also the only mechanism that protects the delicate glomerular capillaries when blood pressure increases. In order to understand autoregulation, the renal blood flow response to changing blood pressure is studied. The steadystate response of blood flow is informative, but limits investigation of the individual mechanisms of autoregulation. The dynamics of autoregulation can be probed with transfer function analysis. The frequency-domain analysis of autoregulation allows investigators to probe the relative activity of each mechanism of autoregulation. We discuss the methodology and interpretation of transfer function analysis. Autoregulation is routinely studied in the rat, of which there are many inbred strains. There are multiple strains of rat that are either selected or inbred as models of human pathology. We discuss relevant characteristics of Brown Norway, Spontaneously hypertensive, Dahl, and Fawn-Hooded hypertensive rats and explore differences among these strains in blood pressure, dynamic autoregulation, and susceptibility to hypertensive renal injury. Finally we show that the use of transfer function analysis in these rat strains has contributed to our understanding of the physiology and pathophysiology of autoregulation and hypertensive renal disease.Interestingly all these strains demonstrate effective tubuloglomerular feedback suggesting that this mechanism is not sufficient for effective autoregulation. In contrast, obligatory or conditional failure of the myogenic mechanism suggests that this component is both necessary and sufficient for autoregulation.

Renal mechanoreceptor dysfunction: an intermediate phenotype in spontaneously hypertensive rats.

PubMed

DiBona, G F; Jones, S Y; Kopp, U C

1999-01-01

This study tested the hypothesis that decreased responsiveness of renal mechanosensitive neurons constitutes an intermediate phenotype in spontaneously hypertensive rats (SHR). Decreased responsiveness of these sensory neurons would contribute to increased renal sympathetic nerve activity and sodium retention, characteristic findings in hypertension. A backcross population, developed by mating borderline hypertensive rats with Wistar-Kyoto rats (WKY) (the F1 of a cross between an SHR and a normotensive WKY), was fed 8% NaCl food for 12 weeks from age 4 to 16 weeks. Responses to increases in ureteral pressure to 20 and 40 mm Hg in 80 backcross rats instrumented for measurement of mean arterial pressure and afferent renal nerve activity were determined. Mean arterial pressure ranged from 110 to 212 mm Hg and was inversely correlated with the magnitude of the increase in afferent renal nerve activity during increased ureteral pressure. Thus, decreased responsiveness of renal mechanosensitive neurons cosegregated with hypertension in this backcross population. This aspect of the complex quantitative trait of altered renal sympathetic neural control of renal function, ie, decreased renal mechanoreceptor responsiveness, is part of an intermediate phenotype in SHR.

Mechanisms responsible for decreased glomerular filtration in hibernation and hypothermia

NASA Technical Reports Server (NTRS)

Tempel, G. E.; Musacchia, X. J.; Jones, S. B.

1977-01-01

Measurements of blood pressure, heart rate, red blood cell and plasma volumes, and relative distribution of cardiac output were made on hibernating and hypothermic adult male and female golden hamsters weighing 120-140 g to study the mechanisms underlying the elimination or marked depression of renal function in hibernation and hypothermia. The results suggest that the elimination or marked depression in renal function reported in hibernation and hypothermia may partly be explained by alterations in cardiovascular system function. Renal perfusion pressure which decreases nearly 60% in both hibernation and hypothermia and a decrease in plasma volume of roughly 35% in the hypothermic animal might both be expected to markedly alter glomerular function.

Surgical treatment reduces blood pressure in children with unilateral congenital hydronephrosis.

PubMed

Al-Mashhadi, Ammar; Nevéus, Tryggve; Stenberg, Arne; Karanikas, Birgitta; Persson, A Erik G; Carlström, Mattias; Wåhlin, Nils

2015-04-01

Renal disorders can cause hypertension, but less is known about the influence of hydronephrosis on blood pressure. Hydronephrosis due to pelvo-ureteric junction obstruction (PUJO) is a fairly common condition (incidence in newborns of 0.5-1%). Although hypertensive effects of hydronephrosis have been suggested, this has not been substantiated by prospective studies in humans [1-3]. Experimental studies with PUJO have shown that animals with induced hydronephrosis develop salt-sensitive hypertension, which strongly correlate to the degree of obstruction [4-7]. Moreover, relief of the obstruction normalized blood pressure [8]. In this first prospective study our aim was to study the blood pressure pattern in pediatric patients with hydronephrosis before and after surgical correction of the ureteral obstruction. Specifically, we investigated if preoperative blood pressure is reduced after surgery and if split renal function and renographic excretion curves provide any prognostic information. Twelve patients with unilateral congenital hydronephrosis were included in this prospective study. Ambulatory blood pressure (24 h) was measured preoperatively and six months after surgery. Preoperative evaluations of bilateral renal function by Tc99m-MAG3 scintigraphy, and renography curves, classified according to O'Reilly, were also performed. As shown in the summary figure, postoperative systolic (103 ± 2 mmHg) and diastolic (62 ± 2 mmHg) blood pressure were significantly lower than those obtained preoperatively (110 ± 4 and 69 ± 2 mmHg, respectively), whereas no changes in circadian variation or pulse pressure were observed. Renal functional share of the hydronephrotic kidney ranged from 11 to 55%. There was no correlation between the degree of renal function impairment and the preoperative excretory pattern, or between the preoperative excretory pattern and the blood pressure reduction postoperatively. However, preoperative MAG3 function of the affected kidney correlated with the magnitude of blood pressure change after surgery. Correction of the obstruction lowered blood pressure, and the reduction in blood pressure appeared to correlate with the degree of renal functional impairment, but not with the excretory pattern. Thus, in the setting of hypertension, it appears that the functional share of the hydronephrotic kidney should be considered an indicator of the need for surgery, whereas the renography curve is less reliable. The strength of the present study is the prospective nature and that ambulatory blood pressure monitoring was used. Future longitudinal prolonged follow-up studies are warranted to confirm the present findings, and to understand if a real nephrogenic hypertension with potential necessity of treatment will develop. This novel prospective study in patients with congenital hydronephrosis demonstrates a reduction in blood pressure following relief of the obstruction. Based on the present results, we propose that the blood pressure level should also be taken into account when deciding whether to correct hydronephrosis surgically or not. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Treatment of pressure ulcers in patients with declining renal function using arginine, glutamine and ß-hydroxy-ß-methylbutyrate.

PubMed

Ogura, Y; Yuki, N; Sukegane, A; Nishi, T; Miyake, Y; Sato, H; Miyamoto, C; Mihara, C

2015-10-01

The aim of this study is to examine the efficacy on healing pressure ulcers (PU) of using a supplement combination containing arginine, glutamine and ß-hydroxy-ß-methylbutyrate, which was given to two elderly patients with renal dysfunction. The PU was surgically opened, decompressed and treated by drugs. A half quantity of the defined dose of the supplement combination, with an enteral nutrition product, was administered to the patients twice a day. This combination improved the PUs, with no effect on renal function. This novel finding may provide a nutritional rationale of arginine, glutamine and ß-hydroxy-ß-methylbutyrate for PUs associated with renal dysfunction.

Revascularization to preserve renal function in patients with atherosclerotic renovascular disease.

PubMed

Novick, A C; Textor, S C; Bodie, B; Khauli, R B

1984-08-01

There are a significant number of patients with advanced atherosclerotic renovascular disease whose blood pressure is well controlled with medical therapy but in whom such vascular disease poses a grave risk to overall renal function. This article reviews current concepts regarding screening, evaluation, and selection of patients with this disease for revascularization to preserve renal function. The underlying rationale for this approach is an increasing awareness that, in selected patients, atherosclerotic renovascular disease represents a surgically correctable cause of progressive renal failure.

Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis.

PubMed

Qiu, Zhenzhen; Zheng, Kai; Zhang, Haoxiang; Feng, Ji; Wang, Lizhi; Zhou, Hao

2017-01-01

Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO 2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits.

Physical Exercise and Patients with Chronic Renal Failure: A Meta-Analysis

PubMed Central

Qiu, Zhenzhen; Zheng, Kai; Zhang, Haoxiang; Feng, Ji; Wang, Lizhi

2017-01-01

Chronic renal failure is a severe clinical problem which has some significant socioeconomic impact worldwide and hemodialysis is an important way to maintain patients' health state, but it seems difficult to get better in short time. Considering these, the aim in our research is to update and evaluate the effects of exercise on the health of patients with chronic renal failure. The databases were used to search for the relevant studies in English or Chinese. And the association between physical exercise and health state of patients with chronic renal failure has been investigated. Random-effect model was used to compare the physical function and capacity in exercise and control groups. Exercise is helpful in ameliorating the situation of blood pressure in patients with renal failure and significantly reduces VO2 in patients with renal failure. The results of subgroup analyses show that, in the age >50, physical activity can significantly reduce blood pressure in patients with renal failure. The activity program containing warm-up, strength, and aerobic exercises has benefits in blood pressure among sick people and improves their maximal oxygen consumption level. These can help patients in physical function and aerobic capacity and may give them further benefits. PMID:28316986

Role of neuropeptide Y in renal sympathetic vasoconstriction: studies in normal and congestive heart failure rats.

PubMed

DiBona, G F; Sawin, L L

2001-08-01

Sympathetic nerve activity, including that in the kidney, is increased in heart failure with increased plasma concentrations of norepinephrine and the vasoconstrictor cotransmitter neuropeptide Y (NPY). We examined the contribution of NPY to sympathetically mediated alterations in kidney function in normal and heart failure rats. Heart failure rats were created by left coronary ligation and myocardial infarction. In anesthetized normal rats, the NPY Y(1) receptor antagonist, H 409/22, at two doses, had no effect on heart rate, arterial pressure, or renal hemodynamic and excretory function. In conscious severe heart failure rats, high-dose H 409/22 decreased mean arterial pressure by 8 +/- 2 mm Hg but had no effect in normal and mild heart failure rats. During graded frequency renal sympathetic nerve stimulation (0 to 10 Hz), high-dose H 409/22 attenuated the decreases in renal blood flow only at 10 Hz (-36% +/- 5%, P <.05) in normal rats but did so at both 4 (-29% +/- 4%, P <.05) and 10 Hz (-33% +/- 5%, P <.05) in heart failure rats. The glomerular filtration rate, urinary flow rate, and sodium excretion responses to renal sympathetic nerve stimulation were not affected by high-dose H 409/22 in either normal or heart failure rats. NPY does not participate in the regulation of kidney function and arterial pressure in normal conscious or anesthetized rats. When sympathetic nervous system activity is increased, as in heart failure and intense renal sympathetic nerve stimulation, respectively, a small contribution of NPY to maintenance of arterial pressure and to sympathetic renal vasoconstrictor responses may be identified.

Neural control of renal function.

PubMed

Johns, Edward J; Kopp, Ulla C; DiBona, Gerald F

2011-04-01

The kidney is innervated with efferent sympathetic nerve fibers that directly contact the vasculature, the renal tubules, and the juxtaglomerular granular cells. Via specific adrenoceptors, increased efferent renal sympathetic nerve activity decreases renal blood flow and glomerular filtration rate, increases renal tubular sodium and water reabsorption, and increases renin release. Decreased efferent renal sympathetic nerve activity produces opposite functional responses. This integrated system contributes importantly to homeostatic regulation of sodium and water balance under physiological conditions and to pathological alterations in sodium and water balance in disease. The kidney contains afferent sensory nerve fibers that are located primarily in the renal pelvic wall where they sense stretch. Stretch activation of these afferent sensory nerve fibers elicits an inhibitory renorenal reflex response wherein the contralateral kidney exhibits a compensatory natriuresis and diuresis due to diminished efferent renal sympathetic nerve activity. The renorenal reflex coordinates the excretory function of the two kidneys so as to facilitate homeostatic regulation of sodium and water balance. There is a negative feedback loop in which efferent renal sympathetic nerve activity facilitates increases in afferent renal nerve activity that in turn inhibit efferent renal sympathetic nerve activity so as to avoid excess renal sodium retention. In states of renal disease or injury, there is activation of afferent sensory nerve fibers that are excitatory, leading to increased peripheral sympathetic nerve activity, vasoconstriction, and increased arterial pressure. Proof of principle studies in essential hypertensive patients demonstrate that renal denervation produces sustained decreases in arterial pressure. © 2011 American Physiological Society. Compr Physiol 1:699-729, 2011.

Impact of Iodinated Contrast on Renal Function and Hemodynamics in Rats with Chronic Hyperglycemia and Chronic Kidney Disease

PubMed Central

Fernandes, Sheila Marques; Martins, Daniel Malisani; da Fonseca, Cassiane Dezoti; Watanabe, Mirian; Vattimo, Maria de Fátima Fernandes

2016-01-01

Iodinated contrast (IC) is clinically used in diagnostic and interventional procedures, but its use can result in contrast-induced acute kidney injury (CI-AKI). Chronic kidney disease (CKD) and chronic hyperglycemia (CH) are important predisposing factors to CI-AKI. The aim of this study was to investigate the impact of iodinated contrast on the renal function and hemodynamics in rats with chronic hyperglycemia and chronic kidney disease. A total of 30 rats were divided into six groups; Sham: control of chronic renal disease; Citrate: control of chronic hyperglycemia (CH); Nx5/6: rats with 5/6 nephrectomy; Chronic Hyperglycemia: rats receiving Streptozotocin 65 mg/kg; Nx5/6 + IC: rats Nx5/6 received 6 mL/kg of IC; CH + IC: Chronic hyperglycemia rats receiving 6 mL/kg of IC. Renal function (inulin clearance; urinary neutrophil gelatinase-associated lipocalin, NGAL) and hemodynamics (arterial blood pressure; renal blood flow; renal vascular resistance) were evaluated. Iodinated contrast significantly increased urinary NGAL and reduced inulin clearance, while the hemodynamics parameters showed changes in arterial blood pressure, renal blood flow, and renal vascular resistance in both CKD and CH groups. The results suggest that the iodinated contrast in risk factors models has important impact on renal function and hemodynamics. NGAL was confirmed to play a role of highlight in diagnosis of CI-AKI. PMID:27034930

Vesicoureteral reflux in the primate IV: does reflux harm the kidney

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, J.A.; Fischman, N.H.; Thomas, R.

1982-09-01

It has been said that vesicoureteral reflux causes renal scarring because of intrarenal reflux. We studied reflux in the monkey because of its similarity to man, especially in regard to the incidence of vesicoureteral reflux and chronic pyelonephritis. High pressure moderate grade reflux was produced and renal function followed by means of quantitative renal camera studies using /sup 131/I hippuran. There was no change in renal function from sterile reflux even when intrarenal reflux occurred. When, however, infection was introduced, renal function decreased. We concluded that sterile moderate vesicoureteral or intrarenal reflux does not harm the kidney.

Arterial stiffness and decline of renal function in a primary care population.

PubMed

van Varik, Bernard J; Vossen, Liv M; Rennenberg, Roger J; Stoffers, Henri E; Kessels, Alfons G; de Leeuw, Peter W; Kroon, Abraham A

2017-01-01

Arterial stiffness is an important pathophysiological factor linking cardiovascular disease and kidney disease. Controversy exists as to whether arterial stiffness causes renal function decline, or kidney dysfunction leads to stiffening or whether the association is mutual. We aimed to investigate the longitudinal association between arterial stiffness and annual rate of renal function decline. We prospectively investigated in a primary care population whether carotid-femoral pulse wave velocity (PWV) was associated with estimated glomerular filtration rate (eGFR) and annual decline in eGFR in participants aged ⩾40 years without overt kidney disease. Baseline data on PWV and eGFR were available for 587 participants; follow-up measurements with a mean duration of 5.6 years were available for 222 patients. PWV, female gender and mean arterial pressure were independently associated with eGFR at baseline, although age confounded this association. More importantly, baseline PWV, age and eGFR were independent predictors of renal function decline. Stratification for age showed that the effect of PWV on rate of eGFR decline was amplified with advancing age. On the other hand, baseline eGFR did not determine annual change in PWV, suggesting a unidirectional association between arterial stiffness and eGFR. Arterial stiffness amplifies age-related renal function decline, suggesting that arterial stiffness plays a causal role in the development of renal damage, at least at later stages of age-related renal function decline, possibly through impaired renal autoregulation and increased arterial blood pressure pulsatility.

Changes in Renal Function and Blood Pressure in Patients with Stone Disease

NASA Astrophysics Data System (ADS)

Worcester, Elaine M.

2007-04-01

Stone disease is a rare cause of renal failure, but a history of kidney stones is associated with an increased risk for chronic kidney disease, particularly in overweight patients. Loss of renal function seems especially notable for patients with stones associated with cystinuria, hyperoxaluria, and renal tubular acidosis, in whom the renal pathology shows deposits of mineral obstructing inner medullary collecting ducts, often diffusely. However, even idiopathic calcium oxalate stone formers have a mild but significant decrease in renal function, compared to age, sex and weight-matched normals, and appear to lose renal function with age at a slightly faster rate than non-stone formers. There is also an increased incidence of hypertension among stone formers, although women are more likely to be affected than men.

Vascular and renal function in experimental thyroid disorders.

PubMed

Vargas, Félix; Moreno, Juan Manuel; Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Osuna, Antonio; Alvarez-Guerra, Miriam; García-Estañ, Joaquín

2006-02-01

This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism. The hypothyroid state is accompanied by a marked decrease in sensitivity to vasoconstrictors, especially to sympathetic agonists, alteration that may play a role in the reduced blood pressure of hypothyroid rats, as well as in the preventive effects of hypothyroidism on experimental hypertension. Moreover, in hypothyroid rats, the endothelium-dependent and nitric oxide donors vasodilation is reduced. Conversely, the vessels from hyperthyroid rats showed an increased endothelium-dependent responsiveness that may be secondary to the shear-stress induced by the hyperdynamic circulation, and that may contribute to the reduced vascular resistance characteristic of this disease. Thyroid hormones also have important effects in the kidney, affecting renal growth, renal haemodynamics, and salt and water metabolism. In hyperthyroidism, there is a resetting of the pressure-natriuresis relationship related to hyperactivity of the renin-angiotensin system, which contributes to the arterial hypertension associated with this endocrine disease. Moreover, thyroid hormones affect the development and/or maintenance of various forms of arterial hypertension. This review also describes recent advances in our understanding of thyroid hormone action on nitric oxide and oxidative stress in the regulation of cardiovascular and renal function and in the long-term control of blood pressure.

Accelerated decline of renal function in type 2 diabetes following severe hypoglycemia.

PubMed

Tsujimoto, Tetsuro; Yamamoto-Honda, Ritsuko; Kajio, Hiroshi; Kishimoto, Miyako; Noto, Hiroshi; Hachiya, Remi; Kimura, Akio; Kakei, Masafumi; Noda, Mitsuhiko

2016-01-01

This study aimed to evaluate whether the pronounced elevation in blood pressure during severe hypoglycemia is associated with subsequent renal insufficiency. We conducted a 3-year cohort study to assess the clinical course of renal function in type 2 diabetes patients with or without blood pressure surge during severe hypoglycemia. Of 111 type 2 diabetes patients with severe hypoglycemia, 76 exhibited an extremely high systolic blood pressure before treatment, whereas 35 demonstrated no such increase (179.1 ± 27.7 mmHg vs. 131.1 ± 20.2 mmHg, P<0.001). At 12h after treatment, systolic blood pressure did not differ significantly (131.5 ± 30.7 mmHg vs. 123.5 ± 20.7 mmHg; P=0.39). The estimated glomerular filtration rate (GFR) before and at the time of severe hypoglycemia did not significantly differ between both groups. A multivariate Cox proportional hazards regression analysis revealed that blood pressure surge during severe hypoglycemia was independently associated with a composite outcome of a more than 15 mL/min/1.73 m(2) decrease in the estimated GFR and initiation of chronic dialysis (hazard ratio, 2.68; 95% confidence interval, 1.12-6.38; P=0.02). Renal function after severe hypoglycemia was significantly worse in type 2 diabetes patients with blood pressure surge during severe hypoglycemia than those without blood pressure surge. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Hemodynamic Measurements for the Selection of Patients With Renal Artery Stenosis: A Systematic Review.

PubMed

van Brussel, Peter M; van de Hoef, Tim P; de Winter, Robbert J; Vogt, Liffert; van den Born, Bert-Jan

2017-05-22

Interventions targeting renal artery stenoses have been shown to lower blood pressure and preserve renal function. In recent studies, the efficacy of catheter-based percutaneous transluminal renal angioplasty with stent placement has been called into question. In the identification of functional coronary lesions, hyperemic measurements have earned a place in daily practice for clinical decision making, allowing discrimination between solitary coronary lesions and diffuse microvascular disease. Next to differences in clinical characteristics, the selection of renal arteries suitable for intervention is currently on the basis of anatomic grading of the stenosis by angiography rather than functional assessment under hyperemia. It is conceivable that, like the coronary circulation, functional measurements may better predict therapeutic efficacy of percutaneous transluminal renal angioplasty with stent placement. In this systematic review, the authors evaluate the available clinical evidence on the optimal hyperemic agents to induce intrarenal hyperemia, their association with anatomic grading, and their predictive value for treatment effects. In addition, the potential value of combined pressure and flow measurements to discriminate macrovascular from microvascular disease is discussed. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Renal Autoregulation: New Perspectives Regarding the Protective and Regulatory Roles of the Underlying Mechanisms

PubMed Central

Loutzenhiser, Rodger; Griffin, Karen; Williamson, Geoffrey; Bidani, Anil

2006-01-01

When the kidney is subjected to acute increases in blood pressure (BP), renal blood flow (RBF) and glomerular filtration rate (GFR) are observed to remain relatively constant. Two mechanisms, tubuloglomerular feedback (TGF) and the myogenic response, are thought to act in concert to achieve a precise moment-by-moment regulation of GFR and distal salt delivery. The current view is that this mechanism insulates renal excretory function from fluctuations in BP. Indeed, the concept that renal autoregulation is necessary for normal renal function and volume homeostasis has long been a cornerstone of renal physiology. This article presents a very different view, at least in regard to the myogenic component of this response. We suggest that its primary purpose is to protect the kidney against the damaging effects of hypertension. The arguments advanced take into consideration the unique properties of the afferent arteriolar myogenic response that allow it to protect against the oscillating systolic pressure, and the accruing evidence that when this response is impaired the primary consequence is not a disturbed volume homeostasis, but rather an increased susceptibility to hypertensive injury. It is suggested that redundant and compensatory mechanisms are capable of achieving volume regulation despite considerable fluctuations in distal delivery and the assumed moment-by-moment regulation of renal hemodynamics is questioned. Evidence is presented suggesting that additional mechanisms may exist to maintain ambient levels of RBF and GFR within normal range despite chronic alterations in BP and severely impaired acute responses to pressure. Finally the implications of this new perspective on the divergent roles of the renal myogenic response to pressure versus the TGF response to changes in distal delivery are considered and it is proposed that, in addition to TGF-induced vasoconstrictor responses, vasodepressor responses to reduced distal delivery may play a more critical role in modulating afferent arteriolar reactivity, in order to integrate the regulatory and protective functions of the renal microvasculature. PMID:16603656

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

PubMed

Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-12-20

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

Renal denervation and hypertension - The need to investigate unintended effects and neural control of the human kidney.

PubMed

Grisk, Olaf

2017-05-01

Increased renal sympathetic nerve activity (RSNA) is present in human and experimental forms of arterial hypertension. Experimental denervation studies showed that renal nerves contribute to the development of hypertension. Clinical trials provided equivocal results on the antihypertensive efficacy of renal denervation in patients spurring discussions on technical aspects of renal denervation and further research on the role of renal nerves for the regulation of kidney function as well as the pathophysiology of hypertension. This review summarizes recent findings on adrenoceptor expression and function in the human kidney, adrenoceptor-dependent regulation of sodium chloride transport in the distal nephron, experimental data on chronic RSNA and the development of high arterial pressure and consequences of renal denervation that may limit its antihypertensive efficacy. Future research needs to reduce the gap between our knowledge on neural control of renal function in animals vs. humans to facilitate translation of experimental animal data to humans. More experimental studies on the temporal relationship between RSNA and arterial pressure in the chronic setting are needed to better define the pathogenetic role of heightened RSNA in different forms of arterial hypertension in order to improve the rational basis for renal denervation in antihypertensive therapy. Finally, research on unintended consequences of renal denervation including but not limited to reinnervation and denervation supersensitivity needs to be intensified to further assess the potential of renal denervation to slow the progression of renal disease and hypertension. Copyright © 2016 Elsevier B.V. All rights reserved.

The renin-angiotensin system in thyroid disorders and its role in cardiovascular and renal manifestations.

PubMed

Vargas, Félix; Rodríguez-Gómez, Isabel; Vargas-Tendero, Pablo; Jimenez, Eugenio; Montiel, Mercedes

2012-04-01

Thyroid disorders are among the most common endocrine diseases and affect virtually all physiological systems, with an especially marked impact on cardiovascular and renal systems. This review summarizes the effects of thyroid hormones on the renin-angiotensin system (RAS) and the participation of the RAS in the cardiovascular and renal manifestations of thyroid disorders. Thyroid hormones are important regulators of cardiac and renal mass, vascular function, renal sodium handling, and consequently blood pressure (BP). The RAS acts globally to control cardiovascular and renal functions, while RAS components act systemically and locally in individual organs. Various authors have implicated the systemic and local RAS in the mediation of functional and structural changes in cardiovascular and renal tissues due to abnormal thyroid hormone levels. This review analyzes the influence of thyroid hormones on RAS components and discusses the role of the RAS in BP, cardiac mass, vascular function, and renal abnormalities in thyroid disorders.

The risk of diabetic renal function impairment in the first decade after diagnosed of diabetes mellitus is correlated with high variability of visit-to-visit systolic and diastolic blood pressure: a case control study.

PubMed

Yeh, Chi-Hsiao; Yu, Hsiu-Chin; Huang, Tzu-Yen; Huang, Pin-Fu; Wang, Yao-Chang; Chen, Tzu-Ping; Yin, Shun-Ying

2017-03-22

The variability of visit-to-visit (VVV) in systolic blood pressure (SBP) and diastolic blood pressure (DBP) is proved as a predictor of renal function deterioration in patients with non-diabetic chronic kidney disease. The purpose of this study was to investigate the relationship of the variability in SBP and the magnitude of renal function impairment for normal renal function patients in the first 10-years diagnosed with type II diabetes mellitus (DM). We retrospectively reviewed the electronic medical records of 789 patients who were first diagnosed with diabetes mellitus during 2000-2002 and regularly followed for 10 years with a total of 53,284 clinic visits. The stages of Chronic Kidney Disease (CKD) of every patient were determined using estimated glomerular filtration rate. The occurrence of nephropathy was defined in those patients whose CKD stages elevated equal or larger than three. Patients were categorized according to the VVV of systolic and diastolic BP into three groups. Patients with high VVV of both SBP and DBP had a 2.44 fold (95% CI: 1.88-3.17, p < 0.001) increased risk of renal function impairment compared with patients with low VVV of both SBP and DBP. Risk of renal function impairment for patients with high VVV of either SBP or DBP had a 1.43-fold increase (95% CI: 1.08-1.89, p = 0.012) compared with patients with low VVV of both SBP and DBP. Cox regression analysis also demonstrated that every 1-year increase of DM diagnosed age significantly raised the risk of renal function impairment with a hazard ration of 1.05 (95% CI: 1.04-1.06, p < 0.001). Not only VVV of SBP but also VVV in DBP is correlated with diabetic nephropathy in the first decade for patients diagnosed with type 2 DM.

EET Enhances Renal Function in Obese Mice Resulting in Restoration of Mfn1/2 -HO-1 Signaling, and Decrease in Hypertension through Inhibition of Sodium Chloride Co-Transporter.

PubMed

Schragenheim, Joseph; Bellner, Lars; Cao, Jian; Singh, Shailendra P; Bamshad, David; McClung, John A; Maayan, Omri; Meissner, Aliza; Grant, Ilana; Stier, Charles T; Abraham, Nader G

2018-05-19

We have previously reported that epoxyeicosatrienoic acid (EET) has multiple beneficial effects on renal and adipose tissue function, in addition to its vasodilatory action; it increases insulin sensitivity and inhibits inflammation. In an examination of the signaling mechanisms by which EET reduces renal and peri-renal fat function, we hypothesized that EET ameliorates obesity-induced renal dysfunction by improving sodium excretion, reducing the sodium-chloride cotransporter NCC, lowering blood pressure, and enhancing mitochondrial and thermogenic gene levels in PGC-1α dependent mice. EET-agonist treatment normalized glucose metabolism, renal ENaC and NCC protein expression, urinary sodium excretion and blood pressure in obese (db/db) mice. A marked improvement in mitochondrial integrity, thermogenic genes, and PGC-1α-HO-1-adiponectin signaling occurred. Knockout of PGC-1α in EET-treated mice resulted in a reversal of these beneficial effects including a decrease in sodium excretion, elevation of blood pressure and an increase in the pro-inflammatory adipokine nephroblastoma overexpressed gene (NOV). In the elucidation of the effects of EET on peri-renal adipose tissue, EET increased adiponectin, mitochondrial integrity, thermogenic genes and decreased NOV, i.e. "Browning' peri-renal adipose phenotype that occurs under high fat diets. Taken together, these data demonstrate a critical role of an EET agonist in the restoration of healthy adipose tissue with reduced release of inflammatory molecules, such as AngII and NOV, thereby preventing their detrimental impact on sodium absorption and NCC levels and the development of obesity-induced renal dysfunction. Copyright © 2018. Published by Elsevier Inc.

Post-partum trend in blood pressure levels, renal function and proteinuria in women with severe preeclampsia and eclampsia in Sub-Saharan Africa: a 6-months cohort study.

PubMed

Kaze, Francois Folefack; Njukeng, Francis A; Kengne, Andre-Pascal; Ashuntantang, Gloria; Mbu, Robinson; Halle, Marie Patrice; Asonganyi, Tazoacha

2014-04-09

Preeclampsia and eclampsia, which are the most frequent hypertensive disorders in pregnancy, are associated with renal involvements. We aimed to assess the time trend in blood pressure levels, renal function and proteinuria after delivery, and investigate their determinants in Cameroonian women with severe preeclampsia and eclampsia. This was a prospective cohort study involving 54 women with severe preeclampsia and eclampsia, conducted between July 2010 and February 2012 at the central maternity unit of the Yaoundé Central Hospital. Clinical and laboratory parameters were recorded from day-1 to 6 months after delivery. Mixed-linear and logistic regression models were used to relate baseline and within follow-up levels of covariates, with changes in blood pressure levels, renal function and proteinuria, as well as persisting hypertension, renal failure and proteinuria. During follow-up, a significant improvement was observed in blood pressure, renal function and proteinuria (all p < 0.002). Thirteen (24.1%) patients with renal failure at delivery recovered completely within six weeks. Twenty-six (48.1%), 17 (31.5%) and 1 (1.8%) patients had persisting proteinuria at 6 weeks, 3 months and 6 months post-delivery, respectively. Corresponding figures for persisting hypertension were 23 (42.6%), 15 (27.8%) and 8 (14.8%). Advanced age, higher body mass index, low gestational age at delivery, low fetal birth weight, and proteinuria at delivery were the main risk factors for persisting hypertension at 3 months, meanwhile low fetal birth weight, severe preeclampsia and proteinuria at delivery were correlated with persisting proteinuria at 3 months. Advanced age and higher body mass index were the only determinants of the composite outcome of persisting hypertension or proteinuria at three and six months. Hypertension and proteinuria are very common beyond the postpartum period in Cameroonian women with severe preeclampsia and eclampsia. Long-term follow-up of these women will help preventing and controlling related complications.

Pulmonary Catherization Data Correlate Poorly with Renal Function in Heart Failure.

PubMed

Masha, Luke; Stone, James; Stone, Danielle; Zhang, Jun; Sheng, Luo

2018-04-10

The mechanisms of renal dysfunction in heart failure are poorly understood. We chose to explore the relationship of cardiac filling pressures and cardiac index (CI) in relation to renal dysfunction in advanced heart failure. To determine the relationship between renal function and cardiac filling pressures using the United Network of Organ Sharing (UNOS) pulmonary artery catherization registry. Patients over the age of 18 years who were listed for single-organ heart transplantation were included. Exclusion criteria included a history of mechanical circulatory support, previous transplantation, any use of renal replacement therapy, prior history of malignancy, and cardiac surgery, amongst others. Correlations between serum creatinine (SCr) and CI, pulmonary capillary wedge pressure (PCWP), pulmonary artery systolic pressure (PASP), and pulmonary artery diastolic pressure (PADP) were assessed by Pearson correlation coefficients and simple linear regression coefficients. Pearson correlation coefficients between SCr and PCWP, PASP, and PADP were near zero with values of 0.1, 0.07, and 0.08, respectively (p < 0.0001). A weak negative correlation coefficient between SCr and CI was found (correlation coefficient, -0.045, p = 0.027). In a subgroup of young patients unlikely to have noncardiac etiologies, no significant correlations between these values were identified. These findings suggest that, as assessed by pulmonary artery catherization, none of the factors - PCWP, PASP, PADP, or CI - play a prominent role in cardiorenal syndromes. © 2018 S. Karger AG, Basel.

Endothelial mineralocorticoid receptor ablation does not alter blood pressure, kidney function or renal vessel contractility

PubMed Central

Laursen, Sidsel B.; Finsen, Stine; Marcussen, Niels; Quaggin, Susan E.

2018-01-01

Aldosterone blockade confers substantial cardiovascular and renal protection. The effects of aldosterone on mineralocorticoid receptors (MR) expressed in endothelial cells (EC) within the renal vasculature have not been delineated. We hypothesized that lack of MR in EC may be protective in renal vasculature and examined this by ablating the Nr3c2 gene in endothelial cells (EC-MR) in mice. Blood pressure, heart rate and PAH clearance were measured using indwelling catheters in conscious mice. The role of the MR in EC on contraction and relaxation was investigated in the renal artery and in perfused afferent arterioles. Urinary sodium excretion was determined by use of metabolic cages. EC-MR transgenics had markedly decreased MR expression in isolated aortic endothelial cells as compared to littermates (WT). Blood pressure and effective renal plasma flow at baseline and following AngII infusion was similar between groups. No differences in contraction and relaxation were observed between WT and EC-MR KO in isolated renal arteries during baseline or following 2 or 4 weeks of AngII infusion. The constriction or dilatations of afferent arterioles between genotypes were not different. No changes were found between the groups with respect to urinary excretion of sodium after 4 weeks of AngII infusion, or in urinary albumin excretion and kidney morphology. In conclusion, deletion of the EC-MR does not confer protection towards the development of hypertension, endothelial dysfunction of renal arteries or renal function following prolonged AngII-infusion. PMID:29466427

Protective effects of AT1-receptor blocker and CA antagonist combination on renal function in salt loaded spontaneously hypertensive rats.

PubMed

Gjorgjievska, K; Zafirov, D; Jurhar-Pavlova, M; Cekovska, S; Atanasovska, E; Pavlovska, K; Zendelovska, D

2015-01-01

Salt sensitive hypertension is known to be a contributing factor for the progression of kidney disease. This study was undertaken to investigate the role of excessive dietary salt on renal function and to evaluate the effect of valsartan and amlodipin given as a combination therapy on blood pressure and parameters specific to the renal function in salt loaded SHR rats. 48 male SHR rats at age of 20 weeks and body weight ranging between 270-350 g were used. SHR rats were divided into 3 groups: control group of rats -SHRC (n = 16) given tab water ad libitum and two salt treated groups in which tab water was replaced with a solution of NaCl (1%) from age of 8 weeks given ad libitum: SHRVAL+AMLO group (n = 16) where investigated drugs were administered at a dose of 10 mg/kg/ b.w. (valsartan) and 5 mg/kg/ b.w. (amlodipin) by gavage and SHR NaCl group (n = 16) that received saline in the same volume and the same time intervals as the SHRVAL+AMLO group. For a period of 12 weeks we have investigated the effect of the VAL+AMLO drug combination on systolic blood pressure (SBP), body weight and renal function tests. Salt loading with 1% solution in the SHR NaCl group has lead to significant increase of blood pressure, proteinuria and decrease in creatinine clearance. Combined treatment with AT1 receptor blocker and calcium antagonist has managed to control blood pressure and ameliorated renal damage.

Reinnervation following catheter-based radio-frequency renal denervation.

PubMed

Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

What is the topic of this review? Does catheter-based renal denervation effectively denervate the afferent and efferent renal nerves and does reinnervation occur? What advances does it highlight? Following catheter-based renal denervation, the afferent and efferent responses to electrical stimulation were abolished, renal sympathetic nerve activity was absent, and levels of renal noradrenaline and immunohistochemistry for tyrosine hydroxylase and calcitonin gene-related peptide were significantly reduced. By 11 months after renal denervation, both the functional responses and anatomical markers of afferent and efferent renal nerves had returned to normal, indicating reinnervation. Renal denervation reduces blood pressure in animals with experimental hypertension and, recently, catheter-based renal denervation was shown to cause a prolonged decrease in blood pressure in patients with resistant hypertension. The randomized, sham-controlled Symplicity HTN-3 trial failed to meet its primary efficacy end-point, but there is evidence that renal denervation was incomplete in many patients. Currently, there is little information regarding the effectiveness of catheter-based renal denervation and the extent of reinnervation. We assessed the effectiveness of renal nerve denervation with the Symplicity Flex catheter and the functional and anatomical reinnervation at 5.5 and 11 months postdenervation. In anaesthetized, non-denervated sheep, there was a high level of renal sympathetic nerve activity, and electrical stimulation of the renal nerve increased blood pressure and reduced heart rate (afferent response) and caused renal vasoconstriction and reduced renal blood flow (efferent response). Immediately after renal denervation, renal sympathetic nerve activity and the responses to electrical stimulation were absent, indicating effective denervation. By 11 months after denervation, renal sympathetic nerve activity was present and the responses to electrical stimulation were normal, indicating reinnervation. Anatomical measures of renal innervation by sympathetic efferent nerves (tissue noradrenaline and tyrosine hydroxylase) and afferent sensory nerves (calcitonin gene-related peptide) demonstrated large decreases at 1 week postdenervation, but normal levels at 11 months postdenervation. In summary, catheter-based renal denervation is effective, but reinnervation occurs. Studies of central and renal changes postdenervation are required to understand the causes of the prolonged hypotensive response to catheter-based renal denervation in human hypertension. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

Renal preservation in children with neurogenic bladder-sphincter dysfunction followed in a national program.

PubMed

Wide, Peter; Glad Mattsson, Gunilla; Mattsson, Sven

2012-04-01

Neurogenic bladder-sphincter dysfunction (NBSD) constitutes the major reason for morbidity in children with spina bifida. The aim of this study was to identify risk factors for renal damage in children with NBSD followed according to the Swedish national guidelines. Records and cystometries from 6 to 16 years (median 11) follow up of 41 consecutive children born 1993-2003 with NBSD were evaluated. The children were divided into a high pressure group (baseline pressure above 30 cmH(2)O at maximal clean intermittent catheterization volume in at least two cystometries) and a low pressure group. Most children (34/41) were followed from birth. Although renal scarring on DMSA-scintigraphy was found in 5/41 children, all but one had normal renal function. Two already had renal scars on entering the follow-up program at age 2.5 and 3 years. Renal scarring was more frequent in the high pressure group (P < 0.01). Most children with renal scars (4/5) had a combination of low compliant bladder and insufficient compliance with treatment and follow up. High baseline pressure is confirmed as a risk factor that, in combination with complex social issues, creates a demanding situation for families and professionals. A structured early follow up with treatment compliance effectively prevents renal damage. Copyright © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

[Expert consensus statement on interventional renal sympathetic denervation for hypertension treatment].

PubMed

Mahfoud, F; Vonend, O; Bruck, H; Clasen, W; Eckert, S; Frye, B; Haller, H; Hausberg, M; Hoppe, U C; Hoyer, J; Hahn, K; Keller, T; Krämer, B K; Kreutz, R; Potthoff, S A; Reinecke, H; Schmieder, R; Schwenger, V; Kintscher, U; Böhm, M; Rump, L C

2011-11-01

This commentary summarizes the expert consensus and recommendations of the working group 'Herz und Niere' of the German Society of Cardiology (DGK), the German Society of Nephrology (DGfN) and the German Hypertension League (DHL) on renal denervation for antihypertensive treatment. Renal denervation is a new, interventional approach to selectively denervate renal afferent and efferent sympathetic fibers. Renal denervation has been demonstrated to reduce office systolic and diastolic blood pressure in patients with resistant hypertension, defined as systolic office blood pressure ≥ 160 mm Hg and ≥ 150 mm Hg in patients with diabetes type 2, which should currently be used as blood pressure thresholds for undergoing the procedure. Exclusion of secondary hypertension causes and optimized antihypertensive drug treatment is mandatory in every patient with resistant hypertension. In order to exclude pseudoresistance, 24-hour blood pressure measurements should be performed. Preserved renal function was an inclusion criterion in the Symplicity studies, therefore, renal denervation should be only considered in patients with a glomerular filtration rate > 45 ml/min. Adequate centre qualification in both, treatment of hypertension and interventional expertise are essential to ensure correct patient selection and procedural safety. Long-term follow-up after renal denervation and participation in the German Renal Denervation (GREAT) Registry are recommended to assess safety and efficacy after renal denervation over time. © Georg Thieme Verlag KG Stuttgart · New York.

Longitudinal Assessment of Vascular Function With Sunitinib in Patients With Metastatic Renal Cell Carcinoma.

PubMed

Catino, Anna B; Hubbard, Rebecca A; Chirinos, Julio A; Townsend, Ray; Keefe, Stephen; Haas, Naomi B; Puzanov, Igor; Fang, James C; Agarwal, Neeraj; Hyman, David; Smith, Amanda M; Gordon, Mary; Plappert, Theodore; Englefield, Virginia; Narayan, Vivek; Ewer, Steven; ElAmm, Chantal; Lenihan, Daniel; Ky, Bonnie

2018-03-01

Sunitinib, used widely in metastatic renal cell carcinoma, can result in hypertension, left ventricular dysfunction, and heart failure. However, the relationships between vascular function and cardiac dysfunction with sunitinib are poorly understood. In a multicenter prospective study of 84 metastatic renal cell carcinoma patients, echocardiography, arterial tonometry, and BNP (B-type natriuretic peptide) measures were performed at baseline and at 3.5, 15, and 33 weeks after sunitinib initiation, correlating with sunitinib cycles 1, 3, and 6. Mean change in vascular function parameters and 95% confidence intervals were calculated. Linear regression models were used to estimate associations between vascular function and left ventricular ejection fraction, longitudinal strain, diastolic function (E/e'), and BNP. After 3.5 weeks of sunitinib, mean systolic blood pressure increased by 9.5 mm Hg (95% confidence interval, 2.0-17.1; P =0.02) and diastolic blood pressure by 7.2 mm Hg (95% confidence interval, 4.3-10.0; P <0.001) across all participants. Sunitinib resulted in increases in large artery stiffness (carotid-femoral pulse wave velocity) and resistive load (total peripheral resistance and arterial elastance; all P <0.05) and changes in pulsatile load (total arterial compliance and wave reflection). There were no statistically significant associations between vascular function and systolic dysfunction (left ventricular ejection fraction and longitudinal strain). However, baseline total peripheral resistance, arterial elastance, and aortic impedance were associated with worsening diastolic function and filling pressures over time. In patients with metastatic renal cell carcinoma, sunitinib resulted in early, significant increases in blood pressure, arterial stiffness, and resistive and pulsatile load within 3.5 weeks of treatment. Baseline vascular function parameters were associated with worsening diastolic but not systolic function. © 2018 American Heart Association, Inc.

The role of sympathetic nervous system in the progression of chronic kidney disease in the era of catheter based sympathetic renal denervation.

PubMed

Petras, Dimitrios; Koutroutsos, Konstantinos; Kordalis, Athanasios; Tsioufis, Costas; Stefanadis, Christodoulos

2013-08-01

The kidney has been shown to be critically involved as both trigger and target of sympathetic nervous system overactivity in both experimental and clinical studies. Renal injury and ischemia, activation of renin angiotensin system and dysfunction of nitric oxide system have been implicated in adrenergic activation from kidney. Conversely, several lines of evidence suggest that sympathetic overactivity, through functional and morphological alterations in renal physiology and structure, may contribute to kidney injury and chronic kidney disease progression. Pharmacologic modulation of sympathetic nervous system activity has been found to have a blood pressure independent renoprotective effect. The inadequate normalization of sympathoexcitation by pharmacologic treatment asks for novel treatment options. Catheter based renal denervation targets selectively both efferent and afferent renal nerves and functionally denervates the kidney providing blood pressure reduction in clinical trials and renoprotection in experimental models by ameliorating the effects of excessive renal sympathetic drive. This review will focus on the role of sympathetic overactivity in the pathogenesis of kidney injury and CKD progression and will speculate on the effect of renal denervation to these conditions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubovsky, E.V.; Curtis, J.J.; Luke, R.G.

Impaired function of renal allografts caused by recurrent disease or rejection is often accompanied by hypertension. The etiology of persistent severe hypertension in recipients with good renal function is more difficult to explain. To study this problem, 33 patients with mean arterial pressure (MAP) > 105 mm Hg (at least one year after transplantation) were tested. When compared to a normotensive group, they were found to have increased renal vascular resistance, lower ERPF, and increased renin-angiotensin activity. The effect of Captopril, a converting enzyme inhibitor, was studied to evaluate the role of angiotension. The paper concludes that Captopril test maymore » permit differentiation between native kidney-dependent hypertension (increase in ERPF) and functionally active renal artery stenosis (decline in ERPF) in patients with persistent hypertension and good renal function.« less

Renal sympathetic denervation for treatment of resistant hypertension: Egyptian experience.

PubMed

Hamza, Mohamed; Khamis, Hazem

2014-08-01

Among the Egyptian population with essential hypertension, a minority are under control (systolic pressure <140 mmHg and diastolic pressure <90 mmHg), despite the use of multiple antihypertensive medications. In this article, we describe our experience with percutaneous treatment using renal artery radiofrequency (RF) ablation. To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension in Egyptian patients. Patients with essential hypertension unresponsive to at least 3 types of antihypertensive medical therapy (baseline office systolic blood pressure ≥160 mmHg) (n = 55) were enrolled between February 2012 and June 2013 and received percutaneous RF ablation. Patients were followed up for 6 months after treatment to detect any change in office-based measurement of blood pressure. Urine and blood samples were taken to evaluate the effects on renal function. A reduction of mean office blood pressure was seen from 174/103 ± 9/5 mmHg at baseline to 150/91 ± 8/5 mmHg at 6 months follow-up (P = 0.001). Also, we noted a significant decrease in plasma renin activity (3.66 ± 0.64 vs. 3.37 ± 0.47 ng/mL per hour; P = 0.003), and there were no periprocedural complications, no adverse events, and no change in renal function during the follow-up period. Also, no change was noted in the number of medications after 6 months (3.95 ± 1.64 vs. 3.67 ± 0.72; P = 0.27). In this observational study, catheter-based renal denervation causes sustained blood pressure reduction in patients with resistant hypertension, without serious adverse events. © 2014, Wiley Periodicals, Inc.

Gender differences in pressure-natriuresis and renal autoregulation: role of the Angiotensin type 2 receptor.

PubMed

Hilliard, Lucinda M; Nematbakhsh, Mehdi; Kett, Michelle M; Teichman, Elleesha; Sampson, Amanda K; Widdop, Robert E; Evans, Roger G; Denton, Kate M

2011-02-01

Sexual dimorphism in arterial pressure regulation has been observed in humans and animal models. The mechanisms underlying this gender difference are not fully known. Previous studies in rats have shown that females excrete more salt than males at a similar arterial pressure. The renin-angiotensin system is a powerful regulator of arterial pressure and body fluid volume. This study examined the role of the angiotensin type 2 receptor (AT₂R) in pressure-natriuresis in male and female rats because AT₂R expression has been reported to be enhanced in females. Renal function was examined at renal perfusion pressures of 120, 100, and 80 mm Hg in vehicle-treated and AT₂R antagonist-treated (PD123319; 1 mg/kg/h) groups. The pressure-natriuresis relationship was gender-dependent such that it was shifted upward in female vs male rats (P < 0.001). AT₂R blockade modulated the pressure-natriuresis relationship, shifting the curve downward in male (P < 0.01) and female (P < 0.01) rats to a similar extent. In females, AT₂R blockade also reduced the lower end of the autoregulatory range of renal blood flow (P < 0.05) and glomerular filtration rate (P < 0.01). Subsequently, the renal blood flow response to graded angiotensin II infusion was also measured with and without AT₂R blockade. We found that AT₂R blockade enhanced the renal vasoconstrictor response to angiotensin II in females but not in males (P < 0.05). In conclusion, the AT₂R modulates pressure-natriuresis, allowing the same level of sodium to be excreted at a lower pressure in both genders. However, a gender-specific role for the AT₂R in renal autoregulation was evident in females, which may be a direct vascular AT₂R effect.

Renal Heme Oxygenase-1 Induction with Hemin Augments Renal Hemodynamics, Renal Autoregulation, and Excretory Function

PubMed Central

Botros, Fady T.; Dobrowolski, Leszek; Navar, L. Gabriel

2012-01-01

Heme oxygenases (HO-1; HO-2) catalyze conversion of heme to free iron, carbon monoxide, and biliverdin/bilirubin. To determine the effects of renal HO-1 induction on blood pressure and renal function, normal control rats (n = 7) and hemin-treated rats (n = 6) were studied. Renal clearance studies were performed on anesthetized rats to assess renal function; renal blood flow (RBF) was measured using a transonic flow probe placed around the left renal artery. Hemin treatment significantly induced renal HO-1. Mean arterial pressure and heart rate were not different (115 ± 5 mmHg versus 112 ± 4 mmHg and 331 ± 16 versus 346 ± 10 bpm). However, RBF was significantly higher (9.1 ± 0.8 versus 7.0 ± 0.5 mL/min/g, P < 0.05), and renal vascular resistance was significantly lower (13.0 ± 0.9 versus 16.6 ± 1.4 [mmHg/(mL/min/g)], P < 0.05). Likewise, glomerular filtration rate was significantly elevated (1.4 ± 0.2 versus 1.0 ± 0.1 mL/min/g, P < 0.05), and urine flow and sodium excretion were also higher (18.9 ± 3.9 versus 8.2 ± 1.0 μL/min/g, P < 0.05 and 1.9 ± 0.6 versus 0.2 ± 0.1 μmol/min/g, P < 0.05, resp.). The plateau of the autoregulation relationship was elevated, and renal vascular responses to acute angiotensin II infusion were attenuated in hemin-treated rats reflecting the vasodilatory effect of HO-1 induction. We conclude that renal HO-1 induction augments renal function which may contribute to the antihypertensive effects of HO-1 induction observed in hypertension models. PMID:22518281

Neural control of renal function: cardiovascular implications.

PubMed

DiBona, G F

1989-06-01

The innervation of the kidney serves to function of its component parts, for example, the blood vessels, the nephron (glomerulus, tubule), and the juxtaglomerular apparatus. Alterations in efferent renal sympathetic nerve activity produce significant changes in renal blood flow, glomerular filtration rate, the reabsorption of water, sodium, and other ions, and the release of renin, prostaglandins, and other vasoactive substances. These functional effects contribute significantly to the renal regulation of total body sodium and fluid volumes with important implications for the control of arterial pressure. The renal nerves, both efferent and afferent, are known to be important contributors to the pathogenesis of hypertension. In addition, the efferent renal nerves participate in the mediation of the excessive renal sodium retention, which characterizes edema-forming states such as congestive heart failure. Thus, the renal nerves play an important role in overall cardiovascular homeostasis in both normal and pathological conditions.

Ambulatory blood pressure profiles in familial dysautonomia.

PubMed

Goldberg, Lior; Bar-Aluma, Bat-El; Krauthammer, Alex; Efrati, Ori; Sharabi, Yehonatan

2018-02-12

Familial dysautonomia (FD) is a rare genetic disease that involves extreme blood pressure fluctuations secondary to afferent baroreflex failure. The diurnal blood pressure profile, including the average, variability, and day-night difference, may have implications for long-term end organ damage. The purpose of this study was to describe the circadian pattern of blood pressure in the FD population and relationships with renal and pulmonary function, use of medications, and overall disability. We analyzed 24-h ambulatory blood pressure monitoring recordings in 22 patients with FD. Information about medications, disease severity, renal function (estimated glomerular filtration, eGFR), pulmonary function (forced expiratory volume in 1 s, FEV1) and an index of blood pressure variability (standard deviation of systolic pressure) were analyzed. The mean (± SEM) 24-h blood pressure was 115 ± 5.6/72 ± 2.0 mmHg. The diurnal blood pressure variability was high (daytime systolic pressure standard deviation 22.4 ± 1.5 mmHg, nighttime 17.2 ± 1.6), with a high frequency of a non-dipping pattern (16 patients, 73%). eGFR, use of medications, FEV1, and disability scores were unrelated to the degree of blood pressure variability or to dipping status. This FD cohort had normal average 24-h blood pressure, fluctuating blood pressure, and a high frequency of non-dippers. Although there was evidence of renal dysfunction based on eGFR and proteinuria, the ABPM profile was unrelated to the measures of end organ dysfunction or to reported disability.

Predictors of Renal Function Decline in Chinese Patients with Type 2 Diabetes Mellitus and in a Subgroup of Normoalbuminuria: A Retrospective Cohort Study.

PubMed

Hu, Ping; Zhou, Xiang-Hai; Wen, Xin; Ji, Linong

2016-10-01

Risk factors related to renal function decline in type 2 diabetes mellitus (T2DM) remain uncertain. This study aimed to investigate risk factors in relation to renal function decline in patients with T2DM and in a subgroup of patients with normoalbuminuria. This study was a retrospective cohort study, which included 451 patients with T2DM aged 63 ± 14 years admitted to a tertiary hospital in Beijing, China, between April and December 2010 and followed up for 6-60 months. Endpoint was renal function decline, defined as estimated glomerular filtration rate less than 60 mL/min 1.73 m 2 or at least twofold increase of serum creatinine. Cox proportional hazards analysis was used to estimate hazard ratios (HRs) for candidate risk factors of renal function decline. After a median follow-up of 3.3 years, 94 (20.8%) patients developed renal function decline. Increased age (HR, 1.045; 95% CI, 1.020-1.070), albuminuria (HR, 1.956; 95%CI, 1.271-3.011), mild renal dysfunction (HR, 4.521; 95%CI, 2.734-7.476), hyperfiltration (HR, 3.897; 95%CI, 1.572-9.663), and increased hemoglobin A1c (HR, 1.128; 95%CI, 1.020-1.249) were identified as major risk factors. Among a subgroup of 344 patients with normoalbuminuria at baseline, 53 (15.4%) patients developed renal function decline. Increased age (HR, 1.089; 95%CI, 1.050-1.129), mild renal dysfunction (HR, 4.667; 95%CI, 2.391-9.107), hyperfiltration (HR, 5.677; 95%CI, 1.544-20.872), smoking (HR, 2.886; 95%CI, 1.370-6.082), higher pulse pressure (HR, 1.022; 95%CI, 1.004-1.040), and increased fasting glucose (HR, 1.104; 95%CI, 1.020-1.194) were major risk factors. Risk factors of diabetic renal impairment in T2DM should be screened and evaluated at an early stage of diabetes. Albuminuria, mild renal dysfunction, hyperfiltration, increased blood glucose, increased pulse pressure, and smoking were all predictors for diabetic renal impairment and interventions that focus on these risk factors may reduce further decline in renal function.

Neural control of renal function in health and disease.

PubMed

DiBona, G F

1994-04-01

The renal sympathetic innervation of the kidney exerts significant effects on multiple aspects of renal function, including renal haemodynamics, tubular sodium and water reabsorption and renin secretion. These effects constitute an important control system which is important in the physiological regulation of arterial pressure and total body fluid and sodium homeostasis. Abnormalities in this regulatory mechanism have pathophysiological consequences and are manifest in clinically relevant human disease states. Decreased renal sympathetic nerve activity results in impaired renin secretion, the inability to conserve sodium normally and an attenuated ability to dispose of both acute and chronic sodium loads. Increased renal sympathetic nerve activity contributes significantly to the excess renal sodium retention and related renal abnormalities observed in both hypertension and oedema forming conditions, such as cardiac failure, cirrhosis and nephrotic syndrome.

Neural mechanisms in body fluid homeostasis.

PubMed

DiBona, G F

1986-12-01

Under steady-state conditions, urinary sodium excretion matches dietary sodium intake. Because extracellular fluid osmolality is tightly regulated, the quantity of sodium in the extracellular fluid determines the volume of this compartment. The left atrial volume receptor mechanism is an example of a neural mechanism of volume regulation. The left atrial mechanoreceptor, which functions as a sensor in the low-pressure vascular system, is located in the left atrial wall, which has a well-defined compliance relating intravascular volume to filling pressure. The left atrial mechanoreceptor responds to changes in wall left atrial tension by discharging into afferent vagal fibers. These fibers have suitable central nervous system representation whose related efferent neurohumoral mechanisms regulate thirst, renal excretion of water and sodium, and redistribution of the extracellular fluid volume. Efferent renal sympathetic nerve activity undergoes appropriate changes to facilitate renal sodium excretion during sodium surfeit and to facilitate renal sodium conservation during sodium deficit. By interacting with other important determinants of renal sodium excretion (e.g., renal arterial pressure), changes in efferent renal sympathetic nerve activity can significantly modulate the final renal sodium excretion response with important consequences in pathophysiological states (e.g., hypertension, edema-forming states).

How to manage hypertension with atherosclerotic renal artery stenosis?

PubMed

Ricco, Jean-Baptiste; Belmonte, Romain; Illuminati, Guilio; Barral, Xavier; Schneider, Fabrice; Chavent, Bertrand

2017-04-01

The management of atherosclerotic renal artery stenosis (ARAS) in patients with hypertension has been the topic of great controversy. Major contemporary clinical trials such as the Cardiovascular Outcomes for Renal Artery lesions (CORAL) and Angioplasty and Stenting for Renal Atherosclerotic lesions (ASTRAL) have failed to show significant benefit of revascularization over medical management in controlling blood pressure and preserving renal function. We present here the implications and limitations of these trials and formulate recommendations for management of ARAS.

Ascites, a New Cause for Bilateral Hydronephrosis: Case Report

PubMed Central

Jain, Deepika; Dorairajan, Smrita; Misra, Madhukar

2009-01-01

Bilateral hydronephrosis secondary to urinary obstruction leads to a buildup of back pressure in the urinary tract and may lead to impairment of renal function. We present a case of a 57-year-old male with a history of alcoholic liver cirrhosis, who presented with tense ascites and acute renal failure. Bilateral hydronephrosis was seen on abdominal ultrasound. Multiple large-volume paracenteses resulted in resolution of hydronephrosis and prompt improvement in renal function. PMID:19802498

Reversal of pulmonary hypertension after percutaneous closure of congenital renal arteriovenous fistula in a 74-year old woman.

PubMed

Brar, Vijaywant; Bernardo, Nelson; Suddath, William; Weissman, Gaby; Asch, Federico; Campia, Umberto

2015-01-01

We report the case of a large right renal arteriovenous fistula (AVF) in a 74-year old woman who presented with heart failure. Transthoracic echocardiography revealed normal left ventricular size and systolic function (ejection fraction 60-65%), moderately dilated right ventricle with severely depressed systolic function, and severe pulmonary hypertension. Right heart catheterization confirmed the elevated pulmonary pressures and showed a high cardiac output. Physical examination was remarkable for a right flank bruit. An abdominal ultrasound revealed an AVF originating from the distal right renal artery and dilated suprarenal inferior vena cava and hepatic veins. These findings were confirmed with an abdominal MRI. Percutaneous endovascular closure of the right renal AVF was successfully performed, with immediate reduction of pulmonary pressures and normalization of cardiac output. The patient's symptoms improved, and a post intervention echocardiogram revealed normalization of right ventricular size. Copyright © 2015 Elsevier Inc. All rights reserved.

Cigarette smoking causes epigenetic changes associated with cardiorenal fibrosis

PubMed Central

Haller, Steven T.; Fan, Xiaoming; Xie, Jeffrey X.; Kennedy, David J.; Liu, Jiang; Yan, Yanling; Hernandez, Dawn-Alita; Mathew, Denzil P.; Cooper, Christopher J.; Shapiro, Joseph I.; Tian, Jiang

2016-01-01

Clinical studies indicate that smoking combustible cigarettes promotes progression of renal and cardiac injury, leading to functional decline in the setting of chronic kidney disease (CKD). However, basic studies using in vivo small animal models that mimic clinical pathology of CKD are lacking. To address this issue, we evaluated renal and cardiac injury progression and functional changes induced by 4 wk of daily combustible cigarette smoke exposure in the 5/6th partial nephrectomy (PNx) CKD model. Molecular evaluations revealed that cigarette smoke significantly (P < 0.05) decreased renal and cardiac expression of the antifibrotic microRNA miR-29b-3 and increased expression of molecular fibrosis markers. In terms of cardiac and renal organ structure and function, exposure to cigarette smoke led to significantly increased systolic blood pressure, cardiac hypertrophy, cardiac and renal fibrosis, and decreased renal function. These data indicate that decreased expression of miR-29b-3p is a novel mechanism wherein cigarette smoke promotes accelerated cardiac and renal tissue injury in CKD. (155 words) PMID:27789733

Lowering of blood pressure by chronic suppression of central sympathetic outflow: insight from prolonged baroreflex activation

PubMed Central

Iliescu, Radu

2012-01-01

Device-based therapy for resistant hypertension by electrical activation of the carotid baroreflex is currently undergoing active clinical investigation, and initial findings from clinical trials have been published. The purpose of this mini-review is to summarize the experimental studies that have provided a conceptual understanding of the mechanisms that account for the long-term lowering of arterial pressure with baroreflex activation. The well established mechanisms mediating the role of the baroreflex in short-term regulation of arterial pressure by rapid changes in peripheral resistance and cardiac function are often extended to long-term pressure control, and the more sluggish actions of the baroreflex on renal excretory function are often not taken into consideration. However, because clinical, experimental, and theoretical evidence indicates that the kidneys play a dominant role in long-term control of arterial pressure, this review focuses on the mechanisms that link baroreflex-mediated reductions in central sympathetic outflow with increases in renal excretory function that lead to sustained reductions in arterial pressure. PMID:22797307

High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure.

PubMed

Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth; Nguy, Lisa; Mikkelsen, Minne Line Nedergaard; Marcussen, Niels; Guron, Gregor

2014-03-15

This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. -4.4 ± 3.8 dB; P < 0.05). Similarly, a high-NaCl diet significantly increased SAPV in the low-frequency range only in ACRF animals. To conclude, a 2-wk period of a high-NaCl diet in ACRF rats significantly impaired dynamic RBFA in the frequency range of the myogenic response and increased SAPV in the low-frequency range. These abnormalities may increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature.

Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension

PubMed Central

Sata, Yusuke; Head, Geoffrey A.; Denton, Kate; May, Clive N.; Schlaich, Markus P.

2018-01-01

The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA) is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target. PMID:29651418

Role of the Sympathetic Nervous System and Its Modulation in Renal Hypertension.

PubMed

Sata, Yusuke; Head, Geoffrey A; Denton, Kate; May, Clive N; Schlaich, Markus P

2018-01-01

The kidneys are densely innervated with renal efferent and afferent nerves to communicate with the central nervous system. Innervation of major structural components of the kidneys, such as blood vessels, tubules, the pelvis, and glomeruli, forms a bidirectional neural network to relay sensory and sympathetic signals to and from the brain. Renal efferent nerves regulate renal blood flow, glomerular filtration rate, tubular reabsorption of sodium and water, as well as release of renin and prostaglandins, all of which contribute to cardiovascular and renal regulation. Renal afferent nerves complete the feedback loop via central autonomic nuclei where the signals are integrated and modulate central sympathetic outflow; thus both types of nerves form integral parts of the self-regulated renorenal reflex loop. Renal sympathetic nerve activity (RSNA) is commonly increased in pathophysiological conditions such as hypertension and chronic- and end-stage renal disease. Increased RSNA raises blood pressure and can contribute to the deterioration of renal function. Attempts have been made to eliminate or interfere with this important link between the brain and the kidneys as a neuromodulatory treatment for these conditions. Catheter-based renal sympathetic denervation has been successfully applied in patients with resistant hypertension and was associated with significant falls in blood pressure and renal protection in most studies performed. The focus of this review is the neural contribution to the control of renal and cardiovascular hemodynamics and renal function in the setting of hypertension and chronic kidney disease, as well as the specific roles of renal efferent and afferent nerves in this scenario and their utility as a therapeutic target.

Renal cytokines improve early after bariatric surgery.

PubMed

Bueter, M; Dubb, S S; Gill, A; Joannou, L; Ahmed, A; Frankel, A H; Tam, F W K; le Roux, C W

2010-12-01

Bariatric surgery has been suggested to improve arterial hypertension and renal function. This prospective controlled observational study aimed to investigate changes in renal inflammation, renal function and arterial blood pressure before and after bariatric surgery. Blood pressure was measured, and urine and blood samples were collected from 34 morbidly obese patients before and 4 weeks after bariatric surgery. Serum levels of cystatin C, creatinine, albumin, cholesterol and C-reactive protein (CRP) were measured, along with urinary cytokine/creatinine ratios for macrophage migration inhibitory factor (MIF), monocyte chemotactic protein (MCP) 1, chemokine ligand (CCL) 18 and CCL-15. Mean(s.e.m.) bodyweight dropped from 124·1(2·6) to 114·8(2·4) kg (P < 0·001) and mean arterial blood pressure decreased from 105·7(1·8) to 95·5(1·2) mmHg (P < 0·001) in 4 weeks. Systemic and urinary inflammatory markers improved, with a reduction in serum CRP level (P < 0·001), and decreased urinary MIF/creatinine (P < 0·001), MCP-1/creatinine (P < 0·001) and CCL-18/creatinine (P = 0·003) ratios. In contrast, urinary CCL-15/creatinine ratios did not change and the glomerular filtration rate, measured by serum cystatin C, was unchanged (P = 0·615). Surgically induced weight loss contributed to a decrease in blood pressure and markers of renal inflammation. The reduced levels of CRP and urinary cytokines suggest that bariatric surgery attenuates systemic and renal inflammatory status. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Pharmacokinetic profile of nifedipine GITS in hypertensive patients with chronic renal impairment.

PubMed

Schneider, R; Stolero, D; Griffel, L; Kobelt, R; Brendel, E; Iaina, A

1994-01-01

25 hypertensive patients with normal or impaired renal function underwent pharmacokinetic and safety studies after single and multiple dose administration of nifedipine GITS (Gastro-Intestinal Therapeutic System) 60mg tablets. Complete pharmacokinetic data were obtained from 23 of these patients. Blood pressure and heart rate changes were compatible with the known properties of the drug. Impaired renal function did not affect the maximum plasma concentrations or bioavailability of nifedipine after single or multiple dose administration of nifedipine GITS, nor was there any evidence of excessive drug accumulation in the presence of renal impairment.

A quantitative systems physiology model of renal function and blood pressure regulation: Model description.

PubMed

Hallow, K M; Gebremichael, Y

2017-06-01

Renal function plays a central role in cardiovascular, kidney, and multiple other diseases, and many existing and novel therapies act through renal mechanisms. Even with decades of accumulated knowledge of renal physiology, pathophysiology, and pharmacology, the dynamics of renal function remain difficult to understand and predict, often resulting in unexpected or counterintuitive therapy responses. Quantitative systems pharmacology modeling of renal function integrates this accumulated knowledge into a quantitative framework, allowing evaluation of competing hypotheses, identification of knowledge gaps, and generation of new experimentally testable hypotheses. Here we present a model of renal physiology and control mechanisms involved in maintaining sodium and water homeostasis. This model represents the core renal physiological processes involved in many research questions in drug development. The model runs in R and the code is made available. In a companion article, we present a case study using the model to explore mechanisms and pharmacology of salt-sensitive hypertension. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Increased renal sympathetic nerve activity leads to hypertension and renal dysfunction in offspring from diabetic mothers.

PubMed

de Almeida Chaves Rodrigues, Aline Fernanda; de Lima, Ingrid Lauren Brites; Bergamaschi, Cássia Toledo; Campos, Ruy Ribeiro; Hirata, Aparecida Emiko; Schoorlemmer, Guus Hermanus Maria; Gomes, Guiomar Nascimento

2013-01-15

The exposure of the fetus to a hyperglycemic environment promotes the development of hypertension and renal dysfunction in the offspring at adult age. We evaluated the role of renal nerves in the hypertension and renal changes seen in offspring of diabetic rats. Diabetes was induced in female Wistar rats (streptozotocin, 60 mg/kg ip) before mating. Male offspring from control and diabetic dams were studied at an age of 3 mo. Systolic blood pressure measured by tail cuff was increased in offspring of diabetic dams (146 ± 1.6 mmHg, n = 19, compared with 117 ± 1.4 mmHg, n = 18, in controls). Renal function, baseline renal sympathetic nerve activity (rSNA), and arterial baroreceptor control of rSNA were analyzed in anesthetized animals. Glomerular filtration rate, fractional sodium excretion, and urine flow were significantly reduced in offspring of diabetic dams. Two weeks after renal denervation, blood pressure and renal function in offspring from diabetic dams were similar to control, suggesting that renal nerves contribute to sodium retention in offspring from diabetic dams. Moreover, basal rSNA was increased in offspring from diabetic dams, and baroreceptor control of rSNA was impaired, with blunted responses to infusion of nitroprusside and phenylephrine. Thus, data from this study indicate that in offspring from diabetic mothers, renal nerves have a clear role in the etiology of hypertension; however, other factors may also contribute to this condition.

Adaptation, allometry, and hypertension.

PubMed

Weder, A B; Schork, N J

1994-08-01

Essential hypertension is a "disease of civilization" but has a clear genetic component. From an evolutionary perspective, persistence in the human genome of elements capable of raising blood pressure presupposes their adaptive significance. Recently, two hypotheses that explicitly appeal to selectionist arguments, the "slavery" and "thrifty gene" theories, have been forwarded. We find neither completely successful, and we advance an alternative explanation of the adaptive importance of genes responsible for hypertension. We propose that blood pressure rises during childhood and adolescence to subserve homeostatic needs of the organism. Specifically, we contend that blood pressure is a flexible element in the repertoire of renal homeostatic mechanisms serving to match renal function to growth. The effect of modern diet and lifestyle on human growth stimulates earlier and more vigorous development, straining biologically necessary relationships between renal and general somatic growth and requiring compensation via homeostatic mechanisms preserved during evolution. Prime among such mechanisms is blood pressure, which rises as a compensation to maintain renal function in the face of greater growth. Since virtually all members of acculturated societies share in the modern lifestyle, the demands imposed by accelerated growth and development result in a populational shift to higher blood pressures, with a consequent increase in the prevalence of hypertension. We propose that hypertension is the product of maladaptation of highly genetically conserved mechanisms subserving important biological homeostatic needs. Elucidation of the mechanisms underlying hypertension will require approaches that examine the developmental processes linking growth to blood pressure.

Effects of carprofen on renal function and results of serum biochemical and hematologic analyses in anesthetized dogs that had low blood pressure during anesthesia.

PubMed

Boström, Ingrid M; Nyman, Görel C; Lord, Peter E; Häggström, Jens; Jones, Bernt E V; Bohlin, Henrik P

2002-05-01

To investigate effects of IV administered carprofen on indices of renal function and results of serum biochemical and hematologic analyses in dogs anesthetized with acepromazine-thiopentone-isoflurane that had low blood pressure during anesthesia. 6 healthy Beagles. A randomized crossover study was conducted, using the following treatments: saline (0.9% NaCl solution)-saline, saline-carprofen, and carprofen-saline. Saline (0.08 ml/kg) and carprofen (4 mg/kg) were administered IV. The first treatment was administered 30 minutes before induction of anesthesia and immediately before administration of acepromazine (0.1 mg/kg, IM). Anesthesia was induced with thiopentone (25 mg/ml, IV) and maintained with inspired isoflurane (2% in oxygen). The second treatment was administered 30 minutes after onset of inhalation anesthesia. Blood gases, circulation, and ventilation were monitored. Renal function was assessed by glomerular filtration rate (GFR), using scintigraphy, serum biochemical analyses, and urinalysis. Hematologic analysis was performed. Statistical analysis was conducted, using ANOVA or Friedman ANOVA. Values did not differ significantly among the 3 treatments. For all treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses, a decrease in mean arterial blood pressure to 65 mm Hg, an increase of 115 pmol/L in angiotensin II concentration, and an increase of 100 seconds in time required to reach maximum activity counts during scintigraphy. Carprofen administered IV before or during anesthesia did not cause detectable significant adverse effects on renal function or results of serum biochemical and hematologic analyses in healthy Beagles with low blood pressure during anesthesia.

Pulse Pressure, Instead of Brachium-Ankle Pulse Wave Velocity, is Associated with Reduced Kidney Function in a Chinese Han Population.

PubMed

Jia, Linpei; Zhang, Weiguang; Ma, Jie; Chen, Xizhao; Chen, Lei; Li, Zuoxiang; Cai, Guangyan; Huang, Jing; Zhang, Jinping; Bai, Xiaojuan; Feng, Zhe; Sun, Xuefeng; Chen, Xiangmei

2017-01-01

In this study, we aim to investigate the association between renal function and arterial stiffness in a Chinese Han population, and further to discuss the effects of smoking on renal function. We collected the data of the brachium-ankle pulse wave velocity (baPWV), blood pressure, blood chemistry and smoking status. Then, the multiple linear regression was done to explore the relationship between estimated glomerular filtration (eGFR) and baPWV. Further, the parameters were compared among the four groups divided according to the quartiles of baPWV. Finally, the baPWV, eGFR and albuminuria values were compared between smokers and non-smokers. baPWV is associated with eGFR in the correlation analysis and univariate linear regression model. After adjustment, the pulse pressure (PP) instead of baPWV showed a significant association with eGFR. Nevertheless, the eGFR values differed among the four baPWV groups; the baPWV values were significantly higher in the subjects at the CKD (eGFR<60 mL/min/1.73 m2) and the early CKD stage (eGFR60-80 mL/min/1.73 m2). The baPWV values and the ratio of proteinuria were significantly increased in smokers. PP but not baPWV is a predictor of declined renal function. Smokers have worse arterial stiffness and worse renal function. © 2017 The Author(s)Published by S. Karger AG, Basel.

[Renal decapsulation for the treatment of anuria : A "forgotten" treatment from the early 20th century].

PubMed

Dräger, D L; Protzel, C; Hakenberg, O W

2017-01-01

In the early 20th century, Harrison first performed renal decapsulation in anuric children with scarlet fever and observed improvement in renal function postoperatively. The pathophysiological explanation was seen in intraparenchymal renal pressure due to edema which was improved by surgical decapsulation. The technique of decapsulation was simple excision after incision and blunt dissection of the renal parenchyma. Renal decapsulation then became a procedure commonly used for many indications in inflammatory renal conditions; indications were renal angioneurosis, hydronephrosis, toxic, bacterial and chronic nephritis, renal abscess and even eclampsia. With the beginning of the antibiotic era, renal decapsulation became obsolete and has disappeared from the urological spectrum completely.

Clinical effectiveness of secondary interventions for restenosis after renal artery stenting

PubMed Central

Simone, Thomas A.; Brooke, Benjamin S.; Goodney, Philip P.; Walsh, Daniel B.; Stone, David H.; Powell, Richard J.; Cronenwett, Jack L.; Nolan, Brian W.

2013-01-01

Objective Secondary interventions for renal artery restenosis (RAS) after renal artery stenting are common, despite limited data about their effectiveness. This study was designed to evaluate the outcomes of endovascular treatment of recurrent RAS. Methods We conducted a retrospective review of patients who underwent renal artery stenting between 2001 and 2011 at Dartmouth-Hitchcock Medical Center. Patients who required secondary interventions were compared with control patients who underwent only primary interventions for RAS. Multivariate regression models were used to identify factors associated with successful outcomes, as measured by changes in blood pressure, estimated glomerular filtration rate, and number of antihypertensive medications required. Results Sixty-five secondary (57 patients) renal interventions were undertaken for recurrent RAS associated with progressive hypertension or renal dysfunction and compared with outcomes after 216 primary (180 patients) renal artery stenting procedures. Patients undergoing primary vs secondary interventions did not differ significantly in the number of preoperative antihypertensive medications used, comorbid conditions, or blood pressure. All primary and secondary interventions were performed with stents and showed no difference in procedural complications. At a mean follow-up of 23 months (range, 1–128 months), similar improvements in renal function and blood pressure were found between patients undergoing primary and secondary interventions, and there was no difference in rates of restenosis or survival between cohorts. Regression models showed that the use of embolic protection devices was associated with improved renal function after primary (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1–3.8; P < .05) and secondary (OR, 4.7; 95% CI, 1.7–12.5; P < .05) interventions, whereas statin therapy was associated with improved renal (OR, 2.0; 95% CI, 1.3–3.2; P < .05) and blood pressure response (OR, 4.1; 95% CI, 1.1–14.9; P < .05) after secondary interventions. Conclusions Patients undergoing secondary interventions for recurrent RAS have outcomes that are comparable with those for primary interventions. These data suggest that repeated endovascular procedures for RAS can be undertaken with similar expectations for clinical improvement and may be further improved by routine use of embolic protection devices and statin therapy. PMID:23688626

Autonomic and Renal Alterations in the Offspring of Sleep-Restricted Mothers During Late Pregnancy.

PubMed

Raimundo, Joyce R S; Bergamaschi, Cassia T; Campos, Ruy R; Palma, Beatriz D; Tufik, Sergio; Gomes, Guiomar N

2016-09-01

Considering that changes in the maternal environment may result in changes in progeny, the aim of this study was to investigate the influence of sleep restriction during the last week of pregnancy on renal function and autonomic responses in male descendants at an adult age. After confirmation of pregnancy, female Wistar rats were randomly assigned to either a control or a sleep restriction group. The sleep-restricted rats were subjected to sleep restriction using the multiple platforms method for over 20 hours per day between the 14th and 20th day of pregnancy. After delivery, the litters were limited to 6 offspring that were designated as offspring from control and offspring from sleep-restricted mothers. Indirect measurements of systolic blood pressure (BPi), renal plasma flow, glomerular filtration rate, glomerular area and number of glomeruli per field were evaluated at three months of age. Direct measurements of cardiovascular function (heart rate and mean arterial pressure), cardiac sympathetic tone, cardiac parasympathetic tone, and baroreflex sensitivity were evaluated at four months of age. The sleep-restricted offspring presented increases in BPi, glomerular filtration rate and glomerular area compared with the control offspring. The sleep-restricted offspring also showed higher basal heart rate, increased mean arterial pressure, increased sympathetic cardiac tone, decreased parasympathetic cardiac tone and reduced baroreflex sensitivity. Our data suggest that reductions in sleep during the last week of pregnancy lead to alterations in cardiovascular autonomic regulation and renal morpho-functional changes in offspring, triggering increases in blood pressure.

Effects of neuropeptide-Y on renal function and its interaction with sympathetic stimulation in conscious dogs.

PubMed Central

Persson, P B; Ehmke, H; Nafz, B; Lang, R; Hackenthal, E; Nobiling, R; Dietrich, M S; Kirchheim, H R

1991-01-01

1. The effects of neuropeptide-Y (NPY) on renal function were investigated in conscious foxhounds. 2. Dose-response curves (n = 7) were obtained for NPY by measuring renal blood flow (RBF), glomerular filtration rate (GFR), urine excretion (VU), sodium excretion (VNa), potassium excretion (VK) and plasma renin activity (PRA) at different infusion rates. All variables decreased with increasing infusion rates except for PRA, which surprisingly did not change during the different infusion rates. 3. The influence of the non-constrictor dose of NPY at control pressure, and after servo-controlling renal arterial pressure at 80 mmHg, was determined for these parameters (n = 6). 4. This was repeated during a reflex sympathetic activation via carotid sinus hypotension, in order to quantify a possible interaction between the sympathetic transmitter and co-transmitter (n = 6). 5. The subthreshold NPY dose raised plasma NPY-like immunoreactivity (NPY-LI IR) significantly (renal venous plasma: 54 +/- 13 vs. 405 +/- 117 pg ml-1; P less than 0.05) and enhanced the pressure-dependent (80 mmHg) antidiuresis (0.48 +/- 0.06 vs. 0.24 +/- 0.02 ml min-1; P less than 0.05), antinatriuresis (46 +/- 11 vs. 25 +/- 3 mumol min-1; P less than 0.05), antikaliuresis (19 +/- 4 vs. 9 +/- 0.7 mumol min-1; P less than 0.05) and pressure-dependent renin release (0.95 +/- 0.27 vs. 3.0 +/- 1.1 ng angiotensin I ml-1 h-1; P less than 0.05). These effects are consistent with a non-uniform vasoconstrictor action of NPY in the renal vascular bed (see accompanying papers). 6. The effects of NPY plus sympathetic activation were less than the sum of the two individual effects, which may rely on a presynaptic mechanism. PMID:1688030

Renal function in juvenile rats subjected to prenatal malnutrition and chronic salt overload.

PubMed

Magalhães, João Carlos G; da Silveira, Alex B; Mota, Diogenes L; Paixão, Ana Durce O

2006-05-01

Dietary sodium may contribute to hypertension and to cardiovascular and renal disease if a primary deficiency of the kidney to excrete sodium exists. In order to investigate whether chronic 1% NaCl in the drinking water changes blood pressure and renal haemodynamics in juvenile Wistar rats subjected to prenatal malnutrition, an evaluation of plasma volume, oxidative stress in the kidney, proteinuria and renal haemodynamics was carried out. Malnutrition was induced by a multideficient diet. Mean arterial pressure, renal blood flow and glomerular filtration rate (GFR) were measured using a blood pressure transducer, a flow probe and inulin clearance, respectively. Plasma volume and oxidative stress were measured by means of the Evans Blue method and by monitoring thiobarbituric acid reactive substances (TBARS) in the kidneys, respectively. Urinary protein was measured by precipitation with 3% sulphosalicylic acid. It was observed that prenatally malnourished rats presented higher values of plasma volume (26%, P < 0.05), kidney TBARS (43%, P < 0.01) and blood pressure (10%, P < 0.01) when compared with the control group. However, they showed no change in renal haemodynamics or proteinuria. Neither prenatally malnourished nor control rats treated with sodium overload presented plasma volume or blood pressure values different from their respective control groups, but both groups presented elevated proteinuria (P < 0.01). The prenatally malnourished group treated with sodium overload presented higher values of kidney TBARS, GFR and filtration fraction (58, 87 and 72% higher, respectively, P < 0.01) than its respective control group. In summary, sodium overload did not exacerbate the hypertension in juvenile prenatally malnourished rats, but induced renal haemodynamic adjustments compatible with the development of renal disease.

Micropuncture studies of the recovery phase of myohemoglobinuric acute renal failure in the rat

PubMed Central

Oken, Donald E.; DiBona, Gerald F.; McDonald, Franklin D.

1970-01-01

Micropuncture studies of the recovery phase of glycerol-induced myohemoglobinuric acute renal failure were performed in rats whose blood urea nitrogen (BUN) had fallen at least 20% below its peak value. The glomerular filtration rate (GFR) of individual nephrons in a single kidney in the recovery period generally either was in the normal range or minimal. Each animal's BUN concentration at the time of the study was inversely related to the proportion of functioning surface nephrons, but did not correlate with individual nephron GFR values. Proximal tubule fractional water absorption was significantly depressed as manifested by both depressed inulin (TF/P) values and supernormal volumes of collections, a finding which, in the absence of a urea-induced osmotic diuresis, suggests impaired sodium transport by the damaged nephron. The mean proximal tubule hydrostatic pressure in recovery was normal and there was little variation in pressure among functioning nephrons. It is concluded that recovery from this model of acute renal failure reflects the progressive recruitment of increasing numbers of functioning nephrons. The recovery of individual nephron glomerular filtration, once begun, was rapid and complete. No evidence could be adduced that the gradual return of renal function towards normal reflects a slow release of tubular obstruction or repair of disrupted tubular epithelium. Rather, recovery appeared to be directly attributable to the return of an adequate effective glomerular filtration pressure. Significant limitation in proximal tubule water absorption persisted after individual nephron GFR had returned to normal or supernormal values in this model of experimental acute renal failure in the rat, a finding which readily accounts for the diuresis associated with the recovery phase of this syndrome. PMID:5443173

Persistent Increase in Blood Pressure After Renal Nerve Stimulation in Accessory Renal Arteries After Sympathetic Renal Denervation.

PubMed

de Jong, Mark R; Hoogerwaard, Annemiek F; Gal, Pim; Adiyaman, Ahmet; Smit, Jaap Jan J; Delnoy, Peter Paul H M; Ramdat Misier, Anand R; van Hasselt, Boudewijn A A M; Heeg, Jan-Evert; le Polain de Waroux, Jean-Benoit; Lau, Elizabeth O Y; Staessen, Jan A; Persu, Alexandre; Elvan, Arif

2016-06-01

Blood pressure response to renal denervation is highly variable, and the proportion of responders is disappointing. This may be partly because of accessory renal arteries too small for denervation, causing incomplete ablation. Renal nerve stimulation before and after renal denervation is a promising approach to assess completeness of renal denervation and may predict blood pressure response to renal denervation. The objective of the current study was to assess renal nerve stimulation-induced blood pressure increase before and after renal sympathetic denervation in main and accessory renal arteries of anaesthetized patients with drug-resistant hypertension. The study included 21 patients. Nine patients had at least 1 accessory renal artery in which renal denervation was not feasible. Renal nerve stimulation was performed in the main arteries of all patients and in accessory renal arteries of 6 of 9 patients with accessory arteries, both before and after renal sympathetic denervation. Renal nerve stimulation before renal denervation elicited a substantial increase in systolic blood pressure, both in main (25.6±2.9 mm Hg; P<0.001) and accessory (24.3±7.4 mm Hg; P=0.047) renal arteries. After renal denervation, renal nerve stimulation-induced systolic blood pressure increase was blunted in the main renal arteries (Δ systolic blood pressure, 8.6±3.7 mm Hg; P=0.020), but not in the nondenervated renal accessory renal arteries (Δ systolic blood pressure, 27.1±7.6 mm Hg; P=0.917). This residual source of renal sympathetic tone may result in persistent hypertension after ablation and partly account for the large response variability. © 2016 American Heart Association, Inc.

Urotensin-II System in Genetic Control of Blood Pressure and Renal Function

PubMed Central

Debiec, Radoslaw; Christofidou, Paraskevi; Denniff, Matthew; Bloomer, Lisa D.; Bogdanski, Pawel; Wojnar, Lukasz; Musialik, Katarzyna; Charchar, Fadi J.; Thompson, John R.; Waterworth, Dawn; Song, Kijoung; Vollenweider, Peter; Waeber, Gerard; Zukowska-Szczechowska, Ewa; Samani, Nilesh J.; Lambert, David; Tomaszewski, Maciej

2013-01-01

Urotensin-II controls ion/water homeostasis in fish and vascular tone in rodents. We hypothesised that common genetic variants in urotensin-II pathway genes are associated with human blood pressure or renal function. We performed family-based analysis of association between blood pressure, glomerular filtration and genes of the urotensin-II pathway (urotensin-II, urotensin-II related peptide, urotensin-II receptor) saturated with 28 tagging single nucleotide polymorphisms in 2024 individuals from 520 families; followed by an independent replication in 420 families and 7545 unrelated subjects. The expression studies of the urotensin-II pathway were carried out in 97 human kidneys. Phylogenetic evolutionary analysis was conducted in 17 vertebrate species. One single nucleotide polymorphism (rs531485 in urotensin-II gene) was associated with adjusted estimated glomerular filtration rate in the discovery cohort (p = 0.0005). It showed no association with estimated glomerular filtration rate in the combined replication resource of 8724 subjects from 6 populations. Expression of urotensin-II and its receptor showed strong linear correlation (r = 0.86, p<0.0001). There was no difference in renal expression of urotensin-II system between hypertensive and normotensive subjects. Evolutionary analysis revealed accumulation of mutations in urotensin-II since the divergence of primates and weaker conservation of urotensin-II receptor in primates than in lower vertebrates. Our data suggest that urotensin-II system genes are unlikely to play a major role in genetic control of human blood pressure or renal function. The signatures of evolutionary forces acting on urotensin-II system indicate that it may have evolved towards loss of function since the divergence of primates. PMID:24391740

[Safety and short-term efficacy of renal sympathetic denervation in the treatment of resistant hypertension].

PubMed

Jiang, Xiong-jing; Liang, Tuo; Dong, Hui; Peng, Meng; Ma, Wen-jun; Guan, Ting; Zhang, Hui-min; Bian, Jin; Xu, Bo; Gao, Run-lin

2012-12-11

Transcatheter renal sympathetic denervation (RDN) is a novel technology/therapy in treating resistant hypertension. The present study aims to evaluate the safety and short-term efficacy of RDN for the treatment of resistant hypertension in a Chinese population. This prospective single-center pilot study was the first one conducted in China with Medtronic Ardian Symplicity Catheter System. Eight patients (6 males and 2 females) with resistant hypertension underwent RDN at our hospital from February to April 2012. All patients were followed up at one month and three months post-RDN. Blood pressure, use of antihypertensive medications, renal function and complications were recorded and analyzed. At one month and three months post-RDN, 24-hour ambulatory blood pressure monitoring showed mean systolic blood pressure and diastolic blood pressure decreased 10 (0 - 18) 13 (3 - 19) and 8 (-2 - 15), 9 (2 - 16) mm Hg throughout 24 hours respectively (P < 0.05, vs baseline). The number of drugs decreased from 4.3 ± 0.5 to 2.8 ± 0.9 and 2.5 ± 0.7 post-RSD respectively (P < 0.01). There was no significant change of renal function (P > 0.05). No complications were observed. The preliminary results revealed that RDN was safe and effective for the treatment of resistant hypertension in the Chinese population during a 3-month follow-up. Further large and long-term studies are warranted.

[Decline in renal function in old age : Part of physiological aging versus age-related disease].

PubMed

Braun, F; Brinkkötter, P T

2016-08-01

The incidence and prevalence of chronic renal disease (CKD) in elderly patients are continuously increasing worldwide. Loss of renal function is not only considered to be part of the aging process itself but also reflects the multimorbidity of many geriatric patients. Calculating the glomerular filtration rate using specific algorithms validated for the elderly population and measuring the amount of proteinuria allow an estimation of renal function in elderly patients with high accuracy. Chronic renal failure has many clinical consequences and not only results in a delayed excretion of toxins cleared by the kidneys but also affects hematogenesis, water and electrolyte balance as well as mineral bone metabolism. Furthermore, CKD directly leads to and aggravates geriatric syndromes and in particular the onset of frailty. Therapeutic strategies to halt progression of CKD not only comprise treatment of the underlying disease but also efficient blood pressure and diabetic control and the avoidance of nephrotoxic medications.

Why, when and how should immunosuppressive therapy considered in patients with immunoglobulin A nephropathy?

PubMed Central

Rasche, F. M.; Rasche, W. G.; Schiekofer, S.; Boldt, A.; Sack, U.; Fahnert, J.

2016-01-01

Summary IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Lifelong mesangial deposition of IgA1 complexes subsist inflammation and nephron loss, but the complex pathogenesis in detail remains unclear. In regard to the heterogeneous course, classical immunosuppressive and specific therapeutic regimens adapted to the loss of renal function will here be discussed in addition to the essential common renal supportive therapy. Renal supportive therapy alleviates secondary, surrogate effects or sequelae on renal function and proteinuria of high intraglomerular pressure and subsequent nephrosclerosis by inhibition of the renin angiotensin system (RAASB). In patients with physiological (ΔGFR < 1·5 ml/min/year) or mild (ΔGFR 1·5–5 ml/min/year) decrease of renal function and proteinuric forms (> 1 g/day after RAASB), corticosteroids have shown a reduction of proteinuria and might protect further loss of renal function. In patients with progressive loss of renal function (ΔGFR > 3 ml/min within 3 months) or a rapidly progressive course with or without crescents in renal biopsy, cyclophosphamide with high‐dose corticosteroids as induction therapy and azathioprine maintenance has proved effective in one randomized controlled study of a homogeneous cohort in loss of renal function (ΔGFR). Mycophenolic acid provided further maintenance in non‐randomized trials. Differentiated, precise, larger, randomized, placebo‐controlled studies focused on the loss of renal function in the heterogeneous forms of IgAN are still lacking. Prospectively, fewer toxic agents will be necessary in the treatment of IgAN. PMID:27283488

Renal angioplasty and stenting under protection: the way for the future?

PubMed

Henry, Michel; Henry, Isabelle; Klonaris, Christos; Polydorou, Antonio; Rath, Pathrap; Lakshmi, Gopalakrishnan; Rajacopal, Sriram; Hugel, Michèle

2003-11-01

The purpose of this study was to evaluate the feasibility and safety of renal artery angioplasty and stenting utilizing a distal protection device to reduce the risk of intraprocedural artery embolism and avoid deterioration of the renal function. Fifty-six hypertensive patients (32 men; mean age, 66 +/- 11.8 years; range, 22-87) with atherosclerotic renal artery stenosis (8 bilateral) underwent angioplasty and stenting with distal protection in 65 renal arteries (58 ostial lesions). Five patients had a solitary kidney, 18 a renal insufficiency. The lesion was crossed either with a GuardWire temporary occlusion balloon (n = 38), which was inflated to provide parenchyma protection or with a filter (EPI Filter; n = 26), or with Angioguard (n = 1), which allows a continuous flow. Generated debris was aspirated and analyzed. Blood pressure and serum creatinine levels were followed. Immediate technical success was 100%. All lesions except one were stented, either directly (43 ostial lesions) or after predilatation (22 ostial lesions). Visible debris were aspirated with the PercuSurge in all patients or removed with filters in 80% of the patients. Mean particle number and diameter were 98.1 +/- 60.0 per procedure (range, 13-208) and 201.0 +/- 76.0 microm (range, 38-6,206), respectively. Mean renal artery occlusion time was 6.55 +/- 2.46 min (range, 2.29-13.21) with the PercuSurge device. Mean time in situ (filters) was 4.25 +/- 1.12 min. Mean follow-up was 22.6 +/- 17.6 months (range, 1-47). Systolic and diastolic blood pressure declined from 169.0 +/- 15.2 and 104.0 +/- 13.0 mm Hg, respectively, to 149.7 +/- 12.4 and 92.7 +/- 6.7 mm Hg after the procedure. The mean creatinine level remains constant during the follow-up. At 6-month follow-up (45 patients), renal function did not deteriorate in any patient, whereas 8 patients with baseline renal insufficiency improved after the procedure. At 3 years (19 patients), renal function deteriorated only in 1 patient with renal insufficiency and in 1 patient treated for bilateral renal stenosis, one side without protection. These preliminary results suggest the feasibility and safety of distal protection during renal interventions to protect against atheroembolism and to avoid renal function deterioration. This technique's beneficial effects should be evaluated by randomized studies. Copyright 2003 Wiley-Liss, Inc.

Eppur Si Muove: The Dynamic Nature of Physiological Control of Renal Blood Flow by the Renal Sympathetic Nerves

PubMed Central

Schiller, Alicia M.; Pellegrino, Peter Ricci; Zucker, Irving H.

2016-01-01

Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. PMID:27514571

Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

PubMed

Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

2017-05-01

Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. Copyright © 2016 Elsevier B.V. All rights reserved.

Chronic kidney disease and worsening renal function in acute heart failure: different phenotypes with similar prognostic impact?

PubMed

Palazzuoli, Alberto; Lombardi, Carlo; Ruocco, Gaetano; Padeletti, Margherita; Nuti, Ranuccio; Metra, Marco; Ronco, Claudio

2016-12-01

Nearly a third of patients with acute heart failure experience concomitant renal dysfunction. This condition is often associated with increased costs of care, length of hospitalisation and high mortality. Although the clinical impact of chronic kidney disease (CKD) has been well established, the exact clinical significance of worsening renal function (WRF) during the acute and post-hospitalisation phases is not completely understood. Therefore, it is still unclear which of the common laboratory markers are able to identify WRF at an early stage. Recent studies comparing CKD with WRF showed contradictory results; this could depend on a different WRF definition, clinical characteristics, haemodynamic disorders and the presence of prior renal dysfunction in the population enrolled. The current definition of acute cardiorenal syndrome focuses on both the heart and kidney but it lacks precise laboratory marker cut-offs and a specific diagnostic approach. WRF and CKD could represent different pathophysiological mechanisms in the setting of acute heart failure; the traditional view includes reduced cardiac output with systemic and renal vasoconstriction. Nevertheless, it has become a mixed model that encompasses both forward and backward haemodynamic dysfunction. Increased central venous pressure, renal congestion with tubular obliteration, tubulo-glomerular feedback and increased abdominal pressure are all potential additional contributors. The impact of WRF on patients who experience preserved renal function and individuals affected with CKD is currently unknown. Therefore it is extremely important to understand the origins, the clinical significance and the prognostic impact of WRF on CKD. © The European Society of Cardiology 2015.

Renoprotective and blood pressure-lowering effect of dietary soy protein via protein kinase C beta II inhibition in a rat model of metabolic syndrome.

PubMed

Palanisamy, Nallasamy; Viswanathan, Periyasamy; Ravichandran, Mambakkam Katchapeswaran; Anuradha, Carani Venkataraman

2010-01-01

We studied whether substitution of soy protein for casein can improve insulin sensitivity, lower blood pressure (BP), and inhibit protein kinase C betaII (PKCbetaII) activation in kidney in an acquired model of metabolic syndrome. Adult male rats were fed 4 different diets: (i) starch (60%) and casein (20%) (CCD), (ii) fructose (60%) and casein (20%) (FCD), (iii) fructose (60%) and soy protein (20%) (FSD), and (iv) starch (60%) and soy protein (20%) (CSD). Renal function parameters, BP, pressor mechanisms, PKCbetaII expression, oxidative stress, and renal histology were evaluated after 60 days. FCD rats displayed insulin resistance and significant changes in body weight, kidney weight, urine volume, plasma and urine electrolytes accompanied by significant changes in renal function parameters compared with CCD rats. Elevated BP, plasma angiotensin-converting enzyme (ACE) activity, renal oxidative stress, and reduced nitrite (NO) and kallikrein activity were observed. Western blot analysis revealed enhanced renal expression of membrane-associated PKCbetaII in the FCD group. Histology showed fatty infiltration and thickening of glomeruli while urinary protein profile revealed a 5-fold increase in albumin. Substitution of soy protein for casein improved insulin sensitivity, lowered BP and PKCbetaII activation and restored renal function. Antioxidant action, inhibitory effect on ACE and PKCbetaII activation, and increased availability of kinins and NO could be contributing mechanisms for the benefits of dietary soy protein.

Renal denervation attenuates NADPH oxidase-mediated oxidative stress and hypertension in rats with hydronephrosis.

PubMed

Peleli, Maria; Al-Mashhadi, Ammar; Yang, Ting; Larsson, Erik; Wåhlin, Nils; Jensen, Boye L; G Persson, A Erik; Carlström, Mattias

2016-01-01

Hydronephrosis is associated with the development of salt-sensitive hypertension. Studies have suggested that increased sympathetic nerve activity and oxidative stress play important roles in hypertension and the modulation of salt sensitivity. The present study primarily aimed to examine the role of renal sympathetic nerve activity in the development of hypertension in rats with hydronephrosis. In addition, we aimed to investigate if NADPH oxidase (NOX) function could be affected by renal denervation. Partial unilateral ureteral obstruction (PUUO) was created in 3-wk-old rats to induce hydronephrosis. Sham surgery or renal denervation was performed at the same time. Blood pressure was measured during normal, high-, and low-salt diets. The renal excretion pattern, NOX activity, and expression as well as components of the renin-angiotensin-aldosterone system were characterized after treatment with the normal salt diet. On the normal salt diet, rats in the PUUO group had elevated blood pressure compared with control rats (115 ± 3 vs. 87 ± 1 mmHg, P < 0.05) and displayed increased urine production and lower urine osmolality. The blood pressure change in response to salt loading (salt sensitivity) was more pronounced in the PUUO group compared with the control group (15 ± 2 vs. 5 ± 1 mmHg, P < 0.05). Renal denervation in PUUO rats attenuated both hypertension (97 ± 3 mmHg) and salt sensitivity (5 ± 1 mmHg, P < 0.05) and normalized the renal excretion pattern, whereas the degree of renal fibrosis and inflammation was not changed. NOX activity and expression as well as renin and ANG II type 1A receptor expression were increased in the renal cortex from PUUO rats and normalized by denervation. Plasma Na(+) and K(+) levels were elevated in PUUO rats and normalized after renal denervation. Finally, denervation in PUUO rats was also associated with reduced NOX expression, superoxide production, and fibrosis in the heart. In conclusion, renal denervation attenuates hypertension and restores the renal excretion pattern, which is associated with reduced renal NOX and components of the renin-angiotensin-aldosterone system. This study emphasizes a link between renal nerves, the development of hypertension, and modulation of NOX function. Copyright © 2016 the American Physiological Society.

[Renal denervation as treatment option for hypertension].

PubMed

Blankestijn, P J; Bots, M L

2016-01-01

The rationale behind catheter-based renal denervation is that afferent and efferent renal nerves play a role in the pathogenesis and maintenance of high blood pressure, and that this can be prevented by blocking the function of the renal nerves. Since the introduction of catheter-based renal denervation, several observational and a small number of randomised controlled trials have been conducted. The available evidence does not allow for a definitive conclusion regarding its efficacy. There have been no serious side-effects reported. The development of this treatment concept has not been finalised; new trials have just commenced or will start in the near future.

βENaC is a molecular component of a VSMC mechanotransducer that contributes to renal blood flow regulation, protection from renal injury, and hypertension.

PubMed

Drummond, Heather A

2012-01-01

Pressure-induced constriction (also known as the "myogenic response") is an important mechano-dependent response in certain blood vessels. The response is mediated by vascular smooth muscle cells (VSMCs) and characterized by a pressure-induced vasoconstriction in small arteries and arterioles in the cerebral, mesenteric, cardiac, and renal beds. The myogenic response has two important roles; it is a mechanism of blood flow autoregulation and provides protection against systemic blood pressure-induced damage to delicate microvessels. However, the molecular mechanism(s) underlying initiation of myogenic response is unclear. Degenerin proteins have a strong evolutionary link to mechanotransduction in the nematode. Our laboratory has addressed the hypothesis that these proteins may also act as mechanosensors in certain mammalian tissues such as VSMCs and arterial baroreceptor neurons. This article discusses the importance of a specific degenerin protein, β Epithelial Na(+) Channel (βENaC) in pressure-induced vasoconstriction in renal vessels and arterial baroreflex function as determined in a mouse model of reduced βENaC (βENaC m/m). We propose that loss of baroreflex sensitivity (due to loss of baroreceptor βENaC) increases blood pressure variability, increasing the likelihood and magnitude of upward swings in systemic pressure. Furthermore, loss of the myogenic constrictor response (due to loss of VSMC βENaC) will permit those pressure swings to be transmitted to the microvasculature in βENaC m/m mice, thus increasing the susceptibility to renal injury and hypertension.

Chronic Sleep Restriction during Pregnancy - Repercussion on Cardiovascular and Renal Functioning of Male Offspring

PubMed Central

Lima, Ingrid L. B.; Rodrigues, Aline F. A. C.; Bergamaschi, Cássia T.; Campos, Ruy R.; Hirata, Aparecida E.; Tufik, Sergio; Xylaras, Beatriz D. P.; Visniauskas, Bruna; Chagas, Jair R.; Gomes, Guiomar N.

2014-01-01

Changes in the maternal environment can induce fetal adaptations that result in the progression of chronic diseases in the offspring. The objective of the present study was to evaluate the effects of maternal chronic sleep restriction on blood pressure, renal function and cardiac baroreflex response on male offspring at adult age. Female 3-month-old Wistar rats were divided in two experimental groups: control (C) and chronic sleep restricted (CSR). Pregnancy was confirmed by vaginal smear. Chronic sleep restricted females were subjected to sleep restriction by the multiple platform technique for 20 h daily, between the 1st and 20th day of pregnancy. After birth, the litters were reduced to 6 rats per mother, and were designated as offspring from control (OC) and offspring from chronic sleep restricted (OCSR). Indirect blood pressure (BPi – tail cuff) was measured by plethysmography in male offspring at 3 months old. Following, the renal function and cardiac baroreflex response were analyzed. Values of BPi in OCSR were significantly higher compared to OC [OC: 127±2.6 (19); OCSR: 144±2.5 (17) mmHg]. The baroreflex sensitivity to the increase of blood pressure was reduced in OCSR [Slope: OC: −2.6±0.15 (9); OCRS: −1.6±0.13 (9)]. Hypothalamic activity of ACE2 was significantly reduced in OCSR compared to OC [OC: 97.4±15 (18); OSR: 60.2±3.6 (16) UAF/min/protein mg]. Renal function alteration was noticed by the increase in glomerular filtration rate (GFR) observed in OCSR [OC: 6.4±0.2 (10); OCSR: 7.4±0.3 (7)]. Chronic sleep restriction during pregnancy caused in the offspring hypertension, altered cardiac baroreflex response, reduced ACE-2 activity in the hypothalamus and renal alterations. Our data suggest that the reduction of sleeping time along the pregnancy is able to modify maternal homeostasis leading to functional alterations in offspring. PMID:25405471

Chronic sleep restriction during pregnancy--repercussion on cardiovascular and renal functioning of male offspring.

PubMed

Lima, Ingrid L B; Rodrigues, Aline F A C; Bergamaschi, Cássia T; Campos, Ruy R; Hirata, Aparecida E; Tufik, Sergio; Xylaras, Beatriz D P; Visniauskas, Bruna; Chagas, Jair R; Gomes, Guiomar N

2014-01-01

Changes in the maternal environment can induce fetal adaptations that result in the progression of chronic diseases in the offspring. The objective of the present study was to evaluate the effects of maternal chronic sleep restriction on blood pressure, renal function and cardiac baroreflex response on male offspring at adult age. Female 3-month-old Wistar rats were divided in two experimental groups: control (C) and chronic sleep restricted (CSR). Pregnancy was confirmed by vaginal smear. Chronic sleep restricted females were subjected to sleep restriction by the multiple platform technique for 20 h daily, between the 1st and 20th day of pregnancy. After birth, the litters were reduced to 6 rats per mother, and were designated as offspring from control (OC) and offspring from chronic sleep restricted (OCSR). Indirect blood pressure (BPi - tail cuff) was measured by plethysmography in male offspring at 3 months old. Following, the renal function and cardiac baroreflex response were analyzed. Values of BPi in OCSR were significantly higher compared to OC [OC: 127 ± 2.6 (19); OCSR: 144 ± 2.5 (17) mmHg]. The baroreflex sensitivity to the increase of blood pressure was reduced in OCSR [Slope: OC: -2.6 ± 0.15 (9); OCRS: -1.6 ± 0.13 (9)]. Hypothalamic activity of ACE2 was significantly reduced in OCSR compared to OC [OC: 97.4 ± 15 (18); OSR: 60.2 ± 3.6 (16) UAF/min/protein mg]. Renal function alteration was noticed by the increase in glomerular filtration rate (GFR) observed in OCSR [OC: 6.4 ± 0.2 (10); OCSR: 7.4 ± 0.3 (7)]. Chronic sleep restriction during pregnancy caused in the offspring hypertension, altered cardiac baroreflex response, reduced ACE-2 activity in the hypothalamus and renal alterations. Our data suggest that the reduction of sleeping time along the pregnancy is able to modify maternal homeostasis leading to functional alterations in offspring.

Flavonoids in Kidney Health and Disease

PubMed Central

Vargas, Félix; Romecín, Paola; García-Guillén, Ana I.; Wangesteen, Rosemary; Vargas-Tendero, Pablo; Paredes, M. Dolores; Atucha, Noemí M.; García-Estañ, Joaquín

2018-01-01

This review summarizes the latest advances in knowledge on the effects of flavonoids on renal function in health and disease. Flavonoids have antihypertensive, antidiabetic, and antiinflammatory effects, among other therapeutic activities. Many of them also exert renoprotective actions that may be of interest in diseases such as glomerulonephritis, diabetic nephropathy, and chemically-induced kidney insufficiency. They affect several renal factors that promote diuresis and natriuresis, which may contribute to their well-known antihypertensive effect. Flavonoids prevent or attenuate the renal injury associated with arterial hypertension, both by decreasing blood pressure and by acting directly on the renal parenchyma. These outcomes derive from their interference with multiple signaling pathways known to produce renal injury and are independent of their blood pressure-lowering effects. Oral administration of flavonoids prevents or ameliorates adverse effects on the kidney of elevated fructose consumption, high fat diet, and types I and 2 diabetes. These compounds attenuate the hyperglycemia-disrupted renal endothelial barrier function, urinary microalbumin excretion, and glomerular hyperfiltration that results from a reduction of podocyte injury, a determinant factor for albuminuria in diabetic nephropathy. Several flavonoids have shown renal protective effects against many nephrotoxic agents that frequently cause acute kidney injury (AKI) or chronic kidney disease (CKD), such as LPS, gentamycin, alcohol, nicotine, lead or cadmium. Flavonoids also improve cisplatin- or methotrexate-induced renal damage, demonstrating important actions in chemotherapy, anticancer and renoprotective effects. A beneficial prophylactic effect of flavonoids has been also observed against AKI induced by surgical procedures such as ischemia/reperfusion (I/R) or cardiopulmonary bypass. In several murine models of CKD, impaired kidney function was significantly improved by the administration of flavonoids from different sources, alone or in combination with stem cells. In humans, cocoa flavanols were found to have vasculoprotective effects in patients on hemodialysis. Moreover, flavonoids develop antitumor activity against renal carcinoma cells with no toxic effects on normal cells, suggesting a potential therapeutic role in patients with renal carcinoma. PMID:29740333

Flavonoids in Kidney Health and Disease.

PubMed

Vargas, Félix; Romecín, Paola; García-Guillén, Ana I; Wangesteen, Rosemary; Vargas-Tendero, Pablo; Paredes, M Dolores; Atucha, Noemí M; García-Estañ, Joaquín

2018-01-01

This review summarizes the latest advances in knowledge on the effects of flavonoids on renal function in health and disease. Flavonoids have antihypertensive, antidiabetic, and antiinflammatory effects, among other therapeutic activities. Many of them also exert renoprotective actions that may be of interest in diseases such as glomerulonephritis, diabetic nephropathy, and chemically-induced kidney insufficiency. They affect several renal factors that promote diuresis and natriuresis, which may contribute to their well-known antihypertensive effect. Flavonoids prevent or attenuate the renal injury associated with arterial hypertension, both by decreasing blood pressure and by acting directly on the renal parenchyma. These outcomes derive from their interference with multiple signaling pathways known to produce renal injury and are independent of their blood pressure-lowering effects. Oral administration of flavonoids prevents or ameliorates adverse effects on the kidney of elevated fructose consumption, high fat diet, and types I and 2 diabetes. These compounds attenuate the hyperglycemia-disrupted renal endothelial barrier function, urinary microalbumin excretion, and glomerular hyperfiltration that results from a reduction of podocyte injury, a determinant factor for albuminuria in diabetic nephropathy. Several flavonoids have shown renal protective effects against many nephrotoxic agents that frequently cause acute kidney injury (AKI) or chronic kidney disease (CKD), such as LPS, gentamycin, alcohol, nicotine, lead or cadmium. Flavonoids also improve cisplatin- or methotrexate-induced renal damage, demonstrating important actions in chemotherapy, anticancer and renoprotective effects. A beneficial prophylactic effect of flavonoids has been also observed against AKI induced by surgical procedures such as ischemia/reperfusion (I/R) or cardiopulmonary bypass. In several murine models of CKD, impaired kidney function was significantly improved by the administration of flavonoids from different sources, alone or in combination with stem cells. In humans, cocoa flavanols were found to have vasculoprotective effects in patients on hemodialysis. Moreover, flavonoids develop antitumor activity against renal carcinoma cells with no toxic effects on normal cells, suggesting a potential therapeutic role in patients with renal carcinoma.

Increased Blood Pressure Variability Prior to Chronic Kidney Disease Exacerbates Renal Dysfunction in Rats

PubMed Central

Freitas, Frederico F. C. T.; Araujo, Gilberto; Porto, Marcella L.; Freitas, Flavia P. S.; Graceli, Jones B.; Balarini, Camille M.; Vasquez, Elisardo C.; Meyrelles, Silvana S.; Gava, Agata L.

2016-01-01

Increased blood pressure variability (BPV), which can be experimentally induced by sinoaortic denervation (SAD), has emerged as a new marker of the prognosis of cardiovascular and renal outcomes. Considering that increased BPV can lead to organ-damage, the goal of the present study was to evaluate the effects of SAD on renal function in an experimental model of chronic kidney disease (CKD). SAD was performed in male Wistar rats 2 weeks before 5/6 nephrectomy and the animals were evaluated 4 weeks after the induction of CKD. Our data demonstrated that BPV was increased in SAD and CKD animals and that the combination of both conditions (SAD+CKD) exacerbated BPV. The baroreflex sensitivity index was diminished in the SAD and CKD groups; this reduction was more pronounced when SAD and CKD were performed together. 5/6 nephrectomy led to hypertension, which was higher in SAD+CKD animals. Regarding renal function, the combination of SAD and CKD resulted in reduced renal plasma and blood flow, increased renal vascular resistance and augmented uraemia when compared to CKD animals. Glomerular filtration rate and BPV were negatively correlated in SAD, CKD, and SAD+CKD animals. Moreover, SAD+CKD animals presented a higher level of glomerulosclerosis when compared to all other groups. Cardiac and renal hypertrophy, as well as oxidative stress, was also further increased when SAD and CKD were combined. These results show that SAD prior to 5/6 nephrectomy exacerbates renal dysfunction, suggesting that previous augmented BPV should be considered as an important factor to the progression of renal diseases. PMID:27721797

Mathematical Modeling of Renal Hemodynamics in Physiology and Pathophysiology

PubMed Central

Sgouralis, Ioannis; Layton, Anita T.

2015-01-01

In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. PMID:25765886

One-year renal and cardiac effects of bisoprolol versus losartan in recently diagnosed hypertensive patients: a randomized, double-blind study.

PubMed

Parrinello, Gaspare; Paterna, Salvatore; Torres, Daniele; Di Pasquale, Pietro; Mezzero, Manuela; La Rocca, Gabriella; Cardillo, Mauro; Trapanese, Caterina; Caradonna, Mario; Licata, Giuseppe

2009-01-01

Hypertension is a significant cause of chronic renal injury and its effective treatment is capable of reducing the rate of renal failure. beta-Adrenoceptor antagonists (beta-blockers) have been reported to induce a deterioration in renal function, while several data have indicated a renoprotective effect of treatment with the angiotensin II type 1 receptor antagonist losartan. Previous studies of the interaction between the selective beta(1)-blocker bisoprolol and kidney function were performed only for short- and medium-term periods. The aim of this study was to compare the antihypertensive efficacy and renal and cardiac haemodynamic effects of bisoprolol with those of losartan over a 1-year time period in patients with essential hypertension. Seventy-two patients (40 males) with recently diagnosed uncomplicated (European Society of Hypertension [ESH] criteria stage 1-2) hypertension (mean +/- SD age 52 +/- 12 years) were enrolled in the study. After a run-in period of 14 days on placebo, the patients were randomized in a double-blind, prospective study to receive either bisoprolol 5 mg or losartan 50 mg, administered once daily for 1 year. At recruitment and 12 months after treatment, cardiac output and renal haemodynamics and function were evaluated by echocardiography and radionuclide studies, respectively. There were no significant differences in baseline clinical data, including glomerular filtration rate and blood pressure, between the two treatment groups. At 1 year, blood pressure had decreased significantly (p < 0.001) with both treatments, and heart rate was reduced only in the group taking bisoprolol. The long-term effects on renal haemodynamics and cardiac function were similar with both drugs, the only change being a significant reduction in the filtration fraction for each group. These data suggest that both bisoprolol and losartan are effective agents for the treatment of patients with recently diagnosed ESH stage 1-2 hypertension. Over a 1-year period, both agents maintained good renal and cardiac performance and haemodynamics.

Inherited renal tubulopathies associated with metabolic alkalosis: effects on blood pressure.

PubMed

Ariceta, Gema; Rodríguez-Soriano, Juan

2006-11-01

Inherited tubular disorders associated with metabolic alkalosis are caused by several gene mutations encoding different tubular transporters responsible for NaCl renal handling. Body volume and renin-angiotensin-aldosterone system status are determined by NaCl reabsorption in the distal nephron. Two common hallmarks in affected individuals: hypokalemia and normal / high blood pressure, support the differential diagnosis. Bartter's syndrome, characterized by hypokalemia and normal blood pressure, is a heterogenic disease caused by the loss of function of SLC12A1 (type 1), KCNJ1 (type 2), CLCNKB (type 3), or BSND genes (type 4). As a result, patients present with renal salt wasting and hypercalciuria. Gitelman's syndrome is caused by the loss of funcion of the SLC12A3 gene and may resemble Bartter's syndrome, though is associated with the very low urinary calcium. Liddle's syndrome, also with similar phenotype but with hypertension, is produced by the gain of function of the SNCC1B or SNCC1G genes, and must be distinguished from other entities of inherited hypertension such as Apparently Mineralocorticoid Excess, of glucocorticoid remediable hypertension.

Renal Perfusion and Function during Pneumoperitoneum: A Systematic Review and Meta-Analysis of Animal Studies

PubMed Central

Warlé, Michiel C.; Hooijmans, Carlijn R.

2016-01-01

Both preclinical and clinical studies indicate that raised intra-abdominal pressure (IAP) associated with pneumoperitoneum during laparoscopic surgical procedures can cause renal damage, the severity of which may be influenced by variables such as pressure level and duration. Several of these variables have been investigated in animal studies, but synthesis of all preclinical data has not been performed. This systematic review summarizes all available pre-clinical evidence on this topic, including an assessment of its quality and risk of bias. We performed meta-analysis to assess which aspects of the pneumoperitoneum determine the severity of its adverse effects. A systematic search in two databases identified 55 studies on the effect of pneumoperitoneum on renal function which met our inclusion criteria. There was high heterogeneity between the studies regarding study design, species, sex, pressure and duration of pneumoperitoneum, and type of gas used. Measures to reduce bias were poorly reported, leading to an unclear risk of bias in the majority of studies. Details on randomisation, blinding and a sample size calculation were not reported in ≥80% of the studies. Meta-analysis showed an overall increase in serum creatinine during pneumoperitoneum, and a decrease in urine output and renal blood flow. Subgroup analysis indicated that for serum creatinine, this effect differed between species. Subgroup analysis of pressure level indicated that urine output decreased as IAP level increased. No differences between types of gas were observed. Data were insufficient to reliably assess whether sex or IAP duration modulate the effect of pneumoperitoneum. Four studies assessing long-term effects indicated that serum creatinine normalized ≥24 hours after desufflation of pneumoperitoneum at 15mmHg. We conclude that harmful effects on renal function and perfusion during pneumoperitoneum appear to be robust, but evidence on long-term effects is very limited. The reliability and clinical relevance of these findings for healthy patients and patients at high risk of renal impairment remain uncertain. We emphasize the need for rigorous reporting of preclinical research methodology, which is of vital importance for clinical translation of preclinical data. PMID:27657740

Germanium in ginseng is low and causes no sodium and water retention or renal toxicity in the diuretic-resistant rats

PubMed Central

Tan, Chunjiang; Xiao, Lu; Chen, Wenlie

2015-01-01

Ginseng preparations contain high concentrations of germanium (Ge), which was reported to contribute to diuretic resistance or renal failure. However, Ge content in ginseng and the influence on renal functions remain unclear. Forty rats were randomly divided into control group, low, moderate, and high Ge ginseng-treated group and observed for 25 days. Daily urine, renal functions, and serum and urine electrolytics were measured. Ge retention in the organs and renal histological changes were also evaluated. Ge content ranged from 0.007 to 0.450 µg/g in various ginseng samples. Four groups showed no difference in the daily urine output, glomerular filtration rate, urinary electrolytes excretions, 24 h-urine protein, as well as plasma and urine urea nitrogen, creatinine, osmotic pressure, and pH values. Ge did not cause any renal pathological effects in this study. No Na and water retention was detected in the ginseng-treated groups. Ge retention in various organs was found highest in spleen, followed by the kidney, liver, lung, stomach, heart, and pancreas. The total Ge contents in various ginsengs were low, and ginseng treatment did not affect renal functions or cause renal histological changes. PMID:25711879

Safety and performance of the second generation EnligHTN™ Renal Denervation System in patients with drug-resistant, uncontrolled hypertension.

PubMed

Worthley, Stephen G; Wilkins, Gerard T; Webster, Mark W; Montarello, Joseph K; Delacroix, Sinny; Whitbourn, Robert J; Warren, Roderic J

2017-07-01

Catheter-based renal denervation for the treatment of drug-resistant hypertension has been intensively investigated in recent years. To date, only limited data have been published using multi-electrode radiofrequency ablation systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and performance of the second generation EnligHTN™ Renal Denervation System. This first-in-human, prospective, multi-center, non-randomized study included 39 patients (62% male, mean age 63 years, and mean baseline office blood pressure 174/93 mmHg) with drug-resistant hypertension. The primary safety and performance objectives were to characterize, from baseline to 6 months post procedure, the rate of serious procedural and device related adverse events, as adjudicated by an independent Clinical Events Committee, and the reduction of office systolic blood pressure. Renal artery denervation, using the second generation EnligHTN multi-electrode system significantly reduced office blood pressure from baseline to 1, 3, 6, 12, 18 and 24 months by 19/7, 26/9, 25/7, 23/7, 25/8 and 27/9 mmHg, respectively (p ≤ 0.0005). No serious device or procedure related adverse events affecting the renal arteries or renal function occurred through 24 months of follow-up. Renal sympathetic denervation using the second generation EnligHTN Renal Denervation System resulted in safe, rapid, and significant mean office blood pressure reduction that was sustained through 24 months. Future studies will need to address the utility of this system against an appropriate sham based comparator. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Pathogenetic role of Arg-Gly-Asp-recognizing integrins in acute renal failure. off.

PubMed Central

Goligorsky, M S; DiBona, G F

1993-01-01

Reorientation of the alpha 3 subunit of integrins from predominantly basal to the apical cell surface of cultured renal tubular epithelial cells subjected to oxidant stress has previously been demonstrated. The present study was designed to assess functional competence of ectopically expressed apical integrins. Cell-cell adhesion assay revealed enhanced cytoatractant properties of stressed cells. Stressed epithelial cells exhibited specific recognition and binding of laminin-coated latex beads. These processes were inhibited with the peptide Gly-Arg-Gly-Asp-Asn-Pro (GRGDNP) suggesting a role of RGD-recognizing integrins in augmented adhesion to stressed cells. Given that such enhanced adhesion in in vivo acute renal failure may govern tubular obstruction by desquamated epithelium, a physiological marker of patency of tubular lumen, proximal tubular pressure, was monitored in rats subjected to 60 min of renal ischemia followed by reperfusion. Proximal tubular pressure increased 2-fold after 2 hr of reperfusion in animals that had undergone 60 min of ischemia. Infusion of GRGDNP into the renal artery during reperfusion period virtually abolished an increase in proximal tubular pressure observed in ischemic acute renal failure. These in vitro and in vivo findings are consistent with the hypothesis that RGD-recognizing integrins play an important role in the pathogenesis of tubular obstruction in ischemic acute renal failure. Images Fig. 2 Fig. 3 PMID:8516318

Nephrotic range proteinuria as a strong risk factor for rapid renal function decline during pre-dialysis phase in type 2 diabetic patients with severely impaired renal function.

PubMed

Kitai, Yuichiro; Doi, Yohei; Osaki, Keisuke; Sugioka, Sayaka; Koshikawa, Masao; Sugawara, Akira

2015-12-01

Proteinuria is an established risk factor for progression of renal disease, including diabetic nephropathy. The predictive power of proteinuria, especially nephrotic range proteinuria, for progressive renal deterioration has been well demonstrated in diabetic patients with normal to relatively preserved renal function. However, little is known about the relationship between severity of proteinuria and renal outcome in pre-dialysis diabetic patients with severely impaired renal function. 125 incident dialysis patients with type 2 diabetes were identified. This study was aimed at retrospectively evaluating the impact of nephrotic range proteinuria (urinary protein-creatinine ratio above 3.5 g/gCr) on renal function decline during the 3 months just prior to dialysis initiation. In total, 103 patients (82.4 %) had nephrotic range proteinuria. The median rate of decline in estimated glomerular filtration rate (eGFR) in this study population was 0.98 (interquartile range 0.51-1.46) ml/min/1.73 m(2) per month. Compared to patients without nephrotic range proteinuria, patients with nephrotic range proteinuria showed significantly faster renal function decline (0.46 [0.24-1.25] versus 1.07 [0.64-1.54] ml/min/1.73 m(2) per month; p = 0.007). After adjusting for gender, age, systolic blood pressure, serum albumin, calcium-phosphorus product, hemoglobin A1c, and use of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, patients with nephrotic range proteinuria showed a 3.89-fold (95 % CI 1.08-14.5) increased risk for rapid renal function decline defined as a decline in eGFR ≥0.5 ml/min/1.73 m(2) per month. Nephrotic range proteinuria is the predominant renal risk factor in type 2 diabetic patients with severely impaired renal function receiving pre-dialysis care.

Direct renal effects of a fructose-enriched diet: interaction with high salt intake

PubMed Central

Ares, Gustavo R.

2015-01-01

Consumption of fructose has increased during the last 50 years. Excessive fructose consumption has a detrimental effect on mammalian health but the mechanisms remain unclear. In humans, a direct relationship exists between dietary intake of added sugars and increased risk for cardiovascular disease mortality (52). While the causes for this are unclear, we recently showed that fructose provided in the drinking water induces a salt-dependent increase in blood pressure in Sprague-Dawley rats in a matter of days (6). However, little is known about the effects of fructose in renal salt handling and whether combined intake of high fructose and salt can lead to salt-sensitive hypertension before the development of metabolic abnormalities. The long-term (more than 4 wk) adverse effects of fructose intake on renal function are not just due to fructose but are also secondary to alterations in metabolism which may have an impact on renal function. This minireview focuses on the acute effect of fructose intake and its effect on salt regulation, as they affect blood pressure. PMID:26447210

Aortic Blood Flow Reversal Determines Renal Function: Potential Explanation for Renal Dysfunction Caused by Aortic Stiffening in Hypertension.

PubMed

Hashimoto, Junichiro; Ito, Sadayoshi

2015-07-01

Aortic stiffness determines the glomerular filtration rate (GFR) and predicts the progressive decline of the GFR. However, the underlying pathophysiological mechanism remains obscure. Recent evidence has shown a close link between aortic stiffness and the bidirectional (systolic forward and early diastolic reverse) flow characteristics. We hypothesized that the aortic stiffening-induced renal dysfunction is attributable to altered central flow dynamics. In 222 patients with hypertension, Doppler velocity waveforms were recorded at the proximal descending aorta to calculate the reverse/forward flow ratio. Tonometric waveforms were recorded to measure the carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocities, to estimate the aortic pressure from the radial waveforms, and to compute the aortic characteristic impedance. In addition, renal hemodynamics was evaluated by duplex ultrasound. The estimated GFR was inversely correlated with the aortic pulse wave velocity, reverse/forward flow ratio, pulse pressure, and characteristic impedance, whereas it was not correlated with the peripheral pulse wave velocity or mean arterial pressure. The association between aortic pulse wave velocity and estimated GFR was independent of age, diabetes mellitus, hypercholesterolemia, and antihypertensive medication. However, further adjustment for the aortic reverse/forward flow ratio and pulse pressure substantially weakened this association, and instead, the reverse/forward flow ratio emerged as the strongest determinant of estimated GFR (P=0.001). A higher aortic reverse/forward flow ratio was also associated with lower intrarenal forward flow velocities. These results suggest that an increase in aortic flow reversal (ie, retrograde flow from the descending thoracic aorta toward the aortic arch), caused by aortic stiffening and impedance mismatch, reduces antegrade flow into the kidney and thereby deteriorates renal function. © 2015 American Heart Association, Inc.

Modeling of the aorta artery aneurysms and renal artery stenosis using cardiovascular electronic system

PubMed Central

Hassani, Kamran; Navidbakhsh, Mahdi; Rostami, Mostafa

2007-01-01

Background The aortic aneurysm is a dilatation of the aortic wall which occurs in the saccular and fusiform types. The aortic aneurysms can rupture, if left untreated. The renal stenosis occurs when the flow of blood from the arteries leading to the kidneys is constricted by atherosclerotic plaque. This narrowing may lead to the renal failure. Previous works have shown that, modelling is a useful tool for understanding of cardiovascular system functioning and pathophysiology of the system. The present study is concerned with the modelling of aortic aneurysms and renal artery stenosis using the cardiovascular electronic system. Methods The geometrical models of the aortic aneurysms and renal artery stenosis, with different rates, were constructed based on the original anatomical data. The pressure drop of each section due to the aneurysms or stenosis was computed by means of computational fluid dynamics method. The compliance of each section with the aneurysms or stenosis is also calculated using the mathematical method. An electrical system representing the cardiovascular circulation was used to study the effects of these pressure drops and the compliance variations on this system. Results The results showed the decreasing of pressure along the aorta and renal arteries lengths, due to the aneurysms and stenosis, at the peak systole. The mathematical method demonstrated that compliances of the aorta sections and renal increased with the expansion rate of the aneurysms and stenosis. The results of the modelling, such as electrical pressure graphs, exhibited the features of the pathologies such as hypertension and were compared with the relevant experimental data. Conclusion We conclude from the study that the aortic aneurysms as well as renal artery stenosis may be the most important determinant of the arteries rupture and failure. Furthermore, these pathologies play important rules in increase of the cardiovascular pulse pressure which leads to the hypertension. PMID:17559685

Afferent renal denervation impairs baroreflex control of efferent renal sympathetic nerve activity.

PubMed

Kopp, Ulla C; Jones, Susan Y; DiBona, Gerald F

2008-12-01

Increasing efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which decreases ERSNA to prevent sodium retention. High-sodium diet enhances ARNA, suggesting an important role for ARNA in suppressing ERSNA during excess sodium intake. Mean arterial pressure (MAP) is elevated in afferent renal denervated by dorsal rhizotomy (DRX) rats fed high-sodium diet. We examined whether the increased MAP in DRX is due to impaired arterial baroreflex function. In DRX and sham DRX rats fed high-sodium diet, arterial baroreflex function was determined in conscious rats by intravenous nitroprusside and phenylephrine or calculation of transfer function gain from arterial pressure to ERSNA (spontaneous baroreflex sensitivity). Increasing MAP did not suppress ERSNA to the same extent in DRX as in sham DRX, -60 +/- 4 vs. -77 +/- 6%. Maximum gain, -4.22 +/- 0.45 vs. -6.04 +/- 0.90% DeltaERSNA/mmHg, and the maximum value of instantaneous gain, -4.19 +/- 0.45 vs. -6.04 +/- 0.81% DeltaERSNA/mmHg, were less in DRX than in sham DRX. Likewise, transfer function gain was lower in DRX than in sham DRX, 3.9 +/- 0.2 vs. 6.1 +/- 0.5 NU/mmHg. Air jet stress produced greater increases in ERSNA in DRX than in sham DRX, 35,000 +/- 4,900 vs. 20,900 +/- 3,410%.s (area under the curve). Likewise, the ERSNA responses to thermal cutaneous stimulation were greater in DRX than in sham DRX. These studies suggest impaired arterial baroreflex suppression of ERSNA in DRX fed high-sodium diet. There were no differences in arterial baroreflex function in DRX and sham DRX fed normal-sodium diet. Impaired arterial baroreflex function contributes to increased ERSNA, which would eventually lead to sodium retention and increased MAP in DRX rats fed high-sodium diet.

A clinician's perspective of the role of renal sympathetic nerves in hypertension

PubMed Central

Briasoulis, Alexandros; Bakris, George L.

2015-01-01

The renal sympathetic nerves have significant contribution to the control of different aspects of kidney function. Early animal studies of renal denervation in a large number of different models of hypertension showed that that RDN improved BP control. Recently, data from prospective cohorts and randomized studies showed that renal denervation therapy (RDN) is a safe procedure but is associated with only modest reduction of ambulatory blood pressure (BP) in patients on intensive medical therapy. The main goal of this article is to review the results of preclinical and clinical studies on the contribution of the renal sympathetic nervous system to hypertension and the therapeutic applications of catheter-based renal denervation. PMID:25859218

Translational medicine: the antihypertensive effect of renal denervation.

PubMed

DiBona, Gerald F; Esler, Murray

2010-02-01

Translational medicine is concerned with the translation of research discoveries into clinical applications for the prevention, diagnosis, and treatment of human diseases. Here we briefly review the research concerning the role of the renal sympathetic nerves (efferent and afferent) in the control of renal function, with particular reference to hypertension. The accumulated evidence is compelling for a primary role of the renal innervation in the pathogenesis of hypertension. These research discoveries led to the development of a catheter-based procedure for renal denervation in human subjects. A proof-of-principle study in patients with hypertension resistant to conventional therapy has demonstrated that the procedure is safe and produces renal denervation with sustained lowering of arterial pressure.

Longitudinal changes in kidney parenchymal volume associated with renal artery stenting.

PubMed

Modrall, J Gregory; Timaran, Carlos H; Rosero, Eric B; Chung, Jayer; Plummer, Mitchell; Valentine, R James; Trimmer, Clayton

2012-03-01

This study assessed the longitudinal changes in renal volume after renal artery stenting (RAS) to determine if renal mass is preserved by stenting. The study cohort consisted of 38 patients with longitudinal imaging available for renal volume quantification before and after RAS. Renal volume was estimated as (kidney length) × (width) × (depth/2) based on preoperative renal imaging. For each patient, the clinical response of blood pressure (BP) and renal function to RAS was categorized according to modified American Heart Association guidelines. Changes in renal volume were assessed using paired nonparametric analyses. The cohort was a median age of 69 years (interquartile range [IQR], 60-74 years). A favorable BP response was observed in 11 of 38 patients (28.9%). At a median interval between imaging studies of 21 months (IQR, 13-32 months), ipsilateral renal volume was significantly increased from baseline (146.8 vs 133.8 cm(3);P = .02). This represents a 6.9% relative increase in ipsilateral kidney volume from baseline. A significant negative correlation between preoperative renal volume and the relative change in renal volume postoperatively (r = -0.42; P = .0055) suggests that smaller kidneys experienced the greatest gains in renal volume after stenting. It is noteworthy that the 25 patients with no change in BP or renal function-clinical failures using traditional definitions-experienced a 12% relative increase in ipsilateral renal volume after RAS. Multivariate analysis determined that stable or improved renal volume after stenting was an independent predictor of stable or improved long-term renal function (odds ratio, 0.008; 95% confidence interval, 0.000-0.206; P = .004). These data lend credence to the belief that RAS preserves renal mass in some patients. This benefit of RAS even extends to those patients who would be considered treatment failures by traditional definitions. Patients with stable or increased renal volume after RAS had more stable renal function during long-term follow-up, whereas patients with renal volume loss after stenting were prone to deterioration of renal function. Published by Mosby, Inc.

The renal compartment: a hydraulic view.

PubMed

Cruces, Pablo; Salas, Camila; Lillo, Pablo; Salomon, Tatiana; Lillo, Felipe; Hurtado, Daniel E

2014-12-01

The hydraulic behavior of the renal compartment is poorly understood. In particular, the role of the renal capsule on the intrarenal pressure has not been thoroughly addressed to date. We hypothesized that pressure and volume in the renal compartment are not linearly related, similar to other body compartments. The pressure-volume curve of the renal compartment was obtained by injecting fluid into the renal pelvis and recording the rise in intrarenal pressure in six anesthetized and mechanically ventilated piglets, using a catheter Camino 4B® inserted into the renal parenchyma. In healthy kidneys, pressure has a highly nonlinear dependence on the injected volume, as revealed by an exponential fit to the data (R (2) = 0.92). On the contrary, a linear relation between pressure and volume is observed in decapsulated kidneys. We propose a biomechanical model for the renal capsule that is able to explain the nonlinear pressure-volume dependence for moderate volume increases. We have presented experimental evidence and a theoretical model that supports the existence of a renal compartment. The mechanical role of the renal capsule investigated in this work may have important implications in elucidating the role of decompressive capsulotomy in reducing the intrarenal pressure in acutely injured kidneys.

Loxosceles gaucho Venom-Induced Acute Kidney Injury – In Vivo and In Vitro Studies

PubMed Central

Lucato, Rui V.; Abdulkader, Regina C. R. M.; Barbaro, Katia C.; Mendes, Glória E.; Castro, Isac; Baptista, Maria A. S. F.; Cury, Patrícia M.; Malheiros, Denise M. C.; Schor, Nestor; Yu, Luis; Burdmann, Emmanuel A.

2011-01-01

Background Accidents caused by Loxosceles spider may cause severe systemic reactions, including acute kidney injury (AKI). There are few experimental studies assessing Loxosceles venom effects on kidney function in vivo. Methodology/Principal Findings In order to test Loxosceles gaucho venom (LV) nephrotoxicity and to assess some of the possible mechanisms of renal injury, rats were studied up to 60 minutes after LV 0.24 mg/kg or saline IV injection (control). LV caused a sharp and significant drop in glomerular filtration rate, renal blood flow and urinary output and increased renal vascular resistance, without changing blood pressure. Venom infusion increased significantly serum creatine kinase and aspartate aminotransferase. In the LV group renal histology analysis found acute epithelial tubular cells degenerative changes, presence of cell debris and detached epithelial cells in tubular lumen without glomerular or vascular changes. Immunohistochemistry disclosed renal deposition of myoglobin and hemoglobin. LV did not cause injury to a suspension of fresh proximal tubules isolated from rats. Conclusions/Significance Loxosceles gaucho venom injection caused early AKI, which occurred without blood pressure variation. Changes in glomerular function occurred likely due to renal vasoconstriction and rhabdomyolysis. Direct nephrotoxicity could not be demonstrated in vitro. The development of a consistent model of Loxosceles venom-induced AKI and a better understanding of the mechanisms involved in the renal injury may allow more efficient ways to prevent or attenuate the systemic injury after Loxosceles bite. PMID:21655312

Single-side renal sympathetic denervation to treat malignant refractory hypertension in a solitary kidney patient.

PubMed

Ribichini, Flavio; Ferrara, Angela; Pighi, Michele; Pesarini, Gabriele; Gambaro, Alessia; Valvo, Enrico; Lupo, Antonio; Vassanelli, Corrado

2014-12-01

Renal sympathetic denervation (RSD) is emerging as a new therapeutic option for patients with severe hypertension refractory to medical therapy. Patients affected by renovascular or anatomical abnormalities have hitherto been systematically excluded from clinical trials with RSD because of concern about safety and the unknown efficacy of the procedure in this subgroup of patients. We describe the management of a case of RSD in a single-kidney patient with refractory hypertension; the patient had had a previous surgical right nephrectomy for renal cell carcinoma that subsequently required no other oncologic treatment. After multidisciplinary assessment, the patient underwent RSD. The procedure was performed through a 6F femoral access using the Symplicity™ RSD system (Medtronic, Mountain View, CA, USA). Radiofrequency was applied to the renal artery wall in 6 different points under general sedation with midazolam to control back pain caused by the procedure, that was performed without periprocedural complications. The patient was discharged 2 days later after a control of the vascular access site and routine biochemical examinations. The following 9-month follow up showed a significant reduction in blood pressure and stable renal function, without signs of renal damage. Our report confirms the feasibility of RSD in this delicate context, without evident negative effects on kidney function and with a significant reduction in blood pressure. Future studies are needed to fully clarify the value of RSD in single-kidney patients.

Renal denervation after Symplicity HTN-3: an update.

PubMed

Persu, Alexandre; Jin, Yu; Fadl Elmula, Fadl Elmula Mohamed; Jacobs, Lotte; Renkin, Jean; Kjeldsen, Sverre

2014-08-01

After three years of excessive confidence, overoptimistic expectations and performance of 15 to 20,000 renal denervation procedures in Europe, the failure of a single well-designed US trial--Symplicity HTN-3--to meet its primary efficacy endpoint has cast doubt on renal denervation as a whole. The use of a sound methodology, including randomisation and blinded endpoint assessment was enough to see the typical 25-30 mmHg systolic blood pressure decrease observed after renal denervation melt down to less than 3 mmHg, the rest being likely explained by Hawthorne and placebo effects, attenuation of white coat effect, regression to the mean and other physician and patient-related biases. The modest blood pressure benefit directly assignable to renal denervation should be balanced with unresolved safety issues, such as potentially increased risk of renal artery stenosis after the procedure (more than ten cases reported up to now, most of them in 2014), unclear long-term impact on renal function and lack of morbidity-mortality data. Accordingly, there is no doubt that renal denervation is not ready for clinical use. Still, renal denervation is supported by a strong rationale and is occasionally followed by major blood pressure responses in at-risk patients who may otherwise have remained uncontrolled. Upcoming research programmes should focus on identification of those few patients with truly resistant hypertension who may derive a substantial benefit from the technique, within the context of well-designed randomised trials and independent registries. While electrical stimulation of baroreceptors and other interventional treatments of hypertension are already "knocking at the door", the premature and uncontrolled dissemination of renal denervation should remain an example of what should not be done, and trigger radical changes in evaluation processes of new devices by national and European health authorities.

Acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis in the dog.

PubMed Central

Anderson, W P; Johnston, C I; Korner, P I

1979-01-01

1. The acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis were studied in chronically instrumented, unanaesthetized dogs. 2. Stenosis was induced over 30 sec by inflation of a cuff around the renal artery to lower distal pressure to 60, 40 or 20 mmHg, with stenosis maintained for 1 hr. This resulted in an immediate fall in renal vascular resistance, but over the next 5--30 min both resistance and renal artery pressure were restored back towards prestenosis values. Only transient increases in systemic arterial blood pressure and plasma renin and angiotensin levels were seen with the two milder stenoses. Despite restoration of renal artery pressure, renal blood flow remained reduced at all grades of stenosis. 3. Pre-treatment with angiotensin I converting enzyme inhibitor or sarosine1, isoleucone8 angiotensin II greatly attenuated or abolished the restoration of renal artery pressure and renal vascular resistance after stenosis, and plasma renin and angiotensin II levels remained high. Renal dilatation was indefinitely maintained, but the normal restoration of resistance and pressure could be simulated by infusing angiotensin II into the renal artery. 4. The effective resistance to blood flow by the stenosis did not remain constant but varied with changes in the renal vascular resistance. PMID:219182

Evaluation of Acute Kidney Injury and Mortality After Intensive Blood Pressure Control in Patients With Intracerebral Hemorrhage.

PubMed

Burgess, L Goodwin; Goyal, Nitin; Jones, G Morgan; Khorchid, Yasser; Kerro, Ali; Chapple, Kristina; Tsivgoulis, Georgios; Alexandrov, Andrei V; Chang, Jason J

2018-04-13

We sought to assess the risk of acute kidney injury (AKI) and mortality associated with intensive systolic blood pressure reduction in acute intracerebral hemorrhage. Patients with acute intracerebral hemorrhage had spontaneous cause and symptom onset within 24 hours. We excluded patients with structural causes, coagulopathy, thrombocytopenia, and preexisting end-stage renal disease. We defined AKI using the Acute Kidney Injury Network criteria. Chronic kidney disease status was included in risk stratification and was defined by Kidney Disease Outcomes Quality Initiative staging. Maximum systolic blood pressure reduction was defined over a 12-hour period and dichotomized using receiver operating characteristic curve analysis. Descriptive statistics were done using independent sample t tests, χ 2 tests, and Mann-Whitney U tests, whereas multivariable logistic regression analysis was used to evaluate for predictors for AKI and mortality. A total of 448 patients with intracerebral hemorrhage met inclusion criteria. Maximum systolic blood pressure reduction was dichotomized to 90 mm Hg and found to increase the risk of AKI in patients with normal renal function (odds ratio, 2.1; 95% confidence interval, 1.19-3.62; P =0.010) and chronic kidney disease (odds ratio, 3.91; 95% confidence interval, 1.26-12.15; P =0.019). The risk of AKI was not significantly different in normal renal function versus chronic kidney disease groups when adjusted for demographics, presentation characteristics, and medications associated with AKI. AKI positively predicted mortality for patients with normal renal function (odds ratio, 2.41; 95% confidence interval, 1.11-5.22; P =0.026) but not for patients with chronic kidney disease (odds ratio, 3.13; 95% confidence interval, 0.65-15.01; P =0.154). These results indicate that intensive systolic blood pressure reduction with a threshold >90 mm Hg in patients with acute intracerebral hemorrhage may be an independent predictor for AKI. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Decrease of nitric oxide and increase in diastolic blood pressure are two events that affect renal function in dogs with pituitary dependent hyperadrenocorticism

PubMed Central

Vidal, Patricia N.; Miceli, Diego D.; Arias, Elber Soler; D’Anna, Elena; García, Jorge D.; Castillo, Victor Alejandro

2018-01-01

Hyperadrenocorticism is a frequent disease in dogs. The excess of circulating cortisol affects different organs and metabolic pathways, producing severe adverse effects that endanger the animal’s life. Among these effects, hypertension and renal damage can be mentioned. A group of 20 dogs with pituitary dependent hyperadrenocorticism (PDH) and 12 control dogs were used to study the following parameters: cortisol and nitric oxide (NO nit/nit) concentrations, diastolic and systolic blood pressure, renal artery resistance index by Doppler ultrasound, the rate of glomerular filtration by radio-renogram excretion and the presence of proteins in urine. Dogs with PDH showed a significantly lower NO nit/nit (P<0.0001) than the controls and this correlated with high values of diastolic and systolic pressure (r = -0.87; P<0.0001 and r = -0.81; P<0.0001 respectively). Most dogs (80%) are hypertensive mainly due to an increase in diastolic pressure, which correlated positively with the UPC (r = 0.8; P<0.001) and negatively with the glomerular rate of filtration (r = -0.58; P=0.007). Systolic pressure only increased in 60% of the cases and did not correlate with the mentioned variables. In PDH the decrease of NO affects blood pressure. The diastolic pressure would seem to have the greatest impact on the kidneys, therefore its evaluation and control are important to avoid and/or control renal damage. PMID:29721437

Mathematical modeling of renal hemodynamics in physiology and pathophysiology.

PubMed

Sgouralis, Ioannis; Layton, Anita T

2015-06-01

In addition to the excretion of metabolic waste and toxin, the kidney plays an indispensable role in regulating the balance of water, electrolyte, acid-base, and blood pressure. For the kidney to maintain proper functions, hemodynamic control is crucial. In this review, we describe representative mathematical models that have been developed to better understand the kidney's autoregulatory processes. We consider mathematical models that simulate glomerular filtration, and renal blood flow regulation by means of the myogenic response and tubuloglomerular feedback. We discuss the extent to which these modeling efforts have expanded the understanding of renal functions in health and disease. Copyright © 2015 Elsevier Inc. All rights reserved.

[ACE inhibitors and the kidney].

PubMed

Hörl, W H

1996-01-01

Treatment with ACE inhibitors results in kidney protection due to reduction of systemic blood pressure, intraglomerular pressure, an antiproliferative effect, reduction of proteinuria and a lipid-lowering effect in proteinuric patients (secondary due to reduction of protein excretion). Elderly patients with diabetes melitus, coronary heart disease or peripheral vascular occlusion are at risk for deterioration of kidney function due to a high frequency of renal artery stenosis in these patients. In patients with renal insufficiency dose reduction of ACE inhibitors is necessary (exception: fosinopril) but more important is the risk for development of hyperkalemia. Patients at risk for renal artery stenosis and patients pretreated with diuretics should receive a low ACE inhibitor dosage initially ("start low - go slow"). For compliance reasons once daily ACE inhibitor dosage is recommended.

[Position paper on the results of Symplicity HTN-3 trial. Grupo de estudio de la hipertensión arterial resistente].

PubMed

Azpiri-López, José Ramón; Assad-Morell, José Luis; Ponce de León-Martínez, Enrique; Monreal-Puente, Rogelio; Dávila-Bortoni, Adrián; Vázquez-Díaz, Luis Alberto; Treviño-Frutos, Ramón Javier; Barrera-Oranday, Félix; Del Angel-Soto, Juan Gustavo; Martínez, José Guadalupe; Arellano-Torres, Marcelo

2015-01-01

Renal artery denervation has shown to be an effective treatment for resistant hypertension. Symplicity HTN 1 and 2 trials showed in small and uncontrolled groups, significant systolic blood pressure reductions down to 30 mm Hg. Symplicity HTN-3, a double blind, randomized, placebo controlled clinical trial shaded this initial enthusiasm. Surprisingly, their results showed that renal denervation has a similar effect to placebo. Pre-specified subgroup analysis showed that non-black race individuals, younger than 65 years and with normal renal function, had a statistically significant systolic blood pressure decrease. This manuscript critically appraises the Symplicity HTN-3 trial, proposing possible explanations for the results. Also declares our group position and future actions regarding renal denervation. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Effect of Angiotensin-Converting Enzyme Inhibitor/Calcium Antagonist Combination Therapy on Renal Function in Hypertensive Patients With Chronic Kidney Disease: Chikushi Anti-Hypertension Trial - Benidipine and Perindopril.

PubMed

Okuda, Tetsu; Okamura, Keisuke; Shirai, Kazuyuki; Urata, Hidenori

2018-02-01

Appropriate blood pressure control suppresses progression of chronic kidney disease (CKD). If an angiotensin-converting enzyme (ACE) inhibitor is ineffective, adding a calcium antagonist is recommended. We compared the long-term effect of two ACE inhibitor/calcium antagonist combinations on renal function in hypertensive patients with CKD. Patients who failed to achieve the target blood pressure (systolic/diastolic: < 130/80 mm Hg) with perindopril monotherapy were randomized to either combined therapy with perindopril and the L-type calcium antagonist amlodipine (group A) or perindopril and the T/L type calcium antagonist benidipine (group B). The primary endpoint was the change of the estimated glomerular filtration rate (eGFR) after 2 years. Eligible patients had a systolic pressure ≥ 130 mm Hg and/or diastolic pressure ≥ 80 mm Hg and CKD (urine protein (+) or higher, eGFR < 60 min/mL/1.73 m 2 ). After excluding 38 patients achieving the target blood pressure with perindopril monotherapy, 121 patients were analyzed (62 in group A and 59 in group B). Blood pressure decreased significantly in both groups, but there was no significant change of the eGFR. However, among patients with diabetes, eGFR unchanged in group B (n = 37, 59.1 ± 15.1 vs. 61.2 ± 27.9, P = 0.273), whereas decreased significantly in group A (n = 31, 57.3 ± 16.0 vs. 53.7 ± 16.7, P = 0.005). In hypertensive patients with diabetic nephropathy, combined therapy with an ACE inhibitor and T/L type calcium antagonist may prevent deterioration of renal function more effectively than an ACE inhibitor/L type calcium antagonist combination.

Renal denervation decreases blood pressure and renal tyrosine hydroxylase but does not augment the effect of hypotensive drugs.

PubMed

Skrzypecki, Janusz; Gawlak, Maciej; Huc, Tomasz; Szulczyk, Paweł; Ufnal, Marcin

2017-01-01

The effect of renal denervation on the efficacy of antihypertensive drugs has not yet been elucidated. Twenty-week-old spontaneously hypertensive rats were treated with metoprolol, losartan, indapamide, or saline (controls) and assigned to renal denervation or a sham procedure. Acute hemodynamic measurements were performed ten days later. Series showing a significant interaction between renal denervation and the drugs were repeated with chronic telemetry measurements. In the saline series, denervated rats showed a significantly lower mean arterial blood pressure (blood pressure) than the sham-operated rats. In contrast, in the metoprolol series denervated rats showed a significantly higher blood pressure than sham rats. There were no differences in blood pressure between denervated and sham rats in the losartan and indapamide series. In chronic studies, a 4-week treatment with metoprolol caused a decrease in blood pressure. Renal denervation and sham denervation performed 10 days after the onset of metoprolol treatment did not affect blood pressure. Denervated rats showed markedly reduced renal nerve tyrosine hydroxylase levels. In conclusion, renal denervation decreases blood pressure in hypertensive rats. The hypotensive action of metoprolol, indapamide, and losartan is not augmented by renal denervation, suggesting the absence of synergy between renal denervation and the drugs investigated in this study.

Molecular bases of circadian rhythmicity in renal physiology and pathology

PubMed Central

Bonny, Olivier; Vinciguerra, Manlio; Gumz, Michelle L.; Mazzoccoli, Gianluigi

2013-01-01

The physiological processes that maintain body homeostasis oscillate during the day. Diurnal changes characterize kidney functions, comprising regulation of hydro-electrolytic and acid-base balance, reabsorption of small solutes and hormone production. Renal physiology is characterized by 24-h periodicity and contributes to circadian variability of blood pressure levels, related as well to nychthemeral changes of sodium sensitivity, physical activity, vascular tone, autonomic function and neurotransmitter release from sympathetic innervations. The circadian rhythmicity of body physiology is driven by central and peripheral biological clockworks and entrained by the geophysical light/dark cycle. Chronodisruption, defined as the mismatch between environmental–social cues and physiological–behavioral patterns, causes internal desynchronization of periodic functions, leading to pathophysiological mechanisms underlying degenerative, immune related, metabolic and neoplastic diseases. In this review we will address the genetic, molecular and anatomical elements that hardwire circadian rhythmicity in renal physiology and subtend disarray of time–dependent changes in renal pathology. PMID:23901050

Comparative effects of avocado oil and losartan on blood pressure, renal vascular function, and mitochondrial oxidative stress in hypertensive rats.

PubMed

Márquez-Ramírez, Cristian Adrián; Hernández de la Paz, José Lucio; Ortiz-Avila, Omar; Raya-Farias, Andrés; González-Hernández, Juan Carlos; Rodríguez-Orozco, Alain Raimundo; Salgado-Garciglia, Rafael; Saavedra-Molina, Alfredo; Godínez-Hernández, Daniel; Cortés-Rojo, Christian

2018-03-20

Angiotensin II (Ang-II) antagonism alleviates hypertensive kidney damage by improving mitochondrial function and decreasing oxidative stress. This condition also is associated with altered renal vascular tone due to enhanced constriction by Ang-II. Thus, approaches ameliorating these events are desirable to alleviate kidney damage. Avocado oil, a source of antioxidants and oleic acid, is known to improve mitochondrial function, while oleic acid has antihypertensive effects. Therefore, the aim of this study was to test whether avocado oil counteracts, to a similar degree as the Ang-II blocker losartan, the deleterious effects of hypertension on blood pressure, renal vascular performance, kidney mitochondrial function, and oxidative stress. Hypertensive rats induced with Nω-nitro-l-arginine methyl ester (L-NAME) were supplemented during 45 d with avocado oil or losartan. Vascular responses were analyzed in perfused kidney. Membrane potential, reactive oxygen species levels, and glutathione were analyzed in isolated kidney mitochondria. In hypertensive rats, avocado oil decreased 21.2% and 15.5% diastolic and systolic blood pressures, respectively, and alleviated impaired renal vasodilation. Hypertension decreased membrane potential by 83.7% and augmented reactive oxygen species levels by 51% in mitochondria fueled with a complex I substrate, whereas it augmented the levels of oxidized glutathione in 48%. These alterations were normalized by avocado oil at a comparable degree to losartan. Because avocado oil mimicked the effects of losartan, we propose that the effects of avocado oil might be mediated by decreasing the actions of Ang-II on mitochondria. These results suggest that avocado oil intake might be a nutritional approach to attenuate the deleterious effects of hypertension on kidney. Copyright © 2018 Elsevier Inc. All rights reserved.

Prognostic Significance of Spot Urine Na/K for Longitudinal Changes in Blood Pressure and Renal Function: The Nagahama Study.

PubMed

Tabara, Yasuharu; Takahashi, Yoshimitsu; Setoh, Kazuya; Kawaguchi, Takahisa; Kosugi, Shinji; Nakayama, Takeo; Matsuda, Fumihiko

2017-09-01

Urinary sodium-to-potassium ratio (Na/K) represents a simple measure of sodium load and has been reported to be associated with blood pressure (BP) levels in a cross-sectional setting even with spot measurements. The aim of the present large-scale cohort study is to determine prognostic significance of spot urine Na/K for longitudinal changes in BP levels and renal function. The present study population consisted of 7,063 individuals from the general population. Clinical parameters were measured at baseline and at a follow-up interval of 5 years. Mean systolic BP was slightly increased during the follow-up period (overall, 124 ± 17 to 125 ± 18 mm Hg; nontreated participants, 119 ± 15 to 122 ± 17 mm Hg). Although, the urinary Na/K demonstrated a linear association with BP in a cross-sectional analysis (P < 0.001), analysis of repeated measured BP values identified baseline Na/K * time interaction, i.e., an intraindividual effect, as an inverse determinant (F = 76.9, P < 0.001) independently of hypertension status and fasting conditions possibly due to regression to the mean of temporary high baseline Na/K values at baseline. Spot urine Na/K values were found to be positively associated with renal function in a cross-sectional analysis (P < 0.001). Although baseline Na/K * time interaction showed inverse associated with renal functional decline (F = 85.8, P < 0.001), this inverse association might not represent physiological relationship in likewise fashion with the analysis for BP. Spot urine Na/K may have limited utility as a prognostic marker of longitudinal BP change, as well as renal functional decline. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

International expert consensus statement: Percutaneous transluminal renal denervation for the treatment of resistant hypertension.

PubMed

Schlaich, Markus P; Schmieder, Roland E; Bakris, George; Blankestijn, Peter J; Böhm, Michael; Campese, Vito M; Francis, Darrel P; Grassi, Guido; Hering, Dagmara; Katholi, Richard; Kjeldsen, Sverre; Krum, Henry; Mahfoud, Felix; Mancia, Giuseppe; Messerli, Franz H; Narkiewicz, Krzysztof; Parati, Gianfranco; Rocha-Singh, Krishna J; Ruilope, Luis M; Rump, Lars C; Sica, Domenic A; Sobotka, Paul A; Tsioufis, Costas; Vonend, Oliver; Weber, Michael A; Williams, Bryan; Zeller, Thomas; Esler, Murray D

2013-12-03

Catheter-based radiofrequency ablation technology to disrupt both efferent and afferent renal nerves has recently been introduced to clinical medicine after the demonstration of significant systolic and diastolic blood pressure reductions. Clinical trial data available thus far have been obtained primarily in patients with resistant hypertension, defined as standardized systolic clinic blood pressure ≥ 160 mm Hg (or ≥ 150 mm Hg in patients with type 2 diabetes) despite appropriate pharmacologic treatment with at least 3 antihypertensive drugs, including a diuretic agent. Accordingly, these criteria and blood pressure thresholds should be borne in mind when selecting patients for renal nerve ablation. Secondary forms of hypertension and pseudoresistance, such as nonadherence to medication, intolerance of medication, and white coat hypertension, should have been ruled out, and 24-h ambulatory blood pressure monitoring is mandatory in this context. Because there are theoretical concerns with regard to renal safety, selected patients should have preserved renal function, with an estimated glomerular filtration rate ≥ 45 ml/min/1.73 m(2). Optimal periprocedural management of volume status and medication regimens at specialized and experienced centers equipped with adequate infrastructure to cope with potential procedural complications will minimize potential patient risks. Long-term safety and efficacy data are limited to 3 years of follow-up in small patient cohorts, so efforts to monitor treated patients are crucial to define the long-term performance of the procedure. Although renal nerve ablation could have beneficial effects in other conditions characterized by elevated renal sympathetic nerve activity, its potential use for such indications should currently be limited to formal research studies of its safety and efficacy. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Safety and efficacy of a multi-electrode renal sympathetic denervation system in resistant hypertension: the EnligHTN I trial

PubMed Central

Worthley, Stephen G.; Tsioufis, Costas P.; Worthley, Matthew I.; Sinhal, Ajay; Chew, Derek P.; Meredith, Ian T.; Malaiapan, Yuvi; Papademetriou, Vasilios

2013-01-01

Aims Catheter-based renal artery sympathetic denervation has emerged as a novel therapy for treatment of patients with drug-resistant hypertension. Initial studies were performed using a single electrode radiofrequency catheter, but recent advances in catheter design have allowed the development of multi-electrode systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and efficacy of the EnligHTN™ multi-electrode system. Methods and results We conducted the first-in-human, prospective, multi-centre, non-randomized study in 46 patients (67% male, mean age 60 years, and mean baseline office blood pressure 176/96 mmHg) with drug-resistant hypertension. The primary efficacy objective was change in office blood pressure from baseline to 6 months. Safety measures included all adverse events with a focus on the renal artery and other vascular complications and changes in renal function. Renal artery denervation, using the EnligHTN™ system significantly reduced the office blood pressure from baseline to 1, 3, and 6 months by −28/10, −27/10 and −26/10 mmHg, respectively (P < 0.0001). No acute renal artery injury or other serious vascular complications occurred. Small, non-clinically relevant, changes in average estimated glomerular filtration rate were reported from baseline (87 ± 19 mL/min/1.73 m2) to 6 months post-procedure (82 ± 20 mL/min/1.73 m2). Conclusion Renal sympathetic denervation, using the EnligHTN™ multi-electrode catheter results in a rapid and significant office blood pressure reduction that was sustained through 6 months. The EnligHTN™ system delivers a promising therapy for the treatment of drug-resistant hypertension. PMID:23782649

Safety and efficacy of a multi-electrode renal sympathetic denervation system in resistant hypertension: the EnligHTN I trial.

PubMed

Worthley, Stephen G; Tsioufis, Costas P; Worthley, Matthew I; Sinhal, Ajay; Chew, Derek P; Meredith, Ian T; Malaiapan, Yuvi; Papademetriou, Vasilios

2013-07-01

Catheter-based renal artery sympathetic denervation has emerged as a novel therapy for treatment of patients with drug-resistant hypertension. Initial studies were performed using a single electrode radiofrequency catheter, but recent advances in catheter design have allowed the development of multi-electrode systems that can deliver lesions with a pre-determined pattern. This study was designed to evaluate the safety and efficacy of the EnligHTN(™) multi-electrode system. We conducted the first-in-human, prospective, multi-centre, non-randomized study in 46 patients (67% male, mean age 60 years, and mean baseline office blood pressure 176/96 mmHg) with drug-resistant hypertension. The primary efficacy objective was change in office blood pressure from baseline to 6 months. Safety measures included all adverse events with a focus on the renal artery and other vascular complications and changes in renal function. Renal artery denervation, using the EnligHTN system significantly reduced the office blood pressure from baseline to 1, 3, and 6 months by -28/10, -27/10 and -26/10 mmHg, respectively (P < 0.0001). No acute renal artery injury or other serious vascular complications occurred. Small, non-clinically relevant, changes in average estimated glomerular filtration rate were reported from baseline (87 ± 19 mL/min/1.73 m2) to 6 months post-procedure (82 ± 20 mL/min/1.73 m2). Renal sympathetic denervation, using the EnligHTN multi-electrode catheter results in a rapid and significant office blood pressure reduction that was sustained through 6 months. The EnligHTN system delivers a promising therapy for the treatment of drug-resistant hypertension.

Impact of cardiac hypertrophy on arterial and cardiopulmonary baroreflex control of renal sympathetic nerve activity in anaesthetized rats.

PubMed

Flanagan, Evelyn T; Buckley, Maria M; Aherne, Claire M; Lainis, Fredolin; Sattar, Munavvar; Johns, Edward J

2008-09-01

This study aimed to quantify the effect of cardiac hypertrophy induced with isoprenaline and caffeine on reflex regulation of renal sympathetic nerve activity by the arterial and cardiopulmonary baroreceptors. Male Wistar rats, untreated or given water containing caffeine and subcutaneous (s.c.) isoprenaline every 72 h for 2 weeks or thyroxine s.c. for 7 days, were anaesthetized and prepared for measurement of renal sympathetic nerve activity or cardiac indices. Both isoprenaline-caffeine and thyroxine treatment blunted weight gain but increased heart weight and heart weight to body weight ratio by 40 and 14% (both P<0.01), respectively. In the isoprenaline-caffeine group, the maximal rate of change of left ventricular pressure and the contractility index were higher by 17 and 14% (both P<0.01), respectively, compared with untreated rats. In the isoprenaline-caffeine-treated rats, baroreflex gain curve sensitivity was depressed by approximately 30% (P<0/05), while the mid-point blood pressure was lower, by 15% (P<0/05), and the range of the curve was 60% (P<0.05) greater than in the untreated rats. An acute intravenous infusion of a saline load decreased renal sympathetic nerve activity by 42% (P<0.05) in the untreated rats but had no effect in the isoprenaline-caffeine- or the thyroxine-treated groups. The isoprenaline-caffeine treatment induced cardiac hypertrophy with raised cardiac performance and an associated depression in the reflex regulation of renal sympathetic nerve activity by both high- and low-pressure baroreceptors. The thyroxine-induced cardiac hypertrophy also blunted the low-pressure baroreceptor-mediated renal sympatho-inhibition. These findings demonstrate that in cardiac hypertrophy without impaired cardiac function, there is a blunted baroreceptor control of renal sympathetic outflow.

Heme oxygenase: the key to renal function regulation

PubMed Central

Cao, Jian; Sacerdoti, David; Li, Xiaoying; Drummond, George

2009-01-01

Heme oxygenase (HO) plays a critical role in attenuating the production of reactive oxygen species through its ability to degrade heme in an enzymatic process that leads to the production of equimolar amounts of carbon monoxide and biliverdin/bilirubin and the release of free iron. The present review examines the beneficial role of HO-1 (inducible form of HO) that is achieved by increased expression of this enzyme in renal tissue. The influence of the HO system on renal physiology, obesity, vascular dysfunction, and blood pressure regulation is reviewed, and the clinical potential of increased levels of HO-1 protein, HO activity, and HO-derived end products of heme degradation is discussed relative to renal disease. The use of pharmacological and genetic approaches to investigate the role of the HO system in the kidney is key to the development of therapeutic approaches to prevent the adverse effects that accrue due to an impairment in renal function. PMID:19570878

[Renal denervation a treatment for resistant hypertension: a French experience].

PubMed

Benamer, H; Mylotte, D; Garcia-Alonso, C; Unterseeh, T; Garot, P; Louvard, Y; Lefevre, T; Morice, M-C

2013-12-01

Arterial hypertension is the largest single contributor to global mortality, and is poorly controlled in approximately 50% of patients despite lifestyle and pharmacologic interventions. Randomized clinical trials have demonstrated that catheter-based renal sympathetic denervation reduces blood pressure (BP) in patients with resistant hypertension. We sought to evaluate the efficacy of this novel therapy in "Real World" clinical practice. Consecutive patients with treatment-resistant primary hypertension, as defined as home BP>160 mmHg despite treatment with ≥3 antihypertensive drugs, were selected for denervation following renal artery screening. Ambulatory and home BP monitoring was performed in all patients prior to and following percutaneous renal sympathetic denervation. In total, 35 patients were selected for catheter-based renal sympathetic denervation. The mean age was 63.6 ± 11.7 years, 37.1% were women, 37.1% were diabetic, and 11.4% had renal impairment (GFR<45 mL/min). The basal BP (home or ambulatory) was 179.1 ± 20.75/99.66 ± 19.76 mmHg, despite an average of 4.91 ± 0.98 medications per patient. Successful bilateral sympathetic denervation was performed in 33/35 patients (1 renal artery stenosis on angiography [not ablated], 1 patient with renal artery spasm [unilateral denervation]), with an average 5.9 ± 1.6 ablations per renal artery. No procedural complications occurred. At 6 months, blood pressure was 15.5 ± 22.37/87.76 ± 13.97 mmHg (P<0.01). At 2 years follow-up, systolic blood pressure (ABPM or Home BP) was 143.8 ± 15.30 mmHg (P<0.0001) and diastolic 83.42 ± 12.80 mmHg (P=0.0004). There were no adverse events during follow-up, and no deterioration in renal function was observed. Catheter-based renal denervation is safe and efficacious treatment, which results in significant reductions in blood pressure in patients with treatment-resistant hypertension, stable at 2 years follow-up. These results are applicable to real-world patient populations. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The effects of heart failure on renal function.

PubMed

Udani, Suneel M; Koyner, Jay L

2010-08-01

Heart-kidney interactions have been increasingly recognized by clinicians and researchers who study and treat heart failure and kidney disease. A classification system has been developed to categorize the different manifestations of cardiac and renal dysfunction. Work has highlighted the significant negative prognostic effect of worsening renal function on outcomes for individuals with heart failure. The etiology of concomitant cardiac and renal dysfunction remains unclear; however, evidence supports alternatives to the established theory of underfilling, including effects of venous congestion and changes in intra-abdominal pressure. Conventional therapy focuses on blockade of the renin-angiotensin-aldosterone system with expanding use of direct renin and aldosterone antagonists. Novel therapeutic interventions using extracorporeal therapy and antagonists of the adenosine pathway show promise and require further investigation. 2010 Elsevier Inc. All rights reserved.

The Effects of Heart Failure on Renal Function

PubMed Central

Udani, Suneel M; Koyner, Jay L

2010-01-01

Summary Heart-kidney interactions have been increasingly recognized by clinicians and researchers involved in the study and treatment of heart failure and kidney disease. A classification system has been developed to categorize the different manifestations of cardiac and renal dysfunction. Recent work has highlighted the significant negative prognostic effect of worsening renal function on outcomes for individuals with heart failure. The etiology of the concomitant cardiac and renal dysfunction remains unclear; however, increasing evidence supports alternatives to the established theory of underfilling, including effects of venous congestion and changes in intra-abdominal pressure. Conventional therapy focuses on blockade of the renin-angiotensin-aldosterone system with expanding use of direct renin and aldosterone antagonists. Novel therapeutic interventions using extracorporeal therapy and antagonists of the adenosine pathway show promise and require further investigation. PMID:20621250

The Non-Classical Renin-Angiotensin System and Renal Function

PubMed Central

Chappell, Mark C.

2014-01-01

The renin-angiotensin-system (RAS) constitutes one of the most important hormonal systems in the physiological regulation of blood pressure through renal and non-renal mechanisms. Indeed, dysregulation of the RAS is considered a major factor in the development of cardiovascular pathologies including kidney injury and blockade of this system by the inhibition of angiotensin converting enzyme (ACE) or blockade of the angiotensin type 1 receptor (AT1R) by selective antagonists constitutes an effective therapeutic regimen. It is now apparent with the identification of multiple components of the RAS within the kidney and other tissues that the system is actually composed of different angiotensin peptides with diverse biological actions mediated by distinct receptor subtypes. The classic RAS can be defined as the ACE-Ang II AT1R axis that promotes vasoconstriction, water intake, sodium retention and other mechanisms to maintain blood pressure, as well as increase oxidative stress, fibrosis, cellular growth and inflammation in pathological conditions. In contrast, the non-classical RAS composed primarily of the AngII/Ang III–AT2R pathway and the ACE2-Ang-(1-7)-AT7R axis generally opposes the actions of a stimulated Ang II-AT1R axis through an increase in nitric oxide and prostaglandins and mediates vasodilation, natriuresis, diuresis, and a reduced oxidative stress. Moreover, increasing evidence suggests that these non-classical RAS components contribute to the therapeutic blockade of the classical system to reduce blood pressure and attenuate various indices of renal injury, as well as contribute to normal renal function. PMID:23720263

SGLT2 Inhibitors and the Diabetic Kidney.

PubMed

Fioretto, Paola; Zambon, Alberto; Rossato, Marco; Busetto, Luca; Vettor, Roberto

2016-08-01

Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. Blood glucose and blood pressure control reduce the risk of developing this complication; however, once DN is established, it is only possible to slow progression. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, the most recent glucose-lowering oral agents, may have the potential to exert nephroprotection not only through improving glycemic control but also through glucose-independent effects, such as blood pressure-lowering and direct renal effects. It is important to consider, however, that in patients with impaired renal function, given their mode of action, SGLT2 inhibitors are less effective in lowering blood glucose. In patients with high cardiovascular risk, the SGLT2 inhibitor empagliflozin lowered the rate of cardiovascular events, especially cardiovascular death, and substantially reduced important renal outcomes. Such benefits on DN could derive from effects beyond glycemia. Glomerular hyperfiltration is a potential risk factor for DN. In addition to the activation of the renin-angiotensin-aldosterone system, renal tubular factors, including SGLT2, contribute to glomerular hyperfiltration in diabetes. SGLT2 inhibitors reduce sodium reabsorption in the proximal tubule, causing, through tubuloglomerular feedback, afferent arteriole vasoconstriction and reduction in hyperfiltration. Experimental studies showed that SGLT2 inhibitors reduced hyperfiltration and decreased inflammatory and fibrotic responses of proximal tubular cells. SGLT2 inhibitors reduced glomerular hyperfiltration in patients with type 1 diabetes, and in patients with type 2 diabetes, they caused transient acute reductions in glomerular filtration rate, followed by a progressive recovery and stabilization of renal function. Interestingly, recent studies consistently demonstrated a reduction in albuminuria. Although these data are promising, only dedicated renal outcome trials will clarify whether SGLT2 inhibitors, in addition to their glycemic and blood pressure benefits, may provide nephroprotective effects. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Uso de recursos y costos de hospitalizaciones por insufi ciencia card í aca: un estudio retrospective multic é ntrico en Argentina.

PubMed

Augustovski, Federico; Caporale, Joaquín; Fosco, Matías; Alcaraz, Andrea; Diez, Mirta; Thierer, Jorge; Peradejordi, Margarita; Pichon Riviere, Andrés

2017-12-01

Heart failure has a great impact on health budget, mainly due to the cost of hospitalizations. Our aim was to describe health resource use and costs of heart failure admissions in three important institutions in Argentina. Multi-center retrospective cohort study, with descriptive and analytical analysis by subgroups of ejection fraction, blood pressure and renal function at admission. Generalized linear models were used to assess the association of independent variables to main outcomes. We included 301 subjects; age 75.3±11.8 years; 37% women; 57% with depressed ejection fraction; 46% of coronary etiology. Blood pressure at admission was 129.8±29.7 mmHg; renal function 57.9±26.2 ml/min/1.73 m 2 . Overall mortality was 7%. Average length of stay was 7.82±7.06 days (median 5.69), and was significantly longer in patients with renal impairment (8.9 vs. 8.18; p=0.03) and shorter in those with high initial blood pressure (6.08±4.03; p=0.009). Mean cost per patient was AR$68,861±96,066 (US$=8,071; 1US$=AR$8.532); 71% attributable to hospital stay, 20% to interventional procedures and 6.7% to diagnostic studies. Variables independently associated with higher costs were depressed ejection fraction, presence of valvular disease, and impaired renal function. Resource use and costs associated to hospitalizations for heart failure is high, and the highest proportion is attributable to the costs related to hospital stay. Copyright © 2017. Published by Elsevier Inc.

Regulation of blood pressure and renal function by NCC and ENaC: lessons from genetically engineered mice.

PubMed

Verouti, Sophia N; Boscardin, Emilie; Hummler, Edith; Frateschi, Simona

2015-04-01

The activity of the thiazide-sensitive Na(+)/Cl(-) cotransporter (NCC) and of the amiloride-sensitive epithelial Na(+) channel (ENaC) is pivotal for blood pressure regulation. NCC is responsible for Na(+) reabsorption in the distal convoluted tubule (DCT) of the nephron, while ENaC reabsorbs the filtered Na(+) in the late DCT and in the cortical collecting ducts (CCD) providing the final renal adjustment to Na(+) balance. Here, we aim to highlight the recent advances made using transgenic mouse models towards the understanding of the regulation of NCC and ENaC function relevant to the control of sodium balance and blood pressure. We thus like to pave the way for common mechanisms regulating these two sodium-transporting proteins and their potential implication in structural remodeling of the nephron segments and Na(+) and Cl(-) reabsorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

A random comparison of fosinopril and nifedipine GITS in patients with primary renal disease.

PubMed

Marin, R; Ruilope, L M; Aljama, P; Aranda, P; Segura, J; Diez, J

2001-10-01

To investigate in a random comparison the capacity of an angiotensin converting enzyme inhibitor (fosinopril), and that of a long-acting dihydropiridine (nifedipine GITS) to modify the decay in renal function in patients with primary renal disease, exhibiting a progressive increase in serum creatinine during the previous 2 years. A randomized, open-label, multicenter study with a minimum follow-up of 3 years. A total of 241 patients were included in the study. All of them were hypertensive and had a 25% or at least 0.5 mg/dl increase in the value of serum creatinine during the 24 months prior to entering the study. Initial doses of fosinopril and nifedipine GITS were 10 and 30 mg respectively, and titration to 30 and 60 mg was performed if needed to obtain the expected blood pressure goal (< 140/90 mmHg). Furosemide, atenolol, and doxazosin were added as second, third, and fourth drugs if necessary, for blood pressure control. The primary end-point of the study was the appearance of double the serum creatinine values and/or the need to enter a dialysis programme. Secondary end-points were cardiovascular events, death, changes in 24 h proteinuria, and the evolution of serum creatinine. Data reflect the analysis performed by intention to treat. Mean age of the group was 54 +/- 14, and 59% were males. Primary glomerulonephritis (31%), nephrosclerosis (26%) and polycystic kidney disease (19%) were the three most frequent diagnostic findings. After 3 years of follow-up, 21% (27/127) of patients treated with fosinopril, and 36% (40/112) of those receiving nifedipine GITS presented a primary end-point, (OR 0.47, 95% confidence intervals 0.26-0.84, P = 0.01). Renal survival was significantly better when fosinopril constituted the first step therapy (P = 0.002). These results did not seem to be influenced by the type of primary renal disease. Proteinuria decreased at the end of the study by a mean of 57% in the fosinopril group and increased by 7% in the group receiving dihydropiridine. Blood pressure control did not differ among groups for diastolic values. During follow-up, however, the patients receiving ACEi showed systolic blood pressure values 4-6 mmHg lower. In patients with chronic renal failure and hypertension due to primary renal disease, fosinopril significantly differed from nifedipine GITS by its capacity to slow the progressive decay in renal function. The drugs also differed by their capacity to lower blood pressure. The better control, in particular of systolic blood pressure, in the fosinopril arm could have contributed in a relevant manner to the attainment of a better outcome when the ACEi was employed.

Outcomes in Patients with Vasodilatory Shock and Renal Replacement Therapy Treated with Intravenous Angiotensin II.

PubMed

Tumlin, James A; Murugan, Raghavan; Deane, Adam M; Ostermann, Marlies; Busse, Laurence W; Ham, Kealy R; Kashani, Kianoush; Szerlip, Harold M; Prowle, John R; Bihorac, Azra; Finkel, Kevin W; Zarbock, Alexander; Forni, Lui G; Lynch, Shannan J; Jensen, Jeff; Kroll, Stew; Chawla, Lakhmir S; Tidmarsh, George F; Bellomo, Rinaldo

2018-06-01

Acute kidney injury requiring renal replacement therapy in severe vasodilatory shock is associated with an unfavorable prognosis. Angiotensin II treatment may help these patients by potentially restoring renal function without decreasing intrarenal oxygenation. We analyzed the impact of angiotensin II on the outcomes of acute kidney injury requiring renal replacement therapy. Post hoc analysis of the Angiotensin II for the Treatment of High-Output Shock 3 trial. ICUs. Patients with acute kidney injury treated with renal replacement therapy at initiation of angiotensin II or placebo (n = 45 and n = 60, respectively). IV angiotensin II or placebo. Primary end point: survival through day 28; secondary outcomes included renal recovery through day 7 and increase in mean arterial pressure from baseline of ≥ 10 mm Hg or increase to ≥ 75 mm Hg at hour 3. Survival rates through day 28 were 53% (95% CI, 38%-67%) and 30% (95% CI, 19%-41%) in patients treated with angiotensin II and placebo (p = 0.012), respectively. By day 7, 38% (95% CI, 25%-54%) of angiotensin II patients discontinued RRT versus 15% (95% CI, 8%-27%) placebo (p = 0.007). Mean arterial pressure response was achieved in 53% (95% CI, 38%-68%) and 22% (95% CI, 12%-34%) of patients treated with angiotensin II and placebo (p = 0.001), respectively. In patients with acute kidney injury requiring renal replacement therapy at study drug initiation, 28-day survival and mean arterial pressure response were higher, and rate of renal replacement therapy liberation was greater in the angiotensin II group versus the placebo group. These findings suggest that patients with vasodilatory shock and acute kidney injury requiring renal replacement therapy may preferentially benefit from angiotensin II.

Long-term verification of functional and structural renal damage after renal sympathetic denervation.

PubMed

Dörr, Oliver; Liebetrau, Christoph; Möllmann, Helge; Gaede, Luise; Troidl, Christian; Wiebe, Jens; Renker, Matthias; Bauer, Timm; Hamm, Christian; Nef, Holger

2016-06-01

Previous studies of renal sympathetic denervation (RSD) excluded patients with impaired renal function to avoid potential RSD-related renal damage. Measurement of the highly sensitive biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) has shown that RSD does not aggravate renal damage during the early post-procedural period. The aim of the present study was to examine the effect of RSD on blood pressure (BP) reduction and renal function after a long-term follow-up. A total of 62 consecutive patients undergoing RSD were included in this study. Serum NGAL and KIM-1 were collected prior to RSD and at 24 hr, 48 hr, and 3 months after RSD. BP measurements, antihypertensive medication use, and safety events were followed over a three-year period. Follow-up data were available over 36.9[±3.4] months in 47 of 62 (75.8%) of the initially included patients. At this time point a significant systolic BP reduction of 23 mm Hg (P > 0.001) was documented, and there were no significant changes in serum creatinine (P = 0.14), blood urea nitrogen (P = 0.33), or estimated glomerular filtration rate (eGFR) (P = 0.2) values. There were also no significant changes documented in patients with impaired renal function (eGFR < 45 mL/min) during the early post- procedural period or the long-term follow-up (P = 0.34). The results of the present study show a sustained effect of RSD on BP reduction after a three-year follow-up, and there was no evidence of renal failure. These results provide verification of the long-term safety and effectiveness of RSD, even in patients with impaired renal function. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Effect of endogenous angiotensin II on the frequency response of the renal vasculature.

PubMed

Dibona, Gerald F; Sawin, Linda L

2004-12-01

The renal vasculature functions as an efficient low-pass filter of the multiple frequencies contained within renal sympathetic nerve activity. This study examined the effect of angiotensin II on the frequency response of the renal vasculature. Physiological changes in the activity of the endogenous renin-angiotensin system were produced by alterations in dietary sodium intake. The frequency response of the renal vasculature was evaluated using pseudorandom binary sequence renal nerve stimulation, and the role of angiotensin II was evaluated by the administration of the angiotensin II AT(1)-receptor antagonist losartan. In low-sodium-diet rats with increased renin-angiotensin system activity, losartan steepened the renal vascular frequency response (i.e., greater attenuation); this was not seen in normal- or high-sodium-diet rats with normal or decreased renin-angiotensin system activity. Analysis of the transfer function from arterial pressure to renal blood flow, i.e., dynamic autoregulation, showed that the tubuloglomerular feedback but not the myogenic component was enhanced in low- and normal- but not in high-sodium-diet rats and that this was reversed by losartan administration. Thus physiological increases in endogenous renin-angiotensin activity inhibit the renal vascular frequency response to renal nerve stimulation while selectively enhancing the tubuloglomerular feedback component of dynamic autoregulation of renal blood flow.

Renal artery anatomy assessed by quantitative analysis of selective renal angiography in 1,000 patients with hypertension.

PubMed

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham Rami; Edelman, Elazer Reuven; Lüscher, Thomas Felix; Blankenstijn, Peter J; Dörr, Oliver; Schlaich, Markus; Sharif, Faisal; Voskuil, Michiel; Zeller, Thomas; Ukena, Christian; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-05-20

With increasing attention to renovascular causes and targets for hypertension there arises a critical need for more detailed knowledge of renal arterial anatomy. However, a standardised nomenclature is lacking. The present study sought to develop a standardised nomenclature for renal anatomy considering the complexity and variation of the renal arterial tree and to assess the applicability of the nomenclature. One thousand hypertensive patients underwent invasive selective renal artery angiography in nine centres. Further, renovasography was performed in 249 healthy swine as a surrogate for normotensive anatomy. Anatomical parameters were assessed by quantitative vascular analysis. Patients' mean blood pressure was 168/90±26/17 mmHg. The right main renal artery was longer than the left (41±15 mm vs. 35±13 mm, p<0.001), but the left had a greater diameter (5.4±1.2 vs. 5.2±1.2 mm, p<0.001). Accessory renal arteries and renal artery disease were documented in 22% and 9% of the patients, respectively. Other than exhibiting a longer left main renal artery in uncontrolled hypertensives (+2.7 mm, p=0.034) there was no anatomical difference between patients with controlled and uncontrolled hypertension. Main renal artery mean diameter was smaller in patients with impaired kidney function (GFR <90 ml/min, left -0.5 mm, right -0.4 mm, both p<0.001). Renal arterial anatomy differs between sides but shows no difference between patients with and without blood pressure control. Impaired GFR was associated with small main renal artery diameter.

Renal artery anatomy affects the blood pressure response to renal denervation in patients with resistant hypertension.

PubMed

Hering, Dagmara; Marusic, Petra; Walton, Antony S; Duval, Jacqueline; Lee, Rebecca; Sata, Yusuke; Krum, Henry; Lambert, Elisabeth; Peter, Karlheinz; Head, Geoff; Lambert, Gavin; Esler, Murray D; Schlaich, Markus P

2016-01-01

Renal denervation (RDN) has been shown to reduce blood pressure (BP), muscle sympathetic nerve activity (MSNA) and target organ damage in patients with resistant hypertension (RH) and bilateral single renal arteries. The safety and efficacy of RDN in patients with multiple renal arteries remains unclear. We measured office and 24-hour BP at baseline, 3 and 6 months following RDN in 91 patients with RH, including 65 patients with single renal arteries bilaterally (group 1), 16 patients with dual renal arteries on either one or both sides (group 2) and 10 patients with other anatomical constellations or structural abnormalities (group 3). Thirty nine out of 91 patients completed MSNA at baseline and follow-up. RDN significantly reduced office and daytime SBP in group 1 at both 3 and 6 months follow-up (P<0.001) but not in groups 2 and 3. Similarly, a significant reduction in resting baseline MSNA was only observed in group 1 (P<0.05). There was no deterioration in kidney function in any group. While RDN can be performed safely irrespective of the underlying renal anatomy, the presence of single renal arteries with or without structural abnormalities is associated with a more pronounced BP and MSNA lowering effect than the presence of dual renal arteries in patients with RH. However, when patients with dual renal arteries received renal nerve ablation in all arteries there was trend towards a greater BP reduction. Insufficient renal sympathetic nerve ablation may account for these differences. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of high saturated free fatty acids feeding on progression of renal failure in rat model of experimental nephrotoxicity.

PubMed

Ibraheem, Zaid O; Sattar, Munavvar A; Abdullah, Nor A; Rathore, Hassaan A; Johns, Edward J

2012-02-01

The current study evaluates the impact of high saturated fat feeding in rat model of experimental nephrotoxicity induced by gentamicin. Sprague-Dawley rats weighing 200 g were randomized into four groups; the first one received the standard rodents chow for 8 weeks and was treated as control, the second group (HFD)received an experimental high fat diet rich in palm kernel oil (40% of Calories as fat) for the same period. The third group (HFDG) was given 80 mg/kg (body weight)/day gentamicin sulphate intraperitoneally during the last 24 days of the feeding period while the fourth group was given gentamicin as above along with the standard rodents chow. Renal function was assessed through measuring serum creatinine, creatinine clearance and absolute and fractional excretion of both sodium and potassium. At the end, rats underwent a surgical procedure for blood pressure measurement. Renal function study showed a stronger nephrotoxicity for HFDG group. Hypertension was observed in HFD group while the pressure declined after gentamicin co-administration. Overall, changing the feeding behavior toward using more SAFFAs for rats injected with gentamicin promotes the progression of renal failure.

Effect of high saturated free fatty acids feeding on progression of renal failure in rat model of experimental nephrotoxicity

PubMed Central

Ibraheem, Zaid O.; Sattar, Munavvar A.; Abdullah, Nor A.; Rathore, Hassaan A.; Johns, Edward J.

2012-01-01

The current study evaluates the impact of high saturated fat feeding in rat model of experimental nephrotoxicity induced by gentamicin. Sprague-Dawley rats weighing 200 g were randomized into four groups; the first one received the standard rodents chow for 8 weeks and was treated as control, the second group (HFD)received an experimental high fat diet rich in palm kernel oil (40% of Calories as fat) for the same period. The third group (HFDG) was given 80 mg/kg (body weight)/day gentamicin sulphate intraperitoneally during the last 24 days of the feeding period while the fourth group was given gentamicin as above along with the standard rodents chow. Renal function was assessed through measuring serum creatinine, creatinine clearance and absolute and fractional excretion of both sodium and potassium. At the end, rats underwent a surgical procedure for blood pressure measurement. Renal function study showed a stronger nephrotoxicity for HFDG group. Hypertension was observed in HFD group while the pressure declined after gentamicin co-administration. Overall, changing the feeding behavior toward using more SAFFAs for rats injected with gentamicin promotes the progression of renal failure. PMID:22364300

Clinical outcome of renal artery stenting for hypertension and chronic kidney disease up to 12 months in the J-RAS Study – prospective, single-arm, multicenter clinical study.

PubMed

Fujihara, Masahiko; Yokoi, Yoshiaki; Abe, Takaaki; Soga, Yoshimitsu; Yamashita, Takehiro; Miyashita, Yusuke; Nakamura, Masato; Yokoi, Hiroyoshi; Ito, Sadayoshi

2015-01-01

Atherosclerotic renal artery stenosis (ARAS) causes renovascular hypertension (HTN) and impairs renal function, leading to chronic kidney disease (CKD). The J-RAS study was a prospective, multicenter study to assess the clinical outcome of renal artery stenting for up to 1 year in Japanese patients with ARAS. One hundred and forty-nine patients were enrolled between November 2010 and January 2013. The patients were classified into an HTN (n=121) group and a CKD (n=108) group in the primary analysis. The primary efficacy endpoints were change in blood pressure for the HTN group and change in estimated glomerular filtration rate (eGFR) for the CKD group at 1 months. The primary safety endpoint was freedom from major cardiovascular or renal events at 12 months. In the HTN group, the mean systolic blood pressure (SBP) significantly decreased from 161.6 ± 21 mmHg at baseline to 137.0 ± 21 mmHg (P<0.0001). In the CKD group, there was no significant difference in eGFR from 40.7 ± 10 ml·min(-1)·1.73 m(-2)at baseline to 40.8 ± 13 ml·min(-1)·1.73 m(-2)(P=0.32). The primary safety endpoint was 89.4% at 12 months. In the J-RAS trial, significant SBP reduction was seen in the HTN group, and stabilization of renal function in the CKD group. Renal artery stenting for ARAS is safe and effective in Japanese patients.

Mild zinc deficiency in male and female rats: early postnatal alterations in renal nitric oxide system and morphology.

PubMed

Tomat, Analia Lorena; Veiras, Luciana Cecilia; Aguirre, Sofía; Fasoli, Héctor; Elesgaray, Rosana; Caniffi, Carolina; Costa, María Ángeles; Arranz, Cristina Teresa

2013-03-01

Fetal and postnatal zinc deficiencies induce an increase in arterial blood pressure and impair renal function in male adult rats. We therefore hypothesized that these renal alterations are present in early stages of life and that there are sexual differences in the adaptations to this nutritional injury. The aim was to study the effects of moderate zinc deficiency during fetal life and lactation on renal morphology, oxidative stress, apoptosis, and the nitric oxide system in male and female rats at 21 d of life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy to weaning. Glomerulus number, morphology, oxidative stress, apoptotic cells, nitric oxide synthase activity, and protein expression were evaluated in the kidneys of offspring at 21 d. Zinc deficiency decreased the nephron number, induced glomerular hypertrophy, increased oxidative damage, and decreased nitric oxide synthase activity in the male and female rat kidneys. Nitric oxide synthase activity was not affected by inhibitors of the neuronal or inducible isoforms, so nitric oxide was mainly generated by the endothelial isoenzyme. Gender differences were observed in glomerular areas and antioxidant enzyme activities. Zinc deficiency during fetal life and lactation induces an early decrease in renal functional units, associated with a decrease in nitric oxide activity and an increase in oxidative stress, which would contribute to increased arterial blood pressure and renal dysfunction in adulthood. The sexual differences observed in this model may explain the dissimilar development of hypertension and renal diseases in adult life. Copyright © 2013 Elsevier Inc. All rights reserved.

Role of renal sensory nerves in physiological and pathophysiological conditions

PubMed Central

2014-01-01

Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation. PMID:25411364

Fetal development and renal function in adult rats prenatally subjected to sodium overload.

PubMed

Cardoso, Henriqueta D; Cabral, Edjair V; Vieira-Filho, Leucio D; Vieyra, Adalberto; Paixão, Ana D O

2009-10-01

The aims of this study were (1) to evaluate two factors that affect fetal development--placental oxidative stress (Ox) and plasma volume (PV)--in dams with sodium overload and (2) to correlate possible alterations in these factors with subsequent modifications in the renal function of adult offspring. Wistar dams were maintained on 0.17 M NaCl instead of water from 20 days before mating until either the twentieth pregnancy day/parturition or weaning. Colorimetric methods were used to measure Ox in maternal and offspring tissues, PV, 24-h urinary protein (U(Prot24 h)) and serum triacylglycerols (TG) and cholesterol (Chol). Renal hemodynamics was evaluated in the offspring at 90 days of age using a blood pressure transducer, a flow probe and inulin clearance to measure mean arterial pressure (MAP), renal blood flow and glomerular filtration rate (GFR), respectively. The number of nephrons (NN) was counted in kidney suspensions. Dams showed unchanged PV, placental Ox and fetal weight but increased U(Prot24 h) (150%, P < 0.05). Prenatally sodium-overloaded pups showed increased U(Prot24 h) (45%, P < 0.05) but unchanged MAP, renal hemodynamics, NN and kidney Ox. Prenatally and postnatally sodium-overloaded rats showed increased U(Prot24 h) (27%, P < 0.05) and kidney Ox (44%, P < 0.05), reduced GFR (12%, P < 0.05), increased PV (26%, P < 0.05) and unchanged MAP and NN. The TG increased in both groups of treated offspring (21%, P < 0.05), whereas Chol increased only in the postnatally sodium-overloaded group. We conclude that salt overload from the prenatal stage until weaning leads to alterations in lipid metabolism and in the renal function of the pups, which are additional to those alterations seen in rats only overloaded prenatally.

Moment-to-moment characteristics of the relationship between arterial pressure and renal interstitial hydrostatic pressure.

PubMed

Komolova, Marina; Adams, Michael A

2010-10-01

The kidney is a key controller of the long-term level of arterial pressure, in part through pressure-natriuresis. Although direct coupling of changes in renal arterial pressure to renal interstitial hydrostatic pressure (RIHP) and consequent sodium excretion is well established, few studies have characterized the moment-to-moment aspects of this process. These studies characterized the short-term hemodynamic component of pressure-natriuresis in vivo before and after autonomic nervous system and renin-angiotensin system inhibition. Changes in RIHP were determined over a range of renal arterial pressures in Wistar rats receiving no treatment, a ganglionic blocker (hexamethonium; 20 mg/kg per hour IV), or an angiotensin II type 1 receptor blocker (losartan; 10 mg/kg per hour IV). After a series of changes in renal arterial pressure, a delay of only ≈1 second was found for the onset of RIHP responses that was independent of the stimulus magnitude and neurohumoral manipulation; however, completion of the full RIHP response was within ≈15 seconds for renal arterial pressure changes of ≤30 mm Hg. The overall slope of the renal arterial pressure- RIHP relationship (0.09±0.01) was also not affected by autonomic nervous system and renin-angiotensin system inhibition despite decreasing renal arterial pressure (↓40% and ↓28%, respectively). Separate assessment of this relationship above and below the prevailing arterial pressure revealed that the pressor versus the depressor portion was blunted (P<0.001), a difference that was abolished after autonomic nervous system and renin-angiotensin system inhibition. The results suggest that spontaneous changes in arterial pressure are coupled to moment-to-moment changes in RIHP over a wide range of pressures, emphasizing a likely role for the dynamic component of the renal arterial pressure-RIHP relationship in the modulation of sodium excretion and, hence, arterial pressure.

Renoprotective effects of combined endothelin-converting enzyme/neutral endopeptidase inhibitor SLV338 in acute and chronic experimental renal damage.

PubMed

Sharkovska, Yuliya; Kalk, Philipp; von Websky, Karoline; Relle, Katharina; Pfab, Thiemo; Alter, Markus; Fischer, Yvan; Hocher, Berthold

2011-01-01

Acute kidney injury (AKI) as well as chronic renal failure are associated with a huge mortality/morbidity. However, so far no drugs have been approved for the treatment of acute kidney failure and only a few for the treatment of chronic kidney disease (CKD). We analysed the effect of SLV338, a neutral endopeptidase (NEP)/endothelin converting enzyme (ECE)-inhibitor in animal models of acute kidney failure as well as chronic renal failure. Acute renal failure was induced in male Wistar rats by uninephrectomy and clamping of the remaining kidney for 55 minutes. SLV338 (total dose: 4.9 mg/kg) or vehicle was continuously infused for 2 hours (starting 20 minutes prior to clamping). Sham operated animals served as controls. Plasma creatinine was measured at baseline and day 2 and 8 after renal ischemia-reperfusion. Hypertensive renal damage was induced in male Sprague Dawley rats by nitric oxide deficiency using L-NAME (50 mg/kg per day, added to drinking water for 4 weeks). One group was treated over the same time period with SLV338 (30 mg/kg per day, mixed with food). Systolic blood pressure was monitored weekly. At study end, urine and blood samples were collected and kidneys were harvested. Acute renal ischemia-reperfusion caused a 5-fold plasma creatinine elevation (day 2), which was significantly attenuated by more than 50% in animals treated with SLV338 (p < 0.05). Renal failure was accompanied by a 67% mortality in vehicle-treated rats, but only 20% after SLV338 treatment (p = 0.03 compared to sham controls). Chronic L-NAME administration caused hypertension, urinary albumin excretion, glomerulosclerosis, renal arterial remodelling, and renal interstitial fibrosis. Treatment with SLV338 did not significantly affect blood pressure, but abolished renal tissue damage (interstitial fibrosis, glomerulosclerosis, renal arterial remodelling (p < 0.05 versus L-NAME group in each case). The dual ECE/NEP inhibitor SLV338 preserves kidney function and reduces mortality in severe acute ischemic renal failure. Moreover, combined ECE/NEP inhibition prevents hypertensive renal tissue damage in a blood pressure independent manner in L-NAME-treated rats.

Renal albumin absorption in physiology and pathology.

PubMed

Birn, H; Christensen, E I

2006-02-01

Albumin is the most abundant plasmaprotein serving multiple functions as a carrier of metabolites, hormones, vitamins, and drugs, as an acid/base buffer, as antioxidant and by supporting the oncotic pressure and volume of the blood. The presence of albumin in urine is considered to be the result of the balance between glomerular filtration and tubular reabsorption. Albuminuria has been accepted as an independent risk factor and a marker for renal as well as cardiovascular disease, and during the past decade, evidence has suggested that albumin itself may cause progression of renal disease. Thus, the reduction of proteinuria and, in particular, albuminuria has become a target in itself to prevent deterioration of renal function. Studies have shown albumin and its ligands to induce expression of inflammatory and fibrogenic mediators, and it has been hypothesized that increased filtration of albumin causes excessive tubular reabsorption, resulting in inflammation and fibrosis, resulting in the loss of renal function. In addition, it is known that tubular dysfunction in itself may cause albuminuria owing to decreased reabsorption of filtered albumin, and, recently, it has been suggested that significant amounts of albumin fragments are excreted in the urine as a result of tubular degradation. Thus, although both tubular and glomerular dysfunction influences renal handling of albumin, it appears that tubular reabsorption plays a central role in mediating the effects of albumin on renal function. The present paper will review the mechanisms for tubular albumin uptake and the possible implications for the development of renal disease.

Renal Safety Pharmacology in Drug Discovery and Development.

PubMed

Benjamin, Amanda; Nogueira da Costa, Andre; Delaunois, Annie; Rosseels, Marie-Luce; Valentin, Jean-Pierre

2015-01-01

The kidney is a complex excretory organ playing a crucial role in various physiological processes such as fluid and electrolyte balance, control of blood pressure, removal of waste products, and drug disposition. Drug-induced kidney injury (DIKI) remains a significant cause of candidate drug attrition during drug development. However, the incidence of renal toxicities in preclinical studies is low, and the mechanisms by which drugs induce kidney injury are still poorly understood. Although some in vitro investigational tools have been developed, the in vivo assessment of renal function remains the most widely used methodology to identify DIKI. Stand-alone safety pharmacology studies usually include assessment of glomerular and hemodynamic function, coupled with urine and plasma analyses. However, as renal function is not part of the ICH S7A core battery, such studies are not routinely conducted by pharmaceutical companies. The most common approach consists in integrating renal/urinary measurements in repeat-dose toxicity studies. In addition to the standard analyses and histopathological examination of kidneys, novel promising urinary biomarkers have emerged over the last decade, offering greater sensitivity and specificity than traditional renal parameters. Seven of these biomarkers have been qualified by regulatory agencies for use in rat toxicity studies.

Renal autotransplantation--a possibility in the treatment of complex renal vascular diseases and ureteric injuries.

PubMed

Hau, Hans Michael; Bartels, Michael; Tautenhahn, Hans-Michael; Morgul, Mehmet Haluk; Fellmer, Peter; Ho-Thi, Phuc; Benckert, Christoph; Uhlmann, Dirk; Moche, Michael; Thelen, Armin; Schmelzle, Moritz; Jonas, Sven

2012-12-31

We report our contemporary experiences with renal autotransplantation in patients with complicated renal vascular diseases and/or complex ureteral injuries. Since its first performance, renal autotransplantation has been steadily improved and become a safe and effective procedure. Between 1998 and 2006, 6 renal autotransplantations in 6 patients were performed at the University Medical Center of Leipzig. After nephrectomy and renal perfusion ex vivo, the kidney was implanted standardized in the fossa iliaca. The vessels were anastomized to the iliac vessels, the ureter was reimplanted in an extravesical tunneled ureteroneocystostomy technique according to Lich-Gregoir. Demographic, clinical, and laboratory data of the patients were collected and analyzed for pre-, intra-, and postoperative period. Indications for renal autotransplantation were complex renovascular diseases in 2 patients (1 with fibromuscular dysplasia and 1 with Takayasu's arteritis) and in 4 patients with complex ureteral injuries. The median duration of follow-up was 9.7 years (range: 5.6-13.3). The laboratory values of our 6 patients showed improvements of creatinine, urea and blood pressure levels in comparison to the preoperative status at the end of follow-up period. The present study reports excellent results of renal autotransplantation in patients with renovascular disease or complex ureteric injuries. After a median follow-up of 9.7 years all 6 patients present with stable renal function as well as normal blood pressure values. Postoperative complications were observed with a rate comparable to other studies.

Exercise training by individuals with predialysis renal failure: cardiorespiratory endurance, hypertension, and renal function.

PubMed

Boyce, M L; Robergs, R A; Avasthi, P S; Roldan, C; Foster, A; Montner, P; Stark, D; Nelson, C

1997-08-01

The purpose of this study was to determine the effects of 4 months of exercise training (ET) on cardiorespiratory function and endurance, blood pressure, muscle strength, hematology, blood lipids, and renal function in individuals with chronic renal failure (CRF) who were not yet on dialysis. Sixteen subjects were recruited to volunteer for participation in this study, but only eight completed all study phases. Subjects were first evaluated before and after a 2-month baseline (BL1 and BL2), after 4 months of ET, and again after 2 months of detraining (DT). ET did not change hematology, blood lipids, or echocardiographic measurements of left ventricular function and mass. Resting systolic and diastolic blood pressures decreased significantly from BL after the ET (146 +/- 15.7/87 +/- 9 mm Hg to 124 +/- 17.5/78 +/- 9.5 mm Hg; P < 0.02), and then increased significantly after DT (139 +/- 14.7 mm Hg and 87 +/- 9.9 mm Hg; P < 0.01). Peak oxygen consumption (pVO2) changed significantly during the study (1.3 +/- 0.3 L/min, 1.5 +/- 0.3 L/min, and 1.4 +/- 0.3 L/min for BL2, ET, and DT, respectively; P < 0.02), as did the VO2 at the ventilatory threshold (0.65 +/- 0.18 L/min, 0.92 +/- 0.19 L/min, and 0.68 +/- 0.23 L/min for BL2, ET, and DT, respectively; P < 0.01). Knee flexion peak torque increased after ET (43.4 +/- 25.6 Nm to 51.0 +/- 30.5 Nm; P < 0.02). GFR, as measured by creatinine clearance, continued to deteriorate during the course of the study (25.3 +/- 12.0 mL/min, 21.8 +/- 13.2 mL/min, and 21.8 +/- 13.2 mL/min for BL2, ET, and DT, respectively; P < 0.001). Individuals with predialysis CRF who undergo ET improve in functional aerobic capacity, muscular strength, and blood pressure.

Posterior Reversible Leukoencephalopathy Syndrome: Case Series and Review of the Literature.

PubMed

Pirola, Juan Pablo; Baenas, Diego Federico; Haye Salinas, María Jezabel; Benzaquén, Nadia Raquel; Colazo, Marcela; Borghi, María Victoria; Lucero, Cecilia; Álvarez, Ana Cecilia; Retamozo, Soledad; Alvarellos, Alejandro; Saurit, Verónica; Caeiro, Francisco

2018-05-30

To describe clinical manifestations, antecedents, comorbidities and associated treatments, imaging findings, and follow-up in patients with posterior reversible encephalopathy syndrome. A retrospective, descriptive analysis of admitted patients was performed between June 2009 and May 2014 in a third-level care hospital. We evaluated age, sex, comorbidities, symptoms, values of blood pressure at admission, renal function, medication and time elapsed until the disappearance of symptoms. Thirteen patients were included. In all, 77% of them had a history of hypertension at baseline and 85% had impaired renal function. The most prevalent comorbidity was renal transplantation, and 85% had deterioration of renal function. Five of the patients had undergone renal transplantation. The most common clinical manifestation was seizures. All had subcortical lesions and bilateral parietooccipital involvement was the finding most frequently observed. This syndrome should be taken into account in the differential diagnoses of patients presenting with acute neurological syndromes and the abovementioned risk factors. Copyright © 2018 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Worsening renal function and prognosis in pulmonary hypertension patients hospitalized for right heart failure.

PubMed

Mielniczuk, Lisa M; Chandy, George; Stewart, Duncan; Contreras-Dominguez, Vladamir; Haddad, Haissam; Pugliese, C; Davies, Ross A

2012-01-01

Increased central venous pressures have been associated with the development of worsening renal function (WRF), an important marker of prognosis. We sought to determine the incidence and prognostic significance of WRF in pulmonary hypertension patients (PH) with isolated right HF. A prospective study of PH clinic patients admitted to hospital for right HF. WRF was defined as a rise in creatinine of 26 μmol/L (0.3 mg/dL) within the first 48 hours of admission. A total of 32 patients were enrolled in this study, 67% of patients had moderate-severe chronic kidney disease with an eGFR ≤ 60 mL/min and 34% (n=11) developed WRF during their admission. The mean right atrial pressure was higher in patients with WRF (19 ± 7 mm Hg vs 12 ± 6 mm Hg, P=.05). A total of 36% of patients with WRF died in hospital compared to 5% in the group that did not develop WRF (OR for hospital death 13.3 ± 16, P=.03). The combined endpoint of death or readmission at 6 months was 45% in the WRF group and 43% in the group without WRF (P=.89). Significant renal dysfunction is common in patients with PH and an acute decline in renal function is an important marker of in hospital death and short term mortality in right heart failure. © 2012 Wiley Periodicals, Inc.

Community nephrology: audit of screening for renal insufficiency in a high risk population.

PubMed

Kissmeyer, L; Kong, C; Cohen, J; Unwin, R J; Woolfson, R G; Neild, G H

1999-09-01

The rate of acceptance onto dialysis programmes has doubled in the past 10 years and is steadily increasing. Early detection and treatment of renal failure slows the rate of progression. Is it feasible to screen for patients who are at increased risk of developing renal failure? We have audited primary care records of patients aged 50-75 years who have either hypertension or diabetes, and are therefore considered to be at high risk of developing renal insufficiency. Our aim was to see whether patients had had their blood pressure measured and urine tested for protein within 12 months, and plasma creatinine measured within 24 months. This was a retrospective study of case notes and computer records in 12 general practices from inner and greater London. A total of 16,855 patients were aged 50-75 years. From this age group, 2693 (15.5%) patients were identified as being either hypertensive or diabetic, or both. Of the 2561 records audited, 1359 (53.1%) contained a plasma creatinine measured within 24 months, and 11% of these (150) had a value > 125 micromol/l. This equates to a prevalence of renal insufficiency of > 110,000 patients per million in this group. Forty two patients (28%) had been referred to a nephrologist. Of records audited, 73% contained a blood pressure measurement and 29% contained a test for proteinuria within 12 months. There is a high prevalence of chronic renal insufficiency in hypertensive and diabetic patients. It is feasible to detect renal insufficiency at a primary care level, but an effective system will require computerized databases that code for age, ethnicity, measurement of blood pressure and renal function, as well as diagnoses.

Systemic and Renal-Specific Sympathoinhibition in Obesity Hypertension

PubMed Central

Lohmeier, Thomas E.; Iliescu, Radu; Liu, Boshen; Henegar, Jeffrey R.; Maric-Bilkan, Christine; Irwin, Eric D.

2012-01-01

Chronic pressure-mediated baroreflex activation suppresses renal sympathetic nerve activity. Recent observations indicate that chronic electrical activation of the carotid baroreflex produces sustained reductions in global sympathetic activity and arterial pressure. Thus, we investigated the effects of global and renal specific suppression of sympathetic activity in dogs with sympathetically-mediated, obesity-induced hypertension by comparing the cardiovascular, renal, and neurohormonal responses to chronic baroreflex activation and bilateral surgical renal denervation. After control measurements, the diet was supplemented with beef fat while sodium intake was held constant. After 4 weeks on the high-fat, when body weight had increased ~a 50%, fat intake was reduced to a level that maintained this body weight. This weight increase was associated with an increase in mean arterial pressure from 100±2 to 117±3 mm Hg and heart rate from 86±3 to 130±4 bpm. The hypertension was associated with a marked increase in cumulative sodium balance despite ~ a 35% increase in GFR. The importance of increased tubular reabsorption to sodium retention was further reflected by ~ a 35% decrease in fractional sodium excretion. Subsequently, both chronic baroreflex activation (7 days) and renal denervation decreased plasma renin activity and abolished the hypertension. However, baroreflex activation also suppressed systemic sympathetic activity and tachycardia and reduced glomerular hyperfiltration while increasing fractional sodium excretion. In contrast, GFR increased further after renal denervation. Thus, by improving autonomic control of cardiac function and diminishing glomerular hyperfiltration, suppression of global sympathetic activity by baroreflex activation may have beneficial effects in obesity beyond simply attenuating hypertension. PMID:22184321

Telemetric signal-driven servocontrol of renal perfusion pressure in acute and chronic rat experiments

PubMed Central

Xia, Min; Li, Pin-Lan; Li, Ningjun

2008-01-01

The present study was designed to take advantage of telemetry data acquisition and develop an easy and reliable system to servocontrol renal perfusion pressure (RPP). Digitized pressure signals from lower abdominal aorta in rats, reflecting RPP, was obtained by a telemetry device and dynamically exported into an Excel worksheet. A computer program (LabVIEW) compared the RPP data with a preselected pressure range and drove a bidirectional syringe pump to control the inflation of a vascular occluder around the aorta above renal arteries. When RPP was higher than the preselected range, the syringe pump inflated the occluder and decreased RPP, and vice versa. If RPP was within range, there was no action. In this way, RPP was servocontrolled within the desired range. In experiments with norepinephrine- or ANG II-induced acute increases in systemic arterial pressure (120–145 mmHg), the system controlled RPP at a constant range of 100–105 mmHg within 30–50 s and differentiated the pressure-dependent and -independent effects on renal functions. In Dahl S rats with high-salt-induced hypertension, this system maintained RPP at 100–120 mmHg over 10 days, while systemic arterial pressures were 150 ± 5.9 mmHg in uncontrolled animals. This system also has the ability of simultaneity and multiplexing to control multiple animals. Our results suggest that this is an effective and reliable system to servocontrol RPP, which can be easily established with general computer knowledge. This system provides a powerful tool and may greatly facilitate the studies in pressure-dependent/-independent effects of a variety of cardiovascular factors. PMID:18815205

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor

PubMed Central

Ojeda, Norma B.; Royals, Thomas P.

2013-01-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg−1·min−1) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg−1·min−1) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats. PMID:23344570

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

PubMed

Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

2013-04-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg(-1)·min(-1)) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

Afferent renal denervation impairs baroreflex control of efferent renal sympathetic nerve activity

PubMed Central

Kopp, Ulla C.; Jones, Susan Y.; DiBona, Gerald F.

2008-01-01

Increasing efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA), which decreases ERSNA to prevent sodium retention. High-sodium diet enhances ARNA, suggesting an important role for ARNA in suppressing ERSNA during excess sodium intake. Mean arterial pressure (MAP) is elevated in afferent renal denervated by dorsal rhizotomy (DRX) rats fed high-sodium diet. We examined whether the increased MAP in DRX is due to impaired arterial baroreflex function. In DRX and sham DRX rats fed high-sodium diet, arterial baroreflex function was determined in conscious rats by intravenous nitroprusside and phenylephrine or calculation of transfer function gain from arterial pressure to ERSNA (spontaneous baroreflex sensitivity). Increasing MAP did not suppress ERSNA to the same extent in DRX as in sham DRX, −60 ± 4 vs. −77 ± 6%. Maximum gain, −4.22 ± 0.45 vs. −6.04 ± 0.90% ΔERSNA/mmHg, and the maximum value of instantaneous gain, −4.19 ± 0.45 vs. −6.04 ± 0.81% ΔERSNA/mmHg, were less in DRX than in sham DRX. Likewise, transfer function gain was lower in DRX than in sham DRX, 3.9 ± 0.2 vs. 6.1 ± 0.5 NU/mmHg. Air jet stress produced greater increases in ERSNA in DRX than in sham DRX, 35,000 ± 4,900 vs. 20,900 ± 3,410%·s (area under the curve). Likewise, the ERSNA responses to thermal cutaneous stimulation were greater in DRX than in sham DRX. These studies suggest impaired arterial baroreflex suppression of ERSNA in DRX fed high-sodium diet. There were no differences in arterial baroreflex function in DRX and sham DRX fed normal-sodium diet. Impaired arterial baroreflex function contributes to increased ERSNA, which would eventually lead to sodium retention and increased MAP in DRX rats fed high-sodium diet. PMID:18945951

[Catastrophic antiphospholipid syndrome in the immediate puerperium].

PubMed

Ortiz, P; Castro, A; Vallés, M; Coll, E; Casas, M; Mauri, J M

2003-01-01

We describe a female previously diagnosed of primary antiphospholipid antibody syndrome who presented a preclampsia in the second pregnancy. An urgent caesaria was made because of a worsening high blood pressure and oliguria. In the immediated puerperium she showed low platelets and persistent high blood pressure. Afterwards acute renal failure and neurological signs with a severe aortic valvulopathy were diagnosed. An haemolytic anemia was also detected. Definitive diagnosis was made by kidney biopsy with the result of a thrombotic microangiopathy. Treatment with low weight heparin and aspirin and systemic corticosteroids was started in the immediate puerperium and fresh frozen plasma was then added with a good response to treatment. Actually she is still with high blood pressure, aortic valvulopathy. Renal function is normal one year later.

Examination of the effect of changing to azilsartan from candesartan in renal transplant patients.

PubMed

Ishii, T; Yasuda, M; Saito, Y; Mori, Y; Hayashi, T; Uemura, H; Nose, K; Nishioka, T

2014-01-01

Azilsartan, an angiotensin receptor blocker (ARB), was administered to renal transplant recipients to investigate the safety and antihypertensive effect in addition to its ARB-characteristic organ-protective effect. The subjects were 20 patients (18 males, 2 females; baseline serum creatinine 2.39 ± 1.33 mg/dL) responding poorly to candesartan, who suffered albuminuria (>0.3 g/g creatinine) and hypertension (>140/90 mm Hg) following renal transplantation. Three months after candesartan was switched to azilsartan 20 mg/d, blood pressure, creatinine-corrected urinary albumin excretion, urinary L-type acid binding protein, urinary 8-hydroxydeoxyguano-sine, serum creatinine, and estimated glomerular filtration rate were evaluated. Thirteen patients received cyclosporine (65.0%) and 7 received tacrolimus (35.0%). Another hypertensive (calcium antagonist) agent was combined in 7 (35.0%). Systolic blood pressure significantly decreased from 139.5 mm Hg (baseline) from 128.7 mm Hg (at 3 months), whereas no significant changes were observed for diastolic blood pressure. The percentage of patients achieving the target level of antihypertensive effect (blood pressure < 130/80 mm Hg) significantly improved from 30.0% (baseline) to 70.0% (at 3 months). No significant changes were observed in renal graft function, oxidative stress marker level, or biochemical examination findings. Sufficient antihypertensive effect was demonstrated soon after switching to azilsartan. However, no significant change was found in renal damage markers. Long-term study must be conducted to confirm the protective effect azilsartan on the transplanted kidney, as found with candesartan. The safety of azilsartan was demonstrated. If the transplanted kidney protection is demonstrated, this drug is expected to contribute to the improved long-term prognosis of renal transplant recipients. Copyright © 2014 Elsevier Inc. All rights reserved.

[Renovascular hypertension in children and adolescents: diagnosis and treatment over 19 years].

PubMed

Alfonzo, J P; Ugarte, C; Banasco, J; Fraxedas, R; Gutiérrez, F; Lahera, J

2006-01-01

SUMMARY Sixty seven hypertensive children age 2-18 with at least one possible clinical sign of renovascular hypertension (RVH) were enrollment into a screening program for diagnose and treatment of RVH over a 19 year period. Patients underwent a variety of biochemical and imaging studies, but in all cases, renal arteriography was used to determine the precise diagnosis and treatment strategy. Of the 67 patients 21 (31.3%) were identified with renal artery stenosis Group 1, 14 (66.6%) unilateral, 5 (23.8%) bilateral and 2 (9.6%) branches. The mean age was 13.9 +/- 3.73 years, with 26.4 +/- 35.2 months of known hypertension, mean systolic blood pressure 191.1 +/- 30.6 mmHg, mean diastolic blood pressure 135.3 +/- 21.2 mmHg and 69% due to fibromuscular dysplasia. Three therapeutic modalities were chosen: percutaneous transluminal angioplasty (PTA), surgery (autotransplant, and nephrectomy), pharmaceutical therapy with antihypertensive drugs and combination of these. The aim of the treatment was blood pressure control, prevention of chronic renal disease and renal function and organ damage preservation. The outcome was categorized as cure, improvement or no change in hypertension. PTA treated eleven patients, 2 combined with surgery (one nephrectomy and 1 autotransplant). Blood pressure was normalized in 9/11 (81.8%) after a mean follow-up of 11.5 years (range 1-18 years). All 6 RVH cases treated by surgery procedure (one after PTA) were cured and 4 cases were managed medically (pharmacological treatment). On december 2004, 19/21 (90%) RVH adolescents blood pressure was normalized with normal serum creatinina, 10 (48%) of these completed cured, 9/21 (43%) improved (normotensión with decrease in medication requirements) and 2 (9%) other cases ware lost of follow-up. The 46 non-RVH adolescents (68.7%) were treated with long term antihypertensive medications; all of these have adequate BP control and normal renal function. We conclude that our work-up used in order to make a proper and timely diagnosis and treatment of renovascular hypertension in adolescent was successful in our population.

Effects of Renal Denervation on Renal Artery Function in Humans: Preliminary Study

PubMed Central

Doltra, Adelina; Hartmann, Arthur; Stawowy, Philipp; Goubergrits, Leonid; Kuehne, Titus; Wellnhofer, Ernst; Gebker, Rolf; Schneeweis, Christopher; Schnackenburg, Bernhard; Esler, Murray; Fleck, Eckart; Kelle, Sebastian

2016-01-01

Aim To study the effects of RD on renal artery wall function non-invasively using magnetic resonance. Methods and Results 32 patients undergoing RD were included. A 3.0 Tesla magnetic resonance of the renal arteries was performed before RD and after 6-month. We quantified the vessel sharpness of both renal arteries using a quantitative analysis tool (Soap-Bubble®). In 17 patients we assessed the maximal and minimal cross-sectional area of both arteries, peak velocity, mean flow, and renal artery distensibility. In a subset of patients wall shear stress was assessed with computational flow dynamics. Neither renal artery sharpness nor renal artery distensibility differed significantly. A significant increase in minimal and maximal areas (by 25.3%, p = 0.008, and 24.6%, p = 0.007, respectively), peak velocity (by 16.9%, p = 0.021), and mean flow (by 22.4%, p = 0.007) was observed after RD. Wall shear stress significantly decreased (by 25%, p = 0.029). These effects were observed in blood pressure responders and non-responders. Conclusions RD is not associated with adverse effects at renal artery level, and leads to an increase in cross-sectional areas, velocity and flow and a decrease in wall shear stress. PMID:27003912

Losartan does not decrease renal oxygenation and norepinephrine effects in rats after resuscitated haemorrhage.

PubMed

Jönsson, Sofia; Melville, Jacqueline M; Becirovic-Agic, Mediha; Hultström, Michael

2018-04-18

Renin-angiotensin-system blockers are thought to increase the risk of acute kidney injury after surgery and haemorrhage. We found that Losartan does not cause renal cortical hypoxia after haemorrhage in rats because of decreased renal vascular resistance, but did not evaluate resuscitation. Study Losartan´s effect on renal cortical and medullary oxygenation, and norepinephrine´s vasopressor effect in a model of resuscitated haemorrhage. After seven days Losartan (60 mg/kg/day) or control treatment, male Wistar rats were haemorrhaged 20 % of the blood volume and resuscitated with Ringer's Acetate. Mean arterial pressure, renal blood flow, and kidney tissue oxygenation was measured at baseline and after resuscitation. Finally, the effect of norepinephrine on mean arterial pressure and renal blood flow was investigated. As expected, Losartan lowered mean arterial pressure but not renal blood flow. Losartan did not affect renal oxygen consumption and oxygen tension. Mean arterial pressure and renal blood flow were lower after resuscitated haemorrhage. Smaller increase of renal vascular resistance in Losartan group translated to smaller decrease in cortical oxygen tension, but no significant difference seen in medullary oxygen tension either between groups or after haemorrhage. The effect of norepinephrine on mean arterial pressure and renal blood flow was similar in controls and Losartan treated rats. Losartan does not decrease renal oxygenation after resuscitated haemorrhage because of a smaller increase in renal vascular resistance. Further, Losartan does not decrease the efficiency of norepinephrine as a vasopressor indicating that blood pressure may be managed effectively during Losartan treatment.

Comparison of the effects of penbutolol and propranolol on glomerular filtration rate in hypertensive patients with impaired renal function.

PubMed Central

van der Meulen, J; Reijn, E; Heidendal, G A; Oe, P L; Donker, A J

1986-01-01

Penbutolol and propranolol were administered orally in a dosage of 40 mg once daily and 80 mg twice daily, respectively to 12 patients with hypertension and impaired renal function. Both drugs caused a significant decrease in mean arterial pressure and heart rate. Serum creatinine concentration increased significantly by 10% during therapy with propranolol without concomitant decrease in creatinine clearance. No such effect was seen with penbutolol. GFR measured with [125I]-iothalamate showed no significant changes with both drugs. PMID:3533129

Intra-renal delivery of mesenchymal stem cells attenuates myocardial injury after reversal of hypertension in porcine renovascular disease.

PubMed

Eirin, Alfonso; Zhu, Xiang-Yang; Ferguson, Christopher M; Riester, Scott M; van Wijnen, Andre J; Lerman, Amir; Lerman, Lilach O

2015-01-19

Percutaneous transluminal renal angioplasty (PTRA) fails to fully improve cardiac injury and dysfunction in patients with renovascular hypertension (RVH). Mesenchymal stem cells (MSCs) restore renal function, but their potential for attenuating cardiac injury after reversal of RVH has not been explored. We hypothesized that replenishment of MSCs during PTRA would improve cardiac function and oxygenation, and decrease myocardial injury in porcine RVH. Pigs were studied after 16 weeks of RVH, RVH treated 4 weeks earlier with PTRA with or without adjunct intra-renal delivery of MSC (10^6 cells), and controls. Cardiac structure, function (fast-computed tomography (CT)), and myocardial oxygenation (Blood-Oxygen-Level-Dependent- magnetic resonance imaging) were assessed in-vivo. Myocardial microvascular density (micro-CT) and myocardial injury were evaluated ex-vivo. Kidney venous and systemic blood levels of inflammatory markers were measured and their renal release calculated. PTRA normalized blood pressure, yet stenotic-kidney glomerular filtration rate, similarly blunted in RVH and RVH + PTRA, normalized only in PTRA + MSC-treated pigs. PTRA attenuated left ventricular remodeling, whereas myocardial oxygenation, subendocardial microvascular density, and diastolic function remained decreased in RVH + PTRA, but normalized in RVH + PTRA-MSC. Circulating isoprostane levels and renal release of inflammatory cytokines increased in RVH and RVH + PTRA, but normalized in RVH + PTRA-MSC, as did myocardial oxidative stress, inflammation, collagen deposition, and fibrosis. Intra-renal MSC delivery during PTRA preserved stenotic-kidney function, reduced systemic oxidative stress and inflammation, and thereby improved cardiac function, oxygenation, and myocardial injury four weeks after revascularization, suggesting a therapeutic potential for adjunctive MSC delivery to preserve cardiac function and structure after reversal of experimental RVH.

Congenital ureteropelvic junction obstruction: physiopathology, decoupling of tout court pelvic dilatation-obstruction semantic connection, biomarkers to predict renal damage evolution.

PubMed

Alberti, C

2012-02-01

The widespread use of fetal ultrasonography results in a frequent antenatally observation of hydronephrosis, ureteropelvic junction obstruction (UPJO) accounting for the greatest fraction of congenital obstructive nephropathy. UPJO may be considered, in most cases, as a functional obstructive condition, depending on defective fetal smooth muscle/nerve development at this level, with lack of peristaltic wave propagation--aperistaltic segment--and, therefore, poor urine ejection from the renal pelvis into the ureter. The UPJO-related physiopathologic events are, at first, the compliant dilatation of renal pelvis that, acting as hydraulic buffer, protects the renal parenchyma from the rising intrapelvic pressure-related potential damages, and, subsequently, beyond such phase of dynamic balance, the tubular cell stretch-stress induced by increased intratubular pressure and following parenchymal inflammatory lesions: inflammatory infiltrates, fibroblast proliferation, activation of myofibroblasts, tubulo-interstitial fibrosis. Reactive oxygen species (ROS), nitric oxide (NO), several chemo- and cytokines, growth factors, prostaglandins and eicosanoids, angiotensin-II are the main pathogenetic mediators of the obstructive nephropathy. Apoptosis of tubular cells is the major cause of the tubular atrophy, together with epithelial-mesenchymal transdifferentiation. Some criticisms on tout court semantic renal pelvis dilatation-obstruction connection have been raised considering that the renal pelvis expansion isn't, in any case, linked to an ostructive condition, as it may be verified by diuretic (furosemide) renogram together with scintiscan-based evaluation of differential renal function. In this regard, rather than repetitive invasive nuclear procedures that expose the children to ionizing radiations, an intriguing noninvasive strategy, based on the evaluation of urinary biomarkers and urinary proteome, can define the UPJO-related possible progress of parenchymal lesions, thus predicting which patients must require an obstruction correcting surgery and in which patients, instead, the hydronephrosis will spontaneously resolve.

Analysis of the dynamics of renal vascular resistance and urine flow rate in the cat following electrical stimulation of the renal nerves.

PubMed

Celler, B G; Stella, A; Golin, R; Zanchetti, A

1996-08-01

In ten sino aortic denervated, vagotomized and aneasthetized cats, renal efferent nerves were stimulated for 30 s with trains of constant current pulses at frequencies in the range 5-30 Hz. The arterial pressure, heart rate, urine flow rate (electronic drop counter) and renal blood flow (electromagnetic technique) were recorded. Subsequent computer processing gave the true means of renal artery pressure (MRAP) and renal blood flow (MRBF) and hence the renal vascular resistance (MRVR), over each cardiac cycle. Recovery of MRVR after the end of stimulation exhibited two distinct time constants. The fast component had a time constant of 2.03 +/- 0.26 s and represented 60.2 +/- 1.71% of the recovery. The time constant of the slower component was 14.1 +/- 1.9 s and represented 36.0 +/- 1.6% of the recovery. The relationship between MRVR and stimulus frequency was sigmoidal with maximum sensitivity at stimulus frequencies of 12.6 +/- 0.76 Hz. Changes in urine flow rate, in contrast, followed a hyperbolic function with maximum response sensitivity occurring at very low stimulus frequencies. Changes in urine flow rate were 50% complete at stimulus frequencies of 5 Hz. Identification of two distinct components in the relaxation phase of renal vascular resistance leads to a reasonable hypothesis that 60% of total renal vascular resistance may lie proximal to the glomerulus, whereas 36% may be accounted for by the efferent arterioles.

A patient with cystinosis presenting like bartter syndrome and review of literature.

PubMed

Ertan, Pelin; Evrengul, Havva; Ozen, Serkan; Emre, Sinan

2012-12-01

Nephropathic cystinosis is an autosomal recessively inherited metabolic disorder presenting with metabolic acidosis, Fanconi syndrome and renal failure. We present a 6-year-old girl with severe growth failure, hyponatremia and hypokalemia. Her parents were 4(th) degree relatives. Two relatives were diagnosed as end stage renal failure. She also had persistant hypokalemic hypochloremic metabolic alkalosis. Her renal function was normal at presentation. She was thought to have Bartter syndrome with supporting findings of elevated levels of renin and aldosterone with normal blood pressure, and hyperplasia of juxtaglomerular apparatus. Her metabolic alkalosis did not resolve despite supportive treatment. At 6(th) month of follow-up proteinuria, glucosuria and deterioration of renal function developed. Diagnosis of cystinosis was made with slit lamp examination and leukocyte cystine levels. At 12(th) month of follow-up her metabolic alkalosis has converted to metabolic acidosis. In children presenting with persistant metabolic alkalosis, with family history of renal failure, and parental consanguinity, cystinosis should always be kept in mind as this disease is an important cause of end stage renal failure which may have features mimmicking Bartter syndrome.

Device-based approaches for renal nerve ablation for hypertension and beyond.

PubMed

Thorp, Alicia A; Schlaich, Markus P

2015-01-01

Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented.

Device-based approaches for renal nerve ablation for hypertension and beyond

PubMed Central

Thorp, Alicia A.; Schlaich, Markus P.

2015-01-01

Animal and human studies have demonstrated that chronic activation of renal sympathetic nerves is critical in the pathogenesis and perpetuation of treatment-resistant hypertension. Bilateral renal denervation has emerged as a safe and effective, non-pharmacological treatment for resistant hypertension that involves the selective ablation of efferent and afferent renal nerves to lower blood pressure. However, the most recent and largest randomized controlled trial failed to confirm the primacy of renal denervation over a sham procedure, prompting widespread re-evaluation of the therapy's efficacy. Disrupting renal afferent sympathetic signaling to the hypothalamus with renal denervation lowers central sympathetic tone, which has the potential to confer additional clinical benefits beyond blood pressure control. Specifically, there has been substantial interest in the use of renal denervation as either a primary or adjunct therapy in pathological conditions characterized by central sympathetic overactivity such as renal disease, heart failure and metabolic-associated disorders. Recent findings from pre-clinical and proof-of-concept studies appear promising with renal denervation shown to confer cardiovascular and metabolic benefits, largely independent of changes in blood pressure. This review explores the pathological rationale for targeting sympathetic renal nerves for blood pressure control. Latest developments in renal nerve ablation modalities designed to improve procedural success are discussed along with prospective findings on the efficacy of renal denervation to lower blood pressure in treatment-resistant hypertensive patients. Preliminary evidence in support of renal denervation as a possible therapeutic option in disease states characterized by central sympathetic overactivity is also presented. PMID:26217232

Renal Function and Remission of Hypertension After Bariatric Surgery: a 5-Year Prospective Cohort Study.

PubMed

Neff, Karl J; Baud, Gregory; Raverdy, Violeta; Caiazzo, Robert; Verkindt, Helene; Noel, Christian; le Roux, Carel W; Pattou, François

2017-03-01

This study examines the effect of Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) on renal function for at least 5 years post-operatively in a tertiary referral center for bariatric surgery. This prospective cohort study of patients undergoing RYGB and LAGB measured renal function, blood pressure, and diabetes status pre-operatively and then 1 and 5 years post-operatively. Renal function was assessed using the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockcroft-Gault formulae. Hypertension and diabetes were defined by the European Society of Hypertension and European Society of Cardiology joint guidelines and American Diabetes Association guidelines, respectively. A sub-group who had completed 10 years post-operative follow-up was also included. Estimated glomerular filtration rate (eGFR) increased over 5 years after RYGB (N = 190; 94 ± 2 mL/min/1.73 m 2 to 102 ± 22 mL/min/1.73 m 2 , p = 0.01) and LAGB (N = 271; 88 ± 1 to 93 ± 22 mL/min/1.73 m 2 , p = 0.02). In a sub-group with up to 10 years post-operative date, this trend was maintained. In patients with renal impairment, eGFR improved over 5 years (52 ± 2 to 68 ± 7 mL/min/1.73 m 2 , p = 0.01). Remission of hypertension was greater after RYGB than LAGB at 1 year (32 vs. 16 %, p = 0.008) and at 5 years post-operatively (23 vs. 11 %, p = 0.02). Bariatric surgery stabilizes eGFR post-operatively for at least 5 years. In a sub-group with renal impairment, eGFR is increased in the first post-operative year and this is maintained for up to 5 years. RYGB is an effective procedure in achieving blood pressure control.

Fluid dynamic modelling of renal pelvic pressure during endoscopic stone removal

NASA Astrophysics Data System (ADS)

Oratis, Alexandros; Subasic, John; Bird, James; Eisner, Brian

2015-11-01

Endoscopic kidney stone removal procedures are known to increase internal pressure in the renal pelvis, the kidney's urinary collecting system. High renal pelvic pressure incites systemic absorption of irrigation fluid, which can increase the risk of postoperative fever and sepsis or the unwanted absorption of electrolytes. Urologists choose the appropriate surgical procedure based on patient history and kidney stone size. However, no study has been conducted to compare the pressure profiles of each procedure, nor is there a precise sense of how the renal pelvic pressure scales with various operational parameters. Here we develop physical models for the flow rates and renal pelvic pressure for various procedures. We show that the results of our models are consistent with existing urological data on each procedure and that the models can predict pressure profiles where data is unavailable.

Effect of weight loss after Roux-en-Y gastric bypass, on renal function and blood pressure in morbidly obese patients.

PubMed

Serpa Neto, Ary; Bianco Rossi, Felipe Martin; Dal Moro Amarante, Rodrigo; Alves Buriti, Nara; Cunha Barbosa Saheb, Gabriel; Rossi, Marçal

2009-01-01

Morbid obesity (MO) is associated with increased renal plasma flow (RPL) and glomerular filtration rate (GFR). This type of obesity usually does not respond to medical treatment, with bariatric surgery being the current treatment of choice. The present study aimed to evaluate whether weight loss may reverse the glomerular hyperfiltration of MO patients. This was a retrospective study of 140 patients submitted to Roux-en-Y gastric bypass (31.5% men, mean body mass index 46.17 +/- 5). Renal glomerular function and anthropometric and biochemical parameters were studied in patients before and 8 months after the surgery. GFR was determined by 24-hour urine samples. In the obese group, GFR before surgery was 148.7 +/- 35.2 ml/min. After the weight loss, GFR decreased to 113.8 +/- 31.7 ml/min (p<0.0001). Homeostasis model assessment-insulin resistance and glycosylated hemoglobin values were higher in MO with hyperfiltration. Weight loss was associated with reduction in blood pressure and GFR. It was found that the variation in systolic and diastolic blood pressure was a predictor of change in GFR. This study shows that obesity-related glomerular hyperfiltration ameliorates after weight loss. The improvement in hyperfiltration may prevent the development.

Hypertension: physiology and pathophysiology.

PubMed

Hall, John E; Granger, Joey P; do Carmo, Jussara M; da Silva, Alexandre A; Dubinion, John; George, Eric; Hamza, Shereen; Speed, Joshua; Hall, Michael E

2012-10-01

Despite major advances in understanding the pathophysiology of hypertension and availability of effective and safe antihypertensive drugs, suboptimal blood pressure (BP) control is still the most important risk factor for cardiovascular mortality and is globally responsible for more than 7 million deaths annually. Short-term and long-term BP regulation involve the integrated actions of multiple cardiovascular, renal, neural, endocrine, and local tissue control systems. Clinical and experimental observations strongly support a central role for the kidneys in the long-term regulation of BP, and abnormal renal-pressure natriuresis is present in all forms of chronic hypertension. Impaired renal-pressure natriuresis and chronic hypertension can be caused by intrarenal or extrarenal factors that reduce glomerular filtration rate or increase renal tubular reabsorption of salt and water; these factors include excessive activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, increased formation of reactive oxygen species, endothelin, and inflammatory cytokines, or decreased synthesis of nitric oxide and various natriuretic factors. In human primary (essential) hypertension, the precise causes of impaired renal function are not completely understood, although excessive weight gain and dietary factors appear to play a major role since hypertension is rare in nonobese hunter-gathers living in nonindustrialized societies. Recent advances in genetics offer opportunities to discover gene-environment interactions that may also contribute to hypertension, although success thus far has been limited mainly to identification of rare monogenic forms of hypertension. © 2012 American Physiological Society

Renal artery stenting in a 2-year-old child with resistant hypertension and neurofibromatosis.

PubMed

Varghese, Kiron; Adhyapak, Srilakshmi M; Lohitashwa, S B; Pais, Priya; Iyengar, Arpana A

2017-07-01

The occurrence of vascular lesions in neurofibromatosis is uncommon but well documented. These vascular lesions when present, occur predominantly in the kidneys, endocrine glands, heart and gastrointestinal tract, causing stenosis or obliteration of the lumen. We report a case of uncontrolled resistant hypertension in a 2-year-old child presenting with neurofibromatosis who was found to have a high-grade ostial left renal artery stenosis and obliteration of the right renal artery. As the right kidney was small and hypo-functioning, and its renal artery was totally occluded, we subjected the child to a left renal angioplasty and bailout stenting. Following stenting, the blood pressure decreased with anti-hypertensive treatment. Based on a review of the literature, and to the best of our knowledge, this is the youngest child to have undergone renal artery stenting.

Mixed compared with single-source proteins in high-protein diets affect kidney structure and function differentially in obese fa/fa Zucker rats.

PubMed

Devassy, Jessay G; Wojcik, Jennifer L; Ibrahim, Naser H M; Zahradka, Peter; Taylor, Carla G; Aukema, Harold M

2017-02-01

Questions remain regarding the potential negative effects of dietary high protein (HP) on kidney health, particularly in the context of obesity in which the risk for renal disease is already increased. To examine whether some of the variability in HP effects on kidney health may be due to source of protein, obese fa/fa Zucker rats were given HP (35% of energy from protein) diets containing either casein, soy protein, or a mixed source of animal and plant proteins for 12 weeks. Control lean and obese rats were given diets containing casein at normal protein (15% of energy from protein) levels. Body weight and blood pressure were measured, and markers of renal structural changes, damage, and function were assessed. Obesity alone resulted in mild renal changes, as evidenced by higher kidney weights, proteinuria, and glomerular volumes. In obese rats, increasing the protein level using the single, but not mixed, protein sources resulted in higher renal fibrosis compared with the lean rats. The mixed-protein HP group also had lower levels of serum monocyte chemoattractant protein-1, even though this diet further increased kidney and glomerular size. Soy and mixed-protein HP diets also resulted in a small number of damaged glomeruli, while soy compared with mixed-protein HP diet delayed the increase in blood pressure over time. Since obesity itself confers added risk of renal disease, an HP diet from mixed-protein sources that enables weight loss but has fewer risks to renal health may be advantageous.

The giraffe kidney tolerates high arterial blood pressure by high renal interstitial pressure and low glomerular filtration rate.

PubMed

Damkjaer, M; Wang, T; Brøndum, E; Østergaard, K H; Baandrup, U; Hørlyck, A; Hasenkam, J M; Smerup, M; Funder, J; Marcussen, N; Danielsen, C C; Bertelsen, M F; Grøndahl, C; Pedersen, M; Agger, P; Candy, G; Aalkjaer, C; Bie, P

2015-08-01

The tallest animal on earth, the giraffe (Giraffa camelopardalis) is endowed with a mean arterial blood pressure (MAP) twice that of other mammals. The kidneys reside at heart level and show no sign of hypertension-related damage. We hypothesized that a species-specific evolutionary adaption in the giraffe kidney allows normal for size renal haemodynamics and glomerular filtration rate (GFR) despite a MAP double that of other mammals. Fourteen anaesthetized giraffes were instrumented with vascular and bladder catheters to measure glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). Renal interstitial hydrostatic pressure (RIHP) was assessed by inserting a needle into the medullary parenchyma. Doppler ultrasound measurements provided renal artery resistive index (RI). Hormone concentrations as well as biomechanical, structural and histological characteristics of vascular and renal tissues were determined. GFR averaged 342 ± 99 mL min(-1) and ERPF 1252 ± 305 mL min(-1) . RIHP varied between 45 and 140 mmHg. Renal pelvic pressure was 39 ± 2 mmHg and renal venous pressure 32 ± 4 mmHg. A valve-like structure at the junction of the renal and vena cava generated a pressure drop of 12 ± 2 mmHg. RI was 0.27. The renal capsule was durable with a calculated burst pressure of 600 mmHg. Plasma renin and AngII were 2.6 ± 0.5 mIU L(-1) and 9.1 ± 1.5 pg mL(-1) respectively. In giraffes, GFR, ERPF and RI appear much lower than expected based on body mass. A strong renal capsule supports a RIHP, which is >10-fold that of other mammals effectively reducing the net filtration pressure and protecting against the high MAP. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Correlation of 24-Hour Blood Pressure and Heart Rate Variability to Renal Function Parameters in Hypertensive Patients. The Effect of Smoking.

PubMed

Liakos, Charalampos I; Karpanou, Eva A; Markou, Maria I; Grassos, Charalampos A; Vyssoulis, Gregory P

2015-12-01

Intrarenal hemodynamics depend on blood pressure (BP), heart rate (HR), and smoking. Although BP levels have been associated with kidney function, the effect of HR levels, BP, and HR variability on renal function are less well clarified. This cross-sectional study sought to determine the association of 24-hour BP and HR variability with kidney function in hypertensive patients, stratified by smoking. The study comprised 9600 nondiabetic, never-treated hypertensive individuals without evident renal impairment examined from 1985 to 2014 (aged 53.3±13.4 years, 55.3% males). The 24-hour systolic BP (SBP) and HR variability were estimated via their coefficient of variation (CV =standard deviation×100/mean value) derived from ambulatory recording. The CV SBP-to-CV HR ratio (CV R) was used as a marker of the interplay between 24-hour SBP and HR variability. Renal function was estimated via 24-hour urine creatinine clearance (CrCl), estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), and 24-hour urine α1 -microglobulin. After adjustment for age, sex, and smoking, CV SBP was found to be weakly correlated to eGFR (r=-0.017, P=.1) and somewhat more strongly to CrCl, ACR, and α1 -microglobulin (r=-0.032, 0.072, and 0.065; P=.002, <.001 and <.001, respectively). CV HR was much better related to renal function, with stronger adjusted correlations to CrCl, eGFR, ACR, and α1 -microglobulin (r=0.185, 0.134, -0.306, -0.247; all P<.001, respectively). CV R also showed equally good adjusted correlations (r=-0.175, -0.125, 0.336, 0.262; all P<.001, respectively). Most adjusted correlations for CV HR and CV R were even better in smokers (r=0.213, 0.158, -0.332, -0.272 and -0.183, -0.118, 0.351, 0.275, respectively; all P<.001). CV HR and CV R emerge as better related to kidney function than CV SBP, especially in smokers. The correlation of CV HR and CV SBP to renal function is inverse to each other. ACR and α1 -microglobulin are better related to variability indices than CrCl and eGFR. However, causal relations cannot be proved. © 2015 Wiley Periodicals, Inc.

Efficacy and Safety of Renal Sympathetic Denervation on Dogs with Pressure Overload-Induced Heart Failure.

PubMed

Chen, Pingan; Leng, Shuilong; Luo, Yishan; Li, Shaonan; Huang, Zicheng; Liu, Zhenxi; Liu, Zhen; Wang, Jie; Lei, Xiaoming

2017-02-01

In dogs with heart failure (HF) induced by overload pressure, the role of renal sympathetic denervation (RSD) on heart failure and in the renal artery is unclear. Therefore, we investigated the efficacy and safety of RSD in dogs with pressure overload-induced heart failure. Twenty mongrel dogs were divided into a sham-operated group, an HF group and an HF + RSD group. In the sham-operated group, the abdominal aorta was located but was not constricted, in the HF group, the abdominal aorta was constricted without RSD, and the HF+RSD group underwent RSD with constriction of the abdominal aorta after 10 weeks. Blood sampling assays, echocardiography, intravascular ultrasound (IVUS) measurement and histopathological examination were performed. Renal sympathetic denervation caused a significant reduction in the levels of noradrenaline (166.62±6.84 vs. 183.48±13.66 pg/ml, P<0.05), plasma renin activity (1.93±0.12 vs. 2.10±0.13 ng/mlh, P<0.05) and B-type natriuretic peptide (71.14±3.86 vs. 83.15±5.73 pg/ml, P<0.05) at eight weeks after RSD in the HF+RSD group. Compared with the HF group at eight weeks, the left ventricular internal dimension at end-diastole and end-systole were lower and the left ventricular ejection fraction was higher (all P<0.05) at eight weeks after RSD in the HF+RSD group. Intravenous ultrasound images showed no changes in the renal artery lumen, and intimal hyperplasia and vascular lumen stenosis were not observed after RSD. Renal sympathetic denervation could improve cardiac function in dogs with HF induced by pressure overload; RSD had no adverse influence on the renal artery. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Residual Renal Function in Children Treated with Chronic Peritoneal Dialysis

PubMed Central

Roszkowska-Blaim, Maria

2013-01-01

Residual renal function (RRF) in patients with end-stage renal disease (ESRD) receiving renal replacement therapy is defined as the ability of native kidneys to eliminate water and uremic toxins. Preserved RRF improves survival and quality of life in adult ESRD patients treated with peritoneal dialysis. In children, RRF was shown not only to help preserve adequacy of renal replacement therapy but also to accelerate growth rate, improve nutrition and blood pressure control, reduce the risk of adverse myocardial changes, facilitate treatment of anemia and calcium-phosphorus balance abnormalities, and result in reduced serum and dialysate fluid levels of advanced glycation end-products. Factors contributing to RRF loss in children treated with peritoneal dialysis include the underlying renal disease such as hemolytic-uremic syndrome and hereditary nephropathy, small urine volume, severe proteinuria at the initiation of renal replacement therapy, and hypertension. Several approaches can be suggested to decrease the rate of RRF loss in pediatric patients treated with chronic peritoneal dialysis: potentially nephrotoxic drugs (e.g., aminoglycosides), episodes of hypotension, and uncontrolled hypertension should be avoided, urinary tract infections should be treated promptly, and loop diuretics may be used to increase salt and water excretion. PMID:24376376

Renoprotective Effects of Vitex megapotamica (Spreng.) Moldenke in C57BL/6 LDLr-Null Mice Undergoing High Fat Diet

PubMed Central

Araújo, Valdinei de Oliveira; Gasparotto, Francielly Mourão; Pires, Vanessa Aranega; Maciel, Aline Antunes; Ortmann, Caroline Flach; Cardozo Junior, Euclides Lara; Lourenço, Emerson Luiz Botelho; Gasparotto Junior, Arquimedes

2015-01-01

Although Vitex megapotamica (Spreng.) Moldenke is used in Brazilian folk medicine as hypolipidemic drug no study has been conducted to evaluate the effects of this species in an experimental model of atherosclerosis. So, the aim of this study was to evaluate the possible renoprotective activity of methanolic extract obtained from Vitex megapotamica (MEVM) using C57BL/6 LDLr-null mice submitted to high fat diet (HFD). MEVM was orally administered at doses of 30, 100, and 300 mg/kg, for three weeks, starting from the 2nd week of HFD. Systolic blood pressure (SBP) and diuretic activity were measured weekly. At the end of experiments the serum lipids, atherogenic index serum (AIS), oxidative stress, and markers of renal function were determined. HFD induced a significant increase in the systolic blood pressure, dyslipidemia, increase in AIS, and lipid peroxidation accompanied by an important reduction in renal function. Treatment with MEVM was able to prevent increase in SBP, total cholesterol, triglycerides, AIS, urea, and creatinine levels in LDLr-null mice. These effects were accompanied by a significant reduction in oxidative stress and renal injury. The data reported here support the potential of Vitex megapotamica as candidate to be an herbal medicine used in cardiovascular or renal diseases. PMID:25788962

Renal Failure in Mice with Gsα Deletion in Juxtaglomerular Cells

PubMed Central

Chen, Limeng; Faulhaber-Walter, Robert; Wen, Yubing; Huang, Yuning; Mizel, Diane; Chen, Min; Sequeira Lopez, Maria Luisa; Weinstein, Lee S.; Gomez, R. Ariel; Briggs, Josephine P.; Schnermann, Jurgen

2010-01-01

Background Mice with deletion of Gsα in renin-producing cells (RC/FF mice) have been shown to have greatly reduced renin production and lack of responsiveness of renin secretion to acute stimuli. In addition, young RC/FF mice are hypotensive and have a vasopressin-resistant concentrating defect. In the present study we have determined the long-term effect on renal function, blood pressure, and renal pathology in this low renin and diuretic mouse model. Methods and Results Urine osmolarity of RC/FF mice was decreased in all age groups. GFR measured at 7, 14 and 20 weeks of age declined progressively. Single nephron GFR similarly declined while fractional proximal fluid absorption was maintained. Expression levels of extracellular matrix proteins (collagen I, IV and fibronectin) and α-smooth muscle actin were increased in kidneys of RC/FF mice at 20 weeks, and this was accompanied by focal segmental glomerulosclerosis and periglomerular interstitial fibrosis. RC/FF mice showed a progressive reduction of body weight, an increase in urine albumin excretion, and an increase of blood pressure with aging. Conclusion A chronic reduction of renin production in mice may be a risk factor in its own right, and does not protect renal function against the profibrotic influence of a chronically elevated urine flow. PMID:20551626

Clinical value of natriuretic peptides in chronic kidney disease.

PubMed

Santos-Araújo, Carla; Leite-Moreira, Adelino; Pestana, Manuel

2015-01-01

According to several lines of evidence, natriuretic peptides (NP) are the main components of a cardiac-renal axis that operate in clinical conditions of decreased cardiac hemodynamic tolerance to regulate sodium homeostasis, blood pressure and vascular function. Even though it is reasonable to assume that NP may exert a relevant role in the adaptive response to renal mass ablation, evidence gathered so far suggest that this contribution is probably complex and dependent on the type and degree of the functional mass loss. In the last years NP have been increasingly used to diagnose, monitor treatment and define the prognosis of several cardiovascular (CV) diseases. However, in many clinical settings, like chronic kidney disease (CKD), the predictive value of these biomarkers has been questioned. In fact, it is now well established that renal function significantly affects the plasmatic levels of NP and that renal failure is the clinical condition associated with the highest plasmatic levels of these peptides. The complexity of the relation between NP plasmatic levels and CV and renal functions has obvious consequences, as it may limit the predictive value of NP in CV assessment of CKD patients and be a demanding exercise for clinicians involved in the daily management of these patients. This review describes the role of NP in the regulatory response to renal function loss and addresses the main factors involved in the clinical valorization of the peptides in the context of significant renal failure. Copyright © 2015 The Authors. Published by Elsevier España, S.L.U. All rights reserved.

Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits.

PubMed

Schiller, Alicia M; Pellegrino, Peter R; Zucker, Irving H

2016-01-15

Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits. Copyright © 2016 the American Physiological Society.

Production and actions of the anandamide metabolite prostamide E2 in the renal medulla.

PubMed

Ritter, Joseph K; Li, Cao; Xia, Min; Poklis, Justin L; Lichtman, Aron H; Abdullah, Rehab A; Dewey, William L; Li, Pin-Lan

2012-09-01

Medullipin has been proposed to be an antihypertensive lipid hormone released from the renal medulla in response to increased arterial pressure and renal medullary blood flow. Because anandamide (AEA) possesses characteristics of this purported hormone, the present study tested the hypothesis that AEA or one of its metabolites represents medullipin. AEA was demonstrated to be enriched in the kidney medulla compared with cortex. Western blotting and enzymatic analyses of renal cortical and medullary microsomes revealed opposite patterns of enrichment of two AEA-metabolizing enzymes, with fatty acid amide hydrolase higher in the renal cortex and cyclooxygenase-2 (COX-2) higher in the renal medulla. In COX-2 reactions with renal medullary microsomes, prostamide E2, the ethanolamide of prostaglandin E₂, was the major product detected. Intramedullarily infused AEA dose-dependently increased urine volume and sodium and potassium excretion (15-60 nmol/kg/min) but had little effect on mean arterial pressure (MAP). The renal excretory effects of AEA were blocked by intravenous infusion of celecoxib (0.1 μg/kg/min), a selective COX-2 inhibitor, suggesting the involvement of a prostamide intermediate. Plasma kinetic analysis revealed longer elimination half-lives for AEA and prostamide E2 compared with prostaglandin E₂. Intravenous prostamide E2 reduced MAP and increased renal blood flow (RBF), actions opposite to those of angiotensin II. Coinfusion of prostamide E2 inhibited angiotensin II effects on MAP and RBF. These results suggest that AEA and/or its prostamide metabolites in the renal medulla may represent medullipin and function as a regulator of body fluid and MAP.

Effect of sodium overload on renal function of offspring from diabetic mothers.

PubMed

Rocco, Luigi; Gil, Frida Zaladek; da Fonseca Pletiskaitz, Thaís Maria; de Fátima Cavanal, Maria; Gomes, Guiomar Nascimento

2008-11-01

The aim if this study was to evaluate the effect of sodium overload on blood pressure and renal function in the offspring of diabetic rat mothers. Diabetes was induced with a single dose of streptozotocin before mating. Experimental groups were control (C), offspring from diabetic mother (D), control with sodium chloride (NaCl) overload (CS), and offspring from diabetic mother submitted to NaCl overload (DS). After weaning, all groups received food ad libitum; groups C and D had water ad libitum, and CS and DS received NaCl 0.15 M as drinking water. Renal morphology and function were evaluated in 3-month-old rats. Glomerular area, macrophage infiltration, interlobular artery wall thickness, and renal vascular resistance were significantly increased in CS, D, and DS compared with C. Renal plasma flow (RPF) and glomerular filtration rate (GFR) were decreased in CS and D compared with C. In DS, GFR and fractional filtration were increased, suggesting a state of hyperfiltration. Hypertension was observed in groups D, CS, and DS from 2 months on and was more severe in DS. Our data suggest that diabetes during intrauterine development and salt overload beginning at an early age can cause hypertension and renal injury. When these conditions were associated, morphological and functional changes were much more intense, suggesting acceleration in the process of kidney injury.

Renal functional reserve and renal hemodynamics in hypertensive patients.

PubMed

Gaipov, Abduzhappar; Solak, Yalcin; Zhampeissov, Nurlan; Dzholdasbekova, Aliya; Popova, Nadezhda; Molnar, Miklos Z; Tuganbekova, Saltanat; Iskandirova, Elmira

2016-10-01

The renal functional reserve (RFR) is the ability of the kidneys to increase renal plasma flow and glomerular filtration rate (GFR) in response to protein intake. It is a measure of functional and anatomic integrity of nephrons. It is not known what relation between RFR and kidney Doppler parameters. We aimed to study the relation between the RFR and renal hemodynamic parameters in hypertensive patients with and without nephropathy who had normal kidney function. Twenty-four hypertensive subjects with nephropathy (HTN-n, n = 10) and hypertension without nephropathy (HTN, n = 14) were included in the study. Control group included 11 healthy subjects. Baseline GFR (GFR1) and GFR after intake of egg protein 1 mg/kg of body weight were determined (GFR2). RFR was calculated by the following formula: (GFR2-GFR1)/GFR1 × 100%. Doppler ultrasonography was performed. Arterial blood pressure (BP), body mass index (BMI), and estimated GFR were also recorded. HTN and HTN-n groups had impaired levels of RFR compared with controls (p < 0.05), significantly decreased value of flow velocity parameters (Vmax, Vmin), and increased RRI compared with controls. There was significant negative correlation of RFR with blood pressure levels (sBP, r = -0.435, p = 0.009; dBP, r = -0.504, p = 0.002), RRI (r = -0.456, p = 0.008), micro albuminuria (MAU, r = -0.366, p = 0.031) and positive correlation with Vmax and Vmin (r = 0.556, p = 0.001 and r = 0.643, respectively, p < 0.001). Linear regression showed that RRI and MAU were independent predictors of decreased RFR. RFR is lower in hypertensive patients despite near-normal level of kidney function and is related to particular level of BP. RRI and MAU were independent predictors of decreased RFR.

What is the relationship between renal function and visit-to-visit blood pressure variability in primary care? Retrospective cohort study from routinely collected healthcare data.

PubMed

Lasserson, Daniel S; Scherpbier de Haan, Nynke; de Grauw, Wim; van der Wel, Mark; Wetzels, Jack F; O'Callaghan, Christopher A

2016-06-10

To determine the relationship between renal function and visit-to-visit blood pressure (BP) variability in a cohort of primary care patients. Retrospective cohort study from routinely collected healthcare data. Primary care in Nijmegen, the Netherlands, from 2007 to 2012. 19 175 patients who had a measure of renal function, and 7 separate visits with BP readings in the primary care record. Visit-to-visit variability in systolic BP, calculated from the first 7 office measurements, including SD, successive variation, absolute real variation and metrics of variability shown to be independent of mean. Multiple linear regression was used to analyse the influence of estimated glomerular filtration rate (eGFR) on BP variability measures with adjustment for age, sex, diabetes, mean BP, proteinuria, cardiovascular disease, time interval between measures and antihypertensive use. In the patient cohort, 57% were women, mean (SD) age was 65.5 (12.3) years, mean (SD) eGFR was 75.6 (18.0) mL/min/1.73m(2) and SD systolic BP 148.3 (21.4) mm Hg. All BP variability measures were negatively correlated with eGFR and positively correlated with age. However, multiple linear regressions demonstrated consistent, small magnitude negative relationships between eGFR and all measures of BP variability adjusting for confounding variables. Worsening renal function is associated with small increases in measures of visit-to-visit BP variability after adjustment for confounding factors. This is seen across the spectrum of renal function in the population, and provides a mechanism whereby chronic kidney disease may raise the risk of cardiovascular events. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Estimation of pressure gradients at renal artery stenoses

NASA Astrophysics Data System (ADS)

Yim, Peter J.; Cebral, Juan R.; Weaver, Ashley; Lutz, Robert J.; Vasbinder, G. Boudewijn C.

2003-05-01

Atherosclerotic disease of the renal artery can reduce the blood flow leading to renovascular hypertension and ischemic nephopathy. The kidney responds to a decrease in blood flow by activation of the renin-angiotensin system that increases blood pressure and can result in severe hypertension. Percutaneous translumenal angioplasty (PTA) may be indicated for treatment of renovascular hypertension (RVH). However, direct measurement of renal artery caliber and degree of stenosis has only moderate specificity for detection of RVH. A confounding factor in assessment of the proximal renal artery is that diffuse atherosclerotic disease of the distal branches of the renal artery can produce the same effect on blood-flow as atherosclerotic disease of the proximal renal artery. A methodology is proposed for estimation of pressure gradients at renal artery stenoses from magnetic resonance imaging that could improve the evaluation of renal artery disease. In the proposed methodology, pressure gradients are estimated using computational fluid dynamics (CFD) modeling. Realistic CFD models are constructed from images of vessel shape and measurements of blood-flow rates which are available from magnetic resonance angiography (MRA) and phase-contrast magnetic resonance (MR) imaging respectively. CFD measurement of renal artery pressure gradients has been validated in a physical flow-through model.

Capsulotomy for treatment of compartment syndrome in patients with post extracorporeal shock wave lithotripsy renal hematomas: safe and effective, but also advisable?

PubMed

Al Ghazal, Andreas; Schnoeller, Thomas J; Baechle, Christian; Steinestel, Julie; Jentzmik, Florian; Steffens, Sandra; Hirning, Christian; Schrader, Mark; Schrader, Andres J

2014-07-08

To examine whether surgical decompression of hematomas by capsulotomy can help to improve long-term renal function following extracorporeal shock wave lithotripsy (SWL). This study retrospectively identified 7 patients who underwent capsulotomy for post SWL renal hematomas between 2008 and 2012. The control group comprised 8 conservatively treated patients. The median follow-up time was 22 months. The two groups were comparable in age, gender, body mass index, risk factors for developing hematomas (renal failure, urinary flow impairment, indwelling ureteral stent and diabetes mellitus) and the selected SWL modalities. Hematoma size was also similar. However, significantly more patients in the surgical group had purely intracapsular hematomas (85.7% vs. 37.5%) without a potentially pressure-relieving capsular rupture. There were no significant differences in the post-interventional drop in hemoglobin, rise in retention parameters or drop in glomerular filtration rate (GFR). No capsulotomy-related complications were observed, but surgery required a significantly longer hospital stay than conservative management (median, 9 days vs. 5 days). The two groups also showed comparable recovery of renal function at long-term follow-up (median change in GFR from baseline, 97.1% and 97.8%, respectively). Since renal function did not differ between the two treatment groups, the conservative management remains the standard treatment for post-SWL renal hematoma.

Assessment of myocardial mechanics in patients with end-stage renal disease and renal transplant recipients using speckle tracking echocardiography.

PubMed

Pirat, Bahar; Bozbas, Huseyin; Simsek, Vahide; Sade, L Elif; Sayin, Burak; Muderrisoglu, Haldun; Haberal, Mehmet

2015-04-01

Velocity vector imaging allows quantitation of myocardial strain and strain rate from 2-dimensional images based on speckle tracking echocardiography. The aim of this study was to analyze the changes in myocardial strain and strain rate patterns in patients with end-stage renal disease and renal transplant recipients. We studied 33 patients with end-stage renal disease on hemodialysis (19 men; mean age, 36 ± 8 y), 24 renal transplant recipients with functional grafts (21 men; mean age, 36 ± 7 y) and 26 age- and sex-matched control subjects. Longitudinal peak systolic strain and strain rate for basal, mid, and apical segments of the left ventricular wall were determined by velocity vector imaging from apical 4- and 2-chamber views. The average longitudinal strain and strain rate for the left ventricle were noted. From short-axis views at the level of papillary muscles, average circumferential, and radial strain, and strain rate were assessed. Mean heart rate and systolic and diastolic blood pressure during imaging were similar between the groups. Longitudinal peak systolic strain and strain rate at basal and mid-segments of the lateral wall were significantly higher in renal transplant recipients and control groups than endstage renal disease patients. Average longitudinal systolic strain from the 4-chamber view was highest in control subjects (-14.5% ± 2.9%) and was higher in renal transplant recipients (-12.5% ± 3.0%) than end-stage renal disease patients (-10.2% ± 1.6%; P ≤ .001). Radial and circumferential strain and strain rate at the level of the papillary muscle were lower in patients with end-stage renal disease than other groups. Differences in myocardial function in patients with end-stage renal disease, renal transplant recipients, and normal controls can be quantified by strain imaging. Myocardial function is improved in renal transplant recipients compared with end-stage renal disease patients.

LDL-oxidation, serum uric acid, kidney function and pulse-wave velocity: Data from the Brisighella Heart Study cohort.

PubMed

Cicero, Arrigo F G; Kuwabara, Masanari; Johnson, Richard; Bove, Marilisa; Fogacci, Federica; Rosticci, Martina; Giovannini, Marina; D'Addato, Sergio; Borghi, Claudio

2018-06-15

Serum uric acid (SUA) and oxidized LDL (oxLDL) may be associated with arterial aging. The aim of our study was to evaluate the relationship between SUA, oxLDL and arterial stiffness in subjects with normal renal function and in patients with mild or moderate renal impairment. From the database of the 2012 Brisighella Heart Study, we compared age-matched adult, non-smoker subjects without cardiovascular disease and with normal renal function (n = 205), subjects with stage II chronic kidney disease (CKD) (n = 118) and subjects with stage III CKD (n = 94). All subjects underwent a determination of the LDL oxidative susceptibility, oxLDL levels, SUA and Pulse Wave Velocity (PWV). By univariate analysis, PWV correlated with a large number of clinical, haemodynamic and metabolic parameters, including estimated glomerular filtration rate (eGFR) in subjects with normal renal function and in those with stage II or III CKD. Stepwise multiple regression analyses showed that in the presence of normal renal function or stage II CKD, the main predictors of PWV were age, systolic blood pressure (SBP), ox-LDL, apolipoprotein B and SUA (p < 0.05), while in the presence of stage III CKD only age, SBP and apolipoprotein B remained significant (p < 0.05). Both ox-LDL and SUA independently predicts PWV only in subjects with normal or mildly reduced renal function, but not in the subjects with more compromised eGFR. This study confirms the complex relationship of SUA with cardiovascular and metabolic disease in the patient with established renal disease. Copyright © 2018 Elsevier B.V. All rights reserved.

Role of pressure in angiotensin II-induced renal injury: chronic servo-control of renal perfusion pressure in rats.

PubMed

Mori, Takefumi; Cowley, Allen W

2004-04-01

Renal perfusion pressure was servo-controlled chronically in rats to quantify the relative contribution of elevated arterial pressure versus angiotensin II (Ang II) on the induction of renal injury in Ang II-induced hypertension. Sprague-Dawley rats fed a 4% salt diet were administered Ang II for 14 days (25 ng/kg per minute IV; saline only for sham rats), and the renal perfusion pressure to the left kidney was continuously servo-controlled to maintain a normal pressure in that kidney throughout the period of hypertension. An aortic occluder was implanted around the aorta between the two renal arteries and carotid and femoral arterial pressure were measured continuously throughout the experiment to determine uncontrolled and controlled renal perfusion pressure, respectively. Renal perfusion pressure of uncontrolled, controlled, and sham kidneys over the period of Ang II or saline infusion averaged 152.6+/-7.0, 117.4+/-3.5, and 110.7+/-2.2 mm Hg, respectively. The high-pressure uncontrolled kidneys exhibited tubular necrosis and interstitial fibrosis, especially prominent in the outer medullary region. Regional glomerular sclerosis and interlobular artery injury were also pronounced. Controlled kidneys were significantly protected from interlobular artery injury, juxtamedullary glomeruli injury, tubular necrosis, and interstitial fibrosis as determined by comparing the level of injury. Glomerular injury was not prevented in the outer cortex. Transforming growth factor (TGF)-beta and active NF-kappaB proteins determined by immunohistochemistry were colocalized in the uncontrolled kidney in regions of interstitial fibrosis. We conclude that the preferential juxtamedullary injury found in Ang II hypertension is largely induced by pressure and is probably mediated through the TGF-beta and NF-kappaB pathway.

Medical therapy is best for atherosclerotic renal artery stenosis: Arguments for.

PubMed

Annigeri, R A

2012-01-01

Atherosclerotic renal artery stenosis (ARAS) is a common condition that causes hypertension and reduction in the glomerular filtration rate and is an independent risk factor for death. Despite high technical success, the clinical benefit of renal artery (RA) angioplasty with stenting in ARAS remains doubtful. The published randomized clinical trials provide no support for the notion that renal angioplasty with stenting significantly improves blood pressure, preserves renal function, or reduces episodes of congestive heart failure in patients with ARAS. RA stenting is associated with procedure-related morbidity and mortality. Agents to block the renin-angiotensin-aldosterone system improve outcome and should be a part of a multifaceted medical regimen in ARAS. Medical therapy effectively controls atherosclerotic renovascular disease at all levels of vasculature and hence is the best therapy for ARAS.

The effects of environmental chemicals on renal function.

PubMed

Kataria, Anglina; Trasande, Leonardo; Trachtman, Howard

2015-10-01

The global incidence of chronic kidney disease (CKD) is increasing among individuals of all ages. Despite advances in proteomics, genomics and metabolomics, there remains a lack of safe and effective drugs to reverse or stabilize renal function in patients with glomerular or tubulointerstitial causes of CKD. Consequently, modifiable risk factors that are associated with a progressive decline in kidney function need to be identified. Numerous reports have documented the adverse effects that occur in response to graded exposure to a wide range of environmental chemicals. This Review summarizes the effects of such chemicals on four aspects of cardiorenal function: albuminuria, glomerular filtration rate, blood pressure and serum uric acid concentration. We focus on compounds that individuals are likely to be exposed to as a consequence of normal consumer activities or medical treatment, namely phthalates, bisphenol A, polyfluorinated alkyl acids, dioxins and furans, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. Environmental exposure to these chemicals during everyday life could have adverse consequences on renal function and might contribute to progressive cumulative renal injury over a lifetime. Regulatory efforts should be made to limit individual exposure to environmental chemicals in an attempt to reduce the incidence of cardiorenal disease.

The effects of environmental chemicals on renal function

PubMed Central

Kataria, Anglina; Trasande, Leonardo; Trachtman, Howard

2015-01-01

The global incidence of chronic kidney disease (CKD) is increasing among individuals of all ages. Despite advances in proteomics, genomics and metabolomics, there remains a lack of safe and effective drugs to reverse or stabilize renal function in patients with glomerular or tubulointerstitial causes of CKD. Consequently, modifiable risk factors that are associated with a progressive decline in kidney function need to be identified. Numerous reports have documented the adverse effects that occur in response to graded exposure to a wide range of environmental chemicals. This Review summarizes the effects of such chemicals on four aspects of cardiorenal function: albuminuria, glomerular filtration rate, blood pressure and serum uric acid concentration. We focus on compounds that individuals are likely to be exposed to as a consequence of normal consumer activities or medical treatment, namely phthalates, bisphenol A, polyfluorinated alkyl acids, dioxins and furans, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. Environmental exposure to these chemicals during everyday life could have adverse consequences on renal function and might contribute to progressive cumulative renal injury over a lifetime. Regulatory efforts should be made to limit individual exposure to environmental chemicals in an attempt to reduce the incidence of cardiorenal disease. PMID:26100504

Effects of complete water fasting and regeneration diet on kidney function, oxidative stress and antioxidants.

PubMed

Mojto, V; Gvozdjakova, A; Kucharska, J; Rausova, Z; Vancova, O; Valuch, J

2018-01-01

The aim of the study was to observe the influence of 11-days complete water fasting (WF) and regeneration diet (RD) on renal function, body weight, blood pressure and oxidative stress. Therapeutic WF is considered a healing method. Ten volunteers drank only water for 11 days, followed by RD for the next 11 days. Data on body weight, blood pressure, kidney functions, antioxidants, lipid peroxidation, cholesterols, triacylglycerols and selected biochemical parameters were obtained. WF increased uric acid and creatinine and decreased glomerular filtration rate. After RD, the parameters were comparable to baseline values. Urea was not affected. Lipid peroxidation (TBARS) decreased and maintained stable after RD. Fasting decreased α-tocopherol and increased γ-tocopherol, no significant changes were found after RD. Coenzyme Q10 decreased after RD. HDL-cholesterol decreased in WF. Total- and LDL-cholesterol decreased after RD. Other biochemical parameters were within the range of reference values. The effect of the complete fasting on kidney function was manifested by hyperuricemia. Renal function was slightly decreased, however maintained within the reference values. After RD, it returned to baseline values. The positive effect of the complete water fasting was in the reduction of oxidative stress, body weight and blood pressure (Tab. 3, Ref. 25).

Anatomic partial nephrectomy: technique evolution.

PubMed

Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

2015-03-01

Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

Swimming exercise demonstrates advantages over running exercise in reducing proteinuria and glomerulosclerosis in spontaneously hypertensive rats.

PubMed

Totou, N L; Moura, S S; Coelho, D B; Oliveira, E C; Becker, L K; Lima, W G

2018-03-01

Experimental studies in animal models have described the benefits of physical exercise (PE) to kidney diseases associated with hypertension. Land- and water-based exercises induce different responses in renal function. Our aim was to evaluate the renal alterations induced by different environments of PE in spontaneously hypertensive rats (SHRs). The SHRs were divided into sedentary (S), swimming exercise (SE), and running exercise (RE) groups, and were trained for 8 weeks under similar intensities (60 min/day). Arterial pressure (AP) and heart rate (HR) were recorded. The renal function was evaluated through urinary volume at each week of training; sodium and potassium excretions, plasma and urinary osmolarities, glomerular filtration rate (GFR), levels of proteinuria, and renal damage were determined. SE and RE rats presented reduced mean AP, systolic blood pressure, and HR in comparison with S group. SE and RE rats showed higher urine osmolarity compared with S. SE rats showed higher free water clearance (P < 0.01), lower urinary density (P < 0.0001), and increased weekly urine volume (P < 0.05) in comparison with RE and S groups. GFR was increased in both SE and RE rats. The proteinuria of SE (7.0 ± 0.8 mg/24 h) rats was decreased at the 8th week of the PE in comparison with RE (9.6 ± 0.8 mg/24 h) and S (9.8 ± 0.5 mg/24 h) groups. The glomerulosclerosis was reduced in SE rats (P < 0.02). SE produced different response in renal function in comparison with RE, in which only swimming-trained rats had better profile for proteinuria and glomerulosclerosis.

The influence of diltiazem and nifedipine on renal function in the rat.

PubMed Central

Johns, E. J.

1985-01-01

The effect of intravenous administration of the calcium-entry blocking drugs, diltiazem and nifedipine, on renal haemodynamic and tubular function was examined in denervated kidneys of pentobarbitone-anaesthetized rats. Infusion of vehicle for the compounds had no effect on renal function which was stable for the duration of the experiments. Diltiazem was infused at 5, 10 and 20 micrograms kg-1 min-1. Blood pressure did not change following 5 micrograms kg-1 min-1 diltiazem but was significantly reduced, by 12 mmHg, after 10 micrograms kg-1 min-1 and by 17 mmHg after 20 micrograms kg-1 min-1. Renal blood flow was not affected by any dose of diltiazem while at the lowest dose of drug, glomerular filtration rate (g.f.r.) was significantly increased, by 24%. Absolute and fractional sodium excretion were increased significantly, 154% and 77% respectively, by 5 micrograms kg-1 min-1 diltiazem, 20% and 24% respectively, by 10 micrograms kg-1 min-1 diltiazem, but were unchanged by 20 micrograms kg-1 min-1. Infusion of nifedipine at 0.5, 1.0 and 2.0 micrograms kg-1 min-1 decreased systemic blood pressure by 9, 9 and 20 mmHg, respectively. Renal blood flow was increased (7%) by 1.0 microgram kg-1 min-1 only, while g.f.r. did not change at any dose. Urine flow, absolute and fractional sodium excretions were increased, 127%, 96% and 90% respectively, by 0.5 microgram kg-1 min-1 nifedipine, 127%, 197% and 194% respectively, by 1.0 microgram kg-1 min-1, while these variables remained unchanged by a dose of 2.0 micrograms kg-1 min-1.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3986432

βENaC acts as a mechanosensor in renal vascular smooth muscle cells that contributes to renal myogenic blood flow regulation, protection from renal injury and hypertension.

PubMed

Drummond, Heather A; Stec, David E

2015-06-01

Pressure-induced constriction (also known as the "myogenic response") is an important mechanodependent response in small renal arteries and arterioles. The response is initiated by vascular smooth muscle cell (VSMC) stretch due to an increase in intraluminal pressure and leads to vasoconstriction. The myogenic response has two important roles as a mechanism of local blood flow autoregulation and protection against systemic blood pressure-induced microvascular damage. However, the molecular mechanisms underlying initiation of myogenic response are unresolved. Although several molecules have been considered initiators of the response, our laboratory has focused on the role of degenerin proteins because of their strong evolutionary link to mechanosensing in the nematode. Our laboratory has addressed the hypothesis that certain degenerin proteins act as mechanosensors in VSMCs. This article discusses the importance of a specific degenerin protein, β Epithelial Na + Channel (βENaC), in pressure-induced vasoconstriction, renal blood flow and susceptibility to renal injury. We propose that loss of the renal myogenic constrictor response delays the correction of renal blood flow that occurs with fluctuations in systemic pressure, which allows pressure swings to be transmitted to the microvasculature, thus increasing the susceptibility to renal injury and hypertension. The role of βENaC in myogenic regulation is independent of tubular βENaC and thus represents a non-tubular role for βENaC in renal-cardiovascular homeostasis.

Predictors of Renal Denervation Efficacy in the Treatment of Resistant Hypertension.

PubMed

Ripp, Tatiana M; Mordovin, Victor F; Pekarskiy, Stanislav E; Ryabova, Tamara R; Zlobina, Marina V; Baev, Andrei E; Anfinogenova, Yana; Popov, Sergey V

2015-12-01

The aims of the study were to evaluate the effects of renal sympathetic denervation (RSD) on the heart and to identify the predictors of RSD efficacy in patients with resistant arterial hypertension. The study comprised 60 RSD patients (54.6 ± 9.5 years) who received full-dose antihypertensive therapy (4.1 drugs) including diuretics. Initially, 58.6% of patients had abnormal left ventricular (LV) diastolic function. All patients received echocardiography before and 24 weeks after RSD. Renal sympathetic denervation was achieved through the endovascular radiofrequency ablation (RFA) of the renal arteries. Drug therapy continued for the entire period of observation. After RSD, all patients were retrospectively assigned to two groups: group 1 comprised patients (n = 22; 36.7%) in whom the myocardial mass (MM) of the left ventricle decreased by more than 10 g after RSD; group 2 comprised patients (n = 38; 63.3%) in whom LV MM increased or decreased by less than 10 g. Anthropometry, arterial blood pressure, heart rate, therapy, and LV end-diastolic dimensions (EDD) were comparable in these groups. After RSD, the values of office blood pressure significantly decreased and MM regressed by more than 10 g in 36.7% of patients; LV diastolic function normalized in 31% of patients, and diastolic dysfunction improved in 14% of patients. The study found the associations between the initial LV wall dimensions and LV MM changes. Unlike LV EDD, arterial blood pressure, or heart rate, the initial values of LV wall thickness predicted LV MM regress. #NCT01499810 https://clinicaltrials.gov/ct2/show/NCT01499810.

Hypertension in chronic kidney disease: the influence of renal transplantation.

PubMed

Azancot, Maria A; Ramos, Natalia; Moreso, Francesc J; Ibernon, Meritxell; Espinel, Eugenia; Torres, Irina B; Fort, Joan; Seron, Daniel

2014-09-15

Hypertension is one of the most prevalent cardiovascular risk factors in chronic kidney disease (CKD) and kidney transplants. The contribution of transplantation to hypertension in comparison to patients with CKD and similar renal function has not been characterized. Ninety-two transplants and 97 CKD patients with an estimated glomerular filtration rate less than 60 mL/min/1.73 m not receiving dialysis were enrolled. At entry, office blood pressure (BP) and 24-hr ambulatory blood pressure monitoring (ABPM) were obtained. Office BP was not different between transplants and CKD patients (139.5±14.3 vs. 135.2±19.3, P=1.00, respectively). ABPM 24-hr systolic blood pressure (SBP) (133.9±14.3 vs. 126.2±16.1, P=0.014), awake SBP (135.6±15.2 vs. 128.7±16.2, P=0.042), and sleep SBP (131.2±16.2 vs. 120.2 ±17.9, P=0.0014) were higher in renal transplants. When patients were classified according to BP patterns associated with highest cardiovascular risk, the proportion of patients with both nocturnal hypertension and non-dipper pattern was higher in transplants (68.5% vs. 47.4%, P=0.03). In the multivariate regression analysis, transplantation was an independent predictor of 24-hr, awake, and sleep SBP. Office BP is similar in kidney transplants and CKD patients with similar renal function. On the contrary, hypertension is more severe in kidney transplants when evaluated with ABPM mainly as a result of increased sleep systolic BP. Thus, precise evaluation of hypertension in kidney transplants requires ABPM.

Parathyroidectomy Halts the Deterioration of Renal Function in Primary Hyperparathyroidism.

PubMed

Tassone, Francesco; Guarnieri, Andrea; Castellano, Elena; Baffoni, Claudia; Attanasio, Roberto; Borretta, Giorgio

2015-08-01

Decreased renal function has been consistently included among factors prompting recommendation for surgery in primary hyperparathyroidism (PHPT). However, most retrospective studies addressing this issue did not show an improvement in renal function after parathyroidectomy (PTX). The aim of this study was to investigate changes in renal function after PTX in PHPT patients subdivided according to renal function at diagnosis. This was a retrospective cross-sectional study. We studied 109 consecutive PHPT patients before and after PTX. Biochemical evaluation included fasting total and ionized serum calcium, phosphate, creatinine, immunoreactive intact PTH, and 25-hydroxyvitamin D3 levels. Glomerular filtration rate (GFR) was assessed with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Mean (± SD) CKD-EPI estimated GFR (eGFR) at diagnosis was 82.4 ± 19.3 mL/min/1.73 m(2) (median, 84.8 mL/min/1.73 m(2); interquartile range, 68.5-94.2 mL/min/1.73 m(2)). Patients with eGFR equal to or higher than 60 mL/min/1.73 m(2) (group 1, n = 95) were significantly younger than patients with eGFR lower than 60 mL/min/1.73 m(2) (group 2, n = 14; P < .0003). After PTX, eGFR did not change in patients of group 2 (P = .509), whereas it was significantly reduced in patients of group 1 (P < .0002). The difference in eGFR between baseline and post-PTX values was correlated negatively with baseline serum creatinine (R = -0.27; P = .0052) and positively with baseline CKD-EPI eGFR (R = 0.32; P = .00062). At multiple regression analysis, only systolic blood pressure and baseline CKD-EPI eGFR were independent predictors of GFR variation. Surgical cure of PHPT halts renal function deterioration in patients with coexisting renal disease. Our study thus supports the indication for surgery in patients with eGFR less than 60 mL/min/1.73 m(2), as recommended by current guidelines. Moreover, our data show that presurgical renal function is a relevant predictor of renal function after PTX.

Changes of renal sinus fat and renal parenchymal fat during an 18-month randomized weight loss trial.

PubMed

Zelicha, Hila; Schwarzfuchs, Dan; Shelef, Ilan; Gepner, Yftach; Tsaban, Gal; Tene, Lilac; Yaskolka Meir, Anat; Bilitzky, Avital; Komy, Oded; Cohen, Noa; Bril, Nitzan; Rein, Michal; Serfaty, Dana; Kenigsbuch, Shira; Chassidim, Yoash; Sarusi, Benjamin; Thiery, Joachim; Ceglarek, Uta; Stumvoll, Michael; Blüher, Matthias; Haviv, Yosef S; Stampfer, Meir J; Rudich, Assaf; Shai, Iris

2018-08-01

Data regarding the role of kidney adiposity, its clinical implications, and its dynamics during weight-loss are sparse. We investigated the effect of long-term weight-loss induced intervention diets on dynamics of renal-sinus-fat, an ectopic fat depot, and %renal-parenchymal-fat, lipid accumulation within the renal parenchyma. We randomized 278 participants with abdominal obesity/dyslipidemia to low-fat or Mediterranean/low-carbohydrate diets, with or without exercise. We quantified renal-sinus-fat and %renal-parenchymal-fat by whole body magnetic-resonance-imaging. Participants (age = 48 years; 89% men; body-mass-index = 31 kg/m 2 ) had 86% retention to the trial after 18 months. Both increased renal-sinus-fat and %renal-parenchymal-fat were directly associated with hypertension, and with higher abdominal deep-subcutaneous-adipose-tissue and visceral-adipose-tissue (p of trend < 0.05 for all) after adjustment for body weight. Higher renal-sinus-fat was associated with lower estimated-glomerular-filtration-rate and with higher microalbuminuria and %HbA1C beyond body weight. After 18 months of intervention, overall renal-sinus-fat (-9%; p < 0.05 vs. baseline) but not %renal-parenchymal-fat (-1.7%; p = 0.13 vs. baseline) significantly decreased, and similarly across the intervention groups. Renal-sinus-fat and %renal-parenchymal-fat changes were correlated with weight-loss per-se (p < 0.05). In a model adjusted for age, sex, and visceral-adipose-tissue changes, 18 months reduction in renal-sinus-fat associated with decreased pancreatic, hepatic and cardiac fats (p < 0.05 for all) and with decreased cholesterol/high-density lipoprotein-cholesterol (HDL-c) (β = 0.13; p = 0.05), triglycerides/HDL-c (β = 0.13; p = 0.05), insulin (β = 0.12; p = 0.05) and gamma glutamyl transpeptidase (β = 0.24; p = 0.001), but not with improved renal function parameters or blood pressure. Decreased intake of sodium was associated with a reduction in %renal-parenchymal-fat, after adjustment for 18 months weight-loss (β = 0.15; p = 0.026) and hypertension (β = 0.14; p = 0.04). Renal-sinus-fat and renal-parenchymal-fat are fairly related to weight-loss. Decreased renal-sinus-fat is associated with improved hepatic parameters, independent of changes in weight or hepatic fat, rather than with improved renal function or blood pressure parameters. CLINICALTRIALS. NCT01530724. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Renal transplantation in patients with hepatitis C virus antibody. A long national experience

PubMed Central

Morales, Jose María; Marcén, Roberto; Andres, Amado; Domínguez-Gil, Beatriz; Campistol, Josep María; Gallego, Roberto; Gutierrez, Alex; Gentil, Miguel Angel; Oppenheimer, Federico; Samaniego, María Luz; Muñoz-Robles, Jorge; Serón, Daniel

2010-01-01

Background. Renal transplantation is the best therapy for patients with hepatitis C virus (HCV) infection with end-stage renal disease. Patient and graft survival are lower in the long term compared with HCV-negative patients. The current study evaluated the results of renal transplantation in Spain in a long period (1990–2002), focusing on graft failure. Methods. Data on the Spanish Chronic Allograft Nephropathy Study Group including 4304 renal transplant recipients, 587 of them with HCV antibody, were used to estimate graft and patient survival at 4 years with multivariate Cox models. Results. Among recipients alive with graft function 1 year post-transplant, the 4-year graft survival was 92.8% in the whole group; this was significantly better in HCV-negative vs HCV-positive patients (94.4% vs 89.5%, P < 0.005). Notably, HCV patients showed more acute rejection, a higher degree of proteinuria accompanied by a diminution of renal function, more graft biopsies and lesions of de novo glomerulonephritis and transplant glomerulopathy. Serum creatinine and proteinuria at 1 year, acute rejection, HCV positivity and systolic blood pressure were independent risk factors for graft loss. Patient survival was 96.3% in the whole group, showing a significant difference between HCV-negative vs HCV-positive patients (96.6% vs 94.5%, P < 0.05). Serum creatinine and diastolic blood pressure at 1 year, HCV positivity and recipient age were independent risk factors for patient death. Conclusions. Renal transplantation is an effective therapy for HCV-positive patients with good survival but inferior than results obtained in HCV-negative patients in the short term. Notably, HCV-associated renal damage appears early with proteinuria, elevated serum creatinine showing chronic allograft nephropathy, transplant glomerulopathy and, less frequently, HCV-associated de novo glomerulonephritis. We suggest that HCV infection should be recognized as a true risk factor for graft failure, and preventive measures could include pre-transplant therapy with interferon. PMID:20508864

Renal Oxidative Stress Induced by Long-Term Hyperuricemia Alters Mitochondrial Function and Maintains Systemic Hypertension

PubMed Central

Cristóbal-García, Magdalena; García-Arroyo, Fernando E.; Arellano-Buendía, Abraham S.; Madero, Magdalena; Rodríguez-Iturbe, Bernardo; Pedraza-Chaverrí, José; Zazueta, Cecilia; Johnson, Richard J.; Sánchez Lozada, Laura-Gabriela

2015-01-01

We addressed if oxidative stress in the renal cortex plays a role in the induction of hypertension and mitochondrial alterations in hyperuricemia. A second objective was to evaluate whether the long-term treatment with the antioxidant Tempol prevents renal oxidative stress, mitochondrial alterations, and systemic hypertension in this model. Long-term (11-12 weeks) and short-term (3 weeks) effects of oxonic acid induced hyperuricemia were studied in rats (OA, 750 mg/kg BW), OA+Allopurinol (AP, 150 mg/L drinking water), OA+Tempol (T, 15 mg/kg BW), or vehicle. Systolic blood pressure, renal blood flow, and vascular resistance were measured. Tubular damage (urine N-acetyl-β-D-glucosaminidase) and oxidative stress markers (lipid and protein oxidation) along with ATP levels were determined in kidney tissue. Oxygen consumption, aconitase activity, and uric acid were evaluated in isolated mitochondria from renal cortex. Short-term hyperuricemia resulted in hypertension without demonstrable renal oxidative stress or mitochondrial dysfunction. Long-term hyperuricemia induced hypertension, renal vasoconstriction, tubular damage, renal cortex oxidative stress, and mitochondrial dysfunction and decreased ATP levels. Treatments with Tempol and allopurinol prevented these alterations. Renal oxidative stress induced by hyperuricemia promoted mitochondrial functional disturbances and decreased ATP content, which represent an additional pathogenic mechanism induced by chronic hyperuricemia. Hyperuricemia-related hypertension occurs before these changes are evident. PMID:25918583

Impaired endogenous nighttime melatonin secretion relates to intrarenal renin-angiotensin system activation and renal damage in patients with chronic kidney disease.

PubMed

Ishigaki, Sayaka; Ohashi, Naro; Isobe, Shinsuke; Tsuji, Naoko; Iwakura, Takamasa; Ono, Masafumi; Sakao, Yukitoshi; Tsuji, Takayuki; Kato, Akihiko; Miyajima, Hiroaki; Yasuda, Hideo

2016-12-01

Activation of the intrarenal renin-angiotensin system (RAS) plays a critical role in the pathophysiology of chronic kidney disease (CKD) and hypertension. The circadian rhythm of intrarenal RAS activation leads to renal damage and hypertension, which are associated with diurnal blood pressure (BP) variation. The activation of intrarenal RAS following reactive oxygen species (ROS) activation, sympathetic hyperactivity and nitric oxide (NO) inhibition leads to the development of renal damage. Melatonin is a hormone regulating the circadian rhythm, and has multiple functions such as anti-oxidant and anti-adrenergic effects and enhancement of NO bioavailability. Nocturnal melatonin concentrations are lower in CKD patients. However, it is not known if impaired endogenous melatonin secretion is related to BP, intrarenal RAS, or renal damage in CKD patients. We recruited 53 CKD patients and conducted 24-h ambulatory BP monitoring. urine was collected during the daytime and nighttime. We investigated the relationship among the melatonin metabolite urinary 6-sulphatoxymelatonin (U-aMT6s), BP, renal function, urinary angiotensinogen (U-AGT), and urinary albumin (U-Alb). Patients' U-aMT6s levels were significantly and negatively correlated with clinical parameters such as renal function, systolic BP, U-AGT, and U-Alb, during both day and night. Multiple regression analyses for U-aMT6s levels were performed using age, gender, renal function, and each parameter (BPs, U-AGT or U-Alb), at daytime and nighttime. U-aMT6s levels were significantly associated with U-AGT (β = -0.31, p = 0.044) and U-Alb (β = -0.25, p = 0.025) only at night. Impaired nighttime melatonin secretion may be associated with nighttime intrarenal RAS activation and renal damage in CKD patients.

Metabolic and hemodynamic effects of sodium-dependent glucose cotransporter 2 inhibitors on cardio-renal protection in the treatment of patients with type 2 diabetes mellitus.

PubMed

Kashiwagi, Atsunori; Maegawa, Hiroshi

2017-07-01

The specific sodium-glucose cotransporter 2 inhibitors (SGLT2 inhibitors) inhibit glucose reabsorption in proximal renal tubular cells, and both fasting and postprandial glucose significantly decrease because of urinary glucose loss. As a result, pancreatic β-cell function and peripheral insulin action significantly improve with relief from glucose toxicity. Furthermore, whole-body energy metabolism changes to relative glucose deficiency and triggers increased lipolysis in fat cells, and fatty acid oxidation and then ketone body production in the liver during treatment with SGLT2 inhibitors. In addition, SGLT2 inhibitors have profound hemodynamic effects including diuresis, dehydration, weight loss and lowering blood pressure. The most recent findings on SGLT2 inhibitors come from results of the Empagliflozin, Cardiovascular Outcomes and Mortality in Type 2 Diabetes trial. SGLT2 inhibitors exert extremely unique and cardio-renal protection through metabolic and hemodynamic effects, with long-term durability on the reduction of blood glucose, bodyweight and blood pressure. Although a site of action of SGLT2 inhibitors is highly specific to inhibit renal glucose reabsorption, whole-body energy metabolism, and hemodynamic and renal functions are profoundly modulated during the treatment of SGLT2 inhibitors. Previous studies suggest multifactorial clinical benefits and safety concerns of SGLT2 inhibitors. Although ambivalent clinical results of this drug are still under active discussion, the present review summarizes promising recent evidence on the cardio-renal and metabolic benefits of SGLT2 inhibitors in the treatment of type 2 diabetes. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Dietary potassium and the renal control of salt balance and blood pressure.

PubMed

Penton, David; Czogalla, Jan; Loffing, Johannes

2015-03-01

Dietary potassium (K(+)) intake has antihypertensive effects, prevents strokes, and improves cardiovascular outcomes. The underlying mechanism for these beneficial effects of high K(+) diets may include vasodilation, enhanced urine flow, reduced renal renin release, and negative sodium (Na(+)) balance. Indeed, several studies demonstrate that dietary K(+) intake induces renal Na(+) loss despite elevated plasma aldosterone. This review briefly highlights the epidemiological and experimental evidences for the effects of dietary K(+) on arterial blood pressure. It discusses the pivotal role of the renal distal tubule for the regulation of urinary K(+) and Na(+) excretion and blood pressure and highlights that it depends on the coordinated interaction of different nephron portions, epithelial cell types, and various ion channels, transporters, and ATPases. Moreover, we discuss the relevance of aldosterone and aldosterone-independent factors in mediating the effects of an altered K(+) intake on renal K(+) and Na(+) handling. Particular focus is given to findings suggesting that an aldosterone-independent downregulation of the thiazide-sensitive NaCl cotransporter significantly contributes to the natriuretic and antihypertensive effect of a K(+)-rich diet. Last but not least, we refer to the complex signaling pathways enabling the kidney to adapt its function to the homeostatic needs in response to an altered K(+) intake. Future work will have to further address the underlying cellular and molecular mechanism and to elucidate, among others, how an altered dietary K(+) intake is sensed and how this signal is transmitted to the different epithelial cells lining the distal tubule.

A Patient with Cystinosis Presenting Like Bartter Syndrome and Review of Literature

PubMed Central

Ertan, Pelin; Evrengul, Havva; Ozen, Serkan; Emre, Sinan

2012-01-01

Background Nephropathic cystinosis is an autosomal recessively inherited metabolic disorder presenting with metabolic acidosis, Fanconi syndrome and renal failure. Case Presentation We present a 6-year-old girl with severe growth failure, hyponatremia and hypokalemia. Her parents were 4th degree relatives. Two relatives were diagnosed as end stage renal failure. She also had persistant hypokalemic hypochloremic metabolic alkalosis. Her renal function was normal at presentation. She was thought to have Bartter syndrome with supporting findings of elevated levels of renin and aldosterone with normal blood pressure, and hyperplasia of juxtaglomerular apparatus. Her metabolic alkalosis did not resolve despite supportive treatment. At 6th month of follow-up proteinuria, glucosuria and deterioration of renal function developed. Diagnosis of cystinosis was made with slit lamp examination and leukocyte cystine levels. At 12th month of follow-up her metabolic alkalosis has converted to metabolic acidosis. Conclusion In children presenting with persistant metabolic alkalosis, with family history of renal failure, and parental consanguinity, cystinosis should always be kept in mind as this disease is an important cause of end stage renal failure which may have features mimmicking Bartter syndrome. PMID:23431081

Parecoxib reduces renal injury in an ischemia/reperfusion model in rats.

PubMed

Calistro Neto, José Pedro; Torres, Rômulo da Costa; Gonçalves, Giovanna Maria; Silva, Leopoldo Muniz da; Domingues, Maria Aparecida Custódio; Módolo, Norma Sueli Pinheiro; Barros, Guilherme Antonio Moreira de

2015-04-01

To evaluate the effect of parecoxib (an NSAID) on renal function by measuring plasma NGAL (serum neutrophil gelatinase-associated lipocalin) levels in an induced-ischemia rat model. Forty male Wistar rats were randomly assigned to one of four groups: Ischemia (I), Ischemia/parecoxib (IP), No-ischemia (NI), and No-ischemia/parecoxib (NIP). Body weight, mean arterial pressure, heart rate, body temperature, NGAL levels, and renal histology were compared across groups. The Ischemia (I) group, which did not receive parecoxib, showed the highest NGAL levels (p=0.001), while the IP group, which received the medication, had NGAL levels similar to those of the non-ischemic (NI and NIP) groups. Parecoxib resulted in renal protection in this experimental model.

Effects of mechanical ventilation on gene expression profiles in renal allografts from brain dead rats.

PubMed

Hottenrott, Maximilia C; Krebs, Joerg; Pelosi, Paolo; Luecke, Thomas; Rocco, Patricia R M; Sticht, Carsten; Breedijk, Annette; Yard, Benito; Tsagogiorgas, Charalambos

2017-12-01

Pathophysiological changes of brain death (BD) are impairing distal organ function and harming potential renal allografts. Whether ventilation strategies influence the quality of renal allografts from BD donors has not been thoroughly studied. 28 adult male Wistar rats were randomly assigned to four groups: 1) no brain death (NBD) with low tidal volume/low positive endexpiratory pressure (PEEP) titrated to minimal static elastance of the respiratory system (LVT/OLPEEP); 2) NBD with high tidal volume/low PEEP (HVT/LPEEP); 3) brain death (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. We hypothesized that HVT/LPEEP in BD leads to increased interleukin 6 (IL-6) gene expression and impairs potential renal allografts after six hours of mechanical ventilation. We assessed inflammatory cytokines in serum, genome wide gene expression profiles and quantitative PCR (qPCR) in kidney tissue. The influence of BD on renal gene-expression profiles was greater than the influence of the ventilation strategy. In BD, LVT ventilation did not influence the inflammatory parameters or kidney function in our experimental model. Copyright © 2017. Published by Elsevier B.V.

Augmented antihypertensive effect of a fixed combination formula of candesartan and hydrochlorothiazide combined with furosemide in a patient on peritoneal dialysis.

PubMed

Kuriyama, Satoru; Otsuka, Yasushi; Ueda, Hiroyuki; Sugano, Naoki; Yoshizawa, Takeo; Yamada, Taku; Hosoya, Tatsuo

2011-02-01

A 38-year-old female patient on peritoneal dialysis (PD) due to type 1 diabetic nephropathy with a well-preserved residual renal function did not respond well to the conventional antihypertensive therapy consisting of candesartan, furosemide, and bunazosin. Switching candesartan for a fixed combination formula of candesartan plus hydrochlorothiazide (HCTZ) while the rest of the other two agents remained unchanged led to the remarkable reduction in both systolic and diastolic blood pressure (BP) without significant changes in the cardiothoracic ratio (CTR), body weight (BW), and residual renal function. This case suggests that when used in combination, diuretics acting on different functional segment of the nephron hold greater potential for enhanced antihypertensive effect, especially in patients on PD whose residual renal function is well preserved. A small dose of HCTZ with an angiotensin II receptor blocker (ARB) may partially explain the therapeutic benefit of this combination therapy in terms of a reliable hypotensive effect, a better adherence, and fewer side effects.

Influence of the renal endothelin system on the autoregulation of renal blood flow in spontaneously hypertensive rats.

PubMed

Braun, C; Lang, C; Hocher, B; Gretz, N; van der Woude, F J; Rohmeiss, P

1997-01-01

The renal endothelin (ET) system has been claimed to play an important role in the regulation of renal blood flow (RBF) and sodium excretion in primary hypertension. The aim of the present study was to investigate the contribution of the endogenous ET system in the autoregulation of total RBF, cortical blood flow (CBF), pressure-dependent plasma renin activity (PRA) and pressure natriuresis in spontaneously hypertensive rats (SHR) by means of the combined (A/B) ET-receptor antagonist, bosentan. In anesthetized rats, RBF was measured by transit-time flow probes and CBF by laser flow probes. During the experiments, the rats received an intrarenal infusion of either bosentan (1 mg/kg/h) or vehicle. Renal perfusion pressure (RPP) was lowered in pressure steps of 5 mm Hg with a servo-controlled electropneumatic device via an inflatable suprarenal cuff. Bosentan had no effect on resting RPP, CBF, PRA and renal sodium excretion, whereas RBF was lowered by 30% (p < 0.05). Furthermore after bosentan the rats revealed a complete loss of RBF autoregulation. In contrast no changes in autoregulation of CBF, pressure-dependent PRA and pressure natriuresis were observed. Our findings demonstrate a significant impairment in total RBF autoregulatory ability during renal ET-receptor blockade which is not confined to the cortical vessels. These data suggest that the renal ET system plays an important role in the dynamic regulation of renal blood flow in SHR.

Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation

PubMed Central

Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

2018-01-01

Case series Patients: Male, 85 • Male, 89 Final Diagnosis: Essential hypertension Symptoms: High blood pressure Medication: Anti-hypertensive agents Clinical Procedure: Operation Specialty: Cardiology and Hypertension Objective: Unusual or unexpected effect of treatment Background: Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. Case Reports: Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. Conclusions: A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective. PMID:29765015

Renalase is a novel, soluble monoamine oxidase that regulates cardiac function and blood pressure

PubMed Central

Xu, Jianchao; Li, Guoyong; Wang, Peili; Velazquez, Heino; Yao, Xiaoqiang; Li, Yanyan; Wu, Yanling; Peixoto, Aldo; Crowley, Susan; Desir, Gary V.

2005-01-01

The kidney not only regulates fluid and electrolyte balance but also functions as an endocrine organ. For instance, it is the major source of circulating erythropoietin and renin. Despite currently available therapies, there is a marked increase in cardiovascular morbidity and mortality among patients suffering from end-stage renal disease. We hypothesized that the current understanding of the endocrine function of the kidney was incomplete and that the organ might secrete additional proteins with important biological roles. Here we report the identification of a novel flavin adenine dinucleotide–dependent amine oxidase (renalase) that is secreted into the blood by the kidney and metabolizes catecholamines in vitro (renalase metabolizes dopamine most efficiently, followed by epinephrine, and then norepinephrine). In humans, renalase gene expression is highest in the kidney but is also detectable in the heart, skeletal muscle, and the small intestine. The plasma concentration of renalase is markedly reduced in patients with end-stage renal disease, as compared with healthy subjects. Renalase infusion in rats caused a decrease in cardiac contractility, heart rate, and blood pressure and prevented a compensatory increase in peripheral vascular tone. These results identify renalase as what we believe to be a novel amine oxidase that is secreted by the kidney, circulates in blood, and modulates cardiac function and systemic blood pressure. PMID:15841207

Effect of endovascular treatment on nitric oxide and renal function in Takayasu's arteritis with renovascular hypertension.

PubMed

Parildar, Zuhal; Gulter, Ceyda; Parildar, Mustafa; Oran, Ismail; Erdener, Dilek; Memis, Ahmet

2002-01-01

Renal involvement in Takayasu's arteritis (TA) effects the disease outcome and endovascular treatment is an effective treatment of choice. We investigated nitric oxide (NO) levels and the effect of endovascular treatment in renovascular hypertensive TA patients. In five hypertensive patients with renal artery stenosis due to TA, serum creatinine, nitrite, nitrate; urinary microalbumin, nitrite, nitrate measurements and blood pressures were recorded at entry and after 24 h and 6 weeks of endovascular treatment. Serum NO levels were higher in patients than controls (p = 0.008). Serum and urine NO levels increased 24 h after the treatment and decreased after 6 weeks (p = 0.015; p = 0.01, respectively). After the treatment blood pressures decreased. Urinary microalbumin excretions increased after the intervention (p = 0.02) and returned to normal in patients 1 and 4, and decreased in the others. There were no significant differences in estimated glomerular filtration rate (EGFR), serum creatinine, urinary sodium and potassium levels. Increased NO secretion in these patients may contribute to improve the prognosis of renal function through its vasodilator and antiproliferative activities possibly by counterbalancing the excessive vasoconstrictor actions. Endovascular treatment causes a dilatation-induced shear stress that may be responsible for the increased NO release, which in turn leads to the rapid hypotensive response. Copyright 2002 S. Karger AG, Basel

Related factors for worsening renal function following percutaneous transluminal renal angioplasty (PTRA) in patients with atherosclerotic renal artery stenosis.

PubMed

Yoshihara, Fumiki; Fukuda, Tetsuya; Iwashima, Yoshio; Nakamura, Satoko; Hayashi, Shin-Ichiro; Kishida, Masatsugu; Ishizuka, Azusa; Kusunoki, Hiroshi; Ohta, Yuko; Kawano, Yuhei

2015-01-01

To identify candidates for PTRA in terms of the preservation of renal function, we herein evaluated factors that caused worsening renal function (WRF) after PTRA. We evaluated 92 patients with atherosclerotic renal artery stenosis (mean age 70.7 ± 8.4 years). WRF was defined as a ≥0.3 mg/dL increase in creatinine levels after PTRA compared to before PTRA. A total of 92 patients exhibited non-WRF 83 (90.2%), WRF 9 (9.8%). Significant differences were observed in serum creatinine levels between two groups both before (non-WRF 1.34 ± 0.49 versus WRF 1.70 ± 0.68 mg/dL, p = 0.0462) and after PTRA (non-WRF 1.31 ± 0.43 versus WRF 2.42 ± 1.12 mg/dL, p < 0.0001). Patients with WRF had higher comorbidity rate of diabetes mellitus (DM) (non-WRF 31.3% versus WRF 66.7%, p = 0.0345) and proteinuria (non-WRF 27.7% versus WRF 66.7%, p = 0.0169), and had higher systolic blood pressure (non-WRF 143.6 ± 18.7 versus WRF 157.1 ± 19.9 mmHg, p = 0.0436), higher plasma B-type natriuretic peptide (BNP) levels, and larger left atrial and left ventricular end-diastolic dimensions before PTRA. Patients with WRF had a higher rate of taking diuretics (non-WRF 27.7% versus WRF 66.7%, p = 0.0169) after PTRA. Multiple logistic regression analysis revealed that comorbidity of DM was an independent related factor for WRF (comorbidity of DM, yes: OR 31.0, 95% CI 2.44-1024.62, p = 0.0055). Comorbidity of DM, coexisting of proteinuria, high creatinine level, high blood pressure, high BNP levels, and large left atrial and ventricular dimensions were related to WRF after PTRA in patients with atherosclerotic renal artery stenosis.

Renal BOLD-MRI relates to kidney function and activity of the renin-angiotensin-aldosterone system in hypertensive patients.

PubMed

Vink, Eva E; de Boer, Anneloes; Hoogduin, Hans J M; Voskuil, Michiel; Leiner, Tim; Bots, Michiel L; Joles, Jaap A; Blankestijn, Peter J

2015-03-01

The renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system are key factors in the pathophysiology of hypertension. Renal hypoxia is the putative mechanism stimulating both systems. Blood oxygen level-dependent MRI (BOLD-MRI) provides a noninvasive tool to determine renal oxygenation in humans. The aim of the current study was to investigate the relation between blood pressure (BP) and kidney function with renal BOLD-MRI. Moreover, the relation between direct and indirect variables of the RAAS and sympathetic nervous system and renal BOLD-MRI was studied. Seventy-five hypertensive patients (38 men) were included. Antihypertensive medication was temporarily stopped. Patients collected urine during 24 h (sodium, catecholamines), blood samples were taken (creatinine, renin, aldosterone), a captopril challenge test was performed, and ambulatory BP was measured. Mean age was 58 (±11) years, day-time BP was 167 (±19)/102 (±16) mmHg, and estimated glomerular filtration rate was 75 (±18) ml/min per 1.73 m). In multivariable regression analysis, renal medullary R2*-values inversely related to estimated glomerular filtration rate (P = 0.02). Moreover, the BP-lowering effect of captopril positively related to cortical (P = 0.02) and medullary (P = 0.008) R2*-values, as well as to P90 (P = 0.02). In patients with hypertension, kidney function relates to medullary R2*-values. Activation of the RAAS is also positively related to the renal R2*-values.

A computational analysis of the long-term regulation of arterial pressure

PubMed Central

Beard, Daniel A.

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex. PMID:24555102

A computational analysis of the long-term regulation of arterial pressure.

PubMed

Beard, Daniel A; Pettersen, Klas H; Carlson, Brian E; Omholt, Stig W; Bugenhagen, Scott M

2013-01-01

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production-the acute pressure-diuresis and pressure-natriuresis curves-physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the "Guyton-Coleman model", no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. representing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

Chronic Inhibition of Renal Outer Medullary Potassium Channel Not Only Prevented but Also Reversed Development of Hypertension and End-Organ Damage in Dahl Salt-Sensitive Rats.

PubMed

Zhou, Xiaoyan; Forrest, Michael J; Sharif-Rodriguez, Wanda; Forrest, Gail; Szeto, Daphne; Urosevic-Price, Olga; Zhu, Yonghua; Stevenson, Andra S; Zhou, Yuchen; Stribling, Sloan; Dajee, Maya; Walsh, Shawn P; Pasternak, Alexander; Sullivan, Kathleen A

2017-02-01

The renal outer medullary potassium (ROMK) channel mediates potassium recycling and facilitates sodium reabsorption through the Na + /K + /2Cl - cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Evidence from the phenotype of humans and rodents with functional ROMK deficiency supports the contention that selective ROMK inhibitors (ROMKi) will represent a novel diuretic with potential of therapeutic benefit for hypertension. ROMKi have recently been synthesized by Merck & Co, Inc. The present studies were designed to examine the effects of ROMKi B on systemic hemodynamics, renal function and structure, and vascular function in Dahl salt-sensitive rats. Four experimental groups-control, high-salt diet alone; ROMKi B 3 mg·kg - 1 ·d - 1 ; ROMKi B 10 mg·kg - 1 ·d - 1 ; and hydrochlorothiazide 25 mg·kg - 1 ·d - 1 -were included in prophylactic (from week 1 to week 9 on high-salt diet) and therapeutic studies (from week 5 to week 9 on high-salt diet), respectively. ROMKi B produced sustained blood pressure reduction and improved renal and vascular function and histological alterations induced by a high-salt diet. ROMKi B was superior to hydrochlorothiazide at reducing blood pressure. Furthermore, ROMKi B provided beneficial effects on both the plasma lipid profile and bone mineral density. Chronic ROMK inhibition not only prevented but also reversed the development of hypertension and end-organ damage in Dahl salt-sensitive rats. Our findings suggest a potential utility of ROMKi B as a novel antihypertensive agent, particularly for the treatment of the salt-sensitive hypertension patient population. © 2016 American Heart Association, Inc.

The Medical and Endovascular Treatment of Atherosclerotic Renal Artery Stenosis (METRAS) study: rationale and study design.

PubMed

Rossi, G P; Seccia, T M; Miotto, D; Zucchetta, P; Cecchin, D; Calò, L; Puato, M; Motta, R; Caielli, P; Vincenzi, M; Ramondo, G; Taddei, S; Ferri, C; Letizia, C; Borghi, C; Morganti, A; Pessina, A C

2012-08-01

It is unclear whether revascularization of renal artery stenosis (RAS) by means of percutaneous renal angioplasty and stenting (PTRAS) is advantageous over optimal medical therapy. Hence, we designed a randomized clinical trial based on an optimized patient selection strategy and hard experimental endpoints. Primary objective of this study is to determine whether PTRAS is superior or equivalent to optimal medical treatment for preserving glomerular filtration rate (GFR) in the ischemic kidney as assessed by 99mTcDTPA sequential renal scintiscan. Secondary objectives of this study are to establish whether the two treatments are equivalent in lowering blood pressure, preserving overall renal function and regressing target organ damage, preventing cardiovascular events and improving quality of life. The study is designed as a prospective multicentre randomized, un-blinded two-arm study. Eligible patients will have clinical and angio-CT evidence of RAS. Inclusion criteria is RAS affecting the main renal artery or its major branches either >70% or, if <70, with post-stenotic dilatation. Renal function will be assessed with 99mTc-DTPA renal scintigraphy. Patients will be randomized to either arms considering both resistance index value in the ischemic kidney and the presence of unilateral/bilateral stenosis. Primary experimental endpoint will be the GFR of the ischemic kidney, assessed as quantitative variable by 99TcDTPA, and the loss of ischemic kidney defined as a categorical variable.

Effect of intraoperative transesophageal Doppler-guided fluid therapy versus central venous pressure-guided fluid therapy on renal allograft outcome in patients undergoing living donor renal transplant surgery: a comparative study.

PubMed

Srivastava, Divya; Sahu, Sandeep; Chandra, Abhilash; Tiwari, Tanmay; Kumar, Sanjay; Singh, P K

2015-12-01

Transesophageal Doppler (TED)-guided intraoperative fluid therapy has shown to noninvasively optimize intravascular volume and reduce postoperative morbidity. The aim of this study was to compare the effects of Doppler-guided intraoperative fluid administration and central venous pressure (CVP)-guided fluid therapy on renal allograft outcome and postoperative complications. A prospective nonrandomized active controlled study was conducted on end-stage renal disease patients scheduled for living donor renal transplant surgery. 110 patients received intraoperative fluid guided by corrected flow time (FTc) and variation in stroke volume values obtained by continuous TED monitoring. Data of 104 patients in whom intraoperative fluid administration was guided by CVP values were retrospectively obtained for a control. The amount of intraoperative fluid given in the study group (12.20 ± 4.24 ml/kg/h) was significantly lower than in the controls (22.21 ± 4.67 ml/kg/h). The amount of colloid used was also significantly less and fewer recipients were seen to require colloid (69 vs 85%). The mean arterial pressures were comparable throughout. CVP reached was 7.18 ± 3.17 mmHg in the study group. It was significantly higher in the controls (13.42 ± 3.12 mmHg). The postoperative graft function and rate of dysfunction were comparable. Side-effects like postoperative dyspnoea (4.8 vs 0%) and tissue edema (9.6 vs 2.7%) were higher in the controls. FTc-guided intraoperative fluid therapy achieved the same rate of immediate graft function as CVP-guided fluid therapy but used a significantly less amount of fluid. The incidence of postoperative complications related to fluid overload was also reduced. The use of TED may replace invasive central line insertions in the future.

Microcirculation of human pancreatic islets transplanted under the renal capsule of nude mice.

PubMed

Jansson, L; Tyrberg, B; Carlsson, P O; Nordin, A; Andersson, A; Källskog O

2001-08-27

The aim was to measure the capillary blood pressure in transplanted human islets. Human islets were isolated at the Central Unit of the beta-cell Transplant in Brussels, Belgium. After transport to our laboratory, the islets were implanted under the renal capsule of normoglycemic nude mice. Two weeks later the capillary and venous blood pressures in the islet graft and adjacent renal parenchyma were measured with a micropuncture technique. Capillary blood pressure was approximately 5-8 mmHg in both graft and renal capillaries: twice as high as in native islets. Venous blood pressures were similar (4-5 mmHg) in the veins draining the graft and in the renal interlobular veins. All veins leading from the graft emptied into the renal parenchyma, that is, into interlobular veins. The capillary hypertension seen in transplanted human islets is probably necessary to secure adequate drainage through the renal veins. Whether this contributes to the poor results of long-term islet graft survival is unknown.

Endothelin-A receptor blockade slows the progression of renal injury in experimental renovascular disease.

PubMed

Kelsen, Silvia; Hall, John E; Chade, Alejandro R

2011-07-01

Endothelin (ET)-1, a potent renal vasoconstrictor with mitogenic properties, is upregulated by ischemia and has been shown to induce renal injury via the ET-A receptor. The potential role of ET-A blockade in chronic renovascular disease (RVD) has not, to our knowledge, been previously reported. We hypothesized that chronic ET-A receptor blockade would preserve renal hemodynamics and slow the progression of injury of the stenotic kidney in experimental RVD. Renal artery stenosis, a major cause of chronic RVD, was induced in 14 pigs and observed for 6 wk. In half of the pigs, chronic ET-A blockade was initiated (RVD+ET-A, 0.75 mg·kg(-1)·day(-1)) at the onset of RVD. Single-kidney renal blood flow, glomerular filtration rate, and perfusion were quantified in vivo after 6 wk using multidetector computer tomography. Renal microvascular density was quantified ex vivo using three-dimensional microcomputer tomography, and growth factors, inflammation, apoptosis, and fibrosis were determined in renal tissue. The degree of stenosis and increase in blood pressure were similar in RVD and RVD+ET-A pigs. Renal hemodynamics, function, and microvascular density were decreased in the stenotic kidney but preserved by ET-A blockade, accompanied by increased renal expression of vascular endothelial growth factor, hepatocyte growth factor, and downstream mediators such as phosphorilated-Akt, angiopoietins, and endothelial nitric oxide synthase. ET-A blockade also reduced renal apoptosis, inflammation, and glomerulosclerosis. This study shows that ET-A blockade slows the progression of renal injury in experimental RVD and preserves renal hemodynamics, function, and microvascular density in the stenotic kidney. These results support a role for ET-1/ET-A as a potential therapeutic target in chronic RVD.

Endothelin-A receptor blockade slows the progression of renal injury in experimental renovascular disease

PubMed Central

Kelsen, Silvia; Hall, John E.

2011-01-01

Endothelin (ET)-1, a potent renal vasoconstrictor with mitogenic properties, is upregulated by ischemia and has been shown to induce renal injury via the ET-A receptor. The potential role of ET-A blockade in chronic renovascular disease (RVD) has not, to our knowledge, been previously reported. We hypothesized that chronic ET-A receptor blockade would preserve renal hemodynamics and slow the progression of injury of the stenotic kidney in experimental RVD. Renal artery stenosis, a major cause of chronic RVD, was induced in 14 pigs and observed for 6 wk. In half of the pigs, chronic ET-A blockade was initiated (RVD+ET-A, 0.75 mg·kg−1·day−1) at the onset of RVD. Single-kidney renal blood flow, glomerular filtration rate, and perfusion were quantified in vivo after 6 wk using multidetector computer tomography. Renal microvascular density was quantified ex vivo using three-dimensional microcomputer tomography, and growth factors, inflammation, apoptosis, and fibrosis were determined in renal tissue. The degree of stenosis and increase in blood pressure were similar in RVD and RVD+ET-A pigs. Renal hemodynamics, function, and microvascular density were decreased in the stenotic kidney but preserved by ET-A blockade, accompanied by increased renal expression of vascular endothelial growth factor, hepatocyte growth factor, and downstream mediators such as phosphorilated-Akt, angiopoietins, and endothelial nitric oxide synthase. ET-A blockade also reduced renal apoptosis, inflammation, and glomerulosclerosis. This study shows that ET-A blockade slows the progression of renal injury in experimental RVD and preserves renal hemodynamics, function, and microvascular density in the stenotic kidney. These results support a role for ET-1/ET-A as a potential therapeutic target in chronic RVD. PMID:21478482

Renal sympathetic denervation for resistant hypertension.

PubMed

Froeschl, Michael; Hadziomerovic, Adnan; Ruzicka, Marcel

2013-05-01

Resistant hypertension is an increasingly prevalent health problem associated with important adverse cardiovascular outcomes. The pathophysiology that underlies this condition involves increased function of both the sympathetic nervous system and the renin-angiotensin II-aldosterone system. A crucial link between these 2 systems is the web of sympathetic fibres that course within the adventitia of the renal arteries. These nerves can be targeted by applying radiofrequency energy from the lumen of the renal arteries to renal artery walls (percutaneous renal sympathetic denervation [RSD]), an approach that has attracted great interest. This paper critically reviews the evidence supporting the use of RSD. Small studies suggest that RSD can produce dramatic blood pressure reductions: In the randomized Symplicity HTN-2 trial of 106 patients, the mean fall in blood pressure at 6 months in patients who received the treatment was 32/12 mm Hg. However, there are limitations to the evidence for RSD in the treatment of resistant hypertension. These include the small number of patients studied; the lack of any placebo-controlled evidence; the fact that blood pressure outcomes were based on office assessments, as opposed to 24-hour ambulatory monitoring; the lack of longer-term efficacy data; and the lack of long-term safety data. Some of these concerns are being addressed in the ongoing Renal Denervation in Patients With Uncontrolled Hypertension (Symplicity HTN-3) trial. The first percutaneous RSD system was approved by Health Canada in the spring of 2012. But until more and better-quality data are available, this procedure should generally be reserved for those patients whose resistant hypertension is truly uncontrolled. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Tailored dialysis start may allow persistence of residual renal function after graft failure: a case report.

PubMed

Piccoli, G B; Motta, D; Gai, M; Mezza, E; Maddalena, E; Bravin, M; Tattoli, F; Consiglio, V; Burdese, M; Bilucaglia, D; Ferrari, A; Segoloni, G P

2004-11-01

Restarting dialysis after kidney transplantation is a critical step with psychological and clinical implications. Maintenance of residual renal function a known factor affecting survival in chronic kidney disease, has so far not been investigated after a kidney transplantation. A 54-year-old woman who started dialysis in 1974 (first graft, 1975-1999) received a second "marginal" kidney graft in February 2001 (donor age, 65 years). Her chronic therapy was tacrolimus and steroids. She had a clinical history as follows: nadir creatinine level of 1.5 mg/dL, moderate-severe hypertension, progressive graft dysfunction, nonresponsiveness to addition of mycophenolate, tapering FK levels, and a rescue switch from tacrolimus to rapamycin. From October to December 2003, the creatinine level increased from 2-2.8 to 7 mg/dL. Biopsy specimen showed malignant and "benign" nephrosclerosis, posttransplantation glomerulopathy, and tacrolimus toxicity. Chronic dialysis was started (GFR <3 mL/min). Rapamycin was discontinued. Dialysis was tailored to reach an equivalent renal clearance of >15 mL/min (2 sessions/wk). Blood pressure control improved, nephrotoxic drugs were avoided, and fluid loss was minimized (maximum 500 mL/hr). By this policy, renal function progressively increased to GFR >10 mL/min in May 2004, allowing a once or twice weekly dialysis schedule, with good clinical balance, and obvious advantages for the quality of life. This long-term patient, who restarted dialysis with severely reduced renal function, regained sufficient renal function to allow once weekly dialysis. Thus, careful tailoring of dialysis sessions at the restart of dialysis may allow preservation of residual kidney function, at least in individuals for whom a subsequent graft is unlikely.

Effects of carprofen on renal function during medetomidine-propofol-isoflurane anesthesia in dogs.

PubMed

Frendin, Jan H M; Boström, Ingrid M; Kampa, Naruepon; Eksell, Per; Häggström, Jens U; Nyman, Görel C

2006-12-01

To investigate effects of carprofen on indices of renal function and results of serum bio-chemical analyses and effects on cardiovascular variables during medetomidine-propofol-isoflurane anesthesia in dogs. 8 healthy male Beagles. A randomized crossover study was conducted with treatments including saline (0.9% NaCl) solution (0.08 mL/kg) and carprofen (4 mg/kg) administered IV. Saline solution or carprofen was administered 30 minutes before induction of anesthesia and immediately before administration of medetomidine (20 microg/kg, IM). Anesthesia was induced with propofol and maintained with inspired isoflurane in oxygen. Blood gas concentrations and ventilation were measured. Cardiovascular variables were continuously monitored via pulse contour cardiac output (CO) measurement. Renal function was assessed via glomerular filtration rate (GFR), renal blood flow (RBF), scintigraphy, serum biochemical analyses, urinalysis, and continuous CO measurements. Hematologic analysis was performed. Values did not differ significantly between the carprofen and saline solution groups. For both treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses; a transient, significant increase in urine alkaline phosphatase activity; and blood flow diversion to the kidneys. The GFR increased significantly in both groups despite decreased CO, mean arterial pressure, and absolute RBF variables during anesthesia. Carprofen administered IV before anesthesia did not cause detectable, significant adverse effects on renal function during medetomidine-propofol-isoflurane anesthesia in healthy Beagles.

Gastrin stimulates renal dopamine production by increasing the renal tubular uptake of l-DOPA.

PubMed

Jiang, Xiaoliang; Zhang, Yanrong; Yang, Yu; Yang, Jian; Asico, Laureano D; Chen, Wei; Felder, Robin A; Armando, Ines; Jose, Pedro A; Yang, Zhiwei

2017-01-01

Gastrin is a peptide hormone that is involved in the regulation of sodium balance and blood pressure. Dopamine, which is also involved in the regulation of sodium balance and blood pressure, directly or indirectly interacts with other blood pressure-regulating hormones, including gastrin. This study aimed to determine the mechanisms of the interaction between gastrin and dopamine and tested the hypothesis that gastrin produced in the kidney increases renal dopamine production to keep blood pressure within the normal range. We show that in human and mouse renal proximal tubule cells (hRPTCs and mRPTCs, respectively), gastrin stimulates renal dopamine production by increasing the cellular uptake of l-DOPA via the l-type amino acid transporter (LAT) at the plasma membrane. The uptake of l-DOPA in RPTCs from C57Bl/6J mice is lower than in RPTCs from normotensive humans. l-DOPA uptake in renal cortical slices is also lower in salt-sensitive C57Bl/6J than in salt-resistant BALB/c mice. The deficient renal cortical uptake of l-DOPA in C57Bl/6J mice may be due to decreased LAT-1 activity that is related to its decreased expression at the plasma membrane, relative to BALB/c mice. We also show that renal-selective silencing of Gast by the renal subcapsular injection of Gast siRNA in BALB/c mice decreases renal dopamine production and increases blood pressure. These results highlight the importance of renal gastrin in stimulating renal dopamine production, which may give a new perspective in the prevention and treatment of hypertension. Copyright © 2017 the American Physiological Society.

Reduction of Blood Pressure Following After Renal Artery Adventitia Stripping During Total Nephroureterectomy: Potential Effect of Renal Sympathetic Denervation.

PubMed

Okamura, Keisuke; Satou, Shunsuke; Setojima, Keita; Shono, Shinjiro; Miyajima, Shigero; Ishii, Tatsu; Shirai, Kazuyuki; Urata, Hidenori

2018-05-16

BACKGROUND Catheter-based renal sympathetic denervation has been reported to be effective for treatment resistance hypertension in Australia and Europe. However, in the blinded SYMPLICITY HTN-3 trial, renal denervation did not achieve a significant decrease in blood pressure (BP) in comparison to sham controls. There have been various discussions on the factors that influenced this result. CASE REPORT Two men on antihypertensive therapy underwent unilateral radical nephroureterectomy for cancer of the renal pelvis. When the renal artery adventitia was stripped and cauterized just before renal artery ligation, the measured BP of the 2 men increased after stripping adventitia and decreased gradually after cauterization of the renal artery. This was presumably due to removal of renal artery sympathetic nerves, similar to the mechanism of catheter-based renal sympathetic denervation, although anesthesia, fluid infusion, and/or mesenteric traction may have had an influence. CONCLUSIONS A similar strategy involving thoracolumbar sympathectomy was reported about 50 years ago. The clinically significant blood pressure reduction in these patients suggests renal denervation is effective.

Nocturnal and Circadian Rhythm of Blood Pressure Is Associated with Renal Structure Damage and Function in Patients with IgAN.

PubMed

Lin, Lirong; Zhang, Huhai; Yang, Jurong; Zhang, Jianguo; Li, Kailong; Huo, Bengang; Dai, Huanzi; Zhang, Weiwei; Yang, Jie; Tan, Wei; He, Yani

2016-01-01

Abnormal circadian rhythm of blood pressure (BP) is closely related to target organ damage in hypertension. However, the association between abnormal circadian rhythm of BP and renal injury is not clear. We investigated whether renal injury is associated with nocturnal BP and circadian rhythm of BP in Chinese IgAN patients. Clinic and 24 h ambulatory BP monitoring data were obtained from 330 Chinese IgAN patients with mean 24 h BP < 130/80 and mean daytime BP < 135/85 mmHg. Renal histopathological injury was determined according to the Oxford classification of IgAN. Among the 330 IgAN subjects, 35.8% suffered from nocturnal hypertension, 61.5% had abnormal circadian BP, and 27% had nocturnal hypertension with a nondipping pattern. Compared with nocturnal normotensive patients, patients with nocturnal hypertension had significantly higher levels of blood cystatin C, blood uric acid, and lower estimated glomerular filtration rate (eGFR), and significantly a higher mean renal tissue injury score. The nondipping hypertensive group had significantly higher nocturnal diastolic and systolic BP, blood uric acid, and glomerulosclerosis rates, whereas eGFR was lower. In nondipping hypertensive patients, urinary sodium excretion and renal tissue injury scores were significantly higher than dipping patients. Nocturnal hypertension and abnormal circadian BP correlated with renal tissue injury, renal interstitial fibrosis, and aortic arch atherosclerosis. Abnormal circadian rhythm of BP and nocturnal hypertension are common clinical manifestations in Chinese IgAN patients with normal mean 24 h BP. Abnormal circadian BP and nocturnal hypertension may accelerate IgAN progression by inducing renal dysfunction and histopathological damage. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Achieving blood pressure control among renal transplant recipients by integrating electronic health technology and clinical pharmacy services.

PubMed

Migliozzi, Daniel R; Zullo, Andrew R; Collins, Christine; Elsaid, Khaled A

2015-11-15

The implementation and outcomes of a program combining electronic home blood pressure monitoring (HBPM) and pharmacist-provided medication therapy management (MTM) services in a renal transplantation clinic are described. Patients enrolled in the program were provided with a computer-enabled blood pressure monitor. A dedicated renal transplantation pharmacist was integrated into the renal transplantation team under a collaborative care practice agreement. The collaborative care agreement allowed the pharmacist to authorize medication additions, deletions, and dosage changes. Comprehensive disease and blood pressure education was provided by a clinical pharmacist. In the pretransplantation setting, the pharmacist interviewed the renal transplant candidate and documents allergies, verified the patient's medication profile, and identified and assessed barriers to medication adherence. A total of 50 renal transplant recipients with at least one recorded home blood pressure reading and at least one year of follow-up were included in our analysis. A significant reduction in mean systolic and diastolic blood pressure values were observed at 30, 90, 180, and 360 days after enrollment in the program (p < 0.05). Pharmacist interventions were documented for 37 patients. Medication-related problems accounted for 46% of these interventions and included dosage modifications, regimen changes, and mitigation of barriers to medication access and adherence. Implementation of electronic HBPM and pharmacist-provided MTM services implemented in a renal transplant clinic was associated with sustained improvements in blood pressure control. Incorporation of a pharmacist in the renal transplant clinic resulted in the detection and resolution of medication-related problems. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Remission of proteinuria and preservation of renal function in patients with renal AA amyloidosis secondary to rheumatoid arthritis.

PubMed

Ueno, Toshiharu; Takeda, Kazuhito; Nagata, Michio

2012-02-01

Renal AA amyloidosis presents as a life-threatening disease in patients with rheumatoid arthritis (RA). Although several newly developed immunosuppressive drugs have been tried, patients often progress to end-stage renal failure with unsatisfactory survival rate. A total of nine consecutive cases of severe nephrotic renal AA amyloidosis presented to us. Complete remission of proteinuria was observed in four cases (responders), and the remaining five reached the end point of haemodialysis or death (non-responders); these groups were retrospectively compared. The patients were treated with immunosuppressants, biological drugs and anti-hypertensive drugs. Levels of serum creatinine (S-Cr), urinary protein-creatinine ratio (UP/UCr), blood pressure (BP) and C-reactive protein (CRP) were measured. Histological characteristics of renal amyloid deposition and extent of kidney injury were also scored. Prior to treatment, clinical data (S-Cr, UP/UCr, BP and CRP) and histological severity (glomerular sclerosis, tubulointerstitial injury and extent of amyloid deposition) observed in the renal biopsy specimen were not significantly different between the groups. Following therapeutic intervention, proteinuria disappeared (UP/UCr <0.3) in responders within 12 ± 5.4 months but persisted in non-responders. Consequently, renal function stabilized in responders, but it deteriorated in all non-responders. Strict inflammatory control along with optimal control of hypertension was achieved in responders during the treatment. Regardless of histological severity, intensive therapeutic intervention that includes strict inflammatory control and optimal control of hypertension may change the histology-predicted prognosis of RA-associated renal AA amyloidosis.

Oxidative Stress in Hypertension: Role of the Kidney

PubMed Central

Araujo, Magali

2014-01-01

Abstract Significance: Renal oxidative stress can be a cause, a consequence, or more often a potentiating factor for hypertension. Increased reactive oxygen species (ROS) in the kidney have been reported in multiple models of hypertension and related to renal vasoconstriction and alterations of renal function. Nicotinamide adenine dinucleotide phosphate oxidase is the central source of ROS in the hypertensive kidney, but a defective antioxidant system also can contribute. Recent Advances: Superoxide has been identified as the principal ROS implicated for vascular and tubular dysfunction, but hydrogen peroxide (H2O2) has been implicated in diminishing preglomerular vascular reactivity, and promoting medullary blood flow and pressure natriuresis in hypertensive animals. Critical Issues and Future Directions: Increased renal ROS have been implicated in renal vasoconstriction, renin release, activation of renal afferent nerves, augmented contraction, and myogenic responses of afferent arterioles, enhanced tubuloglomerular feedback, dysfunction of glomerular cells, and proteinuria. Inhibition of ROS with antioxidants, superoxide dismutase mimetics, or blockers of the renin-angiotensin-aldosterone system or genetic deletion of one of the components of the signaling cascade often attenuates or delays the onset of hypertension and preserves the renal structure and function. Novel approaches are required to dampen the renal oxidative stress pathways to reduced O2−• rather than H2O2 selectivity and/or to enhance the endogenous antioxidant pathways to susceptible subjects to prevent the development and renal-damaging effects of hypertension. Antioxid. Redox Signal. 20, 74–101. PMID:23472618

Caffeine intake antagonizes salt sensitive hypertension through improvement of renal sodium handling

PubMed Central

Yu, Hao; Yang, Tao; Gao, Peng; Wei, Xing; Zhang, Hexuan; Xiong, Shiqiang; Lu, Zongshi; Li, Li; Wei, Xiao; Chen, Jing; Zhao, Yu; Arendshorst, William J.; Shang, Qianhui; Liu, Daoyan; Zhu, Zhiming

2016-01-01

High salt intake is a major risk factor for hypertension. Although acute caffeine intake produces moderate diuresis and natriuresis, caffeine increases the blood pressure (BP) through activating sympathetic activity. However, the long-term effects of caffeine on urinary sodium excretion and blood pressure are rarely investigated. Here, we investigated whether chronic caffeine administration antagonizes salt sensitive hypertension by promoting urinary sodium excretion. Dahl salt-sensitive (Dahl-S) rats were fed with high salt diet with or without 0.1% caffeine in drinking water for 15 days. The BP, heart rate and locomotor activity of rats was analyzed and urinary sodium excretion was determined. The renal epithelial Na+ channel (ENaC) expression and function were measured by in vivo and in vitro experiments. Chronic consumption of caffeine attenuates hypertension induced by high salt without affecting sympathetic nerve activity in Dahl-S rats. The renal α-ENaC expression and ENaC activity of rats decreased after chronic caffeine administration. Caffeine increased phosphorylation of AMPK and decrease α-ENaC expression in cortical collecting duct cells. Inhibiting AMPK abolished the effect of caffeine on α-ENaC. Chronic caffeine intake prevented the development of salt-sensitive hypertension through promoting urinary sodium excretion, which was associated with activation of renal AMPK and inhibition of renal tubular ENaC. PMID:27173481

Improving the efficacy of RAAS blockade in patients with chronic kidney disease.

PubMed

Lambers Heerspink, Hiddo J; de Borst, Martin H; Bakker, Stephan J L; Navis, Gerjan J

2013-02-01

Reduction of blood pressure and proteinuria by blockade of the renin-angiotensin-aldosterone system (RAAS) has been the cornerstone of renoprotective intervention for patients with chronic kidney disease (CKD) for many years. Despite the proven efficacy of RAAS blockade, however, the reduction in proteinuria is insufficient in many patients, and does not prevent further deterioration of renal function. Short-term studies have shown that a variety of treatment intensification strategies have a beneficial effect on blood pressure and proteinuria, including RAAS blockade using either dose escalation or multiple drugs, and restriction of dietary sodium. Large clinical trials have shown that RAAS blockade with multiple drugs does not improve patients' long-term renal or cardiovascular outcome. By contrast, two post-hoc analyses of landmark trials in nephrology show beneficial renal and cardiovascular effects from avoiding excessive dietary sodium intake during single-agent RAAS blockade therapy. The effects of dietary sodium restriction on renal or cardiovascular outcome still require prospective confirmation. However, current data support the implementation of lifestyle changes to reduce dietary sodium intake in combination with single-agent RAAS blockade, rather than dual-agent RAAS blockade, as a potent and feasible strategy to mitigate the burden of renal and cardiovascular disease in patients with CKD.

Renal parameter estimates in unrestrained dogs

NASA Technical Reports Server (NTRS)

Rader, R. D.; Stevens, C. M.

1974-01-01

A mathematical formulation has been developed to describe the hemodynamic parameters of a conceptualized kidney model. The model was developed by considering regional pressure drops and regional storage capacities within the renal vasculature. Estimation of renal artery compliance, pre- and postglomerular resistance, and glomerular filtration pressure is feasible by considering mean levels and time derivatives of abdominal aortic pressure and renal artery flow. Changes in the smooth muscle tone of the renal vessels induced by exogenous angiotensin amide, acetylcholine, and by the anaesthetic agent halothane were estimated by use of the model. By employing totally implanted telemetry, the technique was applied on unrestrained dogs to measure renal resistive and compliant parameters while the dogs were being subjected to obedience training, to avoidance reaction, and to unrestrained caging.

Prognostic value of renal fractional flow reserve in blood pressure response after renal artery stenting (PREFER study).

PubMed

Kądziela, Jacek; Januszewicz, Andrzej; Prejbisz, Aleksander; Michałowska, Ilona; Januszewicz, Magdalena; Florczak, Elżbieta; Kalińczuk, Łukasz; Norwa-Otto, Bożena; Warchoł, Ewa; Witkowski, Adam

2013-01-01

The aim of our study was to determine a potential relationship between resting translesional pressures ratio (Pd/Pa ratio), renal fractional flow reserve (rFFR) and blood pressure response after renal artery stenting. Thirty five hypertensive patients (49% males, mean age 64 years) with at least 60% stenosis in angiography, underwent renal artery stenting. Translesional systolic pressure gradient (TSPG), Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were measured before stent implantation. Ambulatory blood pressure measurements (ABPM) were recorded before the procedure and after 6 months. The ABPM results were presented as blood pressure changes in subgroups of patients with normal (≥ 0.9) vs. abnormal (< 0.9) Pd/Pa ratio and normal (≥ 0.8) vs. abnormal (< 0.8) rFFR. Median Pd/Pa ratio was 0.84 (interquartile range 0.79-0.91) and strongly correlated with TSPG (r = -0.89, p < 0.001), minimal lumen diameter (MLD; r = 0.53, p < 0.005) and diameter stenosis (DS; r = -0.51, p < 0.005). Median rFFR was 0.78 (0.72-0.82). Similarly, significant correlation between rFFR and TSPG (r = -0.86, p < 0.0001), as well as with MLD (r = 0.50, p < 0.005) and DS (r = -0.51, p < 0.005) was observed. Procedural success was obtained in all patients. Baseline Pd/Pa ratio and rFFR did not predict hypertension response after renal artery stenting. Median changes of 24-h systolic/diastolic blood pressure were comparable in patients with abnormal vs. normal Pd/Pa ratio (-4/-3 vs. 0/2 mm Hg; p = NS) and with abnormal vs. normal rFFR (-2/-1 vs. -2/-0.5 mm Hg, respectively). Physiological assessment of renal artery stenosis using Pd/Pa ratio and papaverine- induced renal fractional fl ow reserve did not predict hypertension response after renal artery stenting.

The coexistence of renal artery stenosis and pheochromocytoma.

PubMed Central

Hill, F S; Jander, H P; Murad, T; Diethelm, A G

1983-01-01

The coexistence of renal artery stenosis and pheochromocytoma has been recognized since 1958 and a total of 36 patients reported. This article provides an additional patient with an extra adrenal pheochromocytoma and fibrous bands constricting the left renal artery. Hypertension was confirmed to occur from both excess catecholamine production and hyperreninemia from the left kidney. Surgical removal of the functioning paraganglioma and correction of the renal artery stenosis restored the postoperative plasma catecholamine, renin, and blood pressure to normal. A literature review confirmed the coexistence of these two lesions but failed to provide a common etiology to explain the pathophysiology encountered. However, when the two diseases occur simultaneously, both must be diagnosed accurately and treated in a definitive manner. Images Figs. 1a and b. Figs. 2a and b. PMID:6830355

The impact of serum uric acid reduction on renal function and blood pressure in chronic kidney disease patients with hyperuricemia.

PubMed

Tsuji, Takayuki; Ohishi, Kazuhisa; Takeda, Asumi; Goto, Daiki; Sato, Taichi; Ohashi, Naro; Fujigaki, Yoshihide; Kato, Akihiko; Yasuda, Hideo

2018-04-26

Febuxostat is tolerable in chronic kidney disease (CKD) patients with hyperuricemia. However, the long-term effect of lowering uric acid with febuxostat on renal function and blood pressure has not been elucidated. This was a 2 years retrospective observational study. 86 CKD patients with hyperuricemia who continued with allopurinol (allopurinol group, n = 30), switched from allopurinol to febuxostat (switched group, n = 25), or were newly prescribed febuxostat (febuxostat group, n = 31) were included in this study. Serum uric acid, estimated glomerular filtration rate (eGFR), blood pressure, and urinary protein were analyzed. Moreover, the impact of serum uric acid reduction on renal function and blood pressure was assessed. Serum uric acid in the switched and febuxostat groups was significantly reduced at 6 months (switched group; 8.49 ± 1.32-7.19 ± 1.14 mg/dL, p < 0.0001, febuxostat group; 9.43 ± 1.63-6.31 ± 0.90 mg/dL, p < 0.0001). In the allopurinol group, serum uric acid was increased (6.86 ± 0.87-7.10 ± 0.85 mg/dL, p = 0.0213). eGFR was significantly increased (35.2 ± 12.8-37.3 ± 13.9 mL/min/1.73 m 2 , p = 0.0232), while mean arterial pressure (93.1 ± 10.8-88.2 ± 9.5 mmHg, p = 0.0039) was significantly decreased at 6 months in the febuxostat group, resulting in the retention of eGFR for 2 years. The impact of serum uric acid reduction might have beneficial effects on CKD progression and blood pressure. However, a large prospective study is needed to determine the long-term efficacy of febuxostat therapy in CKD patients with hyperuricemia.

Automated electronic monitoring of circuit pressures during continuous renal replacement therapy: a technical report.

PubMed

Zhang, Ling; Baldwin, Ian; Zhu, Guijun; Tanaka, Aiko; Bellomo, Rinaldo

2015-03-01

Automated electronic monitoring and analysis of circuit pressures during continuous renal replacement therapy (CRRT) has the potential to predict failure and allow intervention to optimise function. Current CRRT machines can measure and store pressure readings for downloading into databases and for analysis. We developed a procedure to obtain such data at intervals of 1 minute and analyse them using the Prismaflex CRRT machine, and we present an example of such analysis. We obtained data on pressures obtained at intervals of 1 minute in a patient with acute kidney injury and sepsis treated with continuous haemofiltration at 2 L/hour of ultrafiltration and a blood flow of 200 mL/minute. Data analysis identified progressive increases in transmembrane pressure (TMP) and prefilter pressure (PFP) from time 0 until 33 hours or clotting. TMP increased from 104 mmHg to 313 mmHg and PFP increased from from 131 mmHg to 185 mmHg. Effluent pressure showed a progressive increase in the negative pressure applied to achieve ultrafiltration from 0 mmHg to -168 mmHg. The inflection point for such changes was also identified. Blood pathway pressures for access and return remained unchanged throughout. Automated electronic monitoring of circuit pressure during CRRT is possible and provides useful information on the evolution of circuit clotting.

Lactic acidosis and hyperamylasaemia associated with phenformin therapy

PubMed Central

Williams, D. N.; Knight, A. H.; Goldberg, D. M.

1974-01-01

A case is described of lactic acidosis and hyperamylasaemia in a diabetic with impaired renal function treated with phenformin. Despite normal blood pressure and adequate tissue perfusion, the patient succumbed. No evidence of pancreatitis could be found at autopsy. PMID:4219857

Salt sensitivity of children with low birth weight.

PubMed

Simonetti, Giacomo D; Raio, Luigi; Surbek, Daniel; Nelle, Mathias; Frey, Felix J; Mohaupt, Markus G

2008-10-01

Compromised intrauterine fetal growth leading to low birth weight (<2500 g) is associated with adulthood renal and cardiovascular disease. The aim of this study was to assess the effect of salt intake on blood pressure (salt sensitivity) in children with low birth weight. White children (n=50; mean age: 11.3+/-2.1 years) born with low (n=35) or normal (n=15) birth weight and being either small or appropriate for gestational age (n=25 in each group) were investigated. The glomerular filtration rate was calculated using the Schwartz formula, and renal size was measured by ultrasound. Salt sensitivity was assigned if mean 24-hour blood pressure increased by >or=3 mm Hg on a high-salt diet as compared with a controlled-salt diet. Baseline office blood pressure was higher and glomerular filtration rate lower in children born with low birth weight as compared with children born at term with appropriate weight (P<0.05). Salt sensitivity was present in 37% and 47% of all of the low birth weight and small for gestational age children, respectively, higher even than healthy young adults from the same region. Kidney length and volume (both P<0.0001) were reduced in low birth weight children. Salt sensitivity inversely correlated with kidney length (r(2)=0.31; P=0.005) but not with glomerular filtration rate. We conclude that a reduced renal mass in growth-restricted children poses a risk for a lower renal function and for increased salt sensitivity. Whether the changes in renal growth are causative or are the consequence of the same abnormal "fetal programming" awaits clarification.

Tumor necrosis factor-α: regulation of renal function and blood pressure

PubMed Central

Garvin, Jeffrey L.

2013-01-01

Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine that becomes elevated in chronic inflammatory states such as hypertension and diabetes and has been found to mediate both increases and decreases in blood pressure. High levels of TNF-α decrease blood pressure, whereas moderate increases in TNF-α have been associated with increased NaCl retention and hypertension. The explanation for these disparate effects is not clear but could simply be due to different concentrations of TNF-α within the kidney, the physiological status of the subject, or the type of stimulus initiating the inflammatory response. TNF-α alters renal hemodynamics and nephron transport, affecting both activity and expression of transporters. It also mediates organ damage by stimulating immune cell infiltration and cell death. Here we will summarize the available findings and attempt to provide plausible explanations for such discrepancies. PMID:23515717

ROLE OF SYMPATHETIC NERVOUS SYSTEM IN OBESITY RELATED HYPERTENSION

PubMed Central

da Silva, Alexandre; doCarmo, Jussara; Dubinion, John; Hall, John E.

2010-01-01

Obesity is recognized as a major, worldwide, health problem. Excess weight is a major cause of increased blood pressure in most patients with essential hypertension, and greatly increases the risk for diabetes, cardiovascular diseases, and end stage renal disease. Although the mechanisms by which obesity raises blood pressure are not completely understood, increased renal sodium reabsorption, impaired pressure natriuresis, and volume expansion appear to play important roles. Several potential mechanisms have been suggested to contribute to altered kidney function and hypertension in obesity, including activation of the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS), and physical compression of the kidneys, especially when visceral obesity is present. Activation of the SNS in obesity may be due, in part, to hyperleptinemia and other factors secreted by adipocytes and the gastrointestinal tract, activation of the central nervous melanocortin pathway, and baroreceptor dysfunction. PMID:19442330

Donors with renal artery stenosis: fit to donate.

PubMed

Reddy, Vemuru Sunil K; Guleria, Sandeep; Bora, Girdhar S

2012-05-01

Kidney donation from hypertensive donors is now an accepted norm in live related kidney transplantation. The use of hypertensive donors with renal artery stenosis due to atherosclerosis and fibromuscular dysplasia is still debated. The prime concern is about the deleterious effect of hypertension on the donor and the risk of recurrence of such lesions in the solitary kidney. Even as the response of atherosclerotic renal artery stenosis to revascularisation is unpredictable, there is an improvement in blood pressure following revascularisation of kidneys with fibro-muscular dysplasia. The first use of such kidney donors was reported in 1984 and, since then, there have been a few reports of successful use of kidneys from donors with renal artery stenosis. We report here two interesting cases of successful transplantation of kidneys from live related kidney donors with hypertension due to renal artery stenosis who became normotensive with good graft function in the recipient. We conclude that moderately hypertensive donors with renal artery stenosis are fit to donate.

Renal arterial resistive index is associated with severe histological changes and poor renal outcome during chronic kidney disease

PubMed Central

2012-01-01

Background Chronic kidney disease (CKD) is a growing public health problem and end stage renal disease (ESRD) represents a large human and economic burden. It is important to identify patients at high risk of ESRD. In order to determine whether renal Doppler resistive index (RI) may discriminate those patients, we analyzed whether RI was associated with identified prognosis factors of CKD, in particular histological findings, and with renal outcome. Methods RI was measured in the 48 hours before renal biopsy in 58 CKD patients. Clinical and biological data were collected prospectively at inclusion. Arteriosclerosis, interstitial fibrosis and glomerulosclerosis were quantitatively assessed on renal biopsy in a blinded fashion. MDRD eGFR at 18 months was collected for 35 (60%) patients. Renal function decline was defined as a decrease in eGFR from baseline of at least 5 mL/min/ 1.73 m2/year or need for chronic renal replacement therapy. Pearson’s correlation, Mann–Whitney and Chi-square tests were used for analysis of quantitative and qualitative variables respectively. Kaplan Meier analysis was realized to determine renal survival according to RI value using the log-rank test. Multiple logistic regression was performed including variables with p < 0.20 in univariate analysis. Results Most patients had glomerulonephritis (82%). Median age was 46 years [21–87], eGFR 59 mL/min/ 1.73m2 [5–130], percentage of interstitial fibrosis 10% [0–90], glomerulosclerosis 13% [0–96] and RI 0.63 [0.31-1.00]. RI increased with age (r = 0.435, p = 0.0063), pulse pressure (r = 0.303, p = 0.022), renal atrophy (r = −0.275, p = 0.038) and renal dysfunction (r = −0.402, p = 0.0018). Patients with arterial intima/media ratio ≥ 1 (p = 0.032), interstitial fibrosis > 20% (p = 0.014) and renal function decline (p = 0.0023) had higher RI. Patients with baseline RI ≥ 0.65 had a poorer renal outcome than those with baseline RI < 0.65 (p = 0.0005). In multiple logistic regression, RI≥0.65 was associated with accelerated renal function decline independently of baseline eGFR and proteinuria/creatininuria ratio (OR=13.04 [1.984-85.727], p = 0.0075). Sensitivity, specificity, predictive positive and predictive negative values of RI ≥ 0.65 for renal function decline at 18 months were respectively 77%, 86%, 71% and 82%. Conclusions Our results suggest that RI ≥ 0.65 is associated with severe interstitial fibrosis and arteriosclerosis and renal function decline. Thus, RI may contribute to identify patients at high risk of ESRD who may benefit from nephroprotective treatments. PMID:23098365

Neutrophil-to-lymphocyte ratio as a predictor of worsening renal function in diabetic patients (3-year follow-up study).

PubMed

Azab, Basem; Daoud, Jacques; Naeem, Fahad Ben; Nasr, Rabih; Ross, Jennifer; Ghimire, Pratima; Siddiqui, Ayesha; Azzi, Nadine; Rihana, Nancy; Abdallah, Marie; Azzi, Nassif; Patel, Parishram; Kleiner, Morton; El-Sayegh, Suzanne

2012-01-01

Previous studies have demonstrated the role of inflammation in diabetic nephropathy (DN). Neutrophil to lymphocyte ratio (NLR) rather than other white cell parameters was found to be a useful inflammatory marker to predict adverse outcomes in medical and surgical conditions. Nevertheless, the value of NLR in predicting DN has not been elucidated. An observational study included 338 diabetic patients, who were followed at our clinic between 2007 and 2009. We arranged our patients into tertiles according to their 2007 NLR. The primary outcome was continuous decrease of GFR >12 mL/min between 2007 and 2009 with the last GFR <60 mL/min. The lowest NLR tertile had fewer patients (2.7%) with primary outcome (i.e., worsening renal function) compared with middle and highest NLR tertiles, which had more patients with primary outcomes (8.7% and 11.5%, respectively) with a significant p-value 0.0164. When other potential confounders were individually analyzed with NLR tertile, the NLR tertiles remained a significant predictor of poor GFR outcome in the presence of other variables (hemoglobin A1C, systolic blood pressure, diastolic blood pressure, age, and congestive heart failure with p-values 0.018, 0.019, 0.017, 0.033, and 0.022, respectively). NLR predicted the worsening of the renal function in diabetic patients. Further studies are needed to confirm this result.

Dual therapy of vildagliptin and telmisartan on diabetic nephropathy in experimentally induced type 2 diabetes mellitus rats.

PubMed

Sharma, Ashish Kumar; Kanawat, Devendra Singh; Mishra, Akanksha; Dhakad, Prashant Kumar; Sharma, Prashant; Srivastava, Varnika; Joshi, Sneha; Joshi, Megha; Raikwar, Sachin Kumar; Kurmi, Muneem Kumar; Srinivasan, Bharthu Parthsarthi

2014-12-01

The objective of this article is to investigate the combination of telmisartan with vildagliptin therapy versus monotherapy of vildagliptin and telmisartan on diabetic nephropathy in type 2 diabetes mellitus rats. In adult rats streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg) were injected intraperitoneally to produce diabetic nephropathy. Rats of either sex allotted to the following groups: (i) triple therapy: metformin (120 mg/kg, o.d.) + pioglitazone (1.25 mg/kg, o.d.) + glimepiride (0.7 mg/kg, o.d.); (ii) dual therapy: vildagliptin (8.76 mg/kg, o.d.) + telmisartan (6.48 mg/kg, o.d.); (iii) vildagliptin (8.76 mg/kg, o.d.); and (iv) telmisartan (6.48 mg/kg, o.d.); therapy was carried out for 35 days orally. Weekly at days 7, 14, 21, 28 and 35, blood pressure, blood glucose level, body weight, blood serum creatinine level, protein albumin level in urine, and blood urea nitrogen (BUN) were estimated. Renal structural changes were observed. Blood pressure, blood glucose level, blood serum creatinine level, protein albumin level in urine, BUN and renal deterioration increased significantly in diabetic rats compared with normal control rats. The vildagliptin + telmisartan treatment group showed no weight gain and controlled blood pressure, renovascular structural and biochemical parameters in diabetic neuropathy rats. The addition of telmisartan to vildagliptin demonstrated the best control over blood pressure, glycemia and diabetic nephropathy markers, renal structural changes and improvement of renal function as opposed to monotherapy with either drug, possibly because of the dual inhibitory effect on the renin-angiotensin system. © The Author(s) 2013.

Endpoint design for future renal denervation trials - Novel implications for a new definition of treatment response to renal denervation.

PubMed

Lambert, Thomas; Nahler, Alexander; Rohla, Miklos; Reiter, Christian; Grund, Michael; Kammler, Jürgen; Blessberger, Hermann; Kypta, Alexander; Kellermair, Jörg; Schwarz, Stefan; Starnawski, Jennifer A; Lichtenauer, Michael; Weiss, Thomas W; Huber, Kurt; Steinwender, Clemens

2016-10-01

Defining an adequate endpoint for renal denervation trials represents a major challenge. A high inter-individual and intra-individual variability of blood pressure levels as well as a partial or total non-adherence on antihypertensive drugs hamper treatment evaluations after renal denervation. Blood pressure measurements at a single point in time as used as primary endpoint in most clinical trials on renal denervation, might not be sufficient to discriminate between patients who do or do not respond to renal denervation. We compared the traditional responder classification (defined as systolic 24-hour blood pressure reduction of -5mmHg six months after renal denervation) with a novel definition of an ideal respondership (based on a 24h blood pressure reduction at no point in time, one, or all follow-up timepoints). We were able to re-classify almost a quarter of patients. Blood pressure variability was substantial in patients traditionally defined as responders. On the other hand, our novel classification of an ideal respondership seems to be clinically superior in discriminating sustained from pseudo-response to renal denervation. Based on our observations, we recommend that the traditional response classification should be reconsidered and possibly strengthened by using a composite endpoint of 24h-BP reductions at different follow-up-visits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of Huanshuai Recipe Oral Liquid ([characters: see text]) on renal dysfunction progression in patients with atherosclerotic renal artery stenosis.

PubMed

Wang, Xiu-juan; Rao, Xiang-rong; Li, Shen; Wang, Li; Liu, Chang; Zhang, Gai-hua; Han, Dong-yan; Zhao, Yu; Zhang, Nan-nan; Li, Xue-xia; Chen, Shuai

2015-11-01

To investigate the effect of Huanshuai Recipe Oral Liquid ([characters: see text], HSR) on retarding the progression of renal dysfunction in patients with atherosclerotic renal artery stenosis (ARAS). A total of 52 ARAS patients with the Chinese medicine (CM) syndrome of qi deficiency and blood stasis, phlegm and dampness retention were recruited and randomly assigned into the treatment group (36 cases) and the control group (16 cases). Both groups received a basic treatment (high-quality low-protein diet, blood pressure control, lipid-lowering, correcting the acidosis, etc.). In addition, the treatment group received 20 mL HSR and the control group received placebo, 3 times a day for 6 months. Renal function (serum creatinine, blood urea nitrogen and uric acid) and blood lipids (cholesterol, triglycerides and low density lipoprotein) were examined monthly. The estimated glomerular filtration rate (eGFR) and CM syndrome score were compared between groups. After treatment, compared with the control group, the serum creatinine level, uric acid level and CM syndrome score of the treatment group were significantly decreased (P<0.05 or P<0.01), and the eGFR in the treatment group were significantly increased (P<0.05). HSR can effectively improve the renal function and clinical symptoms of ARAS patients.

Prediction of primary vs secondary hypertension in children.

PubMed

Baracco, Rossana; Kapur, Gaurav; Mattoo, Tej; Jain, Amrish; Valentini, Rudolph; Ahmed, Maheen; Thomas, Ronald

2012-05-01

Despite current guidelines, variability exists in the workup of hypertensive children due to physician preferences. The study evaluates primary vs secondary hypertension diagnosis from investigations routinely performed in hypertensive children. This retrospective study included children 5 to 19 years with primary and secondary hypertension. The proportions of abnormal laboratory and imaging tests were compared between primary and secondary hypertension groups. Risk factors for primary vs secondary hypertension were evaluated by logistic regression and likelihood function analysis. Patients with secondary hypertension were younger (5-12 years) and had a higher proportion of abnormal creatinine, renal ultrasound, and echocardiogram findings. There was no significant difference in abnormal results of thyroid function, urine catecholamines, plasma renin, and aldosterone. Abnormal renal ultrasound findings and age were predictors of secondary hypertension by regression and likelihood function analysis. Children aged 5 to 12 years with abnormal renal ultrasound findings and high diastolic blood pressures are at higher risk for secondary hypertension that requires detailed evaluation. © 2012 Wiley Periodicals, Inc.

Reflex effects on renal nerve activity characteristics in spontaneously hypertensive rats.

PubMed

DiBona, G F; Jones, S Y; Sawin, L L

1997-11-01

The effects of arterial and cardiac baroreflex activation on the discharge characteristics of renal sympathetic nerve activity were evaluated in conscious spontaneously hypertensive and Wistar-Kyoto rats. In spontaneously hypertensive rats compared with Wistar-Kyoto rats, (1) arterial baroreflex regulation of renal sympathetic nerve activity was reset to a higher arterial pressure and the gain was decreased and (2) cardiac baroreflex regulation of renal sympathetic nerve activity exhibited a lower gain. With the use of sympathetic peak detection analysis, the inhibition of integrated renal sympathetic nerve activity, which occurred during both increased arterial pressure (arterial baroreflex) and right atrial pressure (cardiac baroreflex), was due to parallel decreases in peak height with little change in peak frequency in both spontaneously hypertensive and Wistar-Kyoto rats. Arterial and cardiac baroreflex inhibition of renal sympathetic nerve activity in Wistar-Kyoto and spontaneously hypertensive rats is due to a parallel reduction in the number of active renal sympathetic nerve fibers.

Renal sympathetic nerve ablation for treatment-resistant hypertension

PubMed Central

Krum, Henry; Schlaich, Markus; Sobotka, Paul

2013-01-01

Hypertension is a major risk factor for increased cardiovascular events with accelerated sympathetic nerve activity implicated in the pathogenesis and progression of disease. Blood pressure is not adequately controlled in many patients, despite the availability of effective pharmacotherapy. Novel procedure- as well as device-based strategies, such as percutaneous renal sympathetic nerve denervation, have been developed to improve blood pressure in these refractory patients. Renal sympathetic denervation not only reduces blood pressure but also renal as well as systemic sympathetic nerve activity in such patients. The reduction in blood pressure appears to be sustained over 3 years after the procedure, which suggests absence of re-innervation of renal sympathetic nerves. Safety appears to be adequate. This approach may also have potential in other disorders associated with enhanced sympathetic nerve activity such as congestive heart failure, chronic kidney disease and metabolic syndrome. This review will focus on the current status of percutaneous renal sympathetic nerve denervation, clinical efficacy and safety outcomes and prospects beyond refractory hypertension. PMID:23819768

Effects of high-tone external muscle stimulation on renal function in healthy volunteers.

PubMed

Peckova, Miroslava; Havlin, Jan; Charvat, Jiri; Horackova, Miroslava; Schück, Otto

2013-01-01

Hightone external muscle stimulation (HTEMS) ameliorates pain and discomfort of patients with polyneuropathy. Since some patients reported about an urge to urinate during these treatments, the potential effects of HTEMS application on renal function were investigated. For this purpose in healthy subjects, we analyzed in the current study the acute effects of electrotherapy on parameters of renal function. 24 healthy volunteers (14 women and 10 men), mean age 26 ± 4 years, were enrolled. The protocol was composed of a run-in period, a pre-treatment period, the active HTEMS treatment period of both lower extremities and the post-treatment period. The duration of each period was 60 min. Urine collection and blood samples were taken at the beginning and end of each period. To achieve a sufficient diuresis, the fluid intake was adapted to the amount of diuresis. Parameters of renal function included diuresis, glomerular filtration rate (endogenous creatinine clearance) and absolute and fractional sodium excretion. Moreover blood pressure and heart rate were monitored. HTEMS led to a significant increase of creatinine clearance and fractional sodium excretion which was limited to the active treatment period. These findings show for the first time that HTEMS can transiently increase glomerular filtration rate associated with a decreased tubular sodium reabsorption. The underlying mechanisms are to be elucidated.

Baroreflex activation therapy in patients with prior renal denervation.

PubMed

Wallbach, Manuel; Halbach, Marcel; Reuter, Hannes; Passauer, Jens; Lüders, Stephan; Böhning, Enrico; Zenker, Dieter; Müller, Gerhard A; Wachter, Rolf; Koziolek, Michael J

2016-08-01

Both baroreflex activation therapy (BAT) and renal denervation modulate sympathetic activity. The aim of this study was to systematically investigate whether additive modulation of autonomic nervous system by BAT lowers blood pressure (BP) in patients who still suffer from uncontrolled resistant hypertension despite prior renal denervation. From 2012 to January 2015, patients treated with BAT for uncontrolled resistant hypertension, who prior received renal denervation were consecutively analyzed in four German centers for hypertension. Analyses of office BP, 24-h ambulatory BP, central hemodynamics, parameters of renal function were performed. A total of 28 patients, who underwent renal denervation at least 5 months before and still suffer from uncontrolled BP, were subsequently treated with BAT. The office SBP decreased from 182 ± 28 to 163 ± 27 mmHg (P < 0.01) with a responder rate of 68% (office SBP reduction ≥10 mmHg) at month 6, whereas the number of prescribed antihypertensive drug classes remained unchanged (6.2 ± 1.5 vs. 6.0 ± 1.7, P = 0.30). Serum creatinine, estimated glomerular filtration rate and cystatin C remained stable (P = 1.00, P = 0.41 and P = 0.22, respectively), whereas albuminuria was significantly reduced by a median of -29% (P = 0.02). Central SBP (-15 ± 24 mmHg, P = 0.047) and end systolic pressure (-14 ± 20 mmHg, P = 0.03) were significantly reduced. The present data demonstrate that BAT may exert BP-lowering as well as antiproteinuric effects in patients with prior renal denervation. However, precise evaluation of BAT effects in patients with prior renal denervation will need randomized controlled trials using sham procedures.

Regulation of oxygen utilization by angiotensin II in chronic kidney disease

PubMed Central

Deng, Aihua; Tang, Tong; Singh, Prabhleen; Wang, Chen; Satriano, Joe; Thomson, Scott C; Blantz, Roland C

2010-01-01

Angiotensin II (ANG II) blockade delays progression of chronic kidney disease (CKD) by modifying intrarenal hemodynamics, but the effect on metabolic adaptations has not been examined. Using renal ablation/infarction (A/I) model of CKD in rats at one week, the effects of ANG II blockade by captopril (CAP) and losartan (LOS) on renal O2 consumption (QO2), renal nitric oxide (NO) activity and nitric oxide synthase (NOS) protein expression was examined. A/I kidneys exhibited proteinuria, reduced GFR, renal blood flow (RBF) and NOS-1 protein expression, while QO2 factored by sodium reabsorption (QO2/TNa) was markedly increased. CAP + LOS treatment increased GFR, RBF, and TNa, while QO2 remained unchanged, thus normalizing QO2/TNa. NOS-1 expression was normalized with CAP + LOS, as was proteinuria. Triple antihypertensive therapy administered to control for the blood pressure reduction, and lysine administration to increase GFR and RBF, did not normalize QO2/TNa, suggesting a specific effect of ANG II in elevating QO2/TNa. NOS blockade, to test functional NO activity on QO2 and QO2/TNa, increased QO2 in shams, but not in untreated A/I. The increase in QO2 was restored in CAP + LOS treated A/I. CAP + LOS treatment normalized the increased QO2/TNa and functional NO activity in A/I independent of the blood pressure and GFR effects, providing evidence for an additional mechanism underlying the benefits of ANG II inhibition therapy. PMID:18818681

Long-term treatment of severe hypertension with minoxidil.

PubMed Central

Nawar, T.; Nolin, L.; Plante, G. E.; Caron, C.; Montambault, P.

1977-01-01

Minoxidil, a new potent hypotensive agent, was used as the primary antihypertensive agent in 11 patients--10 men and 1 woman aged 35 to 54 years with severe hypertension that was refractory to treatment with maximal (or maximally tolerated) doses of conventional antihypertensive agents. Six patients had severely impaired renal function and three of them were undergoing long-term hemodialysis. The patients were given 2.5 to 40 mg/d of minoxidil for periods of 2 to 29 months. All except one who was almost anuric received propranolol and diuretics. Blood pressure was controlled satisfactorily in all patients. In two patients the hypertension became partially resistant after 1 year of treatment. The main side effects were sodium retention, tachycardia and hirsutism. Renal function remained stable or improved and hemodialysis was discontinued in two patients. Minoxidil is a remarkably potent hypotensive with relatively few side effects and seems particularly advantageous in patients with chronic renal failure. PMID:603847

Common Drugs for Stabilization of Renal Function in the Progression of Diabetic Nephropathy and Their Relations with Hypertension Therapy.

PubMed

Wang, Yuxuan; Wang, Chengcheng; Zhang, Xiuli; Gu, Harvest F; Wu, Liang

2018-01-01

Diabetic nephropathy is characterized by hypertension, progressive albuminuria, glomerulosclerosis and declines in glomerular filtration rate leading to end stage renal disease. Although the pathogenesis of diabetic nephropathy is not fully understood, current treatment of the patients with diabetic nephropathy is mainly based upon the control of hyperglycaemia and management of blood pressures. Several drugs, which are originally developed for hypertension therapy, have been adopted for stabilization of renal function in diabetic nephropathy. In this review, we first discussed the relationships between diabetic nephropathy and hypertension particularly in the renin-angiotensinaldosterone system. We then summarized chemical structures, pharmacological characteristics and clinical studies of the common drugs used for treatment of diabetic nephropathy, while these drugs have effects against hypertension. This review may provide the constructive information for further drug development in diabetic nephropathy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of reducing blood pressure on renal outcomes in patients with type 2 diabetes: Focus on SGLT2 inhibitors and EMPA-REG OUTCOME.

PubMed

Scheen, A J; Delanaye, P

2017-04-01

Empagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, has enabled remarkable reductions in cardiovascular and all-cause mortality as well as in renal outcomes in patients with type 2 diabetes (T2D) and a history of cardiovascular disease in the EMPA-REG OUTCOME. These results have been attributed to haemodynamic rather than metabolic effects, in part due to the osmotic/diuretic action of empagliflozin and the reduction in arterial blood pressure (BP). The present narrative review includes the results of meta-analyses of trials evaluating the effects on renal outcomes of lowering BP in patients with T2D, with a special focus on the influence of baseline and achieved systolic BP, and compares the renal outcome results of the EMPA-REG OUTCOME with those of other major trials with inhibitors of the renin-angiotensin system in patients with T2D and the preliminary findings with other SGLT2 inhibitors, and also evaluates post hoc analyses from the EMPA-REG OUTCOME of special interest as regards the BP-lowering hypothesis and renal function. While systemic BP reduction associated to empagliflozin therapy may have contributed to the renal benefits reported in EMPA-REG OUTCOME, other local mechanisms related to kidney homoeostasis most probably also played a role in the overall protection observed in the trial. Copyright © 2017. Published by Elsevier Masson SAS.

Sympatho-renal axis in chronic disease.

PubMed

Sobotka, Paul A; Mahfoud, Felix; Schlaich, Markus P; Hoppe, Uta C; Böhm, Michael; Krum, Henry

2011-12-01

Essential hypertension, insulin resistance, heart failure, congestion, diuretic resistance, and functional renal disease are all characterized by excessive central sympathetic drive. The contribution of the kidney's somatic afferent nerves, as an underlying cause of elevated central sympathetic drive, and the consequences of excessive efferent sympathetic signals to the kidney itself, as well as other organs, identify the renal sympathetic nerves as a uniquely logical therapeutic target for diseases linked by excessive central sympathetic drive. Clinical studies of renal denervation in patients with resistant hypertension using an endovascular radiofrequency ablation methodology have exposed the sympathetic link between these conditions. Renal denervation could be expected to simultaneously affect blood pressure, insulin resistance, sleep disorders, congestion in heart failure, cardiorenal syndrome and diuretic resistance. The striking epidemiologic evidence for coexistence of these disorders suggests common causal pathways. Chronic activation of the sympathetic nervous system has been associated with components of the metabolic syndrome, such as blood pressure elevation, obesity, dyslipidemia, and impaired fasting glucose with hyperinsulinemia. Over 50% of patients with essential hypertension are hyperinsulinemic, regardless of whether they are untreated or in a stable program of treatment. Insulin resistance is related to sympathetic drive via a bidirectional mechanism. In this manuscript, we review the data that suggests that selective impairment of renal somatic afferent and sympathetic efferent nerves in patients with resistant hypertension both reduces markers of central sympathetic drive and favorably impacts diseases linked through central sympathetics-insulin resistance, heart failure, congestion, diuretic resistance, and cardiorenal disorders.

Acute baroreflex resetting: differential control of pressure and nerve activity.

PubMed

Drummond, H A; Seagard, J L

1996-03-01

This study evaluated acute resetting of carotid baroreflex control of arterial blood pressure and renal or thoracic sympathetic nerve activity in thiopental-anesthetized mongrel dogs with the use of a vascularly isolated carotid sinus preparation, the experimental model used previously to characterize acute resetting in carotid baroreceptor afferent fibers. Carotid baroreceptors were conditioned with a pulsatile pressure for 20 minutes at three pressure ranges: low (50 to 75 mm Hg), mid (100 to 125), or high (150 to 175). Blood pressure and nerve activity were recorded in response to slow ramp increases in sinus pressure; nonlinear regression and best-fit analyses were used for determination of curve fit parameters of the blood pressure and nerve activity versus sinus pressure response curves. Carotid sinus pressure thresholds for blood pressure and renal nerve activity responses at all conditioning pressures were significantly different; however, only the pressure threshold for thoracic nerve activity at the low conditioning pressure was significantly different from the responses at other conditioning pressures. Average renal activity resetting (0.506 +/- 0.072) was significantly greater than blood pressure resetting (0.335 +/- 0.046) in the same dogs, and thoracic activity (0.200 +/- 0.057) was not different from blood pressure resetting (0.194 +/- 0.031) in the same dogs. In a previous investigation, our laboratory had demonstrated that type 1 carotid baroreceptors acutely reset at a value of about 0.15. These results indicate that (1) renal and thoracic nerve activities and blood pressure acutely reset to a greater degree than type 1 carotid baroreceptors and that (2) renal activity acutely resets to a greater degree than blood pressure and thoracic nerve activity.

The impact of non-dipper circadian rhythm of blood pressure on left ventricular hypertrophy in patients with non-dialysis chronic kidney disease.

PubMed

Che, Xiajing; Mou, Shan; Zhang, Weiming; Zhang, Minfang; Gu, Leyi; Yan, Yucheng; Ying, Hua; Hu, Chunhua; Qian, Jiaqi; Ni, Zhaohui

2017-04-01

Objective The aim of this study was to investigate the correlation between non-dipper circadian rhythm of blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD). Methods and results All 257 patients with stage 1 to 5 CKD were enrolled in the study and classified into a CKD1-3 group and a CKD4-5 group according to renal function. The parameters and circadian rhythm of BP were measured by a GE Marquette Tonoport V Eng dynamic sphygmomanometer, and cardiac structure was examined by echocardiography. The incidence of abnormal circadian BP rhythm (non-dipper rhythm) was quite high (75.4% in all enrolled patients and 71.3% in the patients with normal BP levels) in CKD patients and increased with the deterioration of renal function. Changes of cardiac structure such as LVH in patients with non-dipper BP were more distinct than in patients with dipper BP. The development of left ventricular mass index (LVMI) correlated positively with the incidence of non-dipper BP rhythm. Multiple regression analysis showed that 24-h systolic BP (β = 0.417, P < 0.01), triglycerides (TG) (β = -0.132, P = 0.007), Hb (β = -0.394, P = 0.016) and gender (β = 0.158, P = 0.039) were independent risk factors of LVMI. Conclusions The incidence of non-dipper circadian rhythm of blood pressure was quite high in CKD patients and increased with the deterioration of renal function. Non-dipper circadian rhythm of BP is closely related with LVMI.

Blood Pressure Responses to Endovascular Stimulation: A Potential Therapy for Autonomic Disorders With Vasodilatation.

PubMed

Naksuk, Niyada; Killu, Ammar M; Yogeswaran, Vidhushei; Desimone, Christopher V; Suddendorf, Scott H; Ladewig, Dorothy J; Powers, Joanne M; Weber, Sarah; Madhavan, Malini; Cha, Yong-Mei; Kapa, Suraj; Asirvatham, Samuel J

2016-09-01

We have previously shown that sympathetic ganglia stimulation via the renal vein rapidly increases blood pressure. This study further investigated the optimal target sites and effective energy levels for stimulation of the renal vasculatures and nearby sympathetic ganglia for rapid increase in blood pressure. The pre-study protocol for endovascular stimulations included 2 minutes of stimulation (1-150 V and 10 pulses per second) and at least 2 minutes of rest during poststimulation. If blood pressure and/or heart rate were changed during the stimulation, time to return to baseline was allowed prior to the next stimulation. In 11 acute canine studies, we performed 85 renal artery, 30 renal vein, and 8 hepatic vasculature stimulations. The mean arterial pressure (MAP) rapidly increased during stimulation of renal artery (95 ± 18 mmHg vs. 103 ± 15 mmHg; P < 0.0001), renal vein (90 ± 16 mmHg vs. 102 ± 20 mmHg; P = 0.001), and hepatic vasculatures (74 ± 8 mmHg vs. 82 ± 11 mmHg; P = 0.04). Predictors of a significant increase in MAP were energy >10 V focused on the left renal artery, bilateral renal arteries, and bilateral renal veins (especially the mid segment). Overall, heart rate was unchanged, but muscle fasciculation was observed in 22.0% with an output >10 V (range 15-150 V). Analysis after excluding the stimulations that resulted in fasciculation yielded similar results to the main findings. Stimulation of intra-abdominal vasculatures promptly increased the MAP and thus may be a potential treatment option for hypotension in autonomic disorders. Predictors of optimal stimulation include energy delivery and the site of stimulation (for the renal vasculatures), which informs the design of subsequent research. © 2016 Wiley Periodicals, Inc.

Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial.

PubMed

Kandzari, David E; Böhm, Michael; Mahfoud, Felix; Townsend, Raymond R; Weber, Michael A; Pocock, Stuart; Tsioufis, Konstantinos; Tousoulis, Dimitrios; Choi, James W; East, Cara; Brar, Sandeep; Cohen, Sidney A; Fahy, Martin; Pilcher, Garrett; Kario, Kazuomi

2018-06-09

Previous catheter-based renal denervation studies have reported variable efficacy results. We aimed to evaluate safety and blood pressure response after renal denervation or sham control in patients with uncontrolled hypertension on antihypertensive medications with drug adherence testing. In this international, randomised, single-blind, sham-control, proof-of-concept trial, patients with uncontrolled hypertension (aged 20-80 years) were enrolled at 25 centres in the USA, Germany, Japan, UK, Australia, Austria, and Greece. Eligible patients had an office systolic blood pressure of between 150 mm Hg and 180 mm Hg and a diastolic blood pressure of 90 mm Hg or higher; a 24 h ambulatory systolic blood pressure of between 140 mm Hg and 170 mm Hg at second screening; and were on one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned to undergo renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were masked to randomisation assignments. The primary efficacy endpoint was blood pressure change from baseline (measured at screening visit two), based on ambulatory blood pressure measurements assessed at 6 months, as compared between treatment groups. Drug surveillance was used to assess medication adherence. The primary analysis was done in the intention-to-treat population. Safety events were assessed through 6 months as per major adverse events. This trial is registered with ClinicalTrials.gov, number NCT02439775, and follow-up is ongoing. Between July 22, 2015, and June 14, 2017, 467 patients were screened and enrolled. This analysis presents results for the first 80 patients randomly assigned to renal denervation (n=38) and sham control (n=42). Office and 24 h ambulatory blood pressure decreased significantly from baseline to 6 months in the renal denervation group (mean baseline-adjusted treatment differences in 24 h systolic blood pressure -7·0 mm Hg, 95% CI -12·0 to -2·1; p=0·0059, 24 h diastolic blood pressure -4·3 mm Hg, -7·8 to -0·8; p=0.0174, office systolic blood pressure -6·6 mm Hg, -12·4 to -0·9; p=0·0250, and office diastolic blood pressure -4·2 mm Hg, -7·7 to -0·7; p=0·0190). The change in blood pressure was significantly greater at 6 months in the renal denervation group than the sham-control group for office systolic blood pressure (difference -6·8 mm Hg, 95% CI -12·5 to -1·1; p=0·0205), 24 h systolic blood pressure (difference -7·4 mm Hg, -12·5 to -2·3; p=0·0051), office diastolic blood pressure (difference -3·5 mm Hg, -7·0 to -0·0; p=0·0478), and 24 h diastolic blood pressure (difference -4·1 mm Hg, -7·8 to -0·4; p=0·0292). Evaluation of hourly changes in 24 h systolic blood pressure and diastolic blood pressure showed blood pressure reduction throughout 24 h for the renal denervation group. 3 month blood pressure reductions were not significantly different between groups. Medication adherence was about 60% and varied for individual patients throughout the study. No major adverse events were recorded in either group. Renal denervation in the main renal arteries and branches significantly reduced blood pressure compared with sham control with no major safety events. Incomplete medication adherence was common. Medtronic. Copyright © 2018 Elsevier Ltd. All rights reserved.

Renal Sympathetic Denervation by CT-Guided Ethanol Injection: A Phase II Pilot Trial of a Novel Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricke, J., E-mail: jens.ricke@med.ovgu.de; Seidensticker, M.; Becker, S.

ObjectivesCT-guided ethanol-mediated renal sympathetic denervation in treatment of therapy-resistant hypertension was performed to assess patient safety and collect preliminary data on treatment efficacy.Materials and MethodsEleven patients with therapy-resistant hypertension (blood pressure of >160 mmHg despite three different antihypertensive drugs including a diuretic) and following screening for secondary causes were enrolled in a phase II single arm open label pilot trial of CT-guided neurolysis of sympathetic renal innervation. Primary endpoint was safety, and secondary endpoint was a decrease of the mean office as well as 24-h systolic blood pressure in follow-up. Follow-up visits at 4 weeks, 3, and 6 months included 24-h blood pressuremore » assessments, office blood pressure, laboratory values, as well as full clinical and quality of life assessments.ResultsNo toxicities ≥3° occurred. Three patients exhibited worsened kidney function in follow-up analyses. When accounting all patients, office systolic blood pressure decreased significantly at all follow-up visits (maximal mean decrease −41.2 mmHg at 3 months). The mean 24-h systolic blood pressure values decreased significantly at 3 months, but not at 6 months (mean: −9.7 and −6.3 mmHg, respectively). Exclusion of five patients who had failed catheter-based endovascular denervation and/or were incompliant for antihypertensive drug intake revealed a more pronounced decrease of 24-h systolic blood pressure (mean: −18.3 and −15.2 mmHg at 3 and 6 months, p = 0.03 and 0.06).ConclusionCT-guided sympathetic denervation proved to be safe and applicable under various anatomical conditions with more renal arteries and such of small diameter.« less

Supplemental arginine vasopressin during the resuscitation of severe hemorrhagic shock preserves renal mitochondrial function

PubMed Central

Yuxia, Guan; Singh, Khushboo; Reilly, Patrick M.

2017-01-01

Arginine vasopressin (AVP), a hormone secreted by the posterior pituitary, plays a vital role in maintaining vasomotor tone during acute blood loss. We hypothesized that decompensated hemorrhagic shock is associated with decreased AVP stores and supplementation during resuscitation would improve both blood pressure and renal function. Using a decompensated hemorrhagic shock model, male Long-Evans rats were bled to mean arterial blood pressure (MAP) of 40mmHg and maintained until the MAP could not be sustained without fluid. Once 40% of the shed volume was returned in lactated Ringer’s (Severe Shock), animals were resuscitated over 60 minutes with 4x the shed volume in lactated Ringer’s (LR) or the same fluids with AVP (0.5 units/kg+ 0.03 units/kg/min). Animals (n = 6-9/group) were sacrificed before hemorrhage (Sham), at Severe Shock, following resuscitation (60R, 60R with AVP) or 18 hours post-resuscitation (18hr, 18hr with AVP). Blood samples were taken to measure AVP levels and renal function. Pituitaries were harvested and assayed for AVP. Kidney samples were taken to assess mitochondrial function, histology, and oxidative damage. Baseline pituitary AVP stores (30,364 ± 5311 pg/mg) decreased with severe shock and were significantly depressed post-resuscitation (13,910 ± 3016 pg/ml. p<0.05) and at 18hr (15,592 ±1169 pg/ml, p<0.05). Resuscitation with LR+AVP led to higher serum AVP levels at 60R (31±8 vs 79±12; p<0.01) with an improved MAP both at 60R (125±3 vs 77±7mmHg; p<0.01) and 18hr (82±6 vs 69±5mmHg;p<0.05). AVP supplementation preserved complex I respiratory capacity at 60R and both complex I and II function at 18hr (p<0.05). AVP was also associated with decreased reactive oxygen species at 60R (856±67 vs 622±48F RFU) and significantly decreased oxidative damage as measured by mitochondrial lipid peroxidation (0.9±0.1 vs 1.7±0.1 fold change, p<0.01) and nitrosylation (0.9±0.1 vs 1.4±0.2 fold change, p<0.05). With AVP, renal damage was mitigated at 60R and histologic architecture was conserved at 18 hours. In conclusion, pituitary and serum AVP levels decrease during severe hemorrhage and may contribute to the development of decompensated hemorrhagic shock. Supplementing exogenous AVP during resuscitation improves blood pressure, preserves renal mitochondrial function, and mitigates acute kidney injury. PMID:29065123

Protective effects of efonidipine, a T- and L-type calcium channel blocker, on renal function and arterial stiffness in type 2 diabetic patients with hypertension and nephropathy.

PubMed

Sasaki, Hidehisa; Saiki, Atsuhito; Endo, Kei; Ban, Noriko; Yamaguchi, Takashi; Kawana, Hidetoshi; Nagayama, Daizi; Ohhira, Masahiro; Oyama, Tomokazu; Miyashita, Yoh; Shirai, Kohji

2009-10-01

The three types of calcium channel blocker (CCB), L-, T- and N-type, possess heterogeneous actions on endothelial function and renal microvascular function. In the present study, we evaluated the effects of two CCBs, efonidipine and amlodipine, on renal function and arterial stiffness. Forty type 2 diabetic patients with hypertension and nephropathy receiving angiotensin receptor II blockers were enrolled and randomly divided into two groups: the efonidipine group was administered efonidipine hydrochloride ethanolate 40 mg/day and the amlodipine group was admin-istered amlodipine besilate 5 mg/day for 12 months. Arterial stiffness was evaluated by the cardio-ankle vascular index (CAVI). Changes in blood pressure during the study were almost the same in the two groups. Sig-nificant increases in serum creatinine and urinary albumin and a significant decrease in the esti-mated glomerular filtration rate were observed in the amlodipine group, but not in the efonidipine group. On the other hand, significant decreases in plasma aldosterone, urinary 8-hydroxy-2'-deoxy-guanosine and CAVI were observed after 12 months in the efonidipine group, but not in the amlo-dipine group. These results suggest that efonidipine, which is both a T-type and L-type calcium chan-nel blocker, has more favorable effects on renal function, oxidative stress and arterial stiffness than amlodipine, an L-type calcium channel blocker.

Role of the intrarenal renin-angiotensin system in the progression of renal disease.

PubMed

Urushihara, Maki; Kagami, Shoji

2017-09-01

The intrarenal renin-angiotensin system (RAS) has many well-documented pathophysiologic functions in both blood pressure regulation and renal disease development. Angiotensin II (Ang II) is the major bioactive product of the RAS. It induces inflammation, renal cell growth, mitogenesis, apoptosis, migration, and differentiation. In addition, Ang II regulates the gene expression of bioactive substances and activates multiple intracellular signaling pathways that are involved in renal damage. Activation of the Ang II type 1 (AT1) receptor pathway results in the production of proinflammatory mediators, intracellular formation of reactive oxygen species, cell proliferation, and extracellular matrix synthesis, which in turn facilities renal injury. Involvement of angiotensinogen (AGT) in intrarenal RAS activation and development of renal disease has previously been reported. Moreover, studies have demonstrated that the urinary excretion rates of AGT provide a specific index of the intrarenal RAS status. Enhanced intrarenal AGT levels have been observed in experimental models of renal disease, supporting the concept that AGT plays an important role in the development and progression of renal disease. In this review, we focus on the role of intrarenal RAS activation in the pathophysiology of renal disease. Additionally, we explored the potential of urinary AGT as a novel biomarker of intrarenal RAS status in renal disease.

Copeptin Plasma Levels are Associated With Decline of Renal Function in Patients With Type 2 Diabetes Mellitus.

PubMed

Villela-Torres, Maria De La Luz; Higareda-Mendoza, Ana Edith; Gómez-García, Anel; Alvarez-Paredes, Alfonso Rafael; García-López, Elvia; Stenvikel, Peter; Gu, Harvest F; Rashid-Qureshi, Abbul; Lindholm, Bengt; Alvarez-Aguilar, Cleto

2018-04-14

Chronic kidney disease (CKD) is a leading complication of type 2 diabetes mellitus (T2DM) and is considered as a public health problem. Copeptin is a surrogate marker of arginine vasopressin (AVP) system and is proposed as a biomarker of decline renal function. Evaluate whether plasma copeptin levels may be used as a biomarker of decline renal function in patients with T2DM. A total of 480 patients with T2DM and different stages of CKD were included. Plasma levels of copeptin, cystatin-C, and other biochemical parameters were measured. The correlation between copeptin and glomerular filtration rate (GFR), estimated based on plasma cystatin-C levels, was investigated. Plasma copeptin levels were gradually increased from the stage 1-5 of CKD in the patients with T2DM. In univariate linear regression analysis, high plasma levels of copeptin were associated with lower GFR (Standardized β = -0.535, R 2  = 0.287, p <0.0001). This association remained significant even after being adjusted for glucose levels and years of T2DM diagnosis, mean blood pressure, pharmacological treatment, gender, and age. The results show that high plasma copeptin levels are associated with the decline of renal function in patients with T2DM and, therefore, copeptin may be considered as a biomarker of renal function. Further evaluation of plasma copeptin levels to predict morbidity and mortality of T2DM patients, with or without CKD, has been taken into our consideration. Copyright © 2018. Published by Elsevier Inc.

A clinical evaluation of renal amyloidosis in the Japan renal biopsy registry: a cross-sectional study.

PubMed

Nishi, Shinichi; Muso, Eri; Shimizu, Akira; Sugiyama, Hitoshi; Yokoyama, Hitoshi; Ando, Yukio; Goto, Shunsuke; Fujii, Hideki

2017-08-01

The available clinical data are limited in a rare glomerular disease, renal amyloidosis. We aimed to clarify the clinical features of renal amyloidosis from database of the Japan Renal Biopsy Registry (J-RBR). We performed a cross-sectional study with database of the J-RBR of the Japanese Society of Nephrology. We identified 281 cases of renal amyloidosis from 20,997 cases enrolled into the J-RBR from 2007 to 2014. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were compared among the levels of ages, amount of urine protein excretion (AUPE) or CKD G stages. The prevalence of renal amyloidosis was 1.3 % (281/20,997). DBP significantly decreased in higher age quartiles (P = 0.034). SBP and DBP did not increase in the progression of AUPE levels and CKD G stages. In multiple regression analysis, eGFR was a significant independent factor for SBP in all cases and a subgroup without hypertensive agents. There was a reverse significant relationship between SBP and eGFR. Blood pressure did not significantly increase in elderly and much proteinuric condition in renal amyloidosis. The progression of CKD and decrease of eGFR did not produce the higher SBP. The mechanism underlying these results remains unclear; however, they are unique features of renal amyloidosis. The couple of hypotensive and hypertensive conditions might produce no relationship between blood pressure and CKD stages.

The use of renal replacement therapy in acute decompensated heart failure.

PubMed

Udani, Suneel M; Murray, Patrick T

2009-01-01

The worsening of renal function in the context of decompensated heart failure is an increasingly common clinical scenario, dubbed the cardiorenal syndrome. Its development is not completely understood; however, it results from the hemodynamic and neurohumoral alterations that occur in the setting of left ventricular pressure and volume overload with poor cardiac output. Diuretics have been the mainstay of treatment; however, they are often unsuccessful in reversing the vicious cycle of volume overload, worsening cardiac function, and azotemia. Renal replacement therapy (RRT) in the form of isolated or continuous ultrafiltration (UF) with or without a component of solute clearance (hemofiltration or hemodialysis) has been increasingly utilized as a therapeutic tool in this setting. Initial clinical trial data on the use of UF have demonstrated promising cardiac outcomes with regard to fluid removal and symptom relief without worsening renal function. The addition of a component of solute clearance may provide additional benefits in these patients with varying degrees of renal impairment. The exact clinical setting in which the various forms of RRT should be applied as initial or early therapy for acute decompensated heart failure (ADHF) remains unknown. More research examining the use of RRT in ADHF is necessary; however, it appears that the patients with the most severe clinical presentations have the best chance of benefiting from the early application of RRT.

Proceedings of the First Joint NASA Cardiopulmonary Workshop

NASA Technical Reports Server (NTRS)

Fortney, Suzanne M. (Editor); Hargens, Alan R. (Editor)

1991-01-01

The topics covered include the following: flight echocardiography, pulmonary function, central hemodynamics, glycerol hyperhydration, spectral analysis, lower body negative pressure countermeasures, orthostatic tolerance, autonomic function, cardiac deconditioning, fluid and renal responses to head-down tilt, local fluid regulation, endocrine regulation during bed rest, autogenic feedback, and chronic cardiovascular measurements. The program ended with a general discussion of weightlessness models and countermeasures.

The renal response to electrical stimulation of renal efferent sympathetic nerves in the anaesthetized greyhound.

PubMed Central

Poucher, S M; Karim, F

1991-01-01

1. The effect of direct electrical stimulation of the renal efferent nerves upon renal haemodynamics and function was studied in greyhounds anaesthetized with chloralose and artificially ventilated. The left kidney was neurally and vascularly isolated, and perfused with blood from one of the femoral arteries at a constant pressure of 99 +/- 1 mmHg. Renal blood flow was measured with a cannulating electromagnetic flow probe placed in the perfusion circuit, glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and solute excretion by osmometry. Beta-Adrenergic receptor activation was blocked by the infusion of dl-propranolol (17 micrograms kg-1 min-1). The peripheral ends of the ligated renal nerves were stimulated at 0.5, 1.0, 1.5 and 2.0 Hz. 2. At 0.5 Hz frequency only osmolar excretion was significantly reduced (10.3 +/- 3.2%, P less than 0.05, n = 6). Reductions in sodium excretion (53.6 +/- 8.5%, P less than 0.01, n = 6) and water excretion (26.9 +/- 8.0%, P less than 0.05, n = 6) and further reductions of osmolar excretion (20.7 +/- 3.7%, P less than 0.01, n = 6) were observed at 1.0 Hz; however, these were observed in the absence of significant changes in renal blood flow and glomerular filtration rate. Significant reductions were observed in glomerular filtration rate at 1.5 Hz (16.3 +/- 4.1%, P less than 0.02, n = 5) and in renal blood flow at 2.0 Hz (13.1 +/- 4.0%, P less than 0.05, n = 5). Further reductions in urine flow and sodium excretion were also observed at these higher frequencies. 3. These results clearly show that significant changes in renal tubular function can occur in the absence of changes in renal blood flow and glomerular filtration rate when the renal nerves are stimulated electrically from a zero baseline activity up to a frequency of 1.5 Hz. Higher frequencies caused significant changes in both renal haemodynamics and function. PMID:2023113

The Role of Hydrogen Sulfide in Renal System.

PubMed

Cao, Xu; Bian, Jin-Song

2016-01-01

Hydrogen sulfide has gained recognition as the third gaseous signaling molecule after nitric oxide and carbon monoxide. This review surveys the emerging role of H 2 S in mammalian renal system, with emphasis on both renal physiology and diseases. H 2 S is produced redundantly by four pathways in kidney, indicating the abundance of this gaseous molecule in the organ. In physiological conditions, H 2 S was found to regulate the excretory function of the kidney possibly by the inhibitory effect on sodium transporters on renal tubular cells. Likewise, it also influences the release of renin from juxtaglomerular cells and thereby modulates blood pressure. A possible role of H 2 S as an oxygen sensor has also been discussed, especially at renal medulla. Alternation of H 2 S level has been implicated in various pathological conditions such as renal ischemia/reperfusion, obstructive nephropathy, diabetic nephropathy, and hypertensive nephropathy. Moreover, H 2 S donors exhibit broad beneficial effects in renal diseases although a few conflicts need to be resolved. Further research reveals that multiple mechanisms are underlying the protective effects of H 2 S, including anti-inflammation, anti-oxidation, and anti-apoptosis. In the review, several research directions are also proposed including the role of mitochondrial H 2 S in renal diseases, H 2 S delivery to kidney by targeting D-amino acid oxidase/3-mercaptopyruvate sulfurtransferase (DAO/3-MST) pathway, effect of drug-like H 2 S donors in kidney diseases and understanding the molecular mechanism of H 2 S. The completion of the studies in these directions will not only improves our understanding of renal H 2 S functions but may also be critical to translate H 2 S to be a new therapy for renal diseases.

Atherosclerotic renovascular disease among hypertensive adults

PubMed Central

Davis, Ross P.; Pearce, Jeffrey D.; Craven, Timothy E.; Moore, Phillip S.; Edwards, Matthew S.; Godshall, Christopher J.; Hansen, Kimberley J.

2010-01-01

Purpose Ths report describes the change in atherosclerotic renovascular disease (AS-RVD) among hypertensive adults referred for renal duplex sonography (RDS) scan. Methods From Oct 1993 through July 2008, 20,994 patients had RDS at our center. A total of 434 hypertensive patients with two or more RDS exams without intervention comprised the study cohort. Patient demographics (blood pressures, medications, serum creatinine levels, and data from RDS) were collected. Analyses of longitudinal changes in Doppler scan parameters, blood pressures, and renal function were performed by fitting linear growth-curve models. After confirming the linearity of change in Doppler scan parameters among patients with variable number of studies, estimates of mean slopes were calculated using maximum likelihood techniques. For changes in renal function, quadratic growth curves were required to describe longitudinal change. Results A total of 434 subjects (212 men [49%] and 222 women [51%]; mean age, 64.6 ± 12.2 years) provided 1351 studies (mean, 3.2 ± 2.4; range, 2 to 18) for 863 kidneys over a mean follow-up of 34.4 ± 25.1 months. At baseline, 20.6% of kidneys demonstrated hemodynamically significant stenosis. On follow-up, 72 kidneys (9.1%) demonstrated anatomic progression of disease. A total of 54 kidneys (6.9%) progressed to significant stenosis and 18 (2.3%) progressed to occlusion. Controlling for progression of disease, baseline renal artery status demonstrated a strong association with baseline kidney length (P = .0006). Significant annualized change in renal length was observed (cm change/year ± standard error of the mean [SEM]: 0.042 ± 0.011; P = .0002) among both kidneys with and without critical disease at baseline, however, decline in length was significantly greater among kidneys exhibiting progression of renovascular disease (−0.152 ± 0.028 cm/year; comparison of slopes between groups P = .0005). In the absence of progression, the presence or absence of critical renal artery stenosis at baseline did not affect the rate of decline in renal length. Fitted models for the natural log transform of serum creatinine demonstrated a significant increase during follow-up (P < .0001). No association was observed between change in serum creatinine and baseline renovascular disease status, or its progression. Conclusion A total of 32% of hypertensive adults referred for RDS demonstrated hemodynamically significant renal artery stenosis. Regardless of the presence or absence of baseline disease, a small percentage of patients demonstrated anatomic progression of AS-RVD. A total of 9.1% demonstrated anatomic progression and 2.3% progressed to occlusion. Although anatomic progression of AS-RVD was associated with an increased rate of decline in renal length, progression did not predict a decline in excretory renal function. Intervention for AS-RVD should be selective and reserved for strict indications. PMID:19700093

Renal denervation: unde venis et quo vadis?

PubMed

Nähle, C P; Düsing, R; Schild, H

2015-04-01

Renal denervation is a minimally invasive, catheter-based option for the treatment of refractory hypertension. Indications and contraindications for renal denervation have been defined in an interdisciplinary manner. The efficacy and safety of the procedure were evaluated. Currently, indication for renal denervation is limited to patients with primary hypertension and a systolic blood pressure of ≥ 160 mm Hg (or ≥ 150 mm Hg in diabetes type 2) despite optimal medical therapy with ≥ 3 different antihypertensive drugs. In this specific patient population, an average blood pressure reduction of 32/14 mmHg was observed in non-randomized/-controlled trials after renal denervation. These results were not confirmed in the first randomized controlled trial with a non-significantly superior blood pressure reduction of 14.1 ± 23.9 mm Hg compared to controls (-11.74 ± 25.94 mm Hg, difference -2.39 mm Hg p = 0.26 for superiority with a margin of 5 mm Hg) who underwent a sham procedure. The efficacy and long-term effects of renal denervation need to be re-evaluated in light of the HTN3 study results. To date, renal denervation should not be performed outside of clinical trials. Future trials should also assess if renal denervation can be performed with sufficient safety and efficacy in patients with hypertension-associated diseases. The use of renal denervation as an alternative therapy (e. g. in patients with drug intolerance) can currently not be advocated. The indication for renal denervation should be assessed in an interdisciplinary fashion and according to current guidelines with a special focus on ruling out secondary causes for arterial hypertension. 5 - 10 % of patients with hypertension suffer from refractory hypertension, but only about 1 % of patients meet the criteria for a renal denervation. Renal denervation leads to a significant decrease in office blood pressure; however, the impact on 24-hour blood pressure measurements remains unclear. In the first randomized controlled trial on renal denervation with a control group undergoing a sham procedure, blood pressure reduction failed to reach the anticipated level of superiority over best medical treatment. Periprocedural complications are rare, but long-term safety can currently not be appraised due to the limited data available. © Georg Thieme Verlag KG Stuttgart · New York.

Diets containing salmon fillet delay development of high blood pressure and hyperfusion damage in kidneys in obese Zucker fa/fa rats.

PubMed

Vikøren, Linn A; Drotningsvik, Aslaug; Mwakimonga, Angela; Leh, Sabine; Mellgren, Gunnar; Gudbrandsen, Oddrun A

2018-04-01

Hypertension is the leading risk factor for cardiovascular and chronic renal diseases, affecting more than 1 billion people. Fish intake is inversely correlated with the prevalence of hypertension in several, but not all, studies, and intake of fish oil and fish proteins has shown promising potential to delay development of high blood pressure in rats. The effects of baked and raw salmon fillet intake on blood pressure and renal function were investigated in obese Zucker fa/fa rats, which spontaneously develop hypertension with proteinuria and renal failure. Rats were fed diets containing baked or raw salmon fillet in an amount corresponding to 25% of total protein from salmon and 75% of protein from casein, or casein as the sole protein source (control group) for 4 weeks. Results show lower blood pressure and lower urine concentrations of albumin and cystatin C (relative to creatinine) in salmon diet groups when compared to control group. Morphological examinations revealed less prominent hyperfusion damage in podocytes from rats fed diets containing baked or raw salmon when compared to control rats. In conclusion, diets containing baked or raw salmon fillet delayed the development of hypertension and protected against podocyte damage in obese Zucker fa/fa rats. Copyright © 2018 American Heart Association. Published by Elsevier Inc. All rights reserved.

OBESITY-INDUCED HYPERTENSION: INTERACTION OF NEUROHUMORAL AND RENAL MECHANISMS

PubMed Central

Hall, John E.; do Carmo, Jussara M.; da Silva, Alexandre A.; Wang, Zhen; Hall, Michael E.

2015-01-01

Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65–75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include 1) physical compression of the kidneys by fat in and around the kidneys, 2) activation of the renin-angiotensin-aldosterone system (RAAS), and 3) increased sympathetic nervous system (SNS) activity. Activation of the RAAS system is likely due, in part, to renal compression as well as SNS activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for SNS activation in obesity have not been fully elucidated but appear to require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes, and inflammation. Unless effective anti-obesity drugs are developed, the impact of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase. PMID:25767285

Role of Mas receptor in renal blood flow response to angiotensin-(1-7) in ovariectomized estradiol treated rats.

PubMed

Saberi, Shadan; Dehghani, Aghdas; Nematbakhsh, Mehdi

2016-01-01

The angiotensin 1-7 (Ang 1-7), is abundantly produced in kidneys and antagonizes the function of angiotensin II through Mas receptor (MasR) or other unknown mechanisms. In the current study, the role of MasR and steroid hormone estrogen on renal blood flow response to Ang 1-7 administration was investigated in ovariectomized (OV) female rats. OV female Wistar-rats received estradiol (500 μg/kg/week) or vehicle for two weeks. In the day of the experiment, the animals were anesthetized, cannulated, and the responses including mean arterial pressure, renal blood flow (RBF), and renal vascular resistance at the constant level of renal perfusion pressure to graded infusion of Ang 1-7 at 0, 100 and 300 ng/kg/min were determined in OV and OV estradiol-treated (OVE) rats, treated with vehicle or MasR antagonist; A779. RBF response to Ang 1-7 infusion increased dose-dependently in vehicle (Pdose <0.001) and A779-treated (Pdose <0.01) animals. However, when MasR was blocked, the RBF response to Ang 1-7 significantly increased in OV animals compared with OVE rats (P<0.05). When estradiol was limited by ovariectomy, A779 increased RBF response to Ang 1-7 administration, while this response was attenuated in OVE animals.

Dysfunction of the lower urinary and distal gastrointestinal tracts in pediatric patients with known spinal cord problems.

PubMed

Churchill, B M; Abramson, R P; Wahl, E F

2001-12-01

Destruction of the urinary tract in children with elimination, storage, and holding dysfunction of the lower urinary and the distal GI tracts is caused primarily by high intravesical pressure. UTI accelerates this process. The LPP and the status of the urethral control mechanism and its relationship to the detrusor are the primary determinants of intravesical pressure. Intravesical pressures of more than 40 cm H2O are dangerous because they cause a pressure gradient that is transmitted proximally to the renal papillae, which results in the cessation of renal blood flow and a loss of renal function over time. Hydroureteronephrosis, VUR, UTI, urinary incontinence, and calculi formation also may occur. If these dangerously high intravesical pressures remain untreated, renal failure is likely to occur over time. These children then require dialysis or renal transplantation to survive, which is tragic and represents an enormous economic cost to society. Renal failure and upper urinary tract damage is nearly 100% preventable with early and appropriate evaluation and treatment. CIC is a crucial part of the management of these children and has been shown to be safe and effective, even in newborn boys. The use of the Credé maneuver (i.e., manual compression) to empty the bladder is obsolete and should be abandoned. The distal GI tract is inseparable from the lower urinary tract and must be treated simultaneously. Failure to treat the distal GI tract yields poor clinical results and much patient dissatisfaction and makes it difficult or impossible to treat the child's urinary tract problem successfully. Bowel-management programs must include daily high water and fiber intake, together with digital perianal stimulation or fecal extraction. Neuropathic bladder and bowel problems that are intractable to conservative medical and mechanical (i.e., CIC and digital perianal stimulation or fecal extraction, respectively) management almost always can be corrected surgically with high success rates in cooperative patients. Finally, neuropathic bladder and bowel problems can be extremely isolating and debilitating problems. Psychologic counseling and emotional support must be provided as needed. The care that these patients receive must be organized, comprehensive, and correlated with these patients' lifestyles. If these children are evaluated and treated early, they have the potential to live long, healthy, and productive lives.

Modeling of Kidney Hemodynamics: Probability-Based Topology of an Arterial Network.

PubMed

Postnov, Dmitry D; Marsh, Donald J; Postnov, Dmitry E; Braunstein, Thomas H; Holstein-Rathlou, Niels-Henrik; Martens, Erik A; Sosnovtseva, Olga

2016-07-01

Through regulation of the extracellular fluid volume, the kidneys provide important long-term regulation of blood pressure. At the level of the individual functional unit (the nephron), pressure and flow control involves two different mechanisms that both produce oscillations. The nephrons are arranged in a complex branching structure that delivers blood to each nephron and, at the same time, provides a basis for an interaction between adjacent nephrons. The functional consequences of this interaction are not understood, and at present it is not possible to address this question experimentally. We provide experimental data and a new modeling approach to clarify this problem. To resolve details of microvascular structure, we collected 3D data from more than 150 afferent arterioles in an optically cleared rat kidney. Using these results together with published micro-computed tomography (μCT) data we develop an algorithm for generating the renal arterial network. We then introduce a mathematical model describing blood flow dynamics and nephron to nephron interaction in the network. The model includes an implementation of electrical signal propagation along a vascular wall. Simulation results show that the renal arterial architecture plays an important role in maintaining adequate pressure levels and the self-sustained dynamics of nephrons.

ACE Inhibition in Anti-Thy1 Glomerulonephritis Limits Proteinuria but Does Not Improve Renal Function and Structural Remodeling

PubMed Central

Westerweel, Peter E.; Joles, Jaap A.; den Ouden, Krista; Goldschmeding, Roel; Rookmaaker, Maarten B.; Verhaar, Marianne C.

2012-01-01

Background/Aims ACE inhibitor (ACE-I) treatment effectively inhibits proteinuria and ameliorates the course of various renal diseases. In experimental glomerulonephritis, however, angiotensin II (AngII) infusion has also been shown to be renoprotective. We evaluated the long-term (28 days) course of anti-Thy1 glomerulonephritis in animals with suppressed AngII formation by ACE-I treatment. Methods Brown Norway rats received perindopril (2.8 mg/kg/day, n = 12), dihydropyridine calcium-antagonist amlodipine (Ca-A; 13 mg/kg/day, n = 6) or were left untreated (n = 14). All animals were monitored for blood pressure, proteinuria, and creatinine clearance after anti-Thy1 injection. Renal histology was assessed at day 7 and 28. Results Systolic blood pressure was equally reduced by ACE-I and Ca-A treatment. AngII suppression prevented development of proteinuria, but did not protect against glomerular microaneurysm formation or reduction in creatinine clearance. After resolution of the microaneurysms, animals with suppressed AngII production showed a modest increase in glomerulosclerosis and vasculopathic thickening of intrarenal vessels. Conclusions In anti-Thy1 glomerulonephritis, suppression of AngII formation does not protect against the induction of glomerular damage and is associated with mild aggravation of adverse renal fibrotic remodeling. Proteinuria, however, is effectively prevented by ACE-I treatment. Ca-A treatment did not affect the course of glomerulonephritis, indicating that ACE-I effects are blood pressure independent. PMID:22479264

Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

PubMed Central

Kelle, Ilker; Akkoc, Hasan; Tunik, Selcuk; Nergiz, Yusuf; Erdinc, Meral; Erdinc, Levent

2014-01-01

This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity. PMID:26019553

[Salt, renal function and high blood pressure--reflections on a current issue].

PubMed

Aurell, Mattias

2002-11-21

The role of salt intake for blood pressure control has been discussed for a long time. A brief review is given of some pertinent physiological facts to explain this relationship and evolutionary aspects of renal function are emphasized. Salt intake is very high in the modern society, often as high as 15 g sodium chloride per 24 hours while 3-6 g may be more than enough to maintain an adequate salt balance. If the kidneys cannot cope with this severe sodium overload, blood pressure will rise. Therefore, the kidneys' ability to excrete sodium is a key factor and the salt excretion capacity is the kidneys' major barostatic function. As barostats, the kidneys control the blood pressure by ultimately determining the sodium excretion. Reducing sodium intake is, however, difficult as more than 50% of the intake is contained in the food we buy such as bread, sausages, canned food, chips and fast-food. Food products should therefore be "salt declared", but information on this aspect is generally lacking. If the population's salt intake could be reduced by 50%, the prevalence of hypertension will be much reduced, perhaps also by as much as 50%. The cost to society for treating hypertension would be reduced accordingly. Salt intake is also an important aspect of the overweight problem among today's youth. Salt and overweight impose great health risks later in life. Preventive measures in this area must be given high priority in future health care work.

Clinical and Biochemical Characteristics of Brain-Dead Donors as Predictors of Early- and Long-Term Renal Function After Transplant.

PubMed

Kwiatkowska, Ewa; Domański, Leszek; Bober, Joanna; Safranow, Krzysztof; Pawlik, Andrzej; Ciechanowski, Kazimierz; Wiśniewska, Magda; Kędzierska, Karolina

2017-08-01

Organs from brain-dead donors are the main source of allografts for transplant. Comparisons between living-donor and brain-dead donor kidneys show that the latter are more likely to demonstrate delayed graft function and lower long-term survival. This study aimed to assess the effects of various clinical and biochemical factors of donors on early- and long-term renal function after transplant. We analyzed data from kidney recipients treated between 2006 and 2008 who received organs from brain-dead donors. Data from 54 donors and 89 recipients were analyzed. No relation was observed between donor sodium concentration and the presence of delayed graft function. Donor height was positively correlated with creatinine clearance in recipients in the 1 to 3 months after renal transplant. Donor diastolic blood pressure was negatively correlated with estimated glomerular filtration rate throughout the observation period. Donor age was negatively correlated with the allograft recipient's estimated glomerular filtration rate throughout 4 years of observation. Donor estimated glomerular filtration rate was positively correlated with that of the recipient throughout 3 years of observation. The results of this study indicate that various factors associated with allograft donors may influence graft function.

Effects of renal sympathetic denervation on exercise blood pressure, heart rate, and capacity in patients with resistant hypertension.

PubMed

Ewen, Sebastian; Mahfoud, Felix; Linz, Dominik; Pöss, Janine; Cremers, Bodo; Kindermann, Ingrid; Laufs, Ulrich; Ukena, Christian; Böhm, Michael

2014-04-01

Renal denervation reduces office blood pressure in patients with resistant hypertension. This study investigated the effects of renal denervation on blood pressure, heart rate, and chronotropic index at rest, during exercise, and at recovery in 60 patients (renal denervation group=50, control group=10) with resistant hypertension using a standardized bicycle exercise test protocol performed 6 and 12 months after renal denervation. After renal denervation, exercise blood pressure at rest was reduced from 158±3/90±2 to 141±3/84±4 mm Hg (P<0.001 for systolic blood pressure/P=0.007 for diastolic blood pressure) after 6 months and 139±3/83±4 mm Hg (P<0.001/P=0.022) after 12 months. Exercise blood pressure tended to be lower at all stages of exercise at 6- and 12-month follow-up in patients undergoing renal denervation, although reaching statistical significance only at mild-to-moderate exercise levels (75-100 W). At recovery after 1 minute, blood pressure decreased from 201±4/95±2 to 177±4/88±2 (P<0.001/P=0.066) and 188±6/86±2 mm Hg (P=0.059/P=0.01) after 6 and 12 months, respectively. Heart rate was reduced after renal denervation from 71±3 bpm at rest, 128±5 bpm at maximum workload, and 96±5 bpm at recovery after 1 minute to 66±2 (P<0.001), 115±5 (P=0.107), and 89±3 bpm (P=0.008) after 6 months and to 69±3 (P=0.092), 122±7 (P=0.01), and 93±4 bpm (P=0.032) after 12 months. Mean exercise time increased from 6.59±0.33 to 8.4±0.32 (P<0.001) and 9.0±0.41 minutes (P=0.008), and mean workload increased from 93±2 to 100±2 (P<0.001) and 101±3 W (P=0.007) at 6- and 12-month follow-up, respectively. No changes were observed in the control group. In conclusion, renal denervation reduced blood pressure and heart rate during exercise, improved mean workload, and increased exercise time without impairing chronotropic competence.

Factors associated with cardiovascular target organ damage in children after renal transplantation.

PubMed

Borchert-Mörlins, Bianca; Thurn, Daniela; Schmidt, Bernhard M W; Büscher, Anja K; Oh, Jun; Kier, Tanja; Bauer, Elena; Baig, Sabrina; Kanzelmeyer, Nele; Kemper, Markus J; Büscher, Rainer; Melk, Anette

2017-11-01

Cardiovascular disease is the second-most common cause of death in pediatric renal transplant recipients. The aim of this study was to evaluate subclinical cardiovascular target organ damage defined as the presence of arterio- and atherosclerotic lesions and cardiac remodeling and to analyze contributing risk factors in a large cohort of children after renal transplantation (RT). A total of 109 children aged 13.1 ± 3.3 years who had undergone RT at one of three German transplant centers were enrolled in this study. Patients had been transplanted a mean of 5.5 (±4.0) years prior to being enrolled in the study. Anthropometric data, laboratory values and office- and 24-h ambulatory blood pressure monitoring (ABPM) were evaluated. Cardiovascular target organ damage was determined through non-invasive measurements of aortic pulse wave velocity (PWV), carotid intima-media thickness (IMT) and left ventricular mass (LVM). Elevated PWV or IMT values were detected in 22 and 58% of patients, respectively. Left ventricular hypertrophy was found in as many as 43% of patients. The prevalence of uncontrolled or untreated hypertension was 41%, of which 16% of cases were only detected by ABPM measurements. In the multivariable analysis, higher diastolic blood pressure, everolimus intake and lower estimated glomerular filtration rate were independently associated with high PWV. Higher systolic blood pressure and body mass index were associated with elevated LVM. Our results showed an alarming burden of cardiovascular subclinical organ damage in children after RT. Hypertension, obesity, immunosuppressive regimen and renal function emerged as independent risk factors of organ damage. Whereas the latter is not modifiable, the results of our study strongly indicate that the management of children after RT should focus on the control of blood pressure and weight.

Small-molecule WNK inhibition regulates cardiovascular and renal function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Ken; Park, Hyi-Man; Rigel, Dean F.

The With-No-Lysine (K) (WNK) kinases play a critical role in blood pressure regulation and body fluid and electrolyte homeostasis. Herein, we introduce the first orally bioavailable pan-WNK-kinase inhibitor, WNK463, that exploits unique structural features of the WNK kinases for both affinity and kinase selectivity. In rodent models of hypertension, WNK463 affects blood pressure and body fluid and electro-lyte homeostasis, consistent with WNK-kinase-associated physiology and pathophysiology.

PP108. Post-partum evaluation of the blood pressure and the kidney function in pre-eclamptic women.

PubMed

Pechère-Bertschi, A; Montillier, P; Boulvain, M; Wuerzner, G; Gaspoz, J-M; Burnier, M; Irion, O P

2012-07-01

Recent data have shown that preeclampsia is not just a disease of pregnancy that resolves with delivery. Preeclampsia may be considered a 'risk marker' for later-life diseases, including cardiovascular and renal diseases and the metabolic syndrome. We aimed a longitudinal prospective study to analyze the renal abnormalities in the post-partum. We studied 127 post-preeclamptic women at 6 weeks post-partum. Twenty-four hour urine collection, ambulatory blood pressure and renal function were evaluated. The mean age (±SD) was 32±6years, BMI was 29.4±5.7, the race distribution was Caucasian 69%, Hispanic 14%, Black 12% and Orient 5%. Ten % were active smokers, 10% have been suffering from gestational diabetes. The mean duration of the pregnancy was 36 weeks 3/7±4. Our results show that the prevalence of hypertension defined by office blood pressure ⩾140/90 mmHg or ongoing antihypertensive treatment was 35%. The daytime ambulatory blood pressure (ABPM) was 122±16/85±11 mmHg, heart rate 84±8, and 111±20/75±11 mmHg at nighttime.Sixteen % had a daytime ABPM ⩾135/85mmHg corresponding to the definition of ambulatory hypertension. Ultrasensitive CRP was 4.9±5.1mg/ml, of them 31% had a frank elevation of the CRP >4. The glomerular filtration rate evaluated by the Gault-Cockroft equation showed a hyperfiltration with a mean value of 150±42ml/min. Eleven% had a decreased GFR < 90 ml/min. Microalbumine/creatinine ratio measured in the urine spot was 7 ±4. Mean microalbuminuria was 225±529mg/d measured on the 24h urine collection.Urine 24h Na excretion rate was 204±48 mmol/d. In conclusion, after the post-partum period, women having suffered from a pre-eclampsia display many cardiovascular risk factors with a high prevalence of hypertension, microalbuminuria, renal hyperfiltration and elevated CRP. These women should be carefully screened, and sub-groups with the higher risk have to be targeted for prevention and treatment, and close follow-up. Copyright © 2012. Published by Elsevier B.V.

Long-term Renal Function in Living Kidney Donors Who Had Histological Abnormalities at Donation.

PubMed

Fahmy, Lara M; Massie, Allan B; Muzaale, Abimereki D; Bagnasco, Serena M; Orandi, Babak J; Alejo, Jennifer L; Boyarsky, Brian J; Anjum, Saad K; Montgomery, Robert A; Dagher, Nabil N; Segev, Dorry L

2016-06-01

Recent evidence suggests that living kidney donors are at an increased risk of end-stage renal disease. However, predicting which donors will have renal dysfunction remains challenging, particularly among those with no clinical evidence of disease at the time of donation. Although renal biopsies are not routinely performed as part of the donor evaluation process, they may yield valuable information that improves the ability to predict renal function in donors. We used implantation protocol biopsies to evaluate the association between histological abnormalities in the donated kidney and postdonation renal function (estimated glomerular filtration rate, eGFR) of the remaining kidney in living kidney donors. Longitudinal analysis using mixed-effects linear regression was used to account for multiple eGFR measures per donor. Among 310 donors between 1997 and 2012, median (IQR) follow-up was 6.2 (2.5-8.7; maximum 14.0) years. In this cohort, the overall prevalence of histological abnormalities was 65.8% (19.7% abnormal glomerulosclerosis, 23.9% abnormal interstitial fibrosis and tubular atrophy (IFTA), 4.8% abnormal mesangial matrix increase, 32.0% abnormal arteriolar hyalinosis, and 32.9% abnormal vascular intimal thickening). IFTA was associated with a 5-mL/min/1.73 m decrease of postdonation eGFR after adjusting for donor age at donation, sex, race, preoperative systolic blood pressure, preoperative eGFR, and time since donation (P < 0.01). In this single-center study, among healthy individuals cleared for living donation, IFTA was associated with decreased postdonation eGFR, whereas no other subclinical histological abnormalities provided additional information.

Long-Term Renal Function in Living Kidney Donors who had Histological Abnormalities at Donation

PubMed Central

Fahmy, Lara M.; Massie, Allan B.; Muzaale, Abimereki D.; Bagnasco, Serena M.; Orandi, Babak J.; Alejo, Jennifer L.; Boyarsky, Brian J.; Anjum, Saad K.; Montgomery, Robert A.; Dagher, Nabil N.; Segev, Dorry L.

2016-01-01

Background Recent evidence suggests that living kidney donors are at an increased risk of end-stage renal disease. However, predicting which donors will have renal dysfunction remains challenging, particularly among those with no clinical evidence of disease at the time of donation. Although renal biopsies are not routinely performed as part of the donor evaluation process, they may yield valuable information that improves the ability to predict renal function in donors. Methods We used implantation protocol biopsies to evaluate the association between histological abnormalities in the donated kidney and postdonation renal function (estimated glomerular filtration rate, eGFR) of the remaining kidney in living kidney donors. Longitudinal analysis using mixed-effects linear regression was used to account for multiple eGFR measures per donor. Results Among 310 donors between 1997 and 2012, median (IQR) follow-up was 6.2 (2.5–8.7; maximum 14.0) years. In this cohort, the overall prevalence of histological abnormalities was 65.8% (19.7% abnormal glomerulosclerosis, 23.9% abnormal interstitial fibrosis and tubular atrophy (IFTA), 4.8% abnormal mesangial matrix increase, 32.0% abnormal arteriolar hyalinosis, and 32.9% abnormal vascular intimal thickening). IFTA was associated with a 5-mL/min/1.73m2 decrease of postdonation eGFR after adjusting for donor age at donation, sex, race, preoperative systolic blood pressure, preoperative eGFR, and time since donation (p<0.01). Conclusions In this single-center study, among healthy individuals cleared for living donation, IFTA was associated with decreased postdonation eGFR, while no other subclinical histological abnormalities provided additional information. PMID:27152920

The effect of direct renin inhibition alone and in combination with ACE inhibition on endothelial function, arterial stiffness, and renal function in type 1 diabetes.

PubMed

Cherney, David Z I; Scholey, James W; Jiang, Shan; Har, Ronnie; Lai, Vesta; Sochett, Etienne B; Reich, Heather N

2012-11-01

Diabetes is associated with renin-angiotensin system (RAS) activation, leading to renal and systemic vascular dysfunction that contribute to end-organ injury and significant morbidity. RAS blockade with ACE inhibitors reduces, but does not abolish, RAS effects. Accordingly, our aim was to determine if direct renin inhibition alone, and in combination with an ACE inhibitor, corrects early hemodynamic abnormalities associated with type 1 diabetes. Arterial stiffness (augmentation index), flow-mediated vasodilatation (FMD), and renal hemodynamic function (inulin and paraaminohippurate clearance) were measured at baseline under clamped euglycemic and hyperglycemic conditions (n = 21). Measures were repeated after 4 weeks of aliskiren therapy and again after aliskiren plus ramipril. Blood pressure-lowering effects of aliskiren were similar during clamped euglycemia and hyperglycemia. Combination therapy augmented this effect under both glycemic conditions (P = 0.0005). Aliskiren reduced arterial stiffness under clamped euglycemic and hyperglycemic conditions, and the effects were augmented by dual RAS blockade (-3.4 ± 11.2 to -8.0 ± 11.5 to -14.3 ± 8.4%, respectively, during euglycemia, P = 0.0001). During clamped euglycemia, aliskiren increased FMD; dual therapy exaggerated this effect (5.1 ± 3.3 to 7.5 ± 3.0 to 10.8 ± 3.5%, repeated-measures ANOVA, P = 0.0001). Aliskiren monotherapy caused renal vasodilatation during clamped hyperglycemia only. In contrast, dual therapy augmented renal vasodilatory effects during clamped euglycemia and hyperglycemia. In patients with uncomplicated type 1 diabetes, aliskiren-based dual RAS blockade is associated with greater arterial compliance, FMD, and renal vasodilatation.

Anatomical and procedural determinants of ambulatory blood pressure lowering following catheter-based renal denervation using radiofrequency.

PubMed

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham R; Edelman, Elazer R; Cremers, Bodo; Kulenthiran, Saarraaken; Ukena, Christian; Linz, Dominik; Kindermann, Ingrid; Tsioufis, Costas; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-03-02

Catheter-based renal sympathetic denervation (RDN) has been introduced to lower blood pressure (BP) and sympathetic activity in patients with uncontrolled hypertension with at best equivocal results. It has been postulated that anatomic and procedural elements introduce unaccounted variability and yet little is known of the impact of renal anatomy and procedural parameters on BP response to RDN. Anatomical parameters such as length and diameter were analyzed by quantitative vascular analysis and the prevalence of accessory renal arteries and renal artery disease were documented in 150 patients with resistant hypertension undergoing bilateral RDN using a mono-electrode radiofrequency catheter (Symplicity Flex, Medtronic). Accessory renal arteries and renal artery disease were present in 56 (37%) and 14 patients (9%), respectively. At 6-months, 24 h-ambulatory BP was reduced by 11/6 mm Hg (p < 0.001 for both). Change of systolic blood pressure (SBP) was not related to the presence of accessory renal arteries (p = 0.543) or renal artery disease (p = 0.598). Patients with at least one main renal artery diameter ≤ 4 mm had a more pronounced reduction of 24 h-ambulatory SBP compared to patients where both arteries were >4 mm (-19 vs. -10 mmHg; p = 0.038). Neither the length of the renal artery nor the number of RF ablations influenced 24 h-ambulatory BP reduction at 6 months. 24 h-ambulatory BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, accessory arteries or renal artery disease. Further, there was no dose-response relationship observed with increasing number of ablations. Because little is known of the impact of renal anatomy and procedural parameters on blood pressure (BP) response to renal denervation (RDN), anatomical and procedural data were analyzed in 150 patients undergoing bilateral RDN. BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, the presence of renal artery disease or accessory renal arteries. Further, there was no dose-response relationship observed with increasing number of ablations. Copyright © 2018. Published by Elsevier Inc.

Secondary hypertension in adults

PubMed Central

Puar, Troy Hai Kiat; Mok, Yingjuan; Debajyoti, Roy; Khoo, Joan; How, Choon How; Ng, Alvin Kok Heong

2016-01-01

Secondary hypertension occurs in a significant proportion of adult patients (~10%). In young patients, renal causes (glomerulonephritis) and coarctation of the aorta should be considered. In older patients, primary aldosteronism, obstructive sleep apnoea and renal artery stenosis are more prevalent than previously thought. Primary aldosteronism can be screened by taking morning aldosterone and renin levels, and should be considered in patients with severe, resistant or hypokalaemia-associated hypertension. Symptoms of obstructive sleep apnoea should be sought. Worsening of renal function after starting an angiotensin-converting enzyme inhibitor suggests the possibility of renal artery stenosis. Recognition, diagnosis and treatment of secondary causes of hypertension lead to good clinical outcomes and the possible reversal of end-organ damage, in addition to blood pressure control. As most patients with hypertension are managed at the primary care level, it is important for primary care physicians to recognise these conditions and refer patients appropriately. PMID:27211205

Secondary hypertension in adults.

PubMed

Puar, Troy Hai Kiat; Mok, Yingjuan; Debajyoti, Roy; Khoo, Joan; How, Choon How; Ng, Alvin Kok Heong

2016-05-01

Secondary hypertension occurs in a significant proportion of adult patients (~10%). In young patients, renal causes (glomerulonephritis) and coarctation of the aorta should be considered. In older patients, primary aldosteronism, obstructive sleep apnoea and renal artery stenosis are more prevalent than previously thought. Primary aldosteronism can be screened by taking morning aldosterone and renin levels, and should be considered in patients with severe, resistant or hypokalaemia-associated hypertension. Symptoms of obstructive sleep apnoea should be sought. Worsening of renal function after starting an angiotensin-converting enzyme inhibitor suggests the possibility of renal artery stenosis. Recognition, diagnosis and treatment of secondary causes of hypertension lead to good clinical outcomes and the possible reversal of end-organ damage, in addition to blood pressure control. As most patients with hypertension are managed at the primary care level, it is important for primary care physicians to recognise these conditions and refer patients appropriately. Copyright: © Singapore Medical Association.

Significant association between renal function and area of amyloid deposition in kidney biopsy specimens in both AA amyloidosis associated with rheumatoid arthritis and AL amyloidosis.

PubMed

Kuroda, Takeshi; Tanabe, Naohito; Hasegawa, Eriko; Wakamatsu, Ayako; Nozawa, Yukiko; Sato, Hiroe; Nakatsue, Takeshi; Wada, Yoko; Ito, Yumi; Imai, Naofumi; Ueno, Mitsuhiro; Nakano, Masaaki; Narita, Ichiei

2017-06-01

The kidney is a major target organ for systemic amyloidosis, which results in proteinuria and an elevated serum creatinine level. The clinical manifestations and precursor proteins of amyloid A (AA) and light-chain (AL) amyloidosis are different, and the renal damage due to amyloid deposition also seems to differ. The purpose of this study was to clarify haw the difference in clinical features between AA and AL amyloidosis are explained by the difference in the amount and distribution of amyloid deposition in the renal tissues. A total of 119 patients participated: 58 patients with an established diagnosis of AA amyloidosis (AA group) and 61 with AL amyloidosis (AL group). We retrospectively investigated the correlation between clinical data, pathological manifestations, and the area occupied by amyloid in renal biopsy specimens. In most of the renal specimens the percentage area occupied by amyloid was less than 10%. For statistical analyses, the percentage area of amyloid deposition was transformed to a common logarithmic value (Log 10 %amyloid). The results of sex-, age-, and Log 10 %amyloid-adjusted analyses showed that systolic blood pressure (SBP) was higher in the AA group. In terms of renal function parameters, serum creatinine, creatinine clearance (Ccr) and estimated glomerular filtration rate (eGFR) indicated significant renal impairment in the AA group, whereas urinary protein indicated significant renal impairment in the AL group. Pathological examinations revealed amyloid was predominantly deposited at glomerular basement membrane (GBM) and easily transferred to the mesangial area in the AA group, and it was predominantly deposited at in the AL group. The degree of amyloid deposition in the glomerular capillary was significantly more severe in AL group. The frequency of amyloid deposits in extraglomerular mesangium was not significantly different between the two groups, but in AA group, the degree amyloid deposition was significantly more severe, and the deposition pattern in the glomerulus was nodular. Nodular deposition in extraglomerular mesangium leads to renal impairment in AA group. There are significant differences between AA and AL amyloidosis with regard to the renal function, especially in terms of Ccr, eGFR and urinary protein, even after Log10%amyloid was adjusted; showing that these inter-group differences in renal function would not be depend on the amount of renal amyloid deposits. These differences could be explained by the difference in distribution and morphological pattern of amyloid deposition in the renal tissue.

Active video gaming in patients with renal transplant: a pilot study

PubMed Central

2014-01-01

Background Patients with renal transplant are at higher risk of mortality from cardiovascular disease (CVD) compared with the general population. Physical activity has been shown to reduce the risk of CVD mortality in these patients. Unfortunately, barriers such as the harsh Canadian climate prevent patients from engaging in and harvesting the health benefits of physical activity. This pilot study explored active video gaming (AVG) as a way for patients with renal transplant to obtain physical activity and examined its effect on their functional status and quality of life (QOL). Main text We recruited nine patients for an 8-week prospective pilot study. All patients received a Microsoft Xbox 360™ video gaming console, a Microsoft Kinect™ sensor, and the video game Your Shape Fitness Evolved 2012. Assessment of each participant before and after the intervention included blood pressure measures, a 6-minute walk test, and the Godin Leisure Time Questionnaire (GLTQ). We analyzed all nine patients at the end of the 8-week study period, and found no changes in blood pressure or GLTQ scores. However, there was a significant increase in the 6-minute walk distance (P = 0.022), which represented a consistent increase for most patients (correlation = 0.977). In addition, participants over the age of 45 years (n = 4) were more likely to use the AVG system (P = 0.042). Conclusion AVG has the potential to improve the functional status in patients with renal transplant. Further research is required to corroborate the full health benefits of AVG in this patient population. PMID:25114788

Reduced nephron endowment in the neonates of Indigenous Australian peoples.

PubMed

Kandasamy, Y; Smith, R; Wright, I M R; Lumbers, E R

2014-02-01

Rates of chronic kidney disease (CKD) among Indigenous groups in Australia exceed non-Indigenous rates eight-fold. Using kidney volume as a surrogate for nephron number, we carried out a study to determine if Indigenous neonates have a smaller kidney volume (and thus a reduced nephron number) from birth compared with non-Indigenous neonates. We recruited term and preterm neonates (<32 weeks) at a tertiary care neonatal unit over a 12 months period. Preterm neonates were assessed (renal sonography and renal function measurement) at 32 weeks corrected age (CA) and again at 38 weeks CA when blood pressure was also measured. All term neonates were assessed in the first post-natal week, including renal sonography, renal function and blood pressure measurement. The primary outcome measured was total kidney volume (TKV) and estimated glomerular filtration rate (eGFR) was a secondary outcome. Data was available for 44 preterm (11 Indigenous) and 39 term (13 Indigenous) neonates. TKV of Indigenous neonates was significantly lower at 32 weeks [12.0 (2.0) v. 15.4 (5.1) ml; P=0.03] and 38 weeks CA [18.6 (4.0) v. 22.6 (5.9) ml; P=0.04] respectively. Term Indigenous neonates also had smaller kidney volumes compared with non-Indigenous neonates. Despite a smaller kidney volume (and reduced nephron number), Indigenous neonates did not have a significantly lower eGFR. Indigenous neonates achieve similar eGFRs to Non-Indigenous neonates, presumably through a higher single nephron filtration rate. This places Indigenous neonates at a greater risk of long-term kidney damage later in life.

Cardio-renal and metabolic adaptations during pregnancy in female rats born small: implications for maternal health and second generation fetal growth.

PubMed

Gallo, Linda A; Tran, Melanie; Moritz, Karen M; Mazzuca, Marc Q; Parry, Laura J; Westcott, Kerryn T; Jefferies, Andrew J; Cullen-McEwen, Luise A; Wlodek, Mary E

2012-02-01

Intrauterine growth restriction caused by uteroplacental insufficiency increases risk of cardiovascular and metabolic disease in offspring. Cardio-renal and metabolic responses to pregnancy are critical determinants of immediate and long-term maternal health. However, no studies to date have investigated the renal and metabolic adaptations in growth restricted offspring when they in turn become pregnant. We hypothesised that the physiological challenge of pregnancy in growth restricted females exacerbates disease outcome and compromises next generation fetal growth. Uteroplacental insufficiency was induced by bilateral uterine vessel ligation (Restricted) or sham surgery (Control) on day 18 of gestation in WKY rats and F1 female offspring birth and postnatal body weights were recorded. F1 Control and Restricted females were mated at 4 months and blood pressure, renal and metabolic parameters were measured in late pregnancy and F2 fetal and placental weights recorded. Age-matched non-pregnant Control and Restricted F1 females were also studied. F1 Restricted females were born 10-15% lighter than Controls. Basal insulin secretion and pancreatic β-cell mass were reduced in non-pregnant Restricted females but restored in pregnancy. Pregnant Restricted females, however, showed impaired glucose tolerance and compensatory glomerular hypertrophy, with a nephron deficit but normal renal function and blood pressure. F2 fetuses from Restricted mothers exposed to physiological measures during pregnancy were lighter than Controls highlighting additive adverse effects when mothers born small experience stress during pregnancy. Female rats born small exhibit mostly normal cardio-renal adaptations but altered glucose control during late pregnancy making them vulnerable to lifestyle challenges.

Impact of the NO-Sensitive Guanylyl Cyclase 1 and 2 on Renal Blood Flow and Systemic Blood Pressure in Mice.

PubMed

Mergia, Evanthia; Thieme, Manuel; Hoch, Henning; Daniil, Georgios; Hering, Lydia; Yakoub, Mina; Scherbaum, Christina Rebecca; Rump, Lars Christian; Koesling, Doris; Stegbauer, Johannes

2018-03-23

Nitric oxide (NO) modulates renal blood flow (RBF) and kidney function and is involved in blood pressure (BP) regulation predominantly via stimulation of the NO-sensitive guanylyl cyclase (NO-GC), existing in two isoforms, NO-GC1 and NO-GC2. Here, we used isoform-specific knockout (KO) mice and investigated their contribution to renal hemodynamics under normotensive and angiotensin II-induced hypertensive conditions. Stimulation of the NO-GCs by S -nitrosoglutathione (GSNO) reduced BP in normotensive and hypertensive wildtype (WT) and NO-GC2-KO mice more efficiently than in NO-GC1-KO. NO-induced increase of RBF in normotensive mice did not differ between the genotypes, but the respective increase under hypertensive conditions was impaired in NO-GC1-KO. Similarly, inhibition of endogenous NO increased BP and reduced RBF to a lesser extent in NO-GC1-KO than in NO-GC2-KO. These findings indicate NO-GC1 as a target of NO to normalize RBF in hypertension. As these effects were not completely abolished in NO-GC1-KO and renal cyclic guanosine monophosphate (cGMP) levels were decreased in both NO-GC1-KO and NO-GC2-KO, the results suggest an additional contribution of NO-GC2. Hence, NO-GC1 plays a predominant role in the regulation of BP and RBF, especially in hypertension. However, renal NO-GC2 appears to compensate the loss of NO-GC1, and is able to regulate renal hemodynamics under physiological conditions.

Transient prehypertensive treatment in spontaneously hypertensive rats: a comparison of losartan and amlodipine regarding long-term blood pressure, cardiac and renal protection.

PubMed

Peng, Feng; Lin, Jinxiu; Lin, Liming; Tang, Hong

2012-12-01

The aim of this study was to compare the effectiveness of transient prehypertensive treatment with losartan compared with amlodipine in spontaneously hypertensive rats (SHRs) on long-term blood pressure (BP), cardiac and renal protection. SHRs were prehypertensively treated with losartan, amlodipine or saline. Rats were followed up until 46 weeks of age. The left ventricular (LV) geometry and function were assessed by echocardiography. Angiotensin II (Ang II) and aldosterone (Aldo) were measured by radioimmunoassay. Ang II type 1 (AT1R) and type 2 (AT2R) receptor protein expression was determined by western blotting. The systolic blood pressure (SBP) in losartan-treated SHRs (SHR-Los) was persistently reduced until 46 weeks of age, but returned to untreated SHR levels in amlodipine-treated SHRs (SHR-Aml) from 30 weeks onwards. Compared to untreated SHRs, the albuminuria excretion in SHR-Los at week 46 was markedly decreased, the plasma, myocardium and renal tissue Ang II and Aldo levels in SHR-Los at week 46 were markedly decreased; AT1R and TGF-β1 protein expression was downregulated and AT2R protein was upregulated. Compared to untreated SHRs, the left ventricular mass index (LVMI) and collagen volume fraction (CVF) in SHR-Los were markedly decreased until week 46, and the left ventricular ejection fraction (LVEF) and cardiac brain natriuretic peptide mRNA expression were improved, whereas similar LVMI and elevated CVF were observed in SHR-Aml, and the LVEF decreased significantly below that of untreated SHRs at week 46, with cardiac BNP mRNA expression increasing slightly. Prehypertensive treatment with losartan was more effective than amlodipine on delaying long-term BP increase and ameliorating cardiac, renal structure and function, which may be related to the permanent attenuation of the circulating and local renin-angiotensin systems.

An exceptional case of renal artery restenosis in a patient with polycythaemia vera.

PubMed

Gavriilaki, Eleni; Sampanis, Nikolaos; Kavlakoudis, Christos; Papaioannou, George; Vasileiou, Sotirios

2014-12-01

Polycythaemia vera represents a rare chronic myeloproliferative neoplasm characterized by an increased thrombotic risk. Previous case reports have documented a link between primary or secondary polycythemia and the presence of renal artery stenosis and renovascular hypertension. Herein, we report an exceptional case of renal artery restenosis leading to uncontrolled hypertension in a patient with PV and high haematocrit levels. A 52-year-old female patient with a history of polycythaemia vera under treatment with hydroxyurea and phlebotomy presented in our outpatient clinic with newly diagnosed hypertension caused by left renal artery stenosis. Six months after stenting, patient returned for a follow-up visit due to uncontrolled hypertension and high haematocrit levels. Total restenosis of the left renal artery was found. Patient received optical medical treatment and was prescribed to higher doses of hydroxyurea by her treating haematologist. Since then, blood pressure and Hct levels remain adequately controlled. As described by earlier case reports, renal artery stenosis, hypertension and polycythemia often coexist. However, renovascular hypertension may not only lead to secondary erythrocytosis but also be a thrombotic complication of primary erythrocytosis. Thus, patients with polycythaemia vera should be carefully evaluated and optimally managed when hypertension or impaired renal function coexist.

Association of serum uric acid level and blood pressure in type 2 diabetes mellitus

NASA Astrophysics Data System (ADS)

Savira, M.; Rusdiana; Syahputra, M.

2018-03-01

Uric acid is an end product of purine degradation in humans and primarily excreted through urine. In adulthood, concentrations rise steadily over time and vary with height, body weight, blood pressure, renal function, and alcohol intake. Uric acid is known as anti-oxidant, it has a beneficial role in diseases. Elevated serum uric acid associated with anincreased risk of cardiovascular disease. It has been found that elevated levels of uric acid associated with high risks of acomplication of type 2 diabetes mellitus and It has astrong association between elevated uric acid levels and obesity, metabolic syndrome, diabetes mellitus, hypertension, cardiovascular and renal disorders. The aim of the study analyzed the association between serum uric acid level and blood pressure in type 2 diabetes mellitus patients. This research is descriptive analytic research with a cross sectional design included 50 diabetic subjects aged over 40 years old. Subjects picked by consecutive sampling then we examined the weight, height, waist size, blood pressure, fasting blood sugar, and serum uric acid level. Statistical analysis using chi-square found that there was no significant association between serum uric acid level and systole and diastole pressure in type 2 diabetes mellitus patients (p>0.005).

Renoprotective Effects of SGLT2 Inhibitors: Beyond Glucose Reabsorption Inhibition.

PubMed

Tsimihodimos, V; Filippatos, T D; Filippas-Ntekouan, S; Elisaf, M

2017-01-01

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that inhibit glucose and sodium reabsorption at proximal tubules. These drugs may exhibit renoprotective properties, since they prevent the deterioration of the glomerular filtration rate and reduce the degree of albuminuria in patients with diabetes-associated kidney disease. In this review we consider the pathophysiologic mechanisms that have been recently implicated in the renoprotective properties of SGLT2 inhibitors. The beneficial effects of SGLT2 inhibitors on the conventional risk factors for kidney disease (such as blood pressure, hyperglycaemia, body weight and serum uric acid levels) may explain, at least in part, the observed renal-protecting properties of these compounds. However, it has been hypothesized that the most important mechanisms for this phenomenon include the reduction in the intraglomerular pressure, the changes in the local and systemic degree of activation of the renin-aldosterone-angiotensin system and a shift in renal fuel consumption towards more efficient energy substrates such as ketone bodies. The beneficial effects of SGLT2 inhibitors on various aspects of renal function make them an attractive choice in patients with (and possibly without) diabetes-associated renal impairment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

WNK kinases and renal sodium transport in health and disease: an integrated view

PubMed Central

McCormick, James; Yang, Chao-Ling; Ellison, David H.

2011-01-01

The with no lysine (WNK) kinases comprise a novel branch of the human kinome that plays a central role in regulating renal sodium, potassium, and chloride transport, and, therefore, blood pressure. Mutations of two WNK kinases, WNK1 and WNK4, cause familial hyperkalemic hypertension (Gordon’s syndrome or Type II pseudohypoaldosteronism), a rare monogenic disease. Many aspects of WNK action have been elucidated during the past seven years. WNKs are all expressed along a short segment of renal distal tubule, where they modulate the activity of a wide variety of transport proteins. These diverse effects, however, make it difficult to describe an integrated model of WNK function within the kidney. Recently, work in vivo and in vitro has begun to clarify this picture. The present review emphasizes recent insights into mechanism by which WNK kinases interact to modulate sodium and potassium transport along the aldosterone-sensitive distal nephron. We describe a potential mechanism by which WNK4 mutations convert the action of WNK4 from inhibiting renal sodium chloride retention to stimulating it, thereby affecting both blood pressure and potassium balance. An explanation for how WNK kinases can alter the effects of aldosterone from primarily kaliuretic to primarily sodium chloride retentive, according to physiological need, is also described. PMID:18212265

Infusion of noradrenaline through the proximal line of a migrated central venous catheter.

PubMed

Freer, M; Noble, S

2012-08-01

A 41-year-old, obese, patient was admitted to Accident and Emergency with a history of leg cellulitis. A central line was inserted. Documented aspiration of blood from all lines, central venous pressure trace obtained and correct position noted on the chest X-ray (CXR). The patient became increasingly septic despite antibiotic therapy. He was subsequently commenced on a noradrenaline infusion; however, the blood pressure was unresponsive. On admission to the intensive care unit (ICU), it was noted he had an area of white skin over the right clavicle. The infusions were stopped and a CXR confirmed proximal migration of the line. The central line was re-sited and his noradrenaline recommenced with an improvement in his blood pressure. Acute renal failure developed which required haemofiltration for 24 hours. The condition improved and the patient was discharged from ICU. It took several weeks for his renal function to return to normal, but he was discharged home with no permanent damage.

The pathogenesis and management of hypertension in diabetic kidney disease.

PubMed

Van Buren, Peter N; Toto, Robert D

2013-01-01

Hypertension commonly coexists with diabetes, and its prevalence is even higher in the presence of diabetic kidney disease. The pathogenesis of hypertension in this population stems from increased extracellular volume and increased vasoconstriction that results from mechanisms that may be attributed to both diabetes and the eventual impairment of renal function. Antihypertensive therapy aimed at reducing blood pressure remains a primary goal in preventing the incidence of diabetic kidney and slowing its progression. Initial therapy should consist of an ACE inhibitor or ARB titrated to the maximally tolerated dose. Using combination RAAS therapy further reduces proteinuria, but the benefits of this strategy compared with the potential risks of hyperkalemia and acute deterioration of renal function are still unknown. Endothelin receptor antagonists also lower proteinuria, but these can be associated with volume overload and edema with no clear long-term benefit on renal function yet identified. Further large clinical trials are needed to better understand how progression to ESRD can be slowed or halted in patients with diabetic kidney disease. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison between swallowing and chewing of garlic on levels of serum lipids, cyclosporine, creatinine and lipid peroxidation in renal transplant recipients.

PubMed

Jabbari, Abbas; Argani, Hassan; Ghorbanihaghjo, Amir; Mahdavi, Reza

2005-05-19

Hyperlipidemia and increased degree of oxidative stress are among the important risk factors for Atherosclerosis in renal transplant recipients (RTR). The Medical treatment of hyperlipidemia in RTR because of drugs side effects has been problematic, therefore alternative methods such as using of Garlic as an effective material in cholesterol lowering and inhibition of LDL Oxidation has been noted. For evaluation of garlic effect on RTR, 50 renal transplant patients with stable renal function were selected and divided into 2 groups. They took one clove of garlic (1 gr) by chewing or swallowing for two months, after one month wash-out period, they took garlic by the other route. Results indicated that although lipid profile, BUN, Cr, serum levels of cyclosporine and diastolic blood pressure did not change, Systolic blood pressure decreased from 138.2 to 132.8 mmHg (p=0.001) and Malondialdehyde (MDA) decreased from 2.4 to 1.7 nmol/ml (p=0.009) by swallowing route, Cholesterol decreased from 205.1 to 195.3 mg/dl (p=0.03), triglyceride decreased from 195.7 to 174.8 mg/dl (p=0.008), MDA decreased from 2.5 to 1.6 nmol/ml (p=0.001), systolic blood pressure decreased from 137.5 to 129.8 mmHg (p=0.001), diastolic blood pressure decreased from 84.6 to 77.6 mmHg (p=0.001) and Cr decreased from 1.51 to 1.44 mg/dl (p=0.03) by chewing route too. However HDL, LDL and cyclosporine serum levels had no significant differences by both of swallowing and chewing routes. We conclude that undamaged garlic (swallowed) had no lowering effect on lipid level of serum. But Crushed garlic (chewed) reduces cholesterol, triglyceride, MDA and blood pressure. Additionally creatinine reduced without notable decrease in cyclosporine serum levels may be due to cyclosporine nephrotoxicity ameliorating effect of garlic.

Review of the State of Renal Nerve Ablation for Patients with Severe and Resistant Hypertension

PubMed Central

Gulati, Vinay; White, William B.

2013-01-01

Through modulation of renin secretion, glomerular filtration rate and renal absorption of sodium, the sympathetic innervation of the kidneys plays an important role in the pathogenesis of hypertension. Renal nerve ablation technology is being developed for treatment of drug-treatment resistant hypertension worldwide. Preliminary research with the use of radiofrequency based renal denervation systems have demonstrated encouraging results with significant reduction of blood pressure in patients inadequately controlled despite nearly maximal drug therapy regimens. From work done thus far, the renal denervation procedure has not been associated with serious adverse effects. Long term efficacy and safety still needs to be established for renal nerve ablation. This review focuses on the impact of the renal sympathetic system on blood pressure regulation, the clinical rationale for renal nerve ablation in severe and drug-treatment resistant hypertension and current evidence from the more advanced renal denervation devices. PMID:23953998

Serum bilirubin levels are negatively associated with diabetic retinopathy in patients with type 1 diabetes and normal renal function.

PubMed

Bulum, Tomislav; Tomić, Martina; Duvnjak, Lea

2018-06-01

Previous studies suggested that total serum bilirubin levels are negatively associated with diabetic retinopathy (DR) and nephropathy in patients with diabetes mellitus. The objective of this study was to explore the relationship between serum total bilirubin levels and prevalence of DR in patients with type 1 diabetes (T1DM) and normal renal function. Study included 163 T1DM with normal renal function (urinary albumin excretion rate <30 mg/24 h, estimated glomerular filtration rate (eGFR) >60 ml min -1 1.73 m -2 ). Photo-documented retinopathy status was made according to the EURODIAB protocol. Patients with DR were older (49 vs 42 years, p = 0.001), had higher systolic blood pressure (130 vs 120 mmHg, p = 0.001), triglycerides (0.89 vs 0.77 mmol/L, p = 0.01), and lower serum total bilirubin (12 vs 15 U/L, p = 0.02) and eGFR (100 vs 106 ml min -1 1.73 m -2 , p = 0.03). In multivariate logistic regression analysis, only total serum bilirubin was significantly associated with risk of DR in our subjects (OR 0.88, CI 0.81-0.96, p = 0.006). These data suggest that serum total bilirubin levels are independently negatively associated with DR in T1DM with normal renal function. Prospective studies are needed to confirm whether lower serum total bilirubin has predictive value for the development of DR in T1DM with normal renal function.

Safety and Clinical Outcome of the Delivery of Radiofrequency Nerve Ablation Therapy in a Renal Artery of Unusual Anatomy.

PubMed

de Leon-Martinez, Enrique Ponce; Garza, Javier A; Azpiri-Lopez, Jose R; Dillon, Krista N; Salazar, Leonel Olivas; Canepa-Campos, Francisco; Rousselle, Serge D; Tellez, Armando

2015-12-01

Catheter-based renal sympathetic denervation is an emerging therapy for resistant hypertension (RHTN) patients, resulting in a significant blood pressure reduction. The presence of accessory renal arteries and anomalous branching patterns are reported in approximately 20-27 % of patients. However, accessory renal arteries, when smaller than 4 mm in diameter, they are out of the inclusion criteria for renal denervation therapy. For this reason patients with evidence of accessory renal arteries have been excluded in previous clinical trials. Recent data suggest that accessory renal arteries may play an important role in non-response therapy when they do not receive renal denervation treatment. In this report, we present the outcome of a patient with resistant hypertension and an anomalous right renal artery, having undergone denervation of both principal and accessory renal arteries. The renal ablation by radiofrequency energy of a distant accessory renal artery resulted in a safe procedure with no clinical complications. Consistent with literature the RDN of all, main and accessory renal arteries, was effective in decreasing patient blood pressure while decreasing the need for antihypertensive medication.

Renal sympathetic nerve activity measured by norepinephrine spillover rate in response to changes in blood pressure in conscious rabbits.

PubMed

Sano, N; Way, D; McGrath, B P

1989-04-01

1. Renal sympathetic nerve activity (RSNA) in response to changes in mean arterial pressure (MAP) was examined by measuring renal norepinephrine (NE) spillover rate in conscious rabbits. 2. A chronic renal vein catheter was implanted for sampling renal venous blood without stress in conscious animals. 3. RSNA estimated by renal NE spillover rate significantly increased in response to moderate falls in MAP produced by sodium nitroprusside (SNP) infusion and decreased in response to moderate rises in MAP produced by phenylephrine (PE) infusion. 4. The NE spillover method is sufficiently sensitive to detect responses of RSNA to physiological stimuli in conscious rabbits.

[Normotensive scleroderma renal crisis].

PubMed

Villaverde, Marcelo; González, Alejandra; Orellano, Pablo; Lafage, Matías

2003-01-01

A 60 year old male patient having systemic scleroderma and normotensive scleroderma renal crisis was admitted in our hospital. He presented polyarticular, esophagic, lung and skin compromise. Before admission he had been treated with high doses of corticosteroids. We believe corticosteroids led to the worsening of renal damage with renal failure, microangiopathic hemolytic anemia without high blood pressure. The 10% of these cases have normal blood pressure. The patient was treated with enalapril and hemodialysis. There was no favourable response to this treatment and he died seven days after admission.

Enalapril/amlodipine combination in cyclosporine-treated renal transplant recipients: a prospective randomized trial.

PubMed

Halimi, Jean-Michel; Giraudeau, Bruno; Buchler, Matthias; Al-Najjar, Azmi; Etienne, Isabelle; Laouad, Inass; Bruyère, Franck; Lebranchu, Yvon

2007-01-01

Most hypertensive renal transplant recipients require two or more antihypertensive medications to achieve blood pressure control. However, which medications must be combined is still a matter of debate. A prospective randomized open-label blinded evaluation trial comparing the six-month effects of the amlodipine-enalapril combination (n = 32) vs. enalapril alone (n = 33) and vs. amlodipine alone (n = 34) on arterial pressure, renal function, albuminuria and tolerability. At six months, diastolic arterial pressure was more adequately controlled (i.e., <90 mmHg) in the combination group than in the amlodipine and enalapril groups (100% vs. 82.4% and 84.8%, respectively, p = 0.038). The same trend was observed for systolic arterial pressure (65.6% vs. 58.8% and 51.5%, NS). The six-month change in albuminuria was similar in the combination group and in the enalapril group (-64.7% vs. -59.5%); however, patients in the combination group exhibited a greater reduction in albuminuria than in the amlodipine group (-64.7% vs. -29.0%, p = 0.002). As compared with baseline values, serum creatinine and potassium remained unchanged in the combination group, whereas they increased by 9 +/- 12 micromol/L (p = 0.01) and by 0.2 +/- 0.4 mmol/L (p < 0.01), respectively, in the enalapril group. The cyclosporine trough levels remained unchanged in the combination group, but increased in the amlodipine group. Angiotensin-converting enzyme inhibitor (ACEI)-calcium-channel blocker (CCB) combination controls arterial pressure more adequately than ACEI alone or CCB alone, reduces albuminuria and may prevent the ACEI-induced initial rise in serum creatinine.

Transjugular intrahepatic portosystemic shunt: impact on systemic hemodynamics and renal and cardiac function in patients with cirrhosis.

PubMed

Busk, Troels M; Bendtsen, Flemming; Poulsen, Jørgen H; Clemmesen, Jens O; Larsen, Fin S; Goetze, Jens P; Iversen, Jens S; Jensen, Magnus T; Møgelvang, Rasmus; Pedersen, Erling B; Bech, Jesper N; Møller, Søren

2018-02-01

Transjugular intrahepatic portosystemic shunt (TIPS) alleviates portal hypertension and possibly increases central blood volume (CBV). Moreover, renal function often improves; however, its effects on cardiac function are unclear. The aims of our study were to examine the effects of TIPS on hemodynamics and renal and cardiac function in patients with cirrhosis. In 25 cirrhotic patients, we analyzed systemic, cardiac, and splanchnic hemodynamics by catheterization of the liver veins and right heart chambers before and 1 wk after TIPS. Additionally, we measured renal and cardiac markers and performed advanced echocardiography before, 1 wk after, and 4 mo after TIPS. CBV increased significantly after TIPS (+4.6%, P < 0.05). Cardiac output (CO) increased (+15.3%, P < 0.005) due to an increase in stroke volume (SV) (+11.1%, P < 0.005), whereas heart rate (HR) was initially unchanged. Cardiopulmonary pressures increased after TIPS, whereas copeptin, a marker of vasopressin, decreased (-18%, P < 0.005) and proatrial natriuretic peptide increased (+52%, P < 0.0005) 1 wk after TIPS and returned to baseline 4 mo after TIPS. Plasma neutrophil gelatinase-associated lipocalin, renin, aldosterone, and serum creatinine decreased after TIPS (-36%, P < 0.005; -65%, P < 0.05; -90%, P < 0.005; and -13%, P < 0.005, respectively). Echocardiography revealed subtle changes in cardiac function after TIPS, although these were within the normal range. TIPS increases CBV by increasing CO and SV, whereas HR is initially unaltered. These results indicate an inability to increase the heart rate in response to a hemodynamic challenge that only partially increases CBV after TIPS. These changes, however, are sufficient for improving renal function. NEW & NOTEWORTHY For the first time, we have combined advanced techniques to study the integrated effects of transjugular intrahepatic portosystemic shunt (TIPS) in cirrhosis. We showed that TIPS increases central blood volume (CBV) through improved cardiac inotropy. Advanced echocardiography demonstrated that myocardial function was unaffected by the dramatic increase in preload after TIPS. Finally, renal function improved due to the increase in CBV. Recognition of these physiological changes significantly contributes to our clinical understanding of TIPS.

Enalapril and losartan restored blood pressure and vascular reactivity in intrauterine undernourished rats.

PubMed

Ceravolo, Graziela S; Franco, Maria C P; Carneiro-Ramos, Marcela S; Barreto-Chaves, Maria L M; Tostes, Rita C A; Nigro, Dorothy; Fortes, Zuleica B; Carvalho, Maria Helena C

2007-01-30

Epidemiological studies suggest that intrauterine undernutrition plays an important role in the development of arterial hypertension and endothelial dysfunction in adulthood. We have evaluated the effect of the Renin Angiotensin System inhibition on the blood pressure and the mesenteric arteriolar reactivity of the intrauterine undernourished rats. Wistar rats were fed either normal or 50% of the normal intake diets, during the whole gestational period. In this study only the male offspring was used. At 16 weeks of age, the rats were used for the study of blood pressure, microvascular reactivity studied in vivo-in situ to Angiotensin II (Ang II), Bradykinin (Bk) and Acetylcholine (Ach) before and after either losartan (10 mg/kg/15 days) or enalapril (15 mg/kg/21 days) treatment. We also evaluated the mesenteric and plasmatic Angiotensin Converting Enzyme (ACE), renal function, lipid plasmatic content, and insulin and glucose metabolism. Intrauterine undernutrition induced hypertension and increased response of mesenteric arterioles to Ang II and decreased vasodilation to Bk and Ach. The treatments with losartan or enalapril normalized the blood pressure levels and significantly improved the arteriolar responses to Bk, Ach and reduced the response to Ang II. No differences have been detected to ACE activity, renal function, lipid content and insulin and glucose metabolism. This study shows for the first time that Renin Angiotensin System inhibitors can normalize the cardiovascular alterations induced by intrauterine undernutrition.

The dietary phase 2 protein inducer sulforaphane can normalize the kidney epigenome and improve blood pressure in hypertensive rats.

PubMed

Senanayake, Gamarallage V K; Banigesh, Ali; Wu, Lingyun; Lee, Paul; Juurlink, Bernhard H J

2012-02-01

Our previous studies have shown that broccoli sprouts high in the glucosinolate glucoraphanin decreases renal and vascular oxidative stress and inflammation as well as blood pressure in spontaneously hypertensive stroke-prone (SHRSP) rats. The objective of this study was to determine whether the metabolite of glucoraphanin, sulforaphane, was responsible for this improved blood pressure and whether this is associated with normalization of renal methylated DNA. Sulforaphane was given by gavage to SHRSP and Sprague Dawley (SD) rats over 4 months and blood pressure measured under anesthesia just before euthanasia. Renovascular morphology was determined by histology and methylated deoxycytosine levels analyzed using high-performance liquid chromatography. Mean arterial pressure was 20% higher in vehicle-treated SHRSP when compared to SD. Sulforaphane administration to SHRSP improved blood pressure and lowered this difference to 11%. Vehicle-treated SHRSP had significantly increased wall:lumen ratios in renal arteries, increased numbers of vascular smooth muscle cells (VSMCs), increased renal protein nitration, and decreased (11%) renal DNA methylation compared to SD. Sulforaphane administration to SHRSP significantly lowered arterial wall:lumen ratio by 35%, reduced the number of VSMCs, reduced the level of protein nitration, and increased methylated deoxycytosine levels by 14%. Sulforaphane administration rectified pathological abnormalities in SHRSP kidneys and significantly improved blood pressure. This was associated with normalization of global kidney DNA methylation suggesting that DNA methylation could be associated with hypertension.

Renal Denervation Prevents Immune Cell Activation and Renal Inflammation in Angiotensin II–Induced Hypertension

PubMed Central

Xiao, Liang; Kirabo, Annet; Wu, Jing; Saleh, Mohamed A.; Zhu, Linjue; Wang, Feng; Takahashi, Takamune; Loperena, Roxana; Foss, Jason D.; Mernaugh, Raymond L.; Chen, Wei; Roberts, Jackson; Osborn, John W.; Itani, Hana A.; Harrison, David G.

2015-01-01

Rationale Inflammation and adaptive immunity plays a crucial role in the development of hypertension. Angiotensin II and likely other hypertensive stimuli activate the central nervous system and promote T cell activation and end-organ damage in peripheral tissues. Objective To determine if renal sympathetic nerves mediate renal inflammation and T cell activation in hypertension. Methods and Results Bilateral renal denervation (RDN) using phenol application to the renal arteries reduced renal norepinephrine (NE) levels and blunted angiotensin II induced hypertension. Bilateral RDN also reduced inflammation, as reflected by decreased accumulation of total leukocytes, T cells and both CD4+ and CD8+ T cells in the kidney. This was associated with a marked reduction in renal fibrosis, albuminuria and nephrinuria. Unilateral RDN, which partly attenuated blood pressure, only reduced inflammation in the denervated kidney, suggesting that this effect is pressure independent. Angiotensin II also increased immunogenic isoketal-protein adducts in renal dendritic cells (DCs) and increased surface expression of costimulation markers and production of IL-1α, IL-1β, and IL-6 from splenic dendritic cells. NE also dose dependently stimulated isoketal formation in cultured DCs. Adoptive transfer of splenic DCs from angiotensin II-treated mice primed T cell activation and hypertension in recipient mice. RDN prevented these effects of hypertension on DCs. In contrast to these beneficial effects of ablating all renal nerves, renal afferent disruption with capsaicin had no effect on blood pressure or renal inflammation. Conclusions Renal sympathetic nerves contribute to dendritic cell activation, subsequent T cell infiltration and end-organ damage in the kidney in the development of hypertension. PMID:26156232

ROLE OF NRF2 IN THE OXIDATIVE STRESS-DEPENDENT HYPERTENSION ASSOCIATED WITH THE DEPLETION OF DJ-1

PubMed Central

Cuevas, Santiago; Yang, Yu; Konkalmatt, Prasad; Asico, Laureano; Feranil, Jun; Jones, John; Villar, Van Anthony; Armando, Ines; Jose, Pedro A.

2015-01-01

Renal dopamine 2 receptor dysfunction is associated with oxidative stress and high blood pressure. We have reported that DJ-1, an oxidative stress response protein, is positively regulated by dopamine 2 receptor in the kidney. The transcription factor Nrf2 regulates the expression of several antioxidant genes. We tested the hypothesis that Nrf2 is involved in the renal DJ-1-mediated inhibition of reactive oxygen species production. We have reported that silencing dopamine 2 receptor in mouse renal proximal tubule cells decreases the expression of DJ-1. We now report that silencing DJ-1 or dopamine 2 receptor in mouse proximal tubule cells and mouse kidneys, decreases Nrf2 expression and activity and increases reactive oxygen species production; blood pressure is also increased in mice in which renal DJ-1 or dopamine 2 receptor is silenced. DJ-1−/− mice have decreased renal Nrf2 expression and activity, and increased nitro-tyrosine levels an dopamine 2 receptor d blood pressure. Silencing Nrf2 in mouse proximal tubule cells does not alter the expression of DJ-1 or dopamine 2 receptor, indicating that Nrf2 is downstream of dopamine 2 receptor and DJ-1. A Nrf2 inducer, bardoxolone, normalizes the systolic blood pressure and renal malondialdehyde levels in DJ-1−/− mice without affecting them in their wild-type littermates. Because Nrf2 ubiquitination is increased in DJ-1−/− mice, we conclude that the protective effect of DJ-1 on renal oxidative stress is mediated, in part, by preventing Nrf2 degradation. Moreover, renal dopamine 2 receptor and DJ-1 are necessary for normal Nrf2 activity to keep a normal redox balance and blood pressure. PMID:25895590

Clinical and pathological analysis of IgA nephropathy with chronic renal failure.

PubMed

Liu, Yuyuan; Hu, Qinfeng; Shen, Ping; Tang, Li; Yuan, Gang; Zhou, Yongmei; Chai, Huaqi

2016-10-01

To investigative clinical and pathological characteristics of IgA nephropathy with chronic renal failure. Clinical and pathological findings from 65 cases of IgA nephropathy with chronic renal failure were reviewed. Pathological characteristics of all the cases were analyzed according to WHO definition and Oxford Classification. Evaluating the severity of pathological lesions by the Katafuchi R semiquantitative scoring system, and analyzing their relationship with clinical indexes of renal function. Of all 65 cases the male and female ratio was 1.4, and the mean age was 37 ± 13 years old. Levels of systolic pressure, mean arterial pressure (MAP), blood urea nitrogen (BUN), serum creatinine (Scr), uric acid (UA), album (Alb), serum IgG and 24 h urinary protein were related with eGRF level (p < 0.05, respectively). The most common pathological type was proliferative sclerosis glomerulonephritis (PSGN) and M1S1E0T0 according to WHO definition and Oxford Classification, respectively, and most of the 65 cases had glomerulosclerosis. Simple IgA deposition was the most common immunopathologic type. Of all the cases, 44.6% accompanied with C3 while 4.6% with C1q. Further analysis revealed there were no relationships between severity of pathological lesion and levels of clinical indexes (Scr and eGRF) (p > 0.05). IgA nephropathy with chronic renal failure usually occurred in young adults, and it had severe clinical condition and pathological changes, while there was no significant relationship between them.

Activation of GLP-1 receptors on vascular smooth muscle cells reduces the autoregulatory response in afferent arterioles and increases renal blood flow.

PubMed

Jensen, Elisa P; Poulsen, Steen S; Kissow, Hannelouise; Holstein-Rathlou, Niels-Henrik; Deacon, Carolyn F; Jensen, Boye L; Holst, Jens J; Sorensen, Charlotte M

2015-04-15

Glucagon-like peptide (GLP)-1 has a range of extrapancreatic effects, including renal effects. The mechanisms are poorly understood, but GLP-1 receptors have been identified in the kidney. However, the exact cellular localization of the renal receptors is poorly described. The aim of the present study was to localize renal GLP-1 receptors and describe GLP-1-mediated effects on the renal vasculature. We hypothesized that renal GLP-1 receptors are located in the renal microcirculation and that activation of these affects renal autoregulation and increases renal blood flow. In vivo autoradiography using (125)I-labeled GLP-1, (125)I-labeled exendin-4 (GLP-1 analog), and (125)I-labeled exendin 9-39 (GLP-1 receptor antagonist) was performed in rodents to localize specific GLP-1 receptor binding. GLP-1-mediated effects on blood pressure, renal blood flow (RBF), heart rate, renin secretion, urinary flow rate, and Na(+) and K(+) excretion were investigated in anesthetized rats. Effects of GLP-1 on afferent arterioles were investigated in isolated mouse kidneys. Specific binding of (125)I-labeled GLP-1, (125)I-labeled exendin-4, and (125)I-labeled exendin 9-39 was observed in the renal vasculature, including afferent arterioles. Infusion of GLP-1 increased blood pressure, RBF, and urinary flow rate significantly in rats. Heart rate and plasma renin concentrations were unchanged. Exendin 9-39 inhibited the increase in RBF. In isolated murine kidneys, GLP-1 and exendin-4 significantly reduced the autoregulatory response of afferent arterioles in response to stepwise increases in pressure. We conclude that GLP-1 receptors are located in the renal vasculature, including afferent arterioles. Activation of these receptors reduces the autoregulatory response of afferent arterioles to acute pressure increases and increases RBF in normotensive rats. Copyright © 2015 the American Physiological Society.

Correlation between differential renal function estimation using CT-based functional renal parenchymal volume and (99m)Tc - DTPA renal scan.

PubMed

Sarma, Debanga; Barua, Sasanka K; Rajeev, T P; Baruah, Saumar J

2012-10-01

Nuclear renal scan is currently the gold standard imaging study to determine differential renal function. We propose helical CT as single modality for both the anatomical and functional evaluation of kidney with impaired function. In the present study renal parenchymal volume is measured and percent total renal volume is used as a surrogate marker for differential renal function. The objective of this study is to correlate between differential renal function estimation using CT-based renal parenchymal volume measurement with differential renal function estimation using (99m)TC - DTPA renal scan. Twenty-one patients with unilateral obstructive uropathy were enrolled in this prospective comparative study. They were subjected to (99m)Tc - DTPA renal scan and 64 slice helical CT scan which estimates the renal volume depending on the reconstruction of arterial phase images followed by volume rendering and percent renal volume was calculated. Percent renal volume was correlated with percent renal function, as determined by nuclear renal scan using Pearson coefficient. RESULTS AND OBSERVATION: A strong correlation is observed between percent renal volume and percent renal function in obstructed units (r = 0.828, P < 0.001) as well as in nonobstructed units (r = 0.827, P < 0.001). There is a strong correlation between percent renal volume determined by CT scan and percent renal function determined by (99m)TC - DTPA renal scan both in obstructed and in normal units. CT-based percent renal volume can be used as a single radiological tests for both functional and anatomical assessment of impaired renal units.

Improvement in Renal Hemodynamics following Combined Angiotensin II Infusion and AT1R Blockade in Aged Female Sheep following Fetal Unilateral Nephrectomy

PubMed Central

Singh, Reetu R.; Lankadeva, Yugeesh R.

2013-01-01

Renin-angiotensin system (RAS) is a powerful modulator of renal hemodynamic and fluid homeostasis. Up-regulation in components of intra-renal RAS occurs with ageing. Recently we reported that 2 year old uninephrectomised (uni-x) female sheep have low renin hypertension and reduced renal function. By 5 years of age, these uni-x sheep had augmented decrease in renal blood flow (RBF) compared to sham. We hypothesised that this decrease in RBF in 5 year old uni-x sheep was due to an up-regulation in components of the intra-renal RAS. In this study, renal responses to angiotensin II (AngII) infusion and AngII type 1 receptor (AT1R) blockade were examined in the same 5 year old sheep. We also administered AngII in the presence of losartan to increase AngII bioavailability to the AT2R in order to understand AT2R contribution to renal function in this model. Uni-x animals had significantly lower renal cortical content of renin, AngII (∼40%) and Ang 1–7 (∼60%) and reduced cortical expression of AT1R gene than sham animals. In response to both AngII infusion and AT1R blockade via losartan, renal hemodynamic responses and tubular sodium excretion were significantly attenuated in uni-x animals compared to sham. However, AngII infusion in the presence of losartan caused ∼33% increase in RBF in uni-x sheep compared to ∼14% in sham (P<0.05). This was associated with a significant decrease in renal vascular resistance in the uni-x animals (22% vs 15%, P<0.05) without any changes in systemic blood pressure. The present study shows that majority of the intra-renal RAS components are suppressed in this model of low renin hypertension. However, increasing the availability of AngII to AT2R by AT1R blockade improved renal blood flow in uni-x sheep. This suggests that manipulation of the AT2R maybe a potential therapeutic target for treatment of renal dysfunction associated with a congenital nephron deficit. PMID:23840884

Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy

PubMed Central

Haruhara, Kotaro; Tsuboi, Nobuo; Koike, Kentaro; Kanzaki, Go; Okabayashi, Yusuke; Miyazaki, Yoichi; Kawamura, Tetsuya; Ogura, Makoto; Yokoo, Takashi

2015-01-01

Background Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN. Methods This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP. Results A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters. Conclusions These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients. PMID:26613030

Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy.

PubMed

Haruhara, Kotaro; Tsuboi, Nobuo; Koike, Kentaro; Kanzaki, Go; Okabayashi, Yusuke; Miyazaki, Yoichi; Kawamura, Tetsuya; Ogura, Makoto; Yokoo, Takashi

2015-12-01

Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN. This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP. A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters. These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients.

One Year Clinical Outcomes of Renal Artery Stenting: The Results of ODORI Registry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sapoval, M., E-mail: marc.sapoval2@egp.aphp.f; Tamari, I.; Goffette, P.

2010-06-15

The safety, efficacy and long term clinical benefits of renal artery revascularization by stenting are still a matter of debate. The aim of our study was to define the safety and efficacy of renal artery stenting with the Tsunami peripheral stent (Terumo Corporation, Tokyo, Japan). The ODORI was a prospective, multicentre registry which enrolled 251 consecutive patients, (276 renal arteries) in 36 centres across Europe. The primary endpoint was acute procedural success defined as <30% residual stenosis after stent placement. Secondary endpoints included major adverse events, blood pressure control, serum creatinine level, and target lesion revascularization (TLR) at 6 andmore » 12 months. Patients were 70 {+-} 10 years old, 59% were male, 33% had diabetes, and 96% hypertension. The main indications for renal stent implantation were hypertension in 83% and renal salvage in 39%. Direct stent implantation was performed in 76% of the cases. Acute success rate was 100% with residual stenosis of 2.5 {+-} 5.4%. Systolic/diastolic blood pressure decreased from a mean of 171/89 at baseline to 142/78 mmHg at 6 months (p < 0.0001 vs. baseline), and 141/80 mmHg at 12 months (p < 0.0001 vs. baseline). Mean serum creatinine concentration did not change significantly in the total population. However, there was significant improvement in the highest tercile (from 283 {mu}mol/l at baseline to 205 and 209 {mu}mol/l at 6 and 12 months respectively). At 12-months, rates of restenosis and TLR were 6.6 and 0.8% respectively. The 12 month cumulative rate of all major clinical adverse events was 6.4% while the rate of device or procedure related events was 2.4%. In hypertensive patients with atherosclerotic renal artery stenosis Tsunami peripheral balloon-expandable stent provides a safe revascularization strategy, with a potential beneficial impact on hypertension control and renal function in the highest risk patients.« less

Resistant Hypertension, Time-Updated Blood Pressure Values and Renal Outcome in Type 2 Diabetes Mellitus.

PubMed

Viazzi, Francesca; Piscitelli, Pamela; Ceriello, Antonio; Fioretto, Paola; Giorda, Carlo; Guida, Pietro; Russo, Giuseppina; De Cosmo, Salvatore; Pontremoli, Roberto

2017-09-22

Apparent treatment resistant hypertension (aTRH) is highly prevalent in patients with type 2 diabetes mellitus (T2D) and entails worse cardiovascular prognosis. The impact of aTRH and long-term achievement of recommended blood pressure (BP) values on renal outcome remains largely unknown. We assessed the role of aTRH and BP on the development of chronic kidney disease in patients with T2D and hypertension in real-life clinical practice. Clinical records from a total of 29 923 patients with T2D and hypertension, with normal baseline estimated glomerular filtration rate and regular visits during a 4-year follow-up, were retrieved and analyzed. The association between time-updated BP control (ie, 75% of visits with BP <140/90 mm Hg) and the occurrence of estimated glomerular filtration rate <60 and/or a reduction ≥30% from baseline was assessed. At baseline, 17% of patients had aTRH. Over the 4-year follow-up, 19% developed low estimated glomerular filtration rate and 12% an estimated glomerular filtration rate reduction ≥30% from baseline. Patients with aTRH showed an increased risk of developing both renal outcomes (adjusted odds ratio, 1.31 and 1.43; P <0.001 respectively), as compared with those with non-aTRH. No association was found between BP control and renal outcomes in non-aTRH, whereas in aTRH, BP control was associated with a 30% ( P =0.036) greater risk of developing the renal end points. ATRH entails a worse renal prognosis in T2D with hypertension. BP control is not associated with a more-favorable renal outcome in aTRH. The relationship between time-updated BP and renal function seems to be J-shaped, with optimal systolic BP values between 120 and 140 mm Hg. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

The crosstalk between the kidney and the central nervous system: the role of renal nerves in blood pressure regulation.

PubMed

Nishi, Erika E; Bergamaschi, Cássia T; Campos, Ruy R

2015-04-20

What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic dysfunction is the predominant contributor to systemic hypertension is still debated. In this review, we focus on the role of the renal nerves in a model of renovascular hypertension. The sympathetic nervous system influences the renal regulation of arterial pressure and body fluid composition. Anatomical and physiological evidence has shown that sympathetic nerves mediate changes in urinary sodium and water excretion by regulating the renal tubular water and sodium reabsorption throughout the nephron, changes in the renal blood flow and the glomerular filtration rate by regulating the constriction of renal vasculature, and changes in the activity of the renin-angiotensin system by regulating the renin release from juxtaglomerular cells. Additionally, renal sensory afferent fibres project to the autonomic central nuclei that regulate blood pressure. Hence, renal nerves play a key role in the crosstalk between the kidneys and the CNS to maintain homeostasis in the body. Therefore, the increased sympathetic nerve activity to the kidney and the renal afferent nerve activity to the CNS may contribute to the outcome of diseases, such as hypertension. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Renal function in pregnant rats with two-kidney goldblatt hypertension.

PubMed

Dal Canton, A; Sabbatini, M; Esposito, C; Altomonte, M; Romano, G; Uccello, F; Conte, G; Fuiano, G; Russo, D; Andreucci, V E

1983-01-01

This study was carried out in female Wistar-Münich rats with two-kidney, one-clip hypertension, using clipped normotensive rats as controls. Metabolic studies were performed in the first two weeks of pregnancy, consisting of daily measurement of systolic blood pressure (BP) (tail-cuff), body weight (BW), and salt and water balance. At the end of metabolic studies, glomerular dynamics were studied in the unclipped kidney by micropuncture. During pregnancy, urinary output of Na+ and water was greater in hypertensive than normotensive rats. The greater natriuresis accounted for a reduced Na+ retention and a lower increase in maternal BW. Micropuncture studies showed an impaired renal auto-regulation. These results show that hypertension in pregnancy causes a salt-losing tendency, that may be secondary to incomplete renal autoregulation.

Long-term renal outcome in patients with malignant hypertension: a retrospective cohort study

PubMed Central

2012-01-01

Background Malignant hypertension is frequently complicated by renal insufficiency. Although the survival of this hypertensive emergency has improved, recent data on renal outcome and its predictors are lacking. We assessed renal outcome and its predictors in patients with malignant hypertension. Methods Retrospective analysis of patients admitted with malignant hypertension in Amsterdam, the Netherlands between August 1992–January 2010. Follow-up data on vital status, renal function and blood pressure (BP) were obtained from the outpatient department and from general practitioners. The primary composite endpoint was end-stage renal disease (ESRD) defined as the start of kidney replacement therapy (KRT) or ≥ 50% decline of estimated glomerular filtration rate (eGFR). The secondary endpoint was all cause mortality. Results A total of 120 patients admitted with malignant hypertension were included. After a median follow-up period of 67 months (IQR 28 to 108 months) the primary endpoint was reached by 37 (31%) patients, whereas 18 patients (15%) reached the secondary endpoint. Twenty-nine (24%) patients started KRT and 8 patients (7%) had an eGFR decline ≥ 50%. After the acute phase (> 3 months after admission), initial serum creatinine and follow-up BP were the main predictors of future ESRD with hazard ratios of 6.1 (95% CI, 2.2–17) for patients with initial serum creatinine ≥ 175 μmol /L and 4.3 (95% CI, 1.4–14) for patients with uncontrolled hypertension. Conclusions Progressive renal function decline leading to ESRD remains a major threat to patients with malignant hypertension. BP control during follow-up was an important modifiable predictor of renal outcome. PMID:22846257

Adherence to Antihypertensive Treatment and the Blood Pressure-Lowering Effects of Renal Denervation in the Renal Denervation for Hypertension (DENERHTN) Trial.

PubMed

Azizi, Michel; Pereira, Helena; Hamdidouche, Idir; Gosse, Philippe; Monge, Matthieu; Bobrie, Guillaume; Delsart, Pascal; Mounier-Véhier, Claire; Courand, Pierre-Yves; Lantelme, Pierre; Denolle, Thierry; Dourmap-Collas, Caroline; Girerd, Xavier; Michel Halimi, Jean; Zannad, Faiez; Ormezzano, Olivier; Vaïsse, Bernard; Herpin, Daniel; Ribstein, Jean; Chamontin, Bernard; Mourad, Jean-Jacques; Ferrari, Emile; Plouin, Pierre-François; Jullien, Vincent; Sapoval, Marc; Chatellier, Gilles

2016-09-20

The DENERHTN trial (Renal Denervation for Hypertension) confirmed the blood pressure-lowering efficacy of renal denervation added to a standardized stepped-care antihypertensive treatment for resistant hypertension at 6 months. We report the influence of adherence to antihypertensive treatment on blood pressure control. One hundred six patients with hypertension resistant to 4 weeks of treatment with indapamide 1.5 mg/d, ramipril 10 mg/d (or irbesartan 300 mg/d), and amlodipine 10 mg/d were randomly assigned to renal denervation plus standardized stepped-care antihypertensive treatment, or the same antihypertensive treatment alone. For standardized stepped-care antihypertensive treatment, spironolactone 25 mg/d, bisoprolol 10 mg/d, prazosin 5 mg/d, and rilmenidine 1 mg/d were sequentially added at monthly visits if home blood pressure was ≥135/85 mm Hg after randomization. We assessed adherence to antihypertensive treatment at 6 months by drug screening in urine/plasma samples from 85 patients. The numbers of fully adherent (20/40 versus 21/45), partially nonadherent (13/40 versus 20/45), or completely nonadherent patients (7/40 versus 4/45) to antihypertensive treatment were not different in the renal denervation and the control groups, respectively (P=0.3605). The difference in the change in daytime ambulatory systolic blood pressure from baseline to 6 months between the 2 groups was -6.7 mm Hg (P=0.0461) in fully adherent and -7.8 mm Hg (P=0.0996) in nonadherent (partially nonadherent plus completely nonadherent) patients. The between-patient variability of daytime ambulatory systolic blood pressure was greater for nonadherent than for fully adherent patients. In the DENERHTN trial, the prevalence of nonadherence to antihypertensive drugs at 6 months was high (≈50%) but not different in the renal denervation and control groups. Regardless of adherence to treatment, renal denervation plus standardized stepped-care antihypertensive treatment resulted in a greater decrease in blood pressure than standardized stepped-care antihypertensive treatment alone. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01570777. © 2016 American Heart Association, Inc.

Effect of increased venous pressure on renal hemodynamics.

DOT National Transportation Integrated Search

1962-10-01

Conflicting evidence exists in regard to the effects of increased venous pressure on renal hemodynamics. Experiments to clarify its role were carried on twenty-eight intact innervated or isolated perfused dog kidneys. Findings indicate the absence of...

Effects of exercise and excitement on mesenteric and renal dynamics in conscious, unrestrained baboons

NASA Technical Reports Server (NTRS)

Vatner, S. F.

1978-01-01

Radiotelemetry was used to measure arterial pressure and mesenteric and renal blood flows from nine unrestrained, conscious baboons during periods of rest, moderate exercise, and extreme excitement. A description of the experiments hardware is presented, including artificial depressants phenylcyclidine hydrochloride, 0.5-1.0 mg/kg, and pentobarbital sodium, 15 mg/kg, and an ultrasonic telemetry flow meter. Results showed rising heart rate and arterial pressure coupled with a reduction of mesenteric and renal flows as the level of exercise was increased. These findings are compared with mesenteric and renal flows somewhat above control level, but relatively stable heart rate and arterial pressure, postprandially. Attention is given to a quantitative analysis of the experimental results.

Protective response in renal transplantation: no clinical or molecular differences between open and laparoscopic donor nephrectomy.

PubMed

Machado, Christiano; Malheiros, Denise Maria Avancini Costa; Adamy, Ari; Santos, Luiz Sergio; Silva Filho, Agenor Ferreira da; Nahas, William Carlos; Lemos, Francine Brambate Carvalhinho

2013-04-01

Prolonged warm ischemia time and increased intra-abdominal pressure caused by pneumoperitoneum during a laparoscopic donor nephrectomy could enhance renal ischemia reperfusion injury. For this reason, laparoscopic donor nephrectomy may be associated with a slower graft function recovery. However, an adequate protective response may balance the ischemia reperfusion damage. This study investigated whether laparoscopic donor nephrectomy modified the protective response of renal tissue during kidney transplantation. Patients undergoing live renal transplantation were prospectively analyzed and divided into two groups based on the donor nephrectomy approach used: 1) the control group, recipients of open donor nephrectomy (n = 29), and 2) the study group, recipients of laparoscopic donor nephrectomy (n = 26). Graft biopsies were obtained at two time points: T-1 = after warm ischemia time and T+1 = 45 minutes after kidney reperfusion. The samples were analyzed by immunohistochemistry for the Bcl-2 and HO-1 proteins and by real-time polymerase chain reaction for the mRNA expression of Bcl-2, HO-1 and vascular endothelial growth factor. The area under the curve for creatinine and delayed graft function were similar in both the laparoscopic and open groups. There was no difference in the protective gene expression between the laparoscopic donor nephrectomy and open donor nephrectomy groups. The protein expression of HO-1 and Bcl-2 were similar between the open and laparoscopic groups. Furthermore, the gene expression of B-cell lymphoma 2 correlated with the warm ischemia time in the open group (p = 0.047) and that of vascular endothelial growth factor with the area under the curve for creatinine in the laparoscopic group (p = 0.01). The postoperative renal function and protective factor expression were similar between laparoscopic donor nephrectomy and open donor nephrectomy. These findings ensure laparoscopic donor nephrectomy utilization in renal transplantation.

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats

PubMed Central

Caires, A.; Fernandes, G.S.; Leme, A.M.; Castino, B.; Pessoa, E.A.; Fernandes, S.M.; Fonseca, C.D.; Vattimo, M.F.; Schor, N.; Borges, F.T.

2017-01-01

Cyclosporin-A (CsA) is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF) and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1) receptor blockade with bosentan (BOS) and macitentan (MAC) antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR) were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg) for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg) or MAC (25 mg/kg) by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP), RBF and renal vascular resistance (RVR), and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects. PMID:29267497

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats.

PubMed

Caires, A; Fernandes, G S; Leme, A M; Castino, B; Pessoa, E A; Fernandes, S M; Fonseca, C D; Vattimo, M F; Schor, N; Borges, F T

2017-12-11

Cyclosporin-A (CsA) is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF) and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1) receptor blockade with bosentan (BOS) and macitentan (MAC) antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR) were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg) for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg) or MAC (25 mg/kg) by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP), RBF and renal vascular resistance (RVR), and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erbsloeh-Moeller, B.Du.; Dumas, A.; Roth, D.

We have previously demonstrated the greater sensitivity of 131I-hippuran renography than 99mTC-DTPA scintigraphy to diagnose renovascular hypertension (RVH). This study assesses the predictive diagnostic value of furosemide-131I-hippuran renography after angiotensin-converting enzyme (ACE) inhibition in patients with and without RVH. All patients were investigated at the University of Miami/Jackson Memorial Medical Center. Twenty-eight patients had RVH and 22 did not. Twenty-eight patients had normal or minimally decreased renal function and 22 had renal insufficiency. Renography was performed 60 minutes after oral administration of 50 mg captopril or 10 minutes after intravenous injection of 40 micrograms/kg enalaprilat. Forty milligrams of furosemide weremore » administered intravenously 2 minutes after injection of 131I-hippuran. The residual cortical activity (RCA) of 131I-hippuran was measured at 20 minutes. RVH was unlikely when RCA after ACE inhibition was less than 30% of peak cortical activity. Conversely, RVH was present when 131I-hippuran cortical activity steadily increased throughout the test to reach 100% at 20 minutes. In azotemic patients with RCA between 31% and 100%, RVH was differentiated from intrinsic renal disease by obtaining a baseline renogram without ACE inhibition and comparing RCA in that study and RCA after ACE inhibition. If RCA increased (indicating worsening renal function) after ACE inhibition, RVH was likely; whereas, intrinsic renal disease was more likely if RCA remained unchanged or decreased (indicating improved renal function) with ACE inhibition. The test had a specificity of 95% and a sensitivity of 96% in this population. There was a direct correlation between the results of angioplasty or surgery on high blood pressure and the changes in RCA before and after intervention (n = 20).« less

Validation of an Experimental Model to Study Less Severe Chronic Renal Failure.

PubMed

Fernandes-Charpiot, Ida Mária Maximina; Caldas, Heloisa Cristina; Mendes, Glória Elisa Florido; Gomes de Sá Neto, Luiz; Oliveira, Henrique Lacativa; Baptista, Maria Alice Sperto Ferreira; Abbud-Filho, Mario

2016-10-01

The 5/6 nephrectomy, mimics the stages of human chronic renal failure (CRF), but the procedure causes severe renal functional and morphological damage that could interfere with the evaluation of therapies for slowing the progression of the disease. This study summarizes the results of renal function, histology, and immunohistochemical findings in rats undergoing a 2/3 nephrectomy. The rats were distributed in groups according to the type of nephrectomy: CRF5/6: induced by a 5/6 renal mass reduction and CRF2/3: less severe CRF. The body weight and blood pressure were monitored, and the serum creatinine (SCr), creatinine clearance (CCr), urine osmolality, and 24-h proteinuria (PT24h) were measured. CRF progression was evaluated by the rate of decline of CCr (RCCr). Histology and immunohistochemistry were performed in the remnant kidneys. Statistical analysis was done by unpaired t-test, and a P-value < 0.05 was taken as a statistical significance. Compared to the CRF5/6 group, the CRF2/3 model had a lower SCr, PT24h, CCr, and variations of the SCr from baseline. The disease progression was also significantly slower. The renal histopathological findings revealed fewer chronic lesions in rats with CRF2/3. Similarly, we observed less macrophage accumulation as well as lower proliferative activity and expression of fibronectin and a-smooth muscle-actin in the CRF2/3 model. The CRF2/3 model presented with a pattern of less severe CRF, functionally and morphologically, compared to the classical CRF5/6 model, and the CRF2/3 model may be useful for evaluating therapeutic interventions that target the early stages of CRF.

Atorvastatin prevents the downregulation of aquaporin-2 receptor after bilateral ureteral obstruction and protects renal function in a rat model.

PubMed

Danilovic, Alexandre; Lopes, Roberto Iglesias; Sanches, Talita Rojas; Shimizu, Maria Heloísa Massola; Oshiro, Fabíola M; Andrade, Lúcia; Dénes, Francisco Tibor; Seguro, Antonio Carlos

2012-08-01

To assess the effects of atorvastatin (ATORV) on renal function after bilateral ureteral obstruction (BUO), measuring inulin clearance and its effect on renal hemodynamic, filtration, and inflammatory response, as well as the expression of Aquaporin-2 (AQP2) in response to BUO and after the release of BUO. Adult Munich-Wistar male rats were subjected to BUO for 24 hours and monitored during the following 48 hours. Rats were divided into 5 groups: sham operated (n = 6); sham + ATORV (n = 6); BUO (n = 6); BUO + ATORV (10 mg/kg in drinking water started 2 days before BUO [n = 5]; and BUO + ATORV (10 mg/kg in drinking water started on the day of the release of BUO [n = 5]). We measured blood pressure (BP, mm Hg); inulin clearance (glomerular filtration rate [GFR]; mL/min/100 g); and renal blood flow (RBF, mL/min, by transient-time flowmeter). Inflammatory response was evaluated by histologic analysis of the interstitial area. AQP2 expression was evaluated by electrophoresis and immunoblotting. Renal function was preserved by ATORV treatment, even if initiated on the day of obstruction release, as expressed by GFR, measured by inulin clearance. Relative interstitial area was decreased in both BUO + ATORV groups. Urine osmolality was improved in the ATORV-treated groups. AQP2 protein expression decreased in BUO animals and was reverted by ATORV treatment. ATORV administration significantly prevented and restored impairment in GFR and renal vascular resistance. Furthermore, ATORV also improved urinary concentration by reversing the BUO-induced downregulation of AQP2. These findings have significant clinical implication in treating obstructive nephropathy. Copyright © 2012 Elsevier Inc. All rights reserved.

[Recovery characteristic of donor's and receptor's renal function from age over 55 years living donors donate kidneys].

PubMed

Hu, Xiao-Peng; Yin, Hang; Zhang, Xiao-Dong; Wang, Wei; Ren, Liang; Yang, Xiao-Yong; Li, Xiao-Bei; Liu, Hang; Wang, Yong

2009-10-20

To observe and research clinical characteristics and curative effect and safety of renal transplantation from living elderly donors donating kidneys. Retrospective study on the 19 living kidney donors who were over 55 years old and on the renal transplantation operations completed by our center for the past few years. Among the 19 donors, with an average age of 58 years old. Their mean creatinine clearance was 81.7 +/- 2.2 ml/min. Among the 19 acceptors, with an average age of 34 years old. All kidney before the open circulation transplant performed routine 0 point puncture and histological examination. All donors smoothly spent their perioperative period without any surgical complications. All the donors keep their blood Cr in a normal range one week after the operation. There was no significant difference between posttransplantation one week and six month and one year in blood Cr and Ccr. Blood pressure and blood sugar didn't not have significant changes, urine protein(-). All receptors' renal functions recovered in early stages without DGF. 7 receptors who had Ccr lower than 80 ml/min had their blood Cr decreased slowly. Among the 19 kidneys donated, 3 donors' glomerulosclerosises were higher than 10 percent. The kidney source shortage is the main factor that restricts the development of the renal transplantation currently, undoubtedly, the application of elderly donors will expand the kidney source and save more uremic patients. Renal transplantation is safe and feasible with the help of living elderly donors.

Acute treatment of hypertensive crisis with nifedipine.

PubMed Central

Huysmans, F T; Sluiter, H E; Thien, T A; Koene, R A

1983-01-01

Ten patients with a hypertensive crisis and a decreased renal function were treated with 10 (n = 7) or 20 (n = 3) mg nifedipine sublingually. Blood pressure was reduced in 60 min from 211 +/- 4/134 +/- 5 to 172 +/- 6/107 +/- 6 mm Hg. The decrease of blood pressure was accompanied by a rise in heart rate from 83 +/- 6 to 98 +/- 5 beats/min. In all seven patients with an encephalopathy signs of this complication were reduced. No serious side-effects were observed. PMID:6661359

The impact of intrarenal nitric oxide synthase inhibition on renal blood flow and function in mild and severe hyperdynamic sepsis.

PubMed

Ishikawa, Ken; Bellomo, Rinaldo; May, Clive N

2011-04-01

In experimental hyperdynamic sepsis, renal function deteriorates despite renal vasodilatation and increased renal blood flow. Because nitric oxide is increased in sepsis and participates in renal blood flow control, we investigated the effects of intrarenal Nω-nitro-L-arginine methyl ester, a nonspecific nitric oxide synthase inhibitor, in mild and severe sepsis. Prospective crossover and randomized control interventional studies. University-affiliated research institute. Thirty-two merino ewes. Examination of responses to intrarenal infusion of Nω-nitro-L-arginine methyl ester for 8 hrs in unilaterally nephrectomized normal sheep and in sheep administered Escherichia coli. : In normal sheep, Nω-nitro-L-arginine methyl ester decreased renal blood flow (301 ± 30 to 228 ± 26 mL/min) and creatinine clearance (40.0 ± 5.8 to 31.1 ± 2.8 mL/min), whereas plasma creatinine increased, but fractional excretion of sodium was unchanged. In sheep with nonhypotensive hyperdynamic sepsis, plasma creatinine increased and there were decreases in creatinine clearance (34.5 ± 4.6 to 20.1 ± 3.7 mL/min) and fractional excretion of sodium despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester normalized renal blood flow and increased urine output, but creatinine clearance did not improve and plasma creatinine and fractional excretion of sodium increased. In sheep with severe hypotensive sepsis, creatinine clearance decreased further (31.1 ± 5.4 to 16.0 ± 1.7 mL/min) despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester restored mean arterial pressure and reduced renal blood flow but did not improve plasma creatinine or creatinine clearance. In hyperdynamic sepsis, with or without hypotension, creatinine clearance decreased despite increasing renal blood flow. Intrarenal Nω-nitro-L-arginine methyl ester infusion reduced renal blood flow but did not improve creatinine clearance. These data indicate that septic acute kidney injury is not the result of decreased renal blood flow nor is it improved by nonspecific nitric oxide synthase inhibition.

Functions of the Renal Nerves.

ERIC Educational Resources Information Center

Koepke, John P.; DiBona, Gerald F.

1985-01-01

Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

Accelerated renal disease is associated with the development of metabolic syndrome in a glucolipotoxic mouse model

PubMed Central

Martínez-García, Cristina; Izquierdo, Adriana; Velagapudi, Vidya; Vivas, Yurena; Velasco, Ismael; Campbell, Mark; Burling, Keith; Cava, Fernando; Ros, Manuel; Orešič, Matej; Vidal-Puig, Antonio; Medina-Gomez, Gema

2012-01-01

SUMMARY Individuals with metabolic syndrome are at high risk of developing chronic kidney disease (CKD) through unclear pathogenic mechanisms. Obesity and diabetes are known to induce glucolipotoxic effects in metabolically relevant organs. However, the pathogenic role of glucolipotoxicity in the aetiology of diabetic nephropathy is debated. We generated a murine model, the POKO mouse, obtained by crossing the peroxisome proliferator-activated receptor gamma 2 (PPARγ2) knockout (KO) mouse into a genetically obese ob/ob background. We have previously shown that the POKO mice showed: hyperphagia, insulin resistance, hyperglycaemia and dyslipidaemia as early as 4 weeks of age, and developed a complete loss of normal β-cell function by 16 weeks of age. Metabolic phenotyping of the POKO model has led to investigation of the structural and functional changes in the kidney and changes in blood pressure in these mice. Here we demonstrate that the POKO mouse is a model of renal disease that is accelerated by high levels of glucose and lipid accumulation. Similar to ob/ob mice, at 4 weeks of age these animals exhibited an increased urinary albumin:creatinine ratio and significantly increased blood pressure, but in contrast showed a significant increase in the renal hypertrophy index and an associated increase in p27Kip1 expression compared with their obese littermates. Moreover, at 4 weeks of age POKO mice showed insulin resistance, an alteration of lipid metabolism and glomeruli damage associated with increased transforming growth factor beta (TGFβ) and parathyroid hormone-related protein (PTHrP) expression. At this age, levels of proinflammatory molecules, such as monocyte chemoattractant protein-1 (MCP-1), and fibrotic factors were also increased at the glomerular level compared with levels in ob/ob mice. At 12 weeks of age, renal damage was fully established. These data suggest an accelerated lesion through glucolipotoxic effects in the renal pathogenesis in POKO mice. PMID:22773754

Accelerated renal disease is associated with the development of metabolic syndrome in a glucolipotoxic mouse model.

PubMed

Martínez-García, Cristina; Izquierdo, Adriana; Velagapudi, Vidya; Vivas, Yurena; Velasco, Ismael; Campbell, Mark; Burling, Keith; Cava, Fernando; Ros, Manuel; Oresic, Matej; Vidal-Puig, Antonio; Medina-Gomez, Gema

2012-09-01

Individuals with metabolic syndrome are at high risk of developing chronic kidney disease (CKD) through unclear pathogenic mechanisms. Obesity and diabetes are known to induce glucolipotoxic effects in metabolically relevant organs. However, the pathogenic role of glucolipotoxicity in the aetiology of diabetic nephropathy is debated. We generated a murine model, the POKO mouse, obtained by crossing the peroxisome proliferator-activated receptor gamma 2 (PPARγ2) knockout (KO) mouse into a genetically obese ob/ob background. We have previously shown that the POKO mice showed: hyperphagia, insulin resistance, hyperglycaemia and dyslipidaemia as early as 4 weeks of age, and developed a complete loss of normal β-cell function by 16 weeks of age. Metabolic phenotyping of the POKO model has led to investigation of the structural and functional changes in the kidney and changes in blood pressure in these mice. Here we demonstrate that the POKO mouse is a model of renal disease that is accelerated by high levels of glucose and lipid accumulation. Similar to ob/ob mice, at 4 weeks of age these animals exhibited an increased urinary albumin:creatinine ratio and significantly increased blood pressure, but in contrast showed a significant increase in the renal hypertrophy index and an associated increase in p27(Kip1) expression compared with their obese littermates. Moreover, at 4 weeks of age POKO mice showed insulin resistance, an alteration of lipid metabolism and glomeruli damage associated with increased transforming growth factor beta (TGFβ) and parathyroid hormone-related protein (PTHrP) expression. At this age, levels of proinflammatory molecules, such as monocyte chemoattractant protein-1 (MCP-1), and fibrotic factors were also increased at the glomerular level compared with levels in ob/ob mice. At 12 weeks of age, renal damage was fully established. These data suggest an accelerated lesion through glucolipotoxic effects in the renal pathogenesis in POKO mice.

Twelve shifting paradigms in diabetic renal disease and hypertension.

PubMed

Mogensen, Carl Erik

2008-11-13

In the last 30 years we have seen considerable progress in the management of patients with diabetes, in particular with diabetic renal disease. A number of paradigms have been broken down, namely the following, as a consequence, clinical care has improved dramatically. . Significant renal involvement and albuminuria is rare in patients with essential hypertension. 2. High GFR is good for prognosis. 3. Only proteinuric diabetic patients have a poor prognosis. 4. Microalbuminuria only predicts renal disease. 5. Reducing blood pressure may cause low perfusion in the kidney and other organs with long-term negative effect, especially on the glomerular filtration rate. 6. Only in the presence of high blood pressure, should microalbuminuric patients receive anti-hypertensive treatment, including blockade of the RAS. 7. Only reducing blood pressure by blocking RAS in diabetes is relevant and justified. 8. Normoalbuminuria as indicated in the present definition is 'normal'. 9. ACE-I or ARB can only be used separately. 10. Diastolic blood pressure and later systolic pulse pressure are the best parameters for blood pressure recording. 11. Microalbuminuria is the strongest risk marker in patients with type 1 diabetes. 12. Screening for microalbuminuria is relevant, but follow-up was not proposed (also regarding microalbuminuria). In the present situation, it is well-known that patients with essential hypertension may sometimes have microalbuminuria, and it is known that it predicts a poor prognosis. Interestingly, in type 1 diabetes, hyperfiltration is a marker for poor prognosis related to metabolic control. Thus hyperfiltration is a marker for bad development, but microalbuminuria (below the proteinuric level) is also associated with a poor prognosis. It was originally believed that microalbuminuria only predicts renal disease. However, surprisingly it predicts as well cardiovascular disease and early mortality. The story about blood pressure and progression of renal disease is interesting, because it was earlier believed that a certain high blood pressure was mandatory for preservation of the renal function. This appeared to be a completely wrong concept. The data regarding microalbuminuria suggest that patients with microalbuminuria should receive anti-hypertensive treatment, even patients with so-called normal blood pressure. This was confirmed in several trials and also included in the guidelines. Reducing blood pressure is important, but it appeared to be especially beneficial to block the renin-angiontensin system, and it is clear that albuminuria is a continuous variable and is also a risk factor. Earlier it was suggested to use ACE-inhibitors or ARBs. Now it is clear that it is possible to use a combination, with good theoretical background. In the history of hypertension, it was earlier believed that diastolic blood pressure was most important, but later on it was generally accepted that systolic is a better predictor and the goal for treatment and pulse pressure may be even better. Not only is microalbuminuria an important risk marker, but it is as well clear that regression of microalbuminuria is a good marker for a better prognosis in patients. Microalbuminuria is believed to be the strongest risk factor, but new studies actually suggest that a simple parameter such as self-rated health is crucial along with other factors. Regarding new developments, it is clear that new studies have led to several advancements in management in patients, for instance the Steno II study shows positive effect on mortality by multifactorial intervention. Similarly, the ADVANCE study also showed positive effect on mortality by more intensified anti-hypertensive treatment with an ACE-inhibitor. We are eagerly awaiting the results from glucose arm in the ADVANCE study, especially in the light of the ACCORD study showing increased mortality with too strict glycemic control with a goal of 6% in HbA1c.

Treatment of hepatorenal syndrome as defined by the international ascites club by albumin and furosemide infusion according to the central venous pressure: a prospective pilot study.

PubMed

Péron, Jean-Marie; Bureau, Christophe; Gonzalez, Laurent; Garcia-Ricard, Franck; de Soyres, Olivier; Dupuis, Emmanuel; Alric, Laurent; Pourrat, Jacques; Vinel, Jean-Pierre

2005-12-01

Hepatorenal syndrome (HRS) is a functional renal failure that occurs late during cirrhosis. The prognosis is extremely poor with a mean survival of 1.7 wks from the time of diagnosis. The aim of the present study was to examine the effects of albumin and furosemide administration tailored to central venous pressure (CVP) on renal function and clinical outcome. We treated 20 consecutive patients with HRS. Albumin was given to increase and/or maintain CVP above 3 cm H(2)O. If diuresis remained below 50 mL/h despite effective volume expansion, furosemide was administrated. Patients were considered responders and treatment was discontinued when creatinine clearance rose above 40 mL/min or serum creatinine fell under 132 mumol/L. The need for albumin varied from patient to patient (extremes 40-600 g) and in the same patient from day to day. All but one needed furosemide. Eleven patients (55%) responded to treatment. In this population, diuresis, serum creatinine, and creatinine clearance were all significantly improved. Creatinine clearance at baseline was predictive of treatment efficacy. Survival increased in these patients compared to nonresponders defined as patients with no improvement in renal function (259 days +/- 113 compared to 14 days +/- 3, p < 0.0005). Response to treatment and the type of HRS were the only variables with an independent prognostic value. This study shows that HRS as defined by the International Ascites Club can be treated by albumin administration alone or with furosemide given according to the patient's specific need using CVP.

Is a Long Term Work in Automotive Industry a Risk Factor for Renal Dysfunction?

PubMed Central

Assadi, Seyedeh Negar

2015-01-01

Background: Disorders of renal system can cause renal failure; therefore screening is necessary especially in workers who are exposed to harmful materials. Hypertension, diabetes mellitus, and hazardous exposures are non-occupational and occupational risk factors for renal diseases. Aim: The objective of this study was to determine the effects of working in automotive industry on renal function in Iran. Subjects and Methods: In a historical cohort study, workers of automotive industry who worked in production and had low exposure to metal fumes were selected and divided to three groups with 5–10, 11–20, and 21–30 years work duration. risk factors for renal diseases were collected and analyzed with SPSS using one-way ANOVA, correlation coefficient and with P < 0.05 and relative risk with a confidence interval (CI). Results: The means of work duration in Groups (A), (B) and (C) were 9.8 (0.6), 13.8 (2.0), 22.3 (1.6) years respectively with ANOVA (F) =187.864 and P < 0.01. Glomerular filtration rate (GFR) was 59.75 (0.70), 59.16 (1.52) and 59.10 (2.23) in Groups (A), (B), and (C) respectfully The relative risk of creatinine clearance, uric acid and mean blood pressure were the highest in Group (B); 1.970 - CI, 0.541–7.169, 1.571 95% CI: 0.198–12.470, and 1.519 95% CI: 0.425–5.426, but the differences were not significant. Conclusion: GFRs were decreased with work duration, but the differences were not significant. Working in automotive Industry with low exposure to toxic metals and solvents has no significant effect on GFR, creatinine clearance, uric acid, and mean blood pressure. PMID:25861528

Renal and Glycemic Effects of High-Dose Chromium Picolinate in db/db Mice: Assessment of DNA Damage

PubMed Central

Mozaffari, Mahmood S.; Baban, Babak; Abdelsayed, Rafik; Liu, Jun Yao; Wimborne, Hereward; Rodriguez, Nancy; Abebe, Worku

2011-01-01

This study examined renal and glycemic effects of chromium picolinate (Cr(pic)3) supplementation in the context of its purported potential for DNA damage. In preventional protocol, male obese diabetic db/db mice were fed diets either lacking or containing 5, 10 or 100 mg/kg chromium as Cr(pic)3 from 6 to 24 weeks of age; male lean nondiabetic db/m mice served as controls. Untreated db/db mice displayed increased plasma glucose and insulin, hemoglobin A1c, renal tissue advanced glycation end (AGE) products, albuminuria, glomerular mesangial expansion, urinary 8-hydroxydeoxyguanosine (8-OHdG, an index of oxidative DNA damage) and renal tissue immunostaining for γH2AX (a marker of double-strand DNA breaks) compared to db/m controls. Creatinine clearance was lower while blood pressure was similar between untreated db/db mice and their db/m controls. High Cr(pic)3 intake (i.e., 100 mg/kg diet) mildly improved glycemic status and albuminuria without affecting blood pressure or creatinine clearance. Treatment with Cr(pic)3 did not increase DNA damage despite marked renal accumulation of chromium. In interventional protocol, effects of diets containing 0, 100 and 250 mg/kg supplemental chromium, from 12 to 24 weeks of age, were examined in db/db mice. The results generally revealed similar effects to those of the 100 mg/kg diet of the preventional protocol. In conclusion, the severely hyperglycemic db/db mouse displays renal structural and functional abnormalities in association with DNA damage. High-dose Cr(pic)3 treatment mildly improves glycemic control and it causes moderate reduction in albuminuria, without affecting histopathological appearance of the kidney and increasing the risk for DNA damage. PMID:21959055

Renal and glycemic effects of high-dose chromium picolinate in db/db mice: assessment of DNA damage.

PubMed

Mozaffari, Mahmood S; Baban, Babak; Abdelsayed, Rafik; Liu, Jun Yao; Wimborne, Hereward; Rodriguez, Nancy; Abebe, Worku

2012-08-01

This study examined renal and glycemic effects of chromium picolinate [Cr(pic)3] supplementation in the context of its purported potential for DNA damage. In preventional protocol, male obese diabetic db/db mice were fed diets either lacking or containing 5, 10 or 100 mg/kg chromium as Cr(pic)3 from 6 to 24 weeks of age; male lean nondiabetic db/m mice served as controls. Untreated db/db mice displayed increased plasma glucose and insulin, hemoglobin A1c, renal tissue advanced glycation end products, albuminuria, glomerular mesangial expansion, urinary 8-hydroxydeoxyguanosine (an index of oxidative DNA damage) and renal tissue immunostaining for γH2AX (a marker of double-strand DNA breaks) compared to db/m controls. Creatinine clearance was lower in untreated db/db mice than their db/m controls, while blood pressure was similar. High Cr(pic)3 intake (i.e., 100-mg/kg diet) mildly improved glycemic status and albuminuria without affecting blood pressure or creatinine clearance. Treatment with Cr(pic)3 did not increase DNA damage despite marked renal accumulation of chromium. In interventional protocol, effects of diets containing 0, 100 and 250 mg/kg supplemental chromium, from 12 to 24 weeks of age, were examined in db/db mice. The results generally revealed similar effects to those of the 100-mg/kg diet of the preventional protocol. In conclusion, the severely hyperglycemic db/db mouse displays renal structural and functional abnormalities in association with DNA damage. High-dose Cr(pic)3 treatment mildly improves glycemic control, and it causes moderate reduction in albuminuria, without affecting the histopathological appearance of the kidney and increasing the risk for DNA damage. Copyright © 2012 Elsevier Inc. All rights reserved.

Blood pressure-renal blood flow relationships in conscious angiotensin II- and phenylephrine-infused rats.

PubMed

Polichnowski, Aaron J; Griffin, Karen A; Long, Jianrui; Williamson, Geoffrey A; Bidani, Anil K

2013-10-01

Chronic ANG II infusion in rodents is widely used as an experimental model of hypertension, yet very limited data are available describing the resulting blood pressure-renal blood flow (BP-RBF) relationships in conscious rats. Accordingly, male Sprague-Dawley rats (n = 19) were instrumented for chronic measurements of BP (radiotelemetry) and RBF (Transonic Systems, Ithaca, NY). One week later, two or three separate 2-h recordings of BP and RBF were obtained in conscious rats at 24-h intervals, in addition to separate 24-h BP recordings. Rats were then administered either ANG II (n = 11, 125 ng·kg(-1)·min(-1)) or phenylephrine (PE; n = 8, 50 mg·kg(-1)·day(-1)) as a control, ANG II-independent, pressor agent. Three days later the BP-RBF and 24-h BP recordings were repeated over several days. Despite similar increases in BP, PE led to significantly greater BP lability at the heart beat and very low frequency bandwidths. Conversely, ANG II, but not PE, caused significant renal vasoconstriction (a 62% increase in renal vascular resistance and a 21% decrease in RBF) and increased variability in BP-RBF relationships. Transfer function analysis of BP (input) and RBF (output) were consistent with a significant potentiation of the renal myogenic mechanism during ANG II administration, likely contributing, in part, to the exaggerated reductions in RBF during periods of BP elevations. We conclude that relatively equipressor doses of ANG II and PE lead to greatly different ambient BP profiles and effects on the renal vasculature when assessed in conscious rats. These data may have important implications regarding the pathogenesis of hypertension-induced injury in these models of hypertension.

Antihypertensive effect of etamicastat in dopamine D2 receptor-deficient mice.

PubMed

Armando, Ines; Asico, Laureano D; Wang, Xiaoyan; Jones, John E; Serrão, Maria Paula; Cuevas, Santiago; Grandy, David K; Soares-da-Silva, Patricio; Jose, Pedro A

2018-04-13

Abnormalities of the D 2 R gene (DRD2) play a role in the pathogenesis of human essential hypertension; variants of the DRD2 have been reported to be associated with hypertension. Disruption of Drd2 (D 2 -/- ) in mice increases blood pressure. The hypertension of D 2 -/- mice has been related, in part, to increased sympathetic activity, renal oxidative stress, and renal endothelin B receptor (ETBR) expression. We tested in D 2 -/- mice the effect of etamicastat, a reversible peripheral inhibitor of dopamine-β-hydroxylase that reduces the biosynthesis of norepinephrine from dopamine and decreases sympathetic nerve activity. Blood pressure was measured in anesthetized D 2 -/- mice treated with etamicastat by gavage, (10 mg/kg), conscious D 2 -/- mice, and D 2 +/+ littermates, and mice with the D 2 R selectively silenced in the kidney, treated with etamicastat in the drinking water (10 mg/kg per day). Tissue and urinary catecholamines and renal expression of selected G protein-coupled receptors, enzymes related to the production of reactive oxygen species, and sodium transporters were also measured. Etamicastat decreased blood pressure both in anesthetized and conscious D 2 -/- mice and mice with renal-selective silencing of D 2 R to levels similar or close to those measured in D 2 +/+ littermates. Etamicastat decreased cardiac and renal norepinephrine and increased cardiac and urinary dopamine levels in D 2 -/- mice. It also normalized the increased renal protein expressions of ETBR, NADPH oxidase isoenzymes, and urinary 8-isoprostane, as well as renal NHE3 and NCC, and increased the renal expression of D 1 R but not D 5 R in D 2 -/- mice. In conclusion, etamicastat is effective in normalizing the increased blood pressure and some of the abnormal renal biochemical alterations of D 2 -/- mice.

Eligibility for renal denervation: experience at 11 European expert centers.

PubMed

Persu, Alexandre; Jin, Yu; Baelen, Marie; Vink, Eva; Verloop, Willemien L; Schmidt, Bernhard; Blicher, Marie K; Severino, Francesca; Wuerzner, Grégoire; Taylor, Alison; Pechère-Bertschi, Antoinette; Jokhaji, Fadi; Fadl Elmula, Fadl Elmula M; Rosa, Jan; Czarnecka, Danuta; Ehret, Georg; Kahan, Thomas; Renkin, Jean; Widimsky, Jiři; Jacobs, Lotte; Spiering, Wilko; Burnier, Michel; Mark, Patrick B; Menne, Jan; Olsen, Michael H; Blankestijn, Peter J; Kjeldsen, Sverre; Bots, Michiel L; Staessen, Jan A

2014-06-01

Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center's criteria was 42.5% (95% confidence interval, 38.0%-47.0%) and 39.7% (36.2%-43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ≈40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered.

Renal Sympathetic Denervation in Rats Ameliorates Cardiac Dysfunction and Fibrosis Post-Myocardial Infarction Involving MicroRNAs

PubMed Central

Zheng, Xiaoxin; Li, Xiaoyan; Lyu, Yongnan; He, Yiyu; Wan, Weiguo; Jiang, Xuejun

2016-01-01

Background The role of renal sympathetic denervation (RSD) in ameliorating post-myocardial infarction (MI) left ventricular (LV) fibrosis via microRNA-dependent regulation of connective tissue growth factor (CTGF) remains unknown. Material/Methods MI and RSD were induced in Sprague–Dawley rats by ligating the left coronary artery and denervating the bilateral renal nerves, respectively. Norepinephrine, renin, angiotensin II and aldosterone in plasma, collagen, microRNA21, microRNA 101a, microRNA 133a and CTGF in heart tissue, as well as cardiac function were evaluated six weeks post-MI. Results In the RSD group, parameters of cardiac function were significantly improved as evidenced by increased LV ejection fraction (p<0.01), LV end-systolic diameter (p<0.01), end-diastolic diameter (p<0.05), LV systolic pressure (p<0.05), maximal rate of pressure rise and decline (dP/dtmax and dP/dtmin, p<0.05), and decreased LV end-diastolic pressure (p<0.05) when compared with MI rats. Further, reduced collagen deposition in peri-infarct myocardium was observed in RSD-treated rats along with higher microRNA101a and microRNA133a (p<0.05) and lower microRNA21 expression (p<0.01) than in MI rats. CTGF mRNA and protein levels were decreased in LV following RSD (p<0.01), accompanied by decreased expression of norepinephrine, renin, angiotensin II and aldosterone in plasma (p<0.05) compared with untreated MI rats. Conclusions The potential therapeutic effects of RSD on post-MI LV fibrosis may be partly mediated by inhibition of CTGF expression via upregulation of microRNA 101a and microRNA 133a and downregulation of microRNA21. PMID:27490896

Resistive index and chronic allograft nephropathy evaluated in protocol biopsies as predictors of graft outcome.

PubMed

Vallejos, Augusto; Alperovich, Gabriela; Moreso, Francesc; Cañas, Concepcion; de Lama, M Eugenia; Gomà, Montserrat; Fulladosa, Xavier; Carrera, Marta; Hueso, Miguel; Grinyó, Josep M; Serón, Daniel

2005-11-01

The presence of chronic allograft nephropathy (CAN) in protocol biopsies is negatively associated with graft survival. Although recent studies have indicated that the resistive index (RI) is a predictor of graft failure, it does not correlate with CAN in stable grafts. We therefore studied the relationship between RI and CAN and examined the predictive value of both parameters on graft outcome. Included were patients transplanted between 1997 and 2002 and who had protocol biopsies and RI determinations. Renal lesions were blindly evaluated according to Banff 97 criteria. Mean glomerular volume, cortical interstitial volume fraction and intimal arterial volume fraction were estimated using a point counting technique. RI was determined before biopsy in at least two different renal locations. The outcome variable was defined as graft failure or a 30% serum creatinine increase between protocol biopsy and last follow-up. Eighty-seven patients were included. RI correlated with recipient age (R = 0.52, P < 0.0001), diastolic blood pressure (R = -0.36, P = 0.0006), pulse pressure index (R = 0.27, P = 0.009) and g-score for histological glomerulitis (rho = 0.30, P = 0.0054), but there were no correlations between RI and chronic Banff scores or any morphometric parameter. The presence of CAN (relative risk, 3.5; 95% confidence interval 1.2-10.2; P = 0.02) but not RI was associated with the outcome variable. RI was associated with surrogate measures of vascular compliance such as recipient age and pulse pressure index but not with chronic allograft damage, even when it was evaluated by histomorphometry. Our results indicate that histology may be superior to RI in predicting graft function deterioration, at least in patients with stable renal function.

FGF23 regulates renal sodium handling and blood pressure

PubMed Central

Andrukhova, Olena; Slavic, Svetlana; Smorodchenko, Alina; Zeitz, Ute; Shalhoub, Victoria; Lanske, Beate; Pohl, Elena E; Erben, Reinhold G

2014-01-01

Fibroblast growth factor-23 (FGF23) is a bone-derived hormone regulating renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. Here, we show that FGF23 directly regulates the membrane abundance of the Na+:Cl− co-transporter NCC in distal renal tubules by a signaling mechanism involving the FGF receptor/αKlotho complex, extracellular signal-regulated kinase 1/2 (ERK1/2), serum/glucocorticoid-regulated kinase 1 (SGK1), and with-no lysine kinase-4 (WNK4). Renal sodium (Na+) reabsorption and distal tubular membrane expression of NCC are reduced in mouse models of Fgf23 and αKlotho deficiency. Conversely, gain of FGF23 function by injection of wild-type mice with recombinant FGF23 or by elevated circulating levels of endogenous Fgf23 in Hyp mice increases distal tubular Na+ uptake and membrane abundance of NCC, leading to volume expansion, hypertension, and heart hypertrophy in a αKlotho and dietary Na+-dependent fashion. The NCC inhibitor chlorothiazide abrogates FGF23-induced volume expansion and heart hypertrophy. Our findings suggest that FGF23 is a key regulator of renal Na+ reabsorption and plasma volume, and may explain the association of FGF23 with cardiovascular risk in chronic kidney disease patients. PMID:24797667

Collecting duct prorenin receptor knockout reduces renal function, increases sodium excretion, and mitigates renal responses in ANG II-induced hypertensive mice.

PubMed

Prieto, Minolfa C; Reverte, Virginia; Mamenko, Mykola; Kuczeriszka, Marta; Veiras, Luciana C; Rosales, Carla B; McLellan, Matthew; Gentile, Oliver; Jensen, V Behrana; Ichihara, Atsuhiro; McDonough, Alicia A; Pochynyuk, Oleh M; Gonzalez, Alexis A

2017-12-01

Augmented intratubular angiotensin (ANG) II is a key determinant of enhanced distal Na + reabsorption via activation of epithelial Na + channels (ENaC) and other transporters, which leads to the development of high blood pressure (BP). In ANG II-induced hypertension, there is increased expression of the prorenin receptor (PRR) in the collecting duct (CD), which has been implicated in the stimulation of the sodium transporters and resultant hypertension. The impact of PRR deletion along the nephron on BP regulation and Na + handling remains controversial. In the present study, we investigate the role of PRR in the regulation of renal function and BP by using a mouse model with specific deletion of PRR in the CD ( CD PRR-KO). At basal conditions, CD PRR-KO mice had decreased renal function and lower systolic BP associated with higher fractional Na + excretion and lower ANG II levels in urine. After 14 days of ANG II infusion (400 ng·kg -1 ·min -1 ), the increases in systolic BP and diastolic BP were mitigated in CD PRR-KO mice. CD PRR-KO mice had lower abundance of cleaved αENaC and γENaC, as well as lower ANG II and renin content in urine compared with wild-type mice. In isolated CD from CD PRR-KO mice, patch-clamp studies demonstrated that ANG II-dependent stimulation of ENaC activity was reduced because of fewer active channels and lower open probability. These data indicate that CD PRR contributes to renal function and BP responses during chronic ANG II infusion by enhancing renin activity, increasing ANG II, and activating ENaC in the distal nephron segments. Copyright © 2017 the American Physiological Society.

A study of renal function influence by integrating cloud-based manometers and physician order entry systems.

PubMed

Lin, Yuh-Feng; Sheng, Li-Huei; Wu, Mei-Yi; Zheng, Cai-Mei; Chang, Tian-Jong; Li, Yu-Chuan; Huang, Yu-Hui; Lu, Hsi-Peng

2014-12-01

No evidence exists from randomized trials to support using cloud-based manometers integrated with available physician order entry systems for tracking patient blood pressure (BP) to assist in the control of renal function deterioration. We investigated how integrating cloud-based manometers with physician order entry systems benefits our outpatient chronic kidney disease patients compared with typical BP tracking systems. We randomly assigned 36 chronic kidney disease patients to use cloud-based manometers integrated with physician order entry systems or typical BP recording sheets, and followed the patients for 6 months. The composite outcome was that the patients saw improvement both in BP and renal function. We compared the systolic and diastolic BP (SBP and DBP), and renal function of our patients at 0 months, 3 months, and 6 months after using the integrated manometers and typical BP monitoring sheets. Nighttime SBP and DBP were significantly lower in the study group compared with the control group. Serum creatinine level in the study group improved significantly compared with the control group after the end of Month 6 (2.83 ± 2.0 vs. 4.38 ± 3.0, p = 0.018). Proteinuria improved nonsignificantly in Month 6 in the study group compared with the control group (1.05 ± 0.9 vs. 1.90 ± 1.3, p = 0.09). Both SBP and DBP during the nighttime hours improved significantly in the study group compared with the baseline. In pre-end-stage renal disease patients, regularly monitoring BP by integrating cloud-based manometers appears to result in a significant decrease in creatinine and improvement in nighttime BP control. Estimated glomerular filtration rate and proteinuria were found to be improved nonsignificantly, and thus, larger population and longer follow-up studies may be needed.

Cardiac, renal, and neurological benefits of preoperative levosimendan administration in patients with right ventricular dysfunction and pulmonary hypertension undergoing cardiac surgery: evaluation with two biomarkers neutrophil gelatinase-associated lipocalin and neuronal enolase.

PubMed

Guerrero-Orriach, José Luis; Ariza-Villanueva, Daniel; Florez-Vela, Ana; Garrido-Sánchez, Lourdes; Moreno-Cortés, María Isabel; Galán-Ortega, Manuel; Ramírez-Fernández, Alicia; Alcaide Torres, Juan; Fernandez, Concepción Santiago; Navarro Arce, Isabel; Melero-Tejedor, José María; Rubio-Navarro, Manuel; Cruz-Mañas, José

2016-01-01

To evaluate if the preoperative administration of levosimendan in patients with right ventricular (RV) dysfunction, pulmonary hypertension, and high perioperative risk would improve cardiac function and would also have a protective effect on renal and neurological functions, assessed using two biomarkers neutrophil gelatinase-associated lipocalin (N-GAL) and neuronal enolase. This is an observational study. Twenty-seven high-risk cardiac patients with RV dysfunction and pulmonary hypertension, scheduled for cardiac valve surgery, were prospectively followed after preoperative administration of levosimendan. Levosimendan was administered preoperatively on the day before surgery. All patients were considered high risk of cardiac and perioperative renal complications. Cardiac function was assessed by echocardiography, renal function by urinary N-GAL levels, and the acute kidney injury scale. Neuronal damage was assessed by neuron-specific enolase levels. After surgery, no significant variations were found in mean and SE levels of N-GAL (14.31 [28.34] ng/mL vs 13.41 [38.24] ng/mL), neuron-specific enolase (5.40 [0.41] ng/mL vs 4.32 [0.61] ng/mL), or mean ± SD creatinine (1.06±0.24 mg/dL vs 1.25±0.37 mg/dL at 48 hours). RV dilatation decreased from 4.23±0.7 mm to 3.45±0.6 mm and pulmonary artery pressure from 58±18 mmHg to 42±19 mmHg at 48 hours. Preoperative administration of levosimendan has shown a protective role against cardiac, renal, and neurological damage in patients with a high risk of multiple organ dysfunctions undergoing cardiac surgery.

Differential role of afferent and efferent renal nerves in the maintenance of early- and late-phase Dahl S hypertension

PubMed Central

Foss, Jason D.; Fink, Gregory D.

2015-01-01

Clinical data suggest that renal denervation (RDNX) may be an effective treatment for human hypertension; however, it is unclear whether this therapeutic effect is due to ablation of afferent or efferent renal nerves. We have previously shown that RDNX lowers arterial pressure in hypertensive Dahl salt-sensitive (S) rats to a similar degree observed in clinical trials. In addition, we have recently developed a method for selective ablation of afferent renal nerves (renal-CAP). In the present study, we tested the hypothesis that the antihypertensive effect of RDNX in the Dahl S rat is due to ablation of afferent renal nerves by comparing the effect of complete RDNX to renal-CAP during two phases of hypertension in the Dahl S rat. In the early phase, rats underwent treatment after 3 wk of high-NaCl feeding when mean arterial pressure (MAP) was ∼140 mmHg. In the late phase, rats underwent treatment after 9 wk of high NaCl feeding, when MAP was ∼170 mmHg. RDNX reduced MAP ∼10 mmHg compared with sham surgery in both the early and late phase, whereas renal-CAP had no antihypertensive effect. These results suggest that, in the Dahl S rat, the antihypertensive effect of RDNX is not dependent on pretreatment arterial pressure, nor is it due to ablation of afferent renal nerves. PMID:26661098

Effect and Outcome of Intraoperative Fluid Restriction in Living Liver Donor Hepatectomy.

PubMed

Wang, Chih-Hsien; Cheng, Kwok-Wai; Chen, Chao-Long; Wu, Shao-Chun; Shih, Tsung-Hsiao; Yang, Sheng-Chun; Lee, Ying-En; Jawan, Bruno; Huang, Chiu-En; Juang, Sin-Ei; Huang, Chia-Jung

2017-11-10

BACKGROUND The purpose of this study was to evaluate the effect and outcome of intraoperative fluid restriction in living liver donor hepatectomy, regarding changes in intraoperative CVP levels, blood loss, and postoperative renal function. MATERIAL AND METHODS The charts of 167 patients were reviewed and analyzed retrospectively. Intraoperative central venous pressure levels, blood loss, fluids infused, and urine output per hour, before and after the liver allograft procurement, were calculated. Perioperative renal functions were also analyzed. RESULTS Fluid infused before and after liver allograft procurement was 3.21±1.5 and 9.0±3.9 mL/Kg/h and urine output was 1.5±0.7 and 1.8±1.4 mL/Kg/h, respectively. Intraoperative estimated blood loss was 91.3±78.9 mL. No patients required blood transfusion. Their preoperative and postoperative hemoglobin were 12.3±2.7 and 11.7±1.7 g/dL. CVP levels decreased gradually from 10.4±3.0 to a low of 8.1±1.9 mmHg at the time of transection of the liver parenchyma. Renal functions were not significantly affected based on the determination of BUN and creatinine levels. CONCLUSIONS The methods used to lower CVP are moderate and slow, with 2 main goals achieved: minimal blood loss (91.3±78.9 ml) and no blood transfusion. Furthermore, it did not have any negative effect on renal function.

Clinical characteristics and predictive factors of subclinical diabetic nephropathy.

PubMed

Zhang, Y; Yang, J; Zheng, M; Wang, Y; Ren, H; Xu, Y; Yang, Y; Cheng, J; Han, F; Yang, X; Chen, L; Shan, C; Chang, B

2015-02-01

To investigate the clinical characteristics and predictive factors of subclinical diabetic nephropathy in type 2 diabetes patients. A total of 298 type 2 diabetes patients were divided into 3 groups based on 24-h urinary microalbumin and estimated glomerular filtration rate: patients with normal albuminuria and glomerular filtration rate (NC), patients with normoalbuminuria and glomerular hyperfiltration (SDN) and patients with microalbuminuria (EDN). The renal size, tubular injury markers and ambulatory blood pressure were analyzed. Renal size increased in the SDN and EDN groups compared to the NC group (P<0.05), while renal length in the SDN group was greater than the EDN group (P<0.05). Patients in the SDN and EDN groups had higher level of urine retinol binding protein and N-acetyl-β-D-glucosaminidase and most of them developed proximal tubular dysfunction. The SDN group had higher 24-h mean and nocturnal diastolic blood pressure than the NC group (P<0.05), while the EDN group had higher systolic blood pressure and pulse pressure than the SDN group (P<0.01). More patients developed abnormal blood pressure rhythm in the SDN and EDN groups. The likelihood of a decrease in nocturnal systolic blood pressure was lower as the microalbuminuria increased. Increased renal size, more abnormal tubular injury markers and higher 24-h mean and nocturnal blood pressure were all risk factors of subclinical diabetic nephropathy. Patients with subclinical diabetic nephropathy had increased renal size, abnormal tubular injury markers, high blood pressure and abnormal circadian rhythm. © Georg Thieme Verlag KG Stuttgart · New York.

The role of keto acids in the supportive treatment of children with chronic renal failure.

PubMed

Mir, Sevgi; Ozkayin, Nese; Akgun, Aysegul

2005-07-01

According to the hyperfiltration theory of renal diseases characterized by a decrease in the number of functional nephrons, increased arterial blood pressure, excessive protein intake in the diet, high levels of calcium (Ca) and phosphorus (P), secondary hyperparathyroidism, hypertriglyceridemia and/or hypercholesterolemia, proteinuria and metabolic acidosis are some factors that impair the prognosis of the disease. The amount of protein in the diet is the most important of these factors. A protein-restricted diet administered to patients with chronic renal failure results in the risk of inadequate amino acid intake. To overcome this problem, the use of dysaminated alpha-keto analogues has been considered to reduce the risk of nitrogenemia resulting from the continuous intake of essential amino acids. Currently, the necessity of essential amino acids even in adult patients with chronic renal failure is controversial; besides, trials on the use of these amino acids in pediatric patients are scarce. The aim of this study is to investigate the efficacy and applicability of conservative therapy with a protein-restricted diet supplemented with keto acids in the management of chronic renal insufficiency or failure.

Effect of endogenous angiotensin II on renal nerve activity and its cardiac baroreflex regulation.

PubMed

Dibona, G F; Jones, S Y; Sawin, L L

1998-11-01

The effects of physiologic alterations in endogenous angiotensin II activity on basal renal sympathetic nerve activity and its cardiac baroreflex regulation were studied. The effect of angiotensin II type 1 receptor blockade with intracerebroventricular losartan was examined in conscious rats consuming a low, normal, or high sodium diet that were instrumented for the simultaneous measurement of right atrial pressure and renal sympathetic nerve activity. The gain of cardiac baroreflex regulation of renal sympathetic nerve activity (% delta renal sympathetic nerve activity/mmHg mean right atrial pressure) was measured during isotonic saline volume loading. Intracerebroventricular losartan did not decrease arterial pressure but significantly decreased renal sympathetic nerve activity in low (-36+/-6%) and normal (-24+/-5%), but not in high (-2+/-3%) sodium diet rats. Compared with vehicle treatment, losartan treatment significantly increased cardiac baroreflex gain in low (-3.45+/-0.20 versus -2.89+/-0.17) and normal (-2.89+/-0.18 versus -2.54+/-0.14), but not in high (-2.27+/-0.15 versus -2.22+/-0.14) sodium diet rats. These results indicate that physiologic alterations in endogenous angiotensin II activity tonically influence basal levels of renal sympathetic nerve activity and its cardiac baroreflex regulation.

UK Renal Registry 16th annual report: chapter 11 blood pressure profile of prevalent patients receiving renal replacement therapy in 2012: national and centre-specific analyses.

PubMed

Rao, Anirudh; Pitcher, David; Farrington, Ken

2013-01-01

There continues to be uncertainty in the literature about which blood pressure (BP) recordings in which time period associate best with long-term patient outcomes and therefore optimal target ranges. Patients receiving renal replacement therapy (RRT) on 31st December 2012 with a BP reading in either the fourth or third quarter of 2012 were included. Summary statistics were calculated for each renal centre and country. Data completeness for BP measurements submitted to the UK Renal Registry (UKRR) for all modalities were improved from previous years: it was better for haemodialysis (HD) patients (75% for pre-HD measurements) than for peritoneal dialysis (PD) patients (51%) or transplant recipients (41%). In 2012, the median pre- and post-HD systolic blood pressures (SBPs) were 140 mmHg and 128 mmHg respectively. The median SBP of patients on PD was 137 mmHg. Transplant recipients had a median SBP of 134 mmHg. Median diastolic blood pressures (DBPs) were 71 mmHg (pre-HD), 67 mmHg (post-HD), 78 mmHg (PD) and 79 mmHg (transplant). Only 26% of PD patients achieved the Renal Association guideline of SBP <130 mmHg and DBP <80 mmHg. Amongst transplant patients, 27% achieved the Renal Association guideline of SBP <130 mmHg and DBP <80 mmHg. In 2012 there continued to be significant variation in the achievement of BP standards between UK renal centres. © 2014 S. Karger AG, Basel.

Wound Healing in Patients With Impaired Kidney Function

PubMed Central

Maroz, Natallia; Simman, Richard

2014-01-01

Renal impairment has long been known to affect wound healing. However, information on differences in the spectrum of wound healing depending on the type of renal insufficiency is limited. Acute kidney injury (AKI) may be observed with different wound types. On one hand, it follows acute traumatic conditions such as crush injury, burns, and post-surgical wounds, and on the other hand, it arises as simultaneous targeting of skin and kidneys by autoimmune-mediated vasculitis. Chronic kidney disease (CKD) and end-stage renal disease (ESRD) often occur in older people, who have limited physical mobility and predisposition for developing pressure-related wounds. The common risk factors for poor wound healing, generally observed in patients with CKD and ESRD, include poorly controlled diabetes mellitus, neuropathy, peripheral vascular disease, chronic venous insufficiency, and aging. ESRD patients have a unique spectrum of wounds related to impaired calcium–phosphorus metabolism, including calciphylaxis, in addition to having the risk factors presented by CKD patients. Overall, there is a wide range of uremic toxins: they may affect local mechanisms of wound healing and also adversely affect the functioning of multiple systems. In the present literature review, we discuss the association between different types of renal impairments and their effects on wound healing and examine this association from different aspects related to the management of wounds in renal impairment patients. PMID:26199882

Possible mechanism by which renal sympathetic denervation improves left ventricular remodelling after myocardial infarction.

PubMed

Zheng, Xiao-Xin; Li, Xiao-Yan; Lyu, Yong-Nan; He, Yi-Yu; Wan, Wei-Guo; Zhu, Hong-Ling; Jiang, Xue-Jun

2016-02-01

What is the central question of this study? The enzyme system that is responsible for extracellular matrix (ECM) turnover is the matrix metalloproteinases (MMPs), which can be blocked by the tissue inhibitors of MMPs (TIMPs). Whether renal sympathetic denervation (RSD) is able to ameliorate post-myocardial infarction left ventricular remodelling through attenuation of ECM via regulation of MMP activity and/or the MMP-TIMP complex remains unknown. What is the main finding and its importance? Renal sympathetic denervation has therapeutic effects on post-myocardial infarction left ventricular remodelling, probably by attenuating the ECM through regulation of the MMP9-TIMP1 complex in the transforming growth factor-β1 (a profibrotic cytokine that accelerates ECM remodelling after ischaemia) signalling pathway. Whether renal sympathetic denervation (RSD) is able to ameliorate post-myocardial infarction (post-MI) left ventricular (LV) remodelling by attenuation of the extracellular matrix via regulation of matrix metalloproteinase (MMP) activity and/or the MMP-tissue inhibitor of matrix metalloproteinase (TIMP) complex remains unknown. Sixty-five Sprague-Dawley rats were randomly divided into the following four groups: normal (N, n = 15), RSD (RSD, n = 15), myocardial infarction (MI, n = 15) and RSD 3 days after MI (MI3d+RSD, n = 20). The bilateral renal nerves were surgically denervated 3 days after MI had been induced by coronary artery ligation. Left ventricular function was assessed using echocardiography and a Millar catheter at 6 weeks post-MI. Plasma noradrenaline, angiotensin II and aldosterone, collagen volume fraction, transforming growth factor-β1 (TGF-β1), MMP2, MMP9 and TIMP1 in heart tissue were measured 6 weeks after MI. In rats with MI3d+RSD compared with MI rats, RSD improved systolic and diastolic function, resulting in an improvement in ejection fraction (P < 0.05), fractional shortening (P < 0.05) and LV internal dimension in systole (P < 0.05) and diastole (P < 0.05). Additionally, RSD treatment decreased left ventricular end-diastolic pressure (P < 0.05) and increased LV systolic pressure (P < 0.05) and maximal and minimal rate of LV pressure (both P < 0.05). Meanwhile, RSD reduced collagen content (P < 0.01). TIMP1 was upregulated (P < 0.05), whereas MMP2, MMP9 and TGF-β1 were downregulated in the LV of RSD-treated animals (P < 0.05). Renal sympathetic denervation has therapeutic effects on post-MI LV remodelling, probably owing to effects on the extracellular matrix by regulation of the MMP9-TIMP1 balance in the TGF-β1 signalling pathway. Renal sympathetic denervation may be considered as a non-pharmacological approach for the improvement of post-MI cardiac dysfunction. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

The development of reversible hematuria and oliguria following elevation of renal venous pressure.

DOT National Transportation Integrated Search

1963-01-01

An investigation was completed to study the acute effects of elevated renal venous pressure in the development of reversible gross hematuria and oliguria. Both isolated and intact dog kidney preparations were utilized. Results demonstrate that gross ...

Elevated blood pressure in offspring of rats exposed to diverse chemicals during pregnancy

EPA Science Inventory

Adverse intrauterine environments are associated with increased risk of later disease, including cardiovascular disease and hypertension. As a potential bioindicator of such an adverse environment, we measured blood pressure (BP), renal nephron endowment, renal glucocorticoid rec...

Renal tissue damage induced by focused shock waves

NASA Astrophysics Data System (ADS)

Ioritani, N.; Kuwahara, M.; Kambe, K.; Taguchi, K.; Saitoh, T.; Shirai, S.; Orikasa, S.; Takayama, K.; Lush, P. A.

1990-07-01

Biological evidence of renal arterial wall damage induced by the microjet due to shock wave-cavitation bubble interaction was demonstrated in living dog kidneys. We also intended to clarify the mechanism of renal tissue damage and the effects of different conditions of shock wave exposure (peak pressure of focused area, number of shots, exposure rate) on the renal tissue damage in comparison to stone disintegration. Disruption of arterial wall was the most remarkable histological change in the focused area of the kidneys. This lesion appeared as if the wall had been punctured by a needle. Large hematoma formation in the renal parenchym, and interstitial hemorrhage seemed to be the results of the arterial lesion. This arterial disorder also led to ischemic necrosis of the tubules surrounding the hematoma. Micro-angiographic examination of extracted kidneys also proved such arterial puncture lesions and ischemic lesions. The number of shots required for model stone disintegration was not inversely proportional to peak pressure. It decreased markedly when peak pressure was above 700 bar. Similarly thenumber of shots for hematoma formation was not inversely proportional to peak pressure, however, this decreased markedly above 500 bar. These results suggested that a hematoma could be formed under a lower peak pressure than that required for stone disintegration.

Renal denervation for the treatment of resistant hypertension: review and clinical perspective

PubMed Central

Iliescu, Radu; Lohmeier, Thomas E.; Tudorancea, Ionut; Laffin, Luke

2015-01-01

When introduced clinically 6 years ago, renal denervation was thought to be the solution for all patients whose blood pressure could not be controlled by medication. The initial two studies, SYMPLICITY HTN-1 and HTN-2, demonstrated great magnitudes of blood pressure reduction within 6 mo of the procedure and were based on a number of assumptions that may not have been true, including strict adherence to medication and absence of white-coat hypertension. The SYMPLICITY HTN-3 trial controlled for all possible factors believed to influence the outcome, including the addition of a sham arm, and ultimately proved the demise of the initial overly optimistic expectations. This trial yielded a much lower blood pressure reduction compared with the previous SYMPLICITY trials. Since its publication in 2014, there have been many analyses to try and understand what accounted for the differences. Of all the variables examined that could influence blood pressure outcomes, the extent of the denervation procedure was determined to be inadequate. Beyond this, the physiological mechanisms that account for the heterogeneous fall in arterial pressure following renal denervation remain unclear, and experimental studies indicate dependence on more than simply reduced renal sympathetic activity. These and other related issues are discussed in this paper. Our perspective is that renal denervation works if done properly and used in the appropriate patient population. New studies with new approaches and catheters and appropriate controls will be starting later this year to reassess the efficacy and safety of renal denervation in humans. PMID:26224718

Assessment of renal artery stenosis: side-by-side comparison of angiography and duplex ultrasound with pressure gradient measurements.

PubMed

Drieghe, Benny; Madaric, Juraj; Sarno, Giovanna; Manoharan, Ganesh; Bartunek, Jozef; Heyndrickx, Guy R; Pijls, Nico H J; De Bruyne, Bernard

2008-02-01

A ratio of distal renal pressure to aortic pressure (P(d)/P(a)) <0.90 can be considered a threshold for defining a significant renal artery stenosis (RAS). The aim of this study was to compare renal angiography (QRA) and colour duplex ultrasound (CDUS) to pressure measurements in assessing RAS. In 56 RAS, percent diameter stenosis (DS(angio)), minimal luminal diameter (MLD), Doppler-derived peak systolic velocity (PSV), end-diastolic velocity (EDV), and renal-to-aortic ratio (RAR) were obtained and compared with the P(d)/P(a) measured with a 0.014" pressure wire. P(d)/P(a) correlated with angiography- and CDUS-derived parameters. The best correlation was observed with EDV (R = -0.61). To identify stenosis associated with a P(d)/P(a) < 0.90, the diagnostic accuracy of DS(angio) > 50%, MLD < 2 mm, PSV > 180 cm/s, EDV > 90 cm/s and RAR > 3.5 were, respectively, 60%, 77%, 45%, 77% and 79%, yet, with a high proportion of false positives (38%, 15%, 55%, 11% and 15%, respectively) indicating an overestimation of the severity of the RAS by both QRA and CDUS. New cut-off values for QRA- and CDUS-derived indices were proposed. Generally accepted QRA and CDUS-derived indices of RAS severity overestimate the actual severity of RAS. This 'overdiagnosis' is likely the main cause of the disappointing results of renal angioplasty for renovascular hypertension.

Lifestyle intervention to improve quality of life and prevent weight gain after renal transplantation: Design of the Active Care after Transplantation (ACT) randomized controlled trial.

PubMed

Klaassen, Gerald; Zelle, Dorien M; Navis, Gerjan J; Dijkema, Desie; Bemelman, Frederike J; Bakker, Stephan J L; Corpeleijn, Eva

2017-09-15

Low physical activity and reduced physical functioning are common after renal transplantation, resulting in a reduced quality of life. Another common post-transplantation complication is poor cardio-metabolic health, which plays a main role in long-term outcomes in renal transplant recipients (RTR). It is increasingly recognized that weight gain in the first year after transplantation, especially an increase in fat mass, is a highly common contributor to cardio-metabolic risk. The aim of this study is to compare the outcomes of usual care to the effects of exercise alone, and exercise combined with dietary counseling, on physical functioning, quality of life and post-transplantation weight gain in RTR. The Active Care after Transplantation study is a multicenter randomized controlled trial with three arms in which RTR from 3 Dutch hospitals are randomized within the first year after transplantation to usual care, to exercise intervention (3 months supervised exercise 2 times per week followed by 12 months active follow-up), or to an exercise + diet intervention, consisting of the exercise training with additional dietary counseling (12 sessions over 15 months by a renal dietician). In total, 219 participants (73 per group) will be recruited. The primary outcome is the subdomain physical functioning of quality of life, (SF-36 PF). Secondary outcomes include other evaluations of quality of life (SF-36, KDQOL-SF, EQ-5D), objective measures of physical functioning (aerobic capacity and muscle strength), level of physical activity, gain in adiposity (body fat percentage by bio-electrical impedance assessment, BMI, waist circumference), and cardiometabolic risk factors (blood pressure, lipids, glucose metabolism). Furthermore, data on renal function, medical history, medication, psychological factors (motivation, kinesiophobia, coping style), nutrition knowledge, nutrition intake, nutrition status, fatigue, work participation, process evaluation and cost-effectiveness are collected. Evidence on the effectiveness of an exercise intervention, or an exercise + diet intervention on physical functioning, weight gain and cardiometabolic health in RTR is currently lacking. The outcomes of the present study may help to guide future evidence-based lifestyle care after renal transplantation. Number: NCT01047410 .

Prolonged Baroreflex Activation Abolishes Salt-Induced Hypertension After Reductions in Kidney Mass.

PubMed

Hildebrandt, Drew A; Irwin, Eric D; Lohmeier, Thomas E

2016-12-01

Chronic electric activation of the carotid baroreflex produces sustained reductions in sympathetic activity and arterial pressure and is currently being evaluated for therapy in patients with resistant hypertension. However, patients with significant impairment of renal function have been largely excluded from clinical trials. Thus, there is little information on blood pressure and renal responses to baroreflex activation in subjects with advanced chronic kidney disease, which is common in resistant hypertension. Changes in arterial pressure and glomerular filtration rate were determined in 5 dogs after combined unilateral nephrectomy and surgical excision of the poles of the remaining kidney to produce ≈70% reduction in renal mass. After control measurements, sodium intake was increased from ≈45 to 450 mol/d. While maintained on high salt, animals experienced increases in mean arterial pressure from 102±4 to 121±6 mm Hg and glomerular filtration rate from 40±2 to 45±2 mL/min. During 7 days of baroreflex activation, the hypertension induced by high salt was abolished (103±6 mm Hg) along with striking suppression of plasma norepinephrine concentration from 139±21 to 81±9 pg/mL, but despite pronounced blood pressure lowering, there were no significant changes in glomerular filtration rate (43±2 mL/min). All variables returned to prestimulation values during a recovery period. These findings indicate that after appreciable nephron loss, chronic suppression of central sympathetic outflow by baroreflex activation abolishes hypertension induced by high salt intake. The sustained antihypertensive effects of baroreflex activation occur without significantly compromising glomerular filtration rate in remnant nephrons. © 2016 American Heart Association, Inc.

Sorting Nexin 1 Loss Results in D5 Dopamine Receptor Dysfunction in Human Renal Proximal Tubule Cells and Hypertension in Mice*

PubMed Central

Villar, Van Anthony M.; Jones, John Edward; Armando, Ines; Asico, Laureano D.; Escano, Crisanto S.; Lee, Hewang; Wang, Xiaoyan; Yang, Yu; Pascua-Crusan, Annabelle M.; Palmes-Saloma, Cynthia P.; Felder, Robin A.; Jose, Pedro A.

2013-01-01

The peripheral dopaminergic system plays a crucial role in blood pressure regulation through its actions on renal hemodynamics and epithelial ion transport. The dopamine D5 receptor (D5R) interacts with sorting nexin 1 (SNX1), a protein involved in receptor retrieval from the trans-Golgi network. In this report, we elucidated the spatial, temporal, and functional significance of this interaction in human renal proximal tubule cells and HEK293 cells stably expressing human D5R and in mice. Silencing of SNX1 expression via RNAi resulted in the failure of D5R to internalize and bind GTP, blunting of the agonist-induced increase in cAMP production and decrease in sodium transport, and up-regulation of angiotensin II receptor expression, of which expression was previously shown to be negatively regulated by D5R. Moreover, siRNA-mediated depletion of renal SNX1 in C57BL/6J and BALB/cJ mice resulted in increased blood pressure and blunted natriuretic response to agonist in salt-loaded BALB/cJ mice. These data demonstrate a crucial role for SNX1 in D5R trafficking and that SNX1 depletion results in D5R dysfunction and thus may represent a novel mechanism for the pathogenesis of essential hypertension. PMID:23152498

Central arterial characteristics of gout patients with chronic kidney diseases.

PubMed

Celik, Gulperi; Yilmaz, Sema; Kebapcilar, Levent; Gundogdu, Ali

2017-05-01

The aim of this study was to investigate the relationship between central blood pressure, arterial stiffness parameters and renal function parameters in gout patients with chronic kidney disease (CKD) and without CKD. The study enrolled 48 gout patients and 32 control subjects. Central blood pressure, arterial stiffness parameters and renal function parameters in gout patients were investigated. The vascular measurements were performed with an arteriograph. Of the gout patients, 40.1% had CKD. The 24-h pulse pressure (PP) (P < 0.001), central systolic blood pressure (SBP) (P < 0.001), central diastolic blood pressure (DBP) (P < 0.001), cardiac output (CO) (P < 0.001) and peripheral resistance (P = 0.004) were significantly higher in the all patients with gout compared to healthy control subjects. Moreover, when the gout patients with and without CKD were compared, the gout patients with CKD had higher 24-h PP (P = 0.009), 24-h augmentation index standardized to a heart rate of 75 beats per min (AIx@75) (P < 0.023), daytime PP (P = 0.001), daytime AIx@75 (P = 0.027), and nighttime PP (P = 0.035) than the gout patients without CKD. In our study, gout patients with CKD had worse and more emphasized evidence of arterial stiffness than gout patients without CKD. Further investigations with large sample sizes are needed to evaluate the effect of CKD on the arterial stiffness of gout patients. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Optimum and stepped care standardised antihypertensive treatment with or without renal denervation for resistant hypertension (DENERHTN): a multicentre, open-label, randomised controlled trial.

PubMed

Azizi, Michel; Sapoval, Marc; Gosse, Philippe; Monge, Matthieu; Bobrie, Guillaume; Delsart, Pascal; Midulla, Marco; Mounier-Véhier, Claire; Courand, Pierre-Yves; Lantelme, Pierre; Denolle, Thierry; Dourmap-Collas, Caroline; Trillaud, Hervé; Pereira, Helena; Plouin, Pierre-François; Chatellier, Gilles

2015-05-16

Conflicting blood pressure-lowering effects of catheter-based renal artery denervation have been reported in patients with resistant hypertension. We compared the ambulatory blood pressure-lowering efficacy and safety of radiofrequency-based renal denervation added to a standardised stepped-care antihypertensive treatment (SSAHT) with the same SSAHT alone in patients with resistant hypertension. The Renal Denervation for Hypertension (DENERHTN) trial was a prospective, open-label randomised controlled trial with blinded endpoint evaluation in patients with resistant hypertension, done in 15 French tertiary care centres specialised in hypertension management. Eligible patients aged 18-75 years received indapamide 1·5 mg, ramipril 10 mg (or irbesartan 300 mg), and amlodipine 10 mg daily for 4 weeks to confirm treatment resistance by ambulatory blood pressure monitoring before randomisation. Patients were then randomly assigned (1:1) to receive either renal denervation plus an SSAHT regimen (renal denervation group) or the same SSAHT alone (control group). The randomisation sequence was generated by computer, and stratified by centres. For SSAHT, after randomisation, spironolactone 25 mg per day, bisoprolol 10 mg per day, prazosin 5 mg per day, and rilmenidine 1 mg per day were sequentially added from months two to five in both groups if home blood pressure was more than or equal to 135/85 mm Hg. The primary endpoint was the mean change in daytime systolic blood pressure from baseline to 6 months as assessed by ambulatory blood pressure monitoring. The primary endpoint was analysed blindly. The safety outcomes were the incidence of acute adverse events of the renal denervation procedure and the change in estimated glomerular filtration rate from baseline to 6 months. This trial is registered with ClinicalTrials.gov, number NCT01570777. Between May 22, 2012, and Oct 14, 2013, 1416 patients were screened for eligibility, 106 of those were randomly assigned to treatment (53 patients in each group, intention-to-treat population) and 101 analysed because of patients with missing endpoints (48 in the renal denervation group, 53 in the control group, modified intention-to-treat population). The mean change in daytime ambulatory systolic blood pressure at 6 months was -15·8 mm Hg (95% CI -19·7 to -11·9) in the renal denervation group and -9·9 mm Hg (-13·6 to -6·2) in the group receiving SSAHT alone, a baseline-adjusted difference of -5·9 mm Hg (-11·3 to -0·5; p=0·0329). The number of antihypertensive drugs and drug-adherence at 6 months were similar between the two groups. Three minor renal denervation-related adverse events were noted (lumbar pain in two patients and mild groin haematoma in one patient). A mild and similar decrease in estimated glomerular filtration rate from baseline to 6 months was observed in both groups. In patients with well defined resistant hypertension, renal denervation plus an SSAHT decreases ambulatory blood pressure more than the same SSAHT alone at 6 months. This additional blood pressure lowering effect may contribute to a reduction in cardiovascular morbidity if maintained in the long term after renal denervation. French Ministry of Health. Copyright © 2015 Elsevier Ltd. All rights reserved.

Maternal separation diminishes α-adrenergic receptor density and function in renal vasculature from male Wistar-Kyoto rats.

PubMed

Loria, Analia S; Osborn, Jeffrey L

2017-07-01

Adult rats exposed to maternal separation (MatSep) are normotensive but display lower glomerular filtration rate and increased renal neuroadrenergic drive. The aim of this study was to determine the renal α-adrenergic receptor density and the renal vascular responsiveness to adrenergic stimulation in male rats exposed to MatSep. In addition, baroreflex sensitivity was assessed to determine a component of neural control of the vasculature. Using tissue collected from 4-mo-old MatSep and control rats, α 1 -adrenergic receptors (α 1 -ARs) were measured in renal cortex and isolated renal vasculature using receptor binding assay, and the α-AR subtype gene expression was determined by RT-PCR. Renal cortical α 1 -AR density was similar between MatSep and control tissues (B max = 44 ± 1 vs. 42 ± 2 fmol/mg protein, respectively); however, MatSep reduced α 1 -AR density in renal vasculature (B max = 47 ± 4 vs. 62 ± 4 fmol/mg protein, P < 0.05, respectively). In a separate group of rats, the pressor, bradycardic, and renal vascular constrictor responses to acute norepinephrine injection (NE, 0.03-0.25 μg/μl) were determined under anesthesia. Attenuated NE-induced renal vasoconstriction was observed in rats exposed to MatSep compared with control ( P < 0.05). A third group of rats was infused at steady state with the α 1 agonist phenylephrine (10 μg/min iv) and vasodilator sodium nitroprusside (5 μg/min iv). The difference between the change in heart rate/mean arterial pressure slopes was indicative of reduced baroreflex sensitivity in MatSep vs. control rats (-0.45 ± 0.04 vs. -0.95 ± 0.07 beats·min -1 ·mmHg -1 , P < 0.05). These data support the notion that reduced α-adrenergic receptor expression and function in the renal vasculature could develop secondary to MatSep-induced overactivation of the renal neuroadrenergic tone. Copyright © 2017 the American Physiological Society.

Divergent Effects of Hypertonic Fluid Resuscitation on Renal Pathophysiological and Structural Parameters in Rat Model of Lower Body Ischemia/Reperfusion-Induced Sterile Inflammation.

PubMed

Ergin, Bulent; Zuurbier, Coert J; Kapucu, Aysegul; Ince, Can

2017-12-27

The pathogenesis of acute kidney injury (AKI) is characterized by the deterioration of tissue perfusion and oxygenation and enhanced inflammation. The purpose of this study was to investigate whether or not the hemodynamic and inflammatory effects of hypertonic saline (HS) protect the kidney by promoting renal microcirculatory oxygenation and possible deleterious effects of HS due to its high sodium content on renal functional and structural injury following ischemia/reperfusion. Mechanically ventilated and anesthetized rats were randomly divided into four groups (n = 6 per group): a sham-operated control group; a group subjected to renal ischemia for 45 min by supra-aortic occlusion followed by 2 h of reperfusion (I/R); and I/R group treated with a continuous i.v. infusion (5 mL/kg/h) of either % 0.9 NaCl (IR+NS) or %10 NaCl (I/R+HS) after releasing the clamp. Systemic and renal hemodynamic, renal cortical (CμPO2), and medullar microcirculatory pO2 (MμPO2) are measured by the oxygen-dependent quenching of the phosphorescence lifetime technique. Renal functional, inflammatory, and tissues damage parameters were also assessed. HS, but not NS, treatment restored I/R-induced reduced mean arterial pressure, CμPO2, renal oxygen deliver (DO2ren), and consumption (VO2ren). HS caused a decrease in tubular sodium reabsorption (TNa) that correlated with an elevation of fractional sodium excretion (EFNa) and urine output. HS had an anti-inflammatory effect by reducing the levels TNF-α, IL-6, and hyaluronic acid in the renal tissue samples as compared with the I/R and I/R+NS groups (P < 0.05). HS treatment was also associated with mild acidosis and an increased renal tubular damage. Despite HS resuscitation improving the systemic hemodynamics, microcirculatory oxygenation, and renal oxygen consumption as well as inflammation, it should be limited or strictly controlled for long-term use because of provoking widespread renal structural damage.

Alport syndrome and pregnancy: a case series and literature review.

PubMed

Brunini, Francesca; Zaina, Barbara; Gianfreda, Davide; Ossola, Wally; Giani, Marisa; Fedele, Luigi; Messa, Piergiorgio; Moroni, Gabriella

2018-06-01

To assess pregnancy outcome in women with Alport syndrome and the impact of pregnancy on the disease progression. We describe one of the largest series of pregnancies in Alport syndrome. Seven pregnancies of six women were monitored by a multidisciplinary team of nephrologists and gynecologists. After delivery, patients were followed for at least 3 years. We compare our results with those in the literature. Pregnancy course was uneventful in the patient with isolated microscopic hematuria. In the other cases, all presenting mild proteinuria at conception, some complications occurred. Proteinuria worsened during the last trimester, reaching nephrotic ranges in five out of six pregnancies and was associated with fluid overload leading to hospitalizations and early delivery. The majority of the newborns had a low birth weight. The two patients with arterial hypertension at conception and twin pregnancy developed pre-eclampsia and renal function deterioration persisted after delivery. The one with pre-pregnancy renal dysfunction reached end-stage renal disease. In the other patients, in which renal function and blood pressure were and remained normal, proteinuria improved after delivery and no signs of disease progression were recorded at last observation. Our observations suggest that Alport syndrome should be considered a potential risk factor for pregnancy in proteinuric patients due to the development of pre-eclampsia, renal function deterioration, and/or full-blown nephrotic syndrome that results in anasarca, slowing of fetal growth and pre-term delivery. Thus, all women with Alport syndrome should receive pre-conceptional counseling and be kept in close follow-up during pregnancy.

Comparison of tissue Doppler echocardiography parameters in patients with end-stage renal disease and renal transplant recipients.

PubMed

Pirat, B; Bozbas, H; Demirtas, S; Simsek, V; Sayin, B; Colak, T; Sade, E; Ulucam, M; Muderrisoglu, H; Haberal, M

2008-01-01

Tissue Doppler echocardiography has been introduced as a useful tool to assess systolic myocardial function. In this study we sought to compare patients with end-stage renal disease (ESRD), with renal transplantations and control subjects with regard to tissue Doppler parameters. Thirty recipients with functional grafts of overall mean age 36 +/- 7 years included 24 men. An equal number of patients with ESRD of overall mean age 35 +/- 7 years included 20 men. A third cohort was comprised of 20 age- and gender matched control subjects. Tissue Doppler imaging from the septal and lateral mitral annulus of the left ventricle and free wall of the right ventricle was performed from a 4-chamber view. Mean systolic and diastolic blood pressures were similar among the groups during imaging. Peak systolic velocity (S wave) at the septal annulus was similar in control subjects and recipients. S waves were significantly lower among ESRD patients compared with recipients (10.3 +/- 2.1 vs 12.0 +/- 2.5 cm/s, P = .04, respectively). Isovolumic contraction velocity of the septum and the right ventricular wall were significantly lower in ESRD patients than recipients or controls: 10.2 +/- 2.6 vs 12.5 +/- 2.8 vs 11.4 +/- 1.8 cm/s for septal wall (P = .008) and 13.9 +/- 3.6 vs 17.9 +/- 5.1 vs 16.8 +/- 5.8, for right ventricle (P = .01). Systolic indices of tissue Doppler echocardiography in recipients demonstrated similar values as control subjects and increased values compared with ESRD patients. These results suggested improvement in systolic myocardial function following renal transplantation.

A study of the role of renal nerves in the renal responses to 60° head-up tilt in the anaesthetized dog

PubMed Central

DiBona, G. F.; Johns, E. J.

1980-01-01

1. Renal responses to 10 min of 60° head-up tilt were measured in anaesthetized dogs in which renal perfusion pressure was maintained at a relatively constant value. 2. Tilting was associated with a fall in systemic blood pressure and an increase in heart rate. Renal blood flow and glomerular filtration rate remained constant while there was a significant decrease in both absolute and fractional excretion of sodium. 3. Animals which had undergone acute renal denervation were tilted. The cardiovascular responses were similar to intact animals. A fall in renal blood flow was observed but the glomerular filtration rate was maintained at a steady value during tilting. The decreased renal tubular excretion of sodium measured in intact animals was abolished. 4. Alpha-adrenergic blockade of the kidney was achieved by infusion of phentolamine into the renal artery. Tilting of these animals caused cardiovascular changes similar to those observed in control animals but renal blood flow, glomerular filtration rate and sodium handling remained unchanged. 5. Animals in which both carotid sinuses had been acutely denervated were tilted. Systemic blood pressure fell as in intact animals, but the rise in heart rate was significantly less. Renal blood flow, glomerular filtration rate and the rate of sodium excretion were unchanged. 6. A 10 min period of 60° head-up tilt in anaesthetized dogs resulted in an unchanged renal blood flow and glomerular filtration rate which was associated with a decrease in both fractional excretion of sodium and sodium excretion. The renal sympathetic nerves were shown to be responsible for these changes in tubular sodium handling which appeared to exert their action via renal tubular α-adrenergic receptors. This activation of the renal nerves appeared to be mediated by the carotid sinus baroreceptor reflex. PMID:7381761

Intra-aortic balloon pump combined with mechanical ventilation for treating patients aged > 60 years in cardiogenic shock: Retrospective analysis

PubMed Central

Liu, Hongwei; Wu, Xueping; Zhao, Xiaoning; Zhu, Ping

2016-01-01

Objective To examine if mechanical ventilation with positive end-expiratory pressure (PEEP) combined with intra-aortic balloon pump (IABP) provided a better outcome than IABP alone for the treatment of cardiogenic shock after acute myocardial infarction in patients aged > 60 years. Methods This was a retrospective analysis of data from patients in cardiogenic shock, refractory to pharmacological therapy and treated at a geriatric coronary care unit. Results Sixty-two patients were eligible for study inclusion: 33 received IABP alone; 29 received IABP combined with mechanical ventilation. Patients in the IABP + mechanical ventilation group had lower mean arterial blood pressure (BP), systolic BP and partial pressure of oxygen compared with the IABP group, indicating worse cardiac and pulmonary function. In addition, higher rates of pulmonary infection and renal insufficiency were observed in the IABP + mechanical ventilation group than in the IABP group. A statistically significant improvement of left ventricular function before and after treatment was observed in the IABP + mechanical ventilation group, but not in the IABP group. Pulmonary infection and renal insufficiency were risk factors for all-cause in-hospital mortality; successful revascularization was a negative risk factor. There was no between-group difference in survival. Conclusion Mechanical ventilation with an appropriate level of PEEP appears to enhance the beneficial effects of IABP on left ventricular function for patients in cardiogenic shock. PMID:27020597

Evaluation of renal function in patients with a main renal stone larger than 1 cm and perioperative renal functional change in minimally invasive renal stone surgery: a prospective, observational study.

PubMed

Piao, Songzhe; Park, Juhyun; Son, Hwancheol; Jeong, Hyeon; Cho, Sung Yong

2016-05-01

To compare the perioperative relative renal function and determine predictors of deterioration and recovery of separate renal function in patients with renal stones >10 mm and who underwent mini-percutaneous nephrolithotomy or retrograde intra-renal surgery. A main stone >10 mm or stones growing, high-risk stone formers and extracorporeal shock-wave lithotripsy-resistant stones were prospectively included in 148 patients. Patients with bilateral renal stones and anatomical deformities were excluded. Renal function was evaluated by estimated glomerular filtration rate, 99m-technetium dimercaptosuccinic acid and 99m-technetium diethylenetriamine pentaacetate prior to intervention and at postoperative 3 months. Logistic regression analyses were performed to find predictors of functional deterioration and recovery. The overall stone-free rate was 85.1 %. A third of patients (53/148, 35.8 %) with renal stones >10 mm showed deterioration of separate renal function. Mean renal function of operative sites showed 58.2 % (36.8 %/63.2 %) of that of contralateral sites in these patients. Abnormal separate renal function showed postoperative recovery in 31 patients (58.5 %). Three cases (5.7 %) showed deterioration of separate renal function despite no presence of remnant stones. Improvement rates of the abnormal separate renal function did not differ according to the type of surgery. The presence of hydronephrosis and three or more stones were significant predictors for renal function deterioration. Female gender and three or more stones were significantly correlated with postoperative recovery. Mini-percutaneous nephrolithotomy or retrograde intra-renal surgery was effective and safe for renal function preservation. Patients with multiple large stones should be considered for candidates of active surgical removal.

Cardiovascular and renal manifestations of glutathione depletion induced by buthionine sulfoximine.

PubMed

Vargas, Félix; Rodríguez-Gómez, Isabel; Pérez-Abud, Rocío; Vargas Tendero, Pablo; Baca, Yolanda; Wangensteen, Rosemary

2012-06-01

Oxidative stress contributes to the development of several cardiovascular diseases, including diabetes, renal insufficiency, and arterial hypertension. Animal studies have evidenced the association between higher blood pressure (BP) and increased oxidative stress, and treatment with antioxidants has been shown to reduce BP, while BP reduction due to antihypertensive drugs is associated with reduced oxidative stress. In 2000, it was first reported that oxidative stress and arterial hypertension were produced in normal Sprague-Dawley rats by oral administration of buthionine sulfoximine (BSO), which induces glutathione (GSH) depletion, indicating that oxidative stress may induce hypertension. The contribution of several potential pathogenic factors has been evaluated in the BSO rat model, the prototype of oxidative stress-induced hypertension, including vascular reactivity, endothelium-derived factors, renin-angiotensin system activity, TXA(2)-PGH(2) production, sodium sensitivity, renal dopamine-induced natriuresis, and sympathetic tone. This review summarizes the main factors implicated in the pathogenesis of BSO-induced hypertension and the alterations associated with GSH depletion that are related to renal function or BP control.

[Refractory hypertention in a female patient with renal failure].

PubMed

Zuccalà, A; Losinno, F; Fiorenza, S; Lifrieri, F; Rapanà, R

2005-01-01

We report one sixty-seven years-old female who presented with hypertension refractory to antihypertensive drugs. She had an elevated BP for approximately 15 years. In the last 8-10 months her hypertension had become difficult to control. Her BP ranged between 180/100 mmHg and 220/1220 mmHg on atenolol 100 mg once daily, methyldopa 500 mg three times daily, furosemide 25 mg twice daily, doxazosine 4 mg twice daily. When she was referred to our unit serum creatinine was 2.3 mg/dL and she had a mild proteinuria (70 mg/dL) without microematuria. Ultrasonography showed a left kidney size in the low-normal range (LD 11 cm) and a small right kidney (LD 9 cm). Renal angiography showed a severe, ostial stenosis of the left renal artery and a total thrombosis of the right renal artery with a blood supply to the right kidney provided by collateral channels. An ACE-I was added to the therapy but a sharp increase in serum creatinina (up to 6.4 mg/dL) prompted us to withdraw the drug. She underwent a renal angioplasty on the left side and a Palmaz stent was placed. The control angiography showed a good anatomical result. Three months after the manoeuvre the patient was again referred to our unit with headache, nausea vomiting and hyper-tension refractory to amlodipine 10 mg/day, doxazosine 4 mg twice a a day, atenolol 50 mg/day, furosemide 50 mg/day. A doppler ultrasonography and a magnetic resonance angiogram showed no restenosis on the treated artery. An ACE-I was again administered and BP on this drug was 145/90 mmHg after one month and 130/85 after three months. Headache, nausea and vomiting disappeared. Serum creatinina kept unchanged (2.2 mg/dL). Comment. In this case the benefit of angioplasty on blood pressure control was indirect. Apparently the manoeuvre showed no effect on blood pressure, but the angioplasty allowed us to use of an ACE-Inhibitor, without any negative effect on renal function, and thus to adequately control blood pressure.

Revascularization versus medical therapy for renal-artery stenosis.

PubMed

Wheatley, Keith; Ives, Natalie; Gray, Richard; Kalra, Philip A; Moss, Jonathan G; Baigent, Colin; Carr, Susan; Chalmers, Nicholas; Eadington, David; Hamilton, George; Lipkin, Graham; Nicholson, Anthony; Scoble, John

2009-11-12

Percutaneous revascularization of the renal arteries improves patency in atherosclerotic renovascular disease, yet evidence of a clinical benefit is limited. In a randomized, unblinded trial, we assigned 806 patients with atherosclerotic renovascular disease either to undergo revascularization in addition to receiving medical therapy or to receive medical therapy alone. The primary outcome was renal function, as measured by the reciprocal of the serum creatinine level (a measure that has a linear relationship with creatinine clearance). Secondary outcomes were blood pressure, the time to renal and major cardiovascular events, and mortality. The median follow-up was 34 months. During a 5-year period, the rate of progression of renal impairment (as shown by the slope of the reciprocal of the serum creatinine level) was -0.07x10(-3) liters per micromole per year in the revascularization group, as compared with -0.13x10(-3) liters per micromole per year in the medical-therapy group, a difference favoring revascularization of 0.06x10(-3) liters per micromole per year (95% confidence interval [CI], -0.002 to 0.13; P=0.06). Over the same time, the mean serum creatinine level was 1.6 micromol per liter (95% CI, -8.4 to 5.2 [0.02 mg per deciliter; 95% CI, -0.10 to 0.06]) lower in the revascularization group than in the medical-therapy group. There was no significant between-group difference in systolic blood pressure; the decrease in diastolic blood pressure was smaller in the revascularization group than in the medical-therapy group. The two study groups had similar rates of renal events (hazard ratio in the revascularization group, 0.97; 95% CI, 0.67 to 1.40; P=0.88), major cardiovascular events (hazard ratio, 0.94; 95% CI, 0.75 to 1.19; P=0.61), and death (hazard ratio, 0.90; 95% CI, 0.69 to 1.18; P=0.46). Serious complications associated with revascularization occurred in 23 patients, including 2 deaths and 3 amputations of toes or limbs. We found substantial risks but no evidence of a worthwhile clinical benefit from revascularization in patients with atherosclerotic renovascular disease. (Current Controlled Trials number, ISRCTN59586944.) 2009 Massachusetts Medical Society

Influence of CT-based depth correction of renal scintigraphy in evaluation of living kidney donors on side selection and postoperative renal function: is it necessary to know the relative renal function?

PubMed

Weinberger, Sarah; Klarholz-Pevere, Carola; Liefeldt, Lutz; Baeder, Michael; Steckhan, Nico; Friedersdorff, Frank

2018-03-22

To analyse the influence of CT-based depth correction in the assessment of split renal function in potential living kidney donors. In 116 consecutive living kidney donors preoperative split renal function was assessed using the CT-based depth correction. Influence on donor side selection and postoperative renal function of the living kidney donors were analyzed. Linear regression analysis was performed to identify predictors of postoperative renal function. A left versus right kidney depth variation of more than 1 cm was found in 40/114 donors (35%). 11 patients (10%) had a difference of more than 5% in relative renal function after depth correction. Kidney depth variation and changes in relative renal function after depth correction would have had influence on side selection in 30 of 114 living kidney donors. CT depth correction did not improve the predictability of postoperative renal function of the living kidney donor. In general, it was not possible to predict the postoperative renal function from preoperative total and relative renal function. In multivariate linear regression analysis, age and BMI were identified as most important predictors for postoperative renal function of the living kidney donors. Our results clearly indicate that concerning the postoperative renal function of living kidney donors, the relative renal function of the donated kidney seems to be less important than other factors. A multimodal assessment with consideration of all available results including kidney size, location of the kidney and split renal function remains necessary.

Expression of renin-angiotensin system signalling compounds in maternal protein-restricted rats: effect on renal sodium excretion and blood pressure.

PubMed

Mesquita, Flávia Fernandes; Gontijo, José Antonio Rocha; Boer, Patrícia Aline

2010-02-01

Intrauterine growth restriction due to low maternal dietary protein during pregnancy is associated with retardation of foetal growth, renal alterations and adult hypertension. The renin-angiotensin system (RAS) is a coordinated hormonal cascade in the control of cardiovascular, renal and adrenal function that governs body fluid and electrolyte balance, as well as arterial pressure. In the kidney, all the components of the renin-angiotensin system including angiotensin II type 1 (AT1) and type 2 (AT2) receptors are expressed locally during nephrogenesis. Hence, we investigated whether low protein diet intake during pregnancy altered kidney and adrenal expression of AT1(R) and AT2(R) receptors, their pathways and if the modified expression of the RAS compounds occurs associated with changes in urinary sodium and in arterial blood pressure in sixteen-week-old males' offspring of the underfed group. The pregnancy dams were divided in two groups: with normal protein diet (pups named NP) (17% protein) or low protein diet (pups LP) (6% protein) during all pregnancy. The present data confirm a significant enhancement in arterial pressure in the LP group. Furthermore, the study showed a significantly decreased expression of RAS pathway protein and Ang II receptors in the kidney and an increased expression in the adrenal of LP rats. The detailed immunohistochemical analysis of RAS signalling proteins in the kidney confirm the immunoblotting results for both groups. The present investigation also showed a pronounced decrease in fractional urinary sodium excretion in maternal protein-restricted offspring, compared with the NP age-matched group. This occurred despite unchanged creatinine clearance. The current data led us to hypothesize that foetal undernutrition could be associated with decreased kidney expression of AT(R) resulting in the inability of renal tubules to handle the hydro-electrolyte balance, consequently causing arterial hypertension.

Long-term effects of moderate protein diet on renal function and low-grade inflammation in older adults with type 2 diabetes and chronic kidney disease.

PubMed

Giordano, Mauro; Ciarambino, Tiziana; Castellino, Pietro; Cataliotti, Alessandro; Malatino, Lorenzo; Ferrara, Nicola; Politi, Cecilia; Paolisso, Giuseppe

2014-09-01

The aim of this study was to determine the long-term effects of a moderate protein diet (MPD) on renal function, low-grade inflammation, and oxidative stress in older adults with type 2 diabetes, which to date are unclear. Seventy-four older adults with type 2 diabetes and chronic kidney disease (stage G3b-G4) were enrolled in the study. During the 4-wk baseline period (T0), all patients were asked to follow a normal protein diet regimen, providing 1.1 g/kg daily. Successively, all patients were asked to follow an MPD, for 36 mo, providing 0.7 g/kg daily, for only 6 d/wk. Patients who refused to follow an MPD treatment were included in the control (NPD [normal protein diet] group). During the 36 mo of the study, creatinine clearance, blood urea nitrogen, proteinuria, blood pressure, glycated hemoglobin (Hb)A1c, fat-free mass, low-grade inflammation (interleukin-6 and C-reactive protein) were evaluated monthly and oxidative stress (urinary 8-epiprostaglandin [Epi-PG]F2α) was evaluated every 3 mo. During T0, mean creatinine clearance, proteinuria, blood urea nitrogen, blood pressure, HbA1c, fat free mass, low-grade inflammation, and oxidative stress were similar in both groups. After 36 mo, a significant reduction in decline of renal function was observed in the MPD group but not in controls (2.4 ± 0.2 versus 5.7 ± 0.5 mL·min·y, respectively; P < 0.05 versus control). Similarly, a significant reduction in proteinuria, serum interleukin-6, serum C-reactive protein, and urinary 8-Epi-PGF2α excretion, was observed in the MPD group (P < 0.05 versus NPD). In older adults with type 2 diabetes, long-term effects of an MPD regimen are associated with a significant decline of renal function, proteinuria, low-grade inflammation, and oxidative stress without a change in fat-free mass. Copyright © 2014 Elsevier Inc. All rights reserved.

Congestive kidney failure in cardiac surgery: the relationship between central venous pressure and acute kidney injury.

PubMed

Gambardella, Ivancarmine; Gaudino, Mario; Ronco, Claudio; Lau, Christopher; Ivascu, Natalia; Girardi, Leonard N

2016-11-01

Acute kidney injury (AKI) in cardiac surgery has traditionally been linked to reduced arterial perfusion. There is ongoing evidence that central venous pressure (CVP) has a pivotal role in precipitating acute renal dysfunction in cardiac medical and surgical settings. We can regard this AKI driven by systemic venous hypertension as 'kidney congestive failure'. In the cardiac surgery population as a whole, when the CVP value reaches the threshold of 14 mmHg in postoperative period, the risk of AKI increases 2-fold with an odds ratio (OR) of 1.99, 95% confidence interval (95% CI) of 1.16-3.40. In cardiac surgery subsets where venous hypertension is a hallmark feature, the incidence of AKI is higher (tricuspid disease 30%, carcinoid valve disease 22%). Even in the non-chronically congested coronary artery bypass population, CVP measured 6 h postoperatively showed significant association to renal failure: risk-adjusted OR for AKI was 5.5 (95% CI 1.93-15.5; P = 0.001) with every 5 mmHg rise in CVP for patients with CVP <9 mmHg; for CVP increments of 5 mmHg above the threshold of 9 mmHg, the risk-adjusted OR for AKI was 1.3 (95% CI 1.01-1.65; P = 0.045). This and other clinical evidence are discussed along with the underlying pathophysiological mechanisms, involving the supremacy of volume receptors in regulating the autonomic output in hypervolaemia, and the regional effect of venous congestion on the nephron. The effect of CVP on renal function was found to be modulated by ventricular function class, aetiology and acuity of venous congestion. Evidence suggests that acute increases of CVP should be actively treated to avoid a deterioration of the renal function, particularly in patients with poor ventricular fraction. Besides, the practice of treating right heart failure with fluid loading should be avoided in favour of other ways to optimize haemodynamics in this setting, because of the detrimental effects on the kidney function. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Anesthetic management of patients undergoing extra-anatomic renal bypass surgery for renovascular hypertension.

PubMed

Kumar, Bhupesh; Sinha, Prabhat Kumar; Unnikrishnan, M

2011-01-01

Renal artery disease is the most common cause for surgically curable form of hypertension. In a small subset of patients with severe aortic disease where the aorta is not suitable for endovascular technique and to provide an arterial inflow, an extra-anatomic renal bypass surgery (EARBS) is an option. Anesthetic management of such procedures has not been described so far in the literature. We retrospectively analyzed the anesthetic techniques used in all patients who underwent EARBS between February 1998 and June 2008 at this institute. We also further analyzed data concerning blood pressure (BP) control and renal function response following surgery as outcome variable measures. A total of 11 patients underwent EARBS during this period. Five received oral clonidine with premedication. During laryngoscopy, esmolol was used in 4 patients, while lignocaine was used in remaining 7 patients. Of 11 patients, 7 showed significant hemodynamic response to laryngoscopy and intubation; among these, one had oral clonidine with premedicant, and 6 received lignocaine just before laryngoscopy. Intravenous vasodilators were used to maintain target BP within 20% of baseline during perioperative period. All patients received renal protective measures. During follow-up, 10% were considered cured, 70% had improved BP response, while 20% failed to show improvement in BP response. Renal functions improved in 54.5%, remain unchanged in 36.5%, and worsened in 9% of patients. Use of clonidine during premedication and esmolol before laryngoscopy were beneficial in attenuating hemodynamic response to laryngoscopy, while use of vasodilators to maintain target BP within 20% of baseline, and routine use of renal protective measures appear to be promising in patients undergoing EARBS.

[Aortic dissection spread to the renal arteries: role of renal volumetry after angioplasty].

PubMed

Vautrin, E; Thony, F; Chavanon, O; Hannachi, I; Barone-Rochette, G; Pierre, H; Baguet, J-P

2012-06-01

Type A or B aortic dissection can extend to renal arteries, causing a renal ischemia which treatment is usually endovascular. The aim of our study is to show the interest of the renal volumetry in the follow-up of these patients. Twenty-two patients (16 men, mean age 63.4±11.8years, BMI 25.2±3.4kg/m(2)) with a type A or B aortic dissection spread to one or to both renal arteries and followed at Grenoble university hospital were consecutively included. All patients underwent renal angiography with aorto-renal pressure gradients measurements and follow-up by renal volumetry (scanner Siemens(®)). A renal ischemia was defined by a decrease of 20% or more of the volumetry. Sixteen patients (73%) were hypertensive before the aortic dissection among which ten (62%) were treated. Eight patients (36%) have a significant renal pressure gradient among which five (62%) underwent renal endovascular therapy. The renal volumetry of these five patients remained unchanged while six of 17 patients (36%) without angioplasty have a decreasing volumetry. Renal volumetry appeared an effective and attractive option for the follow-up of the patients with aortic dissection spread to the renal arteries. These results should be taken into account to put the indication of an endovascular treatment. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Renal denervation beyond the bifurcation: The effect of distal ablation placement on safety and blood pressure.

PubMed

Beeftink, Martine M A; Spiering, Wilko; De Jong, Mark R; Doevendans, Pieter A; Blankestijn, Peter J; Elvan, Arif; Heeg, Jan-Evert; Bots, Michiel L; Voskuil, Michiel

2017-04-01

Renal denervation may be more effective if performed distal in the renal artery because of smaller distances between the lumen and perivascular nerves. The authors reviewed the angiographic results of 97 patients and compared blood pressure reduction in relation to the location of the denervation. No significant differences in blood pressure reduction or complications were found between patient groups divided according to their spatial distribution of the ablations (proximal to the bifurcation in both arteries, distal to the bifurcation in one artery and distal in the other artery, or distal to the bifurcation in both arteries), but systolic ambulatory blood pressure reduction was significantly related to the number of distal ablations. No differences in adverse events were observed. In conclusion, we found no reason to believe that renal denervation distal to the bifurcation poses additional risks over the currently advised approach of proximal denervation, but improved efficacy remains to be conclusively established. ©2017 Wiley Periodicals, Inc.

Effect of sodium intake on sympathetic and hemodynamic response to thermal receptor stimulation.

PubMed

DiBona, Gerald F; Jones, Susan Y

2003-02-01

Low dietary sodium intake increases central nervous system angiotensin activity, which increases basal renal sympathetic nerve activity and shifts its arterial baroreflex control to a higher level of arterial pressure. This results in a higher level of renal sympathetic nerve activity for a given level of arterial pressure during low dietary sodium intake than during either normal or high dietary sodium intake, in which there is less central angiotensin activity. Peripheral thermal receptor stimulation overrides arterial baroreflex control and produces a pressor response, tachycardia, increased renal sympathetic nerve activity, and renal vasoconstriction. To test the hypothesis that increased central angiotensin activity would enhance the responses to peripheral thermal receptor stimulation, anesthetized normal rats in balance on low, normal, and high dietary sodium intake were subjected to acute peripheral thermal receptor stimulation. Low sodium rats had greater increases in renal sympathetic nerve activity, greater decreases in RBF, and greater increases in renal vascular resistance than high sodium rats. Responses of normal sodium rats were between those of low and high sodium rats. Arterial pressure and heart rate responses were not different among dietary groups. Spontaneously hypertensive rats, known to have increased central nervous system angiotensin activity, also had greater renal sympathoexcitatory and vasoconstrictor responses than normotensive Wistar-Kyoto rats. These results support the view that increased central nervous system angiotensin activity alters arterial baroreflex control of renal sympathetic nerve activity such that the renal sympathoexcitatory and vasoconstrictor responses to peripheral thermoreceptor stimulation are enhanced.

Uric acid lowering to prevent kidney function loss in diabetes: the preventing early renal function loss (PERL) allopurinol study.

PubMed

Maahs, David M; Caramori, Luiza; Cherney, David Z I; Galecki, Andrzej T; Gao, Chuanyun; Jalal, Diana; Perkins, Bruce A; Pop-Busui, Rodica; Rossing, Peter; Mauer, Michael; Doria, Alessandro

2013-08-01

Diabetic kidney disease causes significant morbidity and mortality among people with type 1 diabetes (T1D). Intensive glucose and blood pressure control have thus far failed to adequately curb this problem and therefore a major need for novel treatment approaches exists. Multiple observations link serum uric acid levels to kidney disease development and progression in diabetes and strongly argue that uric acid lowering should be tested as one such novel intervention. A pilot of such a trial, using allopurinol, is currently being conducted by the Preventing Early Renal Function Loss (PERL) Consortium. Although the PERL trial targets T1D individuals at highest risk of kidney function decline, the use of allopurinol as a renoprotective agent may also be relevant to a larger segment of the population with diabetes. As allopurinol is inexpensive and safe, it could be cost-effective even for relatively low-risk patients, pending the completion of appropriate trials at earlier stages.

Impact of Autologous Stem Cell Transplantation on Blood Pressure and Renal Function in Multiple Myeloma Patients.

PubMed

Balsam, Leah; Saad, Chadi; Arsene, Camelia; Fogel, Joshua

2017-01-01

Autologous stem cell transplantation (ASCT) reverses kidney failure in one-third of multiple myeloma (MM) patients, which may lead to blood pressure (BP) improvement. We evaluate the long term impact of ASCT on BP and renal function in MM patients. We studied 192 MM patients that underwent ASCT. We compared BP readings and glomerular filtration rate (GFR) at 4 weeks before ASCT, on day of ASCT and post-ASCT at 30, 100 and 180 days. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) on day of ASCT and at both 30 and 100 days post-ASCT was significantly lower as compared to pre-ASCT SBP and DBP. There was a significantly higher mean GFR at day of ASCT and 30 days post-ASCT and significantly lower mean GFR at 180 days post-ASCT as compared to pre-ASCT. White patients had similar patterns to the total group for SBP, DBP, and GFR except for SBP which was still significantly lower and GFR which was not significantly different at 180 days. African-American patients showed no significant reductions in the mean values of SBP and DBP and no significant increases for GFR in follow-up after day of ASCT. Furthermore, the mean value of GFR was significantly lower at 180 days post-ASCT. ASCT in MM patients had a positive impact on SBP and DBP and GFR but the impact was minimal for African-American patients. We recommend that clinicians consider closer follow-up of BP and kidney function and more intense therapy in African-Americans with MM. Copyright © 2017 National Medical Association. Published by Elsevier Inc. All rights reserved.

A multinational clinical approach to assessing the effectiveness of catheter-based ultrasound renal denervation: The RADIANCE-HTN and REQUIRE clinical study designs.

PubMed

Mauri, Laura; Kario, Kazuomi; Basile, Jan; Daemen, Joost; Davies, Justin; Kirtane, Ajay J; Mahfoud, Felix; Schmieder, Roland E; Weber, Michael; Nanto, Shinsuke; Azizi, Michel

2018-01-01

Catheter-based renal denervation is a new approach to treat hypertension via modulation of the renal sympathetic nerves. Although nonrandomized and small, open-label randomized studies resulted in significant reductions in office blood pressure 6months after renal denervation with monopolar radiofrequency catheters, the first prospective, randomized, sham-controlled study (Symplicity HTN-3) failed to meet its blood pressure efficacy end point. New clinical trials with new catheters have since been designed to address the limitations of earlier studies. Accordingly, the RADIANCE-HTN and REQUIRE studies are multicenter, blinded, randomized, sham-controlled trials designed to assess the blood pressure-lowering efficacy of the ultrasound-based renal denervation system (Paradise) in patients with established hypertension either on or off antihypertensive medications, is designed to evaluate patients in 2 cohorts-SOLO and TRIO, in the United States and Europe. The SOLO cohort includes patients with essential hypertension, at low cardiovascular risk, and either controlled on 1 to 2 antihypertensive medications or uncontrolled on 0 to 2 antihypertensive medications. Patients undergo a 4-week medication washout period before randomization to renal denervation (treatment) or renal angiogram (sham). The TRIO cohort includes patients with hypertension resistant to at least 3 antihypertensive drugs including a diuretic. Patients will be stabilized on a single-pill, triple-antihypertensive-drug combination for 4weeks before randomization to treatment or sham. Reduction in daytime ambulatory systolic blood pressure (primary end point) will be assessed at 2months in both cohorts. A predefined medication escalation protocol, as needed for blood pressure control, is implemented between 2 and 6months in both cohorts by a study staff member blinded to the randomization process. At 6months, daytime ambulatory blood pressure and antihypertensive treatment score will be assessed. REQUIRE is designed to evaluate patients with resistant hypertension on standard of care medication in Japan and Korea. Reduction in 24-hour ambulatory systolic blood pressure will be assessed at 3months (primary end point). Both studies are enrolling patients, and their results are expected in 2018. Copyright © 2017 Elsevier Inc. All rights reserved.

Renoprotective effect of virgin coconut oil in heated palm oil diet-induced hypertensive rats.

PubMed

Kamisah, Yusof; Ang, Shu-Min; Othman, Faizah; Nurul-Iman, Badlishah Sham; Qodriyah, Hj Mohd Saad

2016-10-01

Virgin coconut oil, rich in antioxidants, was shown to attenuate hypertension. This study aimed to investigate the effects of virgin coconut oil on blood pressure and related parameters in kidneys in rats fed with 5-times-heated palm oil (5HPO). Thirty-two male Sprague-Dawley rats were divided into 4 groups. Two groups were fed 5HPO (15%) diet and the second group was also given virgin coconut oil (1.42 mL/kg, oral) daily for 16 weeks. The other 2 groups were given basal diet without (control) and with virgin coconut oil. Systolic blood pressure was measured pre- and post-treatment. After 16 weeks, the rats were sacrificed and kidneys were harvested. Dietary 5HPO increased blood pressure, renal thiobarbituric acid reactive substance (TBARS), and nitric oxide contents, but decreased heme oxygenase activity. Virgin coconut oil prevented increase in 5HPO-induced blood pressure and renal nitric oxide content as well as the decrease in renal heme oxygenase activity. The virgin coconut oil also reduced the elevation of renal TBARS induced by the heated oil. However, neither dietary 5HPO nor virgin coconut oil affected renal histomorphometry. In conclusion, virgin coconut oil has a potential to reduce the development of hypertension and renal injury induced by dietary heated oil, possibly via its antioxidant protective effects on the kidneys.

Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure.

PubMed

Wang, Y; Mu, J J; Liu, F Q; Ren, K Y; Xiao, H Y; Yang, Z; Yuan, Z Y

2014-02-01

Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13(BN) rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats, and this relationship might depend on the increase in blood pressure.

Valsartan attenuates cardiac and renal hypertrophy in rats with experimental cardiorenal syndrome possibly through down-regulating galectin-3 signaling.

PubMed

Zhang, M-J; Gu, Y; Wang, H; Zhu, P-F; Liu, X-Y; Wu, J

2016-01-01

Aortocaval fistula (AV) induced chronic volume overload in rats with preexisting mild renal dysfunction (right kidney remove: UNX) could mimic the type 4 cardiorenal syndrome (CRS): chronic renocardiac syndrome. Galectin-3, a β-galactoside binding lectin, is an emerging biomarker in cardiovascular as well as renal diseases. We observed the impact of valsartan on cardiac and renal hypertrophy and galectin-3 changes in this model. Adult male Sprague-Dawley (SD) rats (200-250 g) were divided into S (Sham, n = 7), M (UNX+AV, n = 7) and M+V (UNX+AV+valsartan, n = 7) groups. Eight weeks later, cardiac function was measured by echocardiography. Renal outcome was measured by glomerular filtration rate, effective renal plasma flow, renal blood flow and 24 hours albuminuria. Immunohistochemistry and real-time PCR were used to evaluate the expressions of galectin-3 in heart and renal. Cardiac hypertrophy and renal hypertrophy as well as cardiac enlargement were evidenced in this AV shunt induced chronic volume overload rat model with preexisting mild renal dysfunction. Cardiac and renal hypertrophy were significantly attenuated but cardiac enlargement was unaffected by valsartan independent of its blood pressure lowering effect. 24 hours urine albumin was significantly increased, which was significantly reduced by valsartan in this model. Immunohistochemistry and real-time PCR evidenced significantly up-regulated galectin-3 expression in heart and kidney and borderline increased myocardial collagen I expression, which tended to be lower post valsartan treatment. Up-regulated galectin-3 signaling might also be involved in the pathogenesis in this CRS model. The beneficial effects of valsartan in terms of attenuating cardiac and renal hypertrophy and reducing 24 hours albumin in this model might partly be mediated through down-regulating galectin-3 signal pathway.

The Effects of Renal Denervation on Renal Hemodynamics and Renal Vasculature in a Porcine Model

PubMed Central

Verloop, Willemien L.; Hubens, Lisette E. G.; Spiering, Wilko; Doevendans, Pieter A.; Goldschmeding, Roel; Bleys, Ronald L. A. W.; Voskuil, Michiel

2015-01-01

Rationale Recently, the efficacy of renal denervation (RDN) has been debated. It is discussed whether RDN is able to adequately target the renal nerves. Objective We aimed to investigate how effective RDN was by means of functional hemodynamic measurements and nerve damage on histology. Methods and Results We performed hemodynamic measurements in both renal arteries of healthy pigs using a Doppler flow and pressure wire. Subsequently unilateral denervation was performed, followed by repeated bilateral hemodynamic measurements. Pigs were terminated directly after RDN or were followed for 3 weeks or 3 months after the procedure. After termination, both treated and control arteries were prepared for histology to evaluate vascular damage and nerve damage. Directly after RDN, resting renal blood flow tended to increase by 29±67% (P = 0.01). In contrast, renal resistance reserve increased from 1.74 (1.28) to 1.88 (1.17) (P = 0.02) during follow-up. Vascular histopathology showed that most nerves around the treated arteries were located outside the lesion areas (8±7 out of 55±25 (14%) nerves per pig were observed within a lesion area). Subsequently, a correlation was noted between a more impaired adventitia and a reduction in renal resistance reserve (β: -0.33; P = 0.05) at three weeks of follow-up. Conclusion Only a small minority of renal nerves was targeted after RDN. Furthermore, more severe adventitial damage was related to a reduction in renal resistance in the treated arteries at follow-up. These hemodynamic and histological observations may indicate that RDN did not sufficiently target the renal nerves. Potentially, this may explain the significant spread in the response after RDN. PMID:26587981

Results of an Aboriginal community-based renal disease management program incorporating point of care testing for urine albumin:creatinine ratio.

PubMed

Shephard, M D S; Allen, G G; Paizis, K; Barbara, J A J; Batterham, M; Vanajek, A

2006-01-01

There has been a significant increase in the burden of renal disease among Aboriginal Australians over the past 15 years. Urine albumin:creatinine ratio (ACR) is a well-established marker of microalbuminuria and can be conveniently performed on the DCA 2000 point-of-care testing (POCT) analyser (Bayer Australia; Melbourne, VIC, Australia) with an on-site result available in 7 min. The application of the urine ACR POCT for renal disease risk assessment was pioneered by our group in the Umoona Kidney Project. This article describes the results of the management arm of the Umoona Kidney Project, which used point-of-care urine ACR testing for the first time within a management framework to monitor albuminuria in patients at highest risk of renal disease. The article also examines the analytical quality of POCT results and overall community acceptance of the Umoona Kidney Project. Adults clinically assessed by Flinders Medical Centre renal specialists as being at greatest risk for renal disease were offered the ACE inhibitor (ACEI) perindopril on a voluntary basis. Selected renal markers, including POCT urine ACR (conducted on-site by Umoona's Aboriginal health worker team), plasma electrolytes, urea, creatinine, calculated glomerular filtration rate and blood pressure were measured six monthly. Regular quality control testing was undertaken to monitor the analytical performance of the POCT analyser. A culturally appropriate questionnaire was designed and implemented to assess community satisfaction with the project. In all, 231 patient management consultations were conducted over a two year period, with over 70% of patients having four or more (up to a maximum of eight) consultations; 35 patients (mean age 49.2 [+/-2.3] years, 54% males) participated voluntarily in the management arm. All were overtly hypertensive, hypertensive with other risk factors or had diabetes. The renal status of these patients was followed for a mean of 63 +/- 4.5 weeks. In total, 111 POCT urine ACR tests were performed for patient management (mean 3.2 tests per patient). There was no significant difference in POCT urine ACR in the study period with a median (and inter-quartile range) of 5.7 mg/mmol (1.2-15.2) pre-ACEI and 4.3 mg/mmol (1.3-16.7) post-ACEI treatment (p = 0.50, Wilcoxon signed ranks test). The calculated glomerular filtration rate altered from 110 to 118 mL/min (p = 0.019, paired t-test). There was no change in the group plasma potassium, urea and creatinine. Collectively these results indicate a stabilisation in renal function among the management group. Blood pressure (both lying and standing) fell significantly in the study period. The imprecision for urine ACR quality control POCT conducted during the management program was within nationally and internationally accepted precision goals for urine albumin, creatinine and ACR. Fifty community members completed the satisfaction questionnaire. Three-quarters of respondents felt there were no cultural barriers in providing a urine sample for urine ACR POCT. The management arm of the Umoona Kidney Project was effective in stabilising the renal function and improving the blood pressure of community members identified to be at greatest risk of kidney disease. POCT urine ACR testing can be utilised, not only for community risk assessment, but also for patient management. The Umoona Kidney Project was well accepted by the health service and community members.

Renal denervation for the treatment of resistant hypertension: review and clinical perspective.

PubMed

Iliescu, Radu; Lohmeier, Thomas E; Tudorancea, Ionut; Laffin, Luke; Bakris, George L

2015-10-01

When introduced clinically 6 years ago, renal denervation was thought to be the solution for all patients whose blood pressure could not be controlled by medication. The initial two studies, SYMPLICITY HTN-1 and HTN-2, demonstrated great magnitudes of blood pressure reduction within 6 mo of the procedure and were based on a number of assumptions that may not have been true, including strict adherence to medication and absence of white-coat hypertension. The SYMPLICITY HTN-3 trial controlled for all possible factors believed to influence the outcome, including the addition of a sham arm, and ultimately proved the demise of the initial overly optimistic expectations. This trial yielded a much lower blood pressure reduction compared with the previous SYMPLICITY trials. Since its publication in 2014, there have been many analyses to try and understand what accounted for the differences. Of all the variables examined that could influence blood pressure outcomes, the extent of the denervation procedure was determined to be inadequate. Beyond this, the physiological mechanisms that account for the heterogeneous fall in arterial pressure following renal denervation remain unclear, and experimental studies indicate dependence on more than simply reduced renal sympathetic activity. These and other related issues are discussed in this paper. Our perspective is that renal denervation works if done properly and used in the appropriate patient population. New studies with new approaches and catheters and appropriate controls will be starting later this year to reassess the efficacy and safety of renal denervation in humans. Copyright © 2015 the American Physiological Society.

Redo renal denervation using a multi-electrode radiofrequency system in patients with persistent therapy-resistant hypertension.

PubMed

Daemen, J; Feyz, L; Van Zandvoort, L; Van Mieghem, N M

2017-06-01

Renal sympathetic denervation has been studied as a potential therapeutic option for patients with therapy-resistant hypertension; however, a significant proportion of patients do not show a significant reduction in blood pressure and are classified as non-responders. The objective of the present study was to assess whether a redo renal denervation procedure increases response rates. We present a case series of three consecutive renal denervation non-responders treated with the multi-electrode radiofrequency St. Jude EnligHTN catheter after an average of 22 months. Patients were followed for 6 months. Mean age was 66 years and two patients were male. Patients were previously treated using either ReCor's Paradise system, the Vessix V2 system or the Covidien OneShot system. Mean office blood pressure one year after the initial procedure was 187/102 mm Hg with a mean 24 h ambulatory blood pressure of 166/102 mm Hg. All patients underwent a successful redo procedure using the EnligHTN system because of persistent therapy-resistant hypertension. At 6 months a significant drop in both office and ambulatory blood pressure of -27/-6 mm Hg and -15/-13 mm Hg, respectively, was observed. No significant renal artery stenosis was observed at 6 months. In patients with therapy-resistant hypertension who do not respond to an initial renal denervation procedure, a redo procedure using the St. Jude EnligHTN system may help to significantly improve blood pressure control.

[Influence of Sympathetic Denervation of the Renal Artery on the Level of Arterial Blood Pressure, Cerebral Blood Flow and Cognitive Function In Patients With Resistant Arterial Hypertension].

PubMed

Efimova, Y N; Lichikaki, A V; Lishmanov, B Y

2017-07-01

To study the effect of radiofrequency ablation of renal arteries on regional cerebral blood flow and cognitive function in patients with resistant arterial hypertension (AH). Transcatheter renal denervation (TRD) was performed in 17 patients with resistant AH. Examination before and after TRD included SPECT with mTc-HMPAO, 24-hours blood pressure (BP) monitoring, and comprehensive neuropsychological testing. Fifteen patients without angiographic signs of carotid atherosclerosis, coronary artery disease and AH, neurological and psychiatric disorders were investigated as control group. Compared with control group patients with AH had decreases of regional cerebral blood flow (rCBF) in right (by 13.5%, p=0.00002) and left (by 15.5%, p=0.0006) inferior frontal lobes, in right temporal brain region (by 11.5%, p=0.008); in right and left occipital lobes (by 8.2%, p=0.04). In 6 months after TRD we observed significant improvement of cognitive function, parameters of 24-hour BP monitoring, and rCBF. We also noted definite close interdependence between changes of rCBF, indices of 24-hours BP monitoring, and dynamics of cognitive function. Improvement of long-term verbal memory correlated with increases of rCBF in left superior frontal and right occipital regions while dynamics of mentation and attention correlated positively with augmentation of rCBF in right posterior parietal region. Changes of perfusion in inferior parts of left frontal lobe and in right occipital region correlated with dynamics of index of diurnal diastolic hypertension time (R2=0.64, p=0.001, and R2=0.60, p=0.03, respectively). Our results suggest, that in patients with resistant AH positive effect of TRD on levels of 24-hour mean BP as well as on indices of BP load leads to in augmentation of rCBF and improvement of cognitive function.

The kidney and type 2 diabetes mellitus: therapeutic implications of SGLT2 inhibitors.

PubMed

Weir, Matthew R

2016-01-01

Understanding the role of the kidneys in type 2 diabetes mellitus (T2DM) has taken on an increased importance in recent years with the arrival of sodium-glucose co-transporter 2 (SGLT2) inhibitors - antihyperglycemic agents (AHAs) that specifically target the kidneys. This review includes an update on the physiology of the kidneys, their role in the pathophysiology of T2DM, and the mechanisms implicated in the development and progression of diabetic kidney disease, such as glomerular hyperfiltration and inflammation. It also discusses renal issues that could influence the choice of AHA for patients with T2DM, including special populations such as patients with concomitant chronic kidney disease. The most recent data published on the clinical efficacy and safety of the SGLT2 inhibitors canagliflozin, dapagliflozin, and empagliflozin and their effects on renal function are presented, showing how the renally mediated mechanisms of action of these agents translate into clinical benefits, including the potential for renoprotection. The observed positive effects of these agents on measures such as glucose control, estimated glomerular filtration rate, albumin-to-creatinine ratio, blood pressure, and body weight in patients both with and without impaired renal function suggest that SGLT2 inhibitors represent an important extension to the diabetes treatment armamentarium.

Elevations in serum creatinine with RAAS blockade: why isn't it a sign of kidney injury?

PubMed

Ryan, Michael J; Tuttle, Katherine R

2008-09-01

The aim of this article is to review the pertinent physiology and pathophysiology of the renin-angiotensin-aldosterone system (RAAS), summarize the proven beneficial cardiovascular and renal effects of RAAS blockade, examine clinical situations in which RAAS blockade may induce reductions in glomerular filtration rate, and explore why increases in serum creatinine in the setting of angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) therapy do not necessarily signify the presence of clinically relevant kidney failure. RAAS inhibition appears to reduce the likelihood of atrial fibrillation. RAAS inhibition leads to improved insulin sensitivity and glycemic control, but does not appear to prevent diabetes. The beneficial effects of ACEi/ARB therapy extend to those with significant renal disease. Combination ACEi/ARB is safe, and reduces proteinuria more than either agent alone in patients with macroalbuminuric nephropathy. Acute deteriorations in renal function that result from RAAS inhibition are usually reversible. RAAS blockade exerts potent hemodynamic, antihypertensive, and antiinflammatory effects, and slows progression of kidney disease beyond that due to lowering of blood pressure. The benefit extends to those with advanced disease. In spite of established benefit, ACEi and ARB therapy remains underutilized, in part due to concerns about acute deteriorations in renal function that result from interruption of the RAAS.

Association of haemodynamic changes measured by serial central venous saturation during ultrafiltration for acutely decompensated heart failure with diuretic resistance and change in renal function.

PubMed

Vazir, Ali; Simpkin, Victoria L; Marino, Philip; Ludman, Andrew; Banya, Winston; Tavazzi, Guido; Bastin, Anthony J; Trenfield, Sarah; Ghori, Arshad; Alexander, Peter D; Griffiths, Mark; Price, Susanna; Sharma, Rakesh; Cowie, Martin R

2016-10-01

Patients with acute decompensated heart failure with diuretic resistance (ADHF-DR) have a poor prognosis. The aim of this study was to assess in patients with ADHF-DR, whether haemodynamic changes during ultrafiltration (UF) are associated with changes in renal function (Δcreatinine) and whether Δcreatinine post UF is associated with mortality. Seventeen patients with ADHF-DR underwent 20 treatments with UF. Serial bloods (4-6 hourly) from the onset of UF treatment were measured for renal function, electrolytes and central venous saturation (CVO2). Univariate and multivariate analysis were performed to assess the relationship between changes in markers of haemodynamics [heart rate (HR), systolic blood pressure (SBP), packed cell volume (PCV) and CVO2] and Δcreatinine. Patients were followed up and mortality recorded. Cox-regression survival analysis was performed to determine covariates associated with mortality. Renal function worsened after UF in 17 of the 20 UF treatments (baseline vs. post UF creatinine: 164±58 vs. 185±69μmol/l, P<0.01). ΔCVO2 was significantly associated with Δcreatinine [β-coefficient of -1.3 95%CI (-1.8 to -0.7), P<0.001] and remained significantly associated with Δcreatinine after considering changes in SBP, HR and PCV [P<0.001]. Ten (59%) patients died at 1-year and 15(88%) by 2-years. Δcreatinine was independently associated with mortality (adjusted-hazard ratio 1.03 (1.01 to 1.07) per 1μmol/l increase in creatinine; P=0.02). Haemodynamic changes during UF as measured by the surrogate of cardiac output was associated with Δcreatinine. Worsening renal function at end of UF treatment occurred in the majority of patients and was associated with mortality. Copyright © 2016. Published by Elsevier Ireland Ltd.

Urinary Angiotensinogen Excretion Level Is Associated With Elevated Blood Pressure in the Normotensive General Population.

PubMed

Sato, Emiko; Wang, An Yi; Satoh, Michihiro; Nishikiori, Yoko; Oba-Yabana, Ikuko; Yoshida, Mai; Sato, Hiroshi; Ito, Sadayoshi; Hida, Wataru; Mori, Takefumi

2018-05-07

Inflammation, intrarenal renin-angiotensin system (RAS) activation, oxidative stress, and carbonyl stress have been postulated to play a fundamental role in controlling blood pressure. However, little is known about the association among renal RAS activation, carbonyl stress, and blood pressure elevation. We evaluated the relationship between blood pressure elevation and either renal RAS activity or carbonyl stress in the general population (N = 355) in Japan. To minimize the effect of antihypertensive drug therapy, we divided participants into 3 groups (normotensive, hypertensive-with-non-medication, and hypertensive-with-medication). Intrarenal RAS activity and carbonyl stress were indicated by the urinary angiotensinogen (AGT) and carbonyl compound excretion levels, respectively. The urinary AGT and carbonyl compound excretion levels were significantly associated with blood pressure. Using a stepwise multiple regression analysis, we found that the urinary AGT excretion levels were strongly associated with blood pressure elevation, compared with inflammation, oxidative stress, and carbonyl stress markers, in all groups. Urinary carbonyl compound excretion was significantly associated with blood pressure in only the hypertensive-without-medication group. Furthermore, blood pressure was significantly increased in these participants, and both the urinary AGT and carbonyl compound levels were high. The urinary AGT excretion levels were strongly associated with elevated blood pressure in normotensive people, and inappropriate renal RAS activity and carbonyl stress independently contributed to the development of hypertension. These findings suggest that RAS activation, particularly renal RAS activation exert a fundamental role in the pathogenesis of hypertension in the general population.

Effects of RAAS Inhibitors in Patients with Kidney Disease.

PubMed

Zhang, Fan; Liu, Hong; Liu, Di; Liu, Yexin; Li, Huiqiong; Tan, Xia; Liu, Fuyou; Peng, Youming; Zhang, Hongqing

2017-08-08

Proteinuria and decline of renal function are associated with progression of kidney disease. The Renin Angiotensin Aldosterone System (RAAS) plays an important role in blood pressure regulation, fluid volume, and sodium balance. Overactivity of RAAS contributes to the pathogenesis of a variety of clinical conditions including progress of chronic kidney disease (CKD). This review summarizes the use of RAAS inhibitors as dual therapy or monotherapy in different stages of kidney disease. Experimental and clinical studies have demonstrated RAAS inhibitors prevent proteinuria, kidney fibrosis and slow decline of renal function and thus play a protective role in both early and end stages of kidney disease. While combination use of RAAS inhibitors showed higher efficiency compared with monotherapy, it is also associated with higher incidence of adverse events. Besides ACEI/ARBs, more mechanism research of mineralocorticoid receptor antagonists in kidney disease should be performed.

High protein weight loss diets in obese subjects with type 2 diabetes mellitus.

PubMed

Pedersen, E; Jesudason, D R; Clifton, P M

2014-05-01

Diets where carbohydrate has been partially exchanged for protein have shown beneficial changes in persons with type 2 diabetes but no studies have enrolled people with albuminuria. We aim to determine if a high protein to carbohydrate ratio (HPD) in an energy reduced diet has a beneficial effect on metabolic control and cardiovascular risk factors without negatively affecting renal function. Adult, overweight participants with type 2 diabetes, with albuminuria (30-600 mg/24 h or an albumin-to-creatinine ratio of 3.0-60 mg/mmol), and estimated GFR of >40 ml/min/1.73 m(2) were enrolled. Participants were randomized to an HPD or an SPD. Protein:fat:carbohydrate ratio was 30:30:40% of energy for the HPD and 20:30:50% for the SPD. Main outcomes were renal function, weight loss, blood pressure, serum lipids and glycaemic control. We recruited 76 volunteers and 45 (35 men and 10 women) finished. There were no overall changes in renal function at 12 months and no significant differences in weight loss between groups (9.7 ± 2.9 kg and 6.6 ± 1.4 kg HPD and SPD group respectively; p = 0.32). Fasting blood glucose decreased significantly with no treatment effect. The decrease in HbA1c differed between treatments at 6 months (HPD -0.9 vs. SPD -0.3%; p = 0.039) but not at 12 months. HDL increased significantly with no treatment effects. There were no changes in LDL or blood pressure overall but DBP was lower in the HPD group (p = 0.024) at 12 months. Weight loss improved overall metabolic control in this group of well controlled participants with type 2 diabetes regardless of diet composition. Copyright © 2013 Elsevier B.V. All rights reserved.

Impact of albumin compared to saline on organ function and mortality of patients with severe sepsis.

PubMed

Finfer, Simon; McEvoy, Suzanne; Bellomo, Rinaldo; McArthur, Colin; Myburgh, John; Norton, Robyn

2011-01-01

To determine the effect of random assignment to fluid resuscitation with albumin or saline on organ function and mortality in patients with severe sepsis. Pre-defined subgroup analysis of a randomized controlled trial conducted in the intensive care units of 16 hospitals in Australia and New Zealand. Of 1,218 patients with severe sepsis at baseline, 603 and 615 were assigned to receive albumin and saline, respectively. The two groups had similar baseline characteristics. During the first 7 days mean arterial pressure was similar in the two groups, but patients assigned albumin had a lower heart rate on days 1 and 3 (p = 0.002 and p = 0.03, respectively) and a higher central venous pressure on days 1-3 (p < 0.005 each day). There was no difference in the renal or total Sequential Organ Failure Assessment score of the two groups; 113/603 (18.7%) of patients assigned albumin were treated with renal replacement therapy compared to 112/615 (18.2%) assigned saline (p = 0.98). The unadjusted relative risk of death for albumin versus saline was 0.87 [95% confidence interval (CI) 0.74-1.02] for patients with severe sepsis and 1.05 (0.94-1.17) for patients without severe sepsis (p = 0.06 for heterogeneity). From multivariate logistic regression analysis adjusting for baseline factors in patients with complete baseline data (919/1,218, 75.5%), the adjusted odds ratio for death for albumin versus saline was 0.71 (95% CI: 0.52-0.97; p = 0.03). Administration of albumin compared to saline did not impair renal or other organ function and may have decreased the risk of death.

Rationale and design of a large registry on renal denervation: the Global SYMPLICITY registry.

PubMed

Böhm, Michael; Mahfoud, Felix; Ukena, Christian; Bauer, Axel; Fleck, Eckart; Hoppe, Uta C; Kintscher, Ulrich; Narkiewicz, Krzysztof; Negoita, Manuela; Ruilope, Luis; Rump, L Christian; Schlaich, Markus; Schmieder, Roland; Sievert, Horst; Weil, Joachim; Williams, Bryan; Zeymer, Uwe; Mancia, Giuseppe

2013-08-22

Hypertension is a global healthcare concern associated with a wide range of comorbidities. The recognition that elevated sympathetic drive plays an important role in the pathogenesis of hypertension led to the use of renal artery denervation to interrupt the efferent and afferent sympathetic nerves between the brain and kidneys to lower blood pressure. Clinical trials of the Symplicity™ renal denervation system have demonstrated that radiofrequency ablation of renal artery nerves is safe and significantly lowers blood pressure in patients with severe resistant (systolic BP >160 mmHg) hypertension. Smaller ancillary studies in hypertensive patients suggest a benefit from renal denervation in a variety of conditions such as chronic kidney disease, glucose intolerance, sleep apnoea and heart failure. The Global SYMPLICITY registry, which incorporates the GREAT SYMPLICITY registry initiated in Germany, is being conducted worldwide to evaluate the safety and efficacy of treatment with the Symplicity renal denervation system in real-world uncontrolled hypertensive patients, looking first at subjects with severe resistant hypertension to confirm the results of prior clinical trials, but then also subjects with a wider range of baseline blood pressure and coexisting comorbidities. The rationale, design and first baseline data from the Global SYMPLICITY registry are presented.

Prevalence of chronic cardiovascular and metabolic diseases in Senegalese workers: a cross-sectional study, 2010.

PubMed

Seck, Sidy Mohamed; Guéye, Serigne; Tamba, Kéba; Ba, Issa

2013-01-01

Noncommunicable diseases (NCDs) are a major public health threat, particularly in developing countries. In sub-Saharan Africa, the scarcity of reliable data on NCDs in the general population makes it difficult to develop efficient prevention strategies. The objective of this cross-sectional study was to assess the prevalence of 4 cardiometabolic NCDs among 402 private-sector workers in Dakar, Senegal: high blood pressure (HBP), diabetes, obesity, and chronic kidney disease (CKD). We collected demographic, clinical, and biological data for each worker during routine occupational health visits between September 1 and November 30, 2010. Multivariate analyses were performed to identify risk factors associated with NCDs. Among the 402 study participants, 24.1% had HBP, 9.7% had diabetes, 16.7% were obese, and 22.4% had CKD. About half of participants (48.5%) were not aware of their diseases before the screening. Univariate analysis showed that age was significantly associated with blood pressure, fasting blood glucose, and renal function. After adjusting for age and sex, systolic blood pressure was correlated with renal function, and physical inactivity was significantly associated with obesity. Despite its small sample size, our study provides a perspective on the extent of cardiometabolic NCDs in Senegalese workers. Our study also suggests that targeted screening activities focusing on socio-professional groups may be helpful in the absence of national integrated prevention programs.

Transient renal tubulopathy in a racing Greyhound.

PubMed

Abraham, L A; Tyrrell, D; Charles, J A

2006-11-01

A 2-year-old female Greyhound was presented for inappetence and lethargy. On referral, results of diagnostic tests indicated renal glucosuria, increased excretion of selected amino acids and abnormal fractional excretion of electrolytes consistent with renal tubular dysfunction. Systemic blood pressure was elevated. Renal biopsy revealed mild proximal renal tubular damage consistent with a subacute toxic or hypoxic insult. Systemic hypertension, renal glucosuria and altered fractional excretion of electrolytes resolved during the 7 day period of hospital treatment. The Greyhound resumed training without recurrence of renal dysfunction.

Inappropriate Prescription and Renal Function Among Older Patients with Cognitive Impairment.

PubMed

Sönnerstam, Eva; Sjölander, Maria; Gustafsson, Maria

2016-12-01

Older people are more sensitive to drugs and adverse drug reactions than younger people because of age-related physiological changes such as impaired renal function. As people with dementia are particularly vulnerable to the effects of drugs, it is especially important to evaluate the dosages of renally cleared medications in this group. The aim of this study was to estimate the prevalence of impaired renal function and inappropriate prescriptions on the basis of renal function among older patients with dementia or cognitive impairment. The medical records of 428 patients aged ≥65 years who were admitted to two hospitals in northern Sweden were reviewed and renally cleared medications were identified. The Cockcroft-Gault equation was used to evaluate renal function. Doses were evaluated according to the Geriatric Dosage Handbook. Renal function was impaired (estimated glomerular filtration rate <60 ml/min) in 65.4 % of the study population. Impaired renal function was associated with increasing age. Among 547 prescriptions identified as renally cleared medications, 9.1 % were inappropriate based on the patient's renal function; 13.5 % of the 326 patients prescribed renally cleared medications had inappropriate prescriptions. Inappropriate prescriptions were more common among patients living in nursing homes. Impaired renal function is common and inappropriate prescription is prevalent among old people with cognitive impairment in northern Sweden. Continuous consideration of renal function is important when prescribing medications to this group.

Clinical application of calculated split renal volume using computed tomography-based renal volumetry after partial nephrectomy: Correlation with technetium-99m dimercaptosuccinic acid renal scan data.

PubMed

Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo

2017-06-01

To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P < 0.001 and r = 0.94, P < 0.001). The preoperative and postoperative split estimated glomerular filtration rate of the operated kidney showed a moderate correlation with split renal function (r = 0.39, P = 0.004 and r = 0.49, P < 0.001). The correlation between reductions in split renal function and split renal volume of the operated kidney (r = 0.87, P < 0.001) was stronger than that between split renal function and percent reduction in split estimated glomerular filtration rate (r = 0.64, P < 0.001). The split renal volume calculated using computed tomography-based renal volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.

Altered central nervous system processing of baroreceptor input following hindlimb unloading in rats

NASA Technical Reports Server (NTRS)

Moffitt, J. A.; Schadt, J. C.; Hasser, E. M.

1999-01-01

The effect of cardiovascular deconditioning on central nervous system processing of baroreceptor afferent activity was evaluated following 14 days of hindlimb unloading (HU). Inactin-anesthetized rats were instrumented with catheters, renal sympathetic nerve electrodes, and aortic depressor nerve electrodes for measurement of mean arterial pressure, heart rate, renal sympathetic nerve activity (RSNA), and aortic depressor nerve activity (ADNA). Baroreceptor and baroreflex functions were assessed during infusion of phenylephrine and sodium nitroprusside. Central processing of baroreceptor afferent input was evaluated by linear regression relating RSNA to ADNA. The maximum baroreflex-elicited increase in RSNA was significantly reduced in HU rats (122 +/- 3.8 vs. 144 +/- 4.9% of baseline RSNA), whereas ADNA was not altered. The slope (-0.18 +/- 0.04 vs. -0.40 +/- 0.04) and y-intercept (121 +/- 3.2 vs. 146 +/- 4.3) of the linear regression relating increases in efferent RSNA to decreases in afferent ADNA during hypotension were significantly reduced in HU rats. There were no differences during increases in arterial pressure. Results demonstrate that the attenuation in baroreflex-mediated increases in RSNA following HU is due to changes in central processing of baroreceptor afferent information rather than aortic baroreceptor function.

Alport syndrome and pregnancy: Good obstetric and nephrological outcomes in a pregnant woman with homozygous autosomal recessive Alport syndrome.

PubMed

Nishizawa, Yoko; Takei, Takashi; Miyaoka, Tokiko; Kamei, Daigo; Mochizuki, Toshio; Nitta, Kosaku

2016-03-01

We describe the course of pregnancy in a 27-year-old woman with homozygous autosomal recessive Alport syndrome. Genetic analysis revealed a homozygous COL4A4 mutation in exon 36 (c.3307G > A) with p.G1102R inherited from her parents (who were parallel cousins) 1 year before conception. Before pregnancy, the patient's renal function and blood pressure were normal, and her urinary protein excretion was below 2 g/day. The pregnancy course was uneventful in the first and second trimesters. She was detected to have nephrotic-range proteinuria during the third trimester, but was observed closely on an outpatient basis without any medications, as her general condition was good, her renal function and blood pressure remained stable, and the fetal well-being was maintained. At 39(+0) weeks of pregnancy, she vaginally gave birth to an appropriate-birthweight infant and her urinary protein excretion returned to pre-pregnancy level. This is the first report of pregnancy in a patient with autosomal recessive Alport syndrome with good obstetric and nephrological outcomes in the absence of any treatment or hospitalization. © 2015 Japan Society of Obstetrics and Gynecology.

Uric acid is a strong independent predictor of renal dysfunction in patients with rheumatoid arthritis.

PubMed

Daoussis, Dimitrios; Panoulas, Vasileios; Toms, Tracey; John, Holly; Antonopoulos, Ioannis; Nightingale, Peter; Douglas, Karen M J; Klocke, Rainer; Kitas, George D

2009-01-01

Recent evidence suggests that uric acid (UA), regardless of crystal deposition, may play a direct pathogenic role in renal disease. We have shown that UA is an independent predictor of hypertension and cardiovascular disease (CVD), and that CVD risk factors associate with renal dysfunction, in patients with rheumatoid arthritis (RA). In this study we investigated whether UA associates with renal dysfunction in patients with RA and whether such an association is independent or mediated through other comorbidities or risk factors for renal impairment. Renal function was assessed in 350 consecutive RA patients by estimated glomerular filtration rate (GFR) using the six-variable Modification of Diet in Renal Disease equation. Risk factors for renal dysfunction were recorded or measured in all participants. Linear regression was used to test the independence of the association between GFR and UA. Univariable analysis revealed significant associations between GFR and age, systolic blood pressure, total cholesterol, triglycerides, RA duration and UA. UA had the most powerful association with renal dysfunction (r = -0.45, P < 0.001). A basic model was created, incorporating all of the above parameters along with body mass index and gender. UA ranked as the first correlate of GFR (P < 0.001) followed by age. Adjustments for the use of medications (diuretics, low-dose aspirin, cyclooxygenase II inhibitors and nonsteroidal anti-inflammatory drugs) and further adjustment for markers of inflammation and insulin resistance did not change the results. UA is a strong correlate of renal dysfunction in RA patients. Further studies are needed to address the exact causes and clinical implications of this new finding. RA patients with elevated UA may require screening for renal dysfunction and appropriate management.

Cardiorespiratory response to exercise after renal sympathetic denervation in patients with resistant hypertension.

PubMed

Ukena, Christian; Mahfoud, Felix; Kindermann, Ingrid; Barth, Christine; Lenski, Matthias; Kindermann, Michael; Brandt, Mathias C; Hoppe, Uta C; Krum, Henry; Esler, Murray; Sobotka, Paul A; Böhm, Michael

2011-09-06

This study sought to investigate the effects of interventional renal sympathetic denervation (RD) on cardiorespiratory response to exercise. RD reduces blood pressure at rest in patients with resistant hypertension. We enrolled 46 patients with therapy-resistant hypertension as extended investigation of the Symplicity HTN-2 (Renal Denervation With Uncontrolled Hypertension) trial. Thirty-seven patients underwent bilateral RD and 9 patients were assigned to the control group. Cardiopulmonary exercise tests were performed at baseline and 3-month follow-up. In the RD group, compared with baseline examination, blood pressure at rest and at maximum exercise after 3 months was significantly reduced by 31 ± 13/9 ± 13 mm Hg (p < 0.0001) and by 21 ± 20/5 ± 14 mm Hg (p < 0.0001), respectively. Achieved work rate increased by 5 ± 13 W (p = 0.029) whereas peak oxygen uptake remained unchanged. Blood pressure 2 min after exercise was significantly reduced by 29 ± 17/8 ± 15 mm Hg (p < 0.001 for systolic blood pressure; p = 0.002 for diastolic blood pressure). Heart rate at rest decreased after RD (4 ± 11 beats/min; p = 0.028), whereas maximum heart rate and heart rate increase during exercise were not different. Heart rate recovery improved significantly by 4 ± 7 beats/min after renal denervation (p = 0.009). In the control group, there were no significant changes in blood pressure, heart rate, maximum work rate, or ventilatory parameters after 3 months. RD reduces blood pressure during exercise without compromising chronotropic competence in patients with resistant hypertension. Heart rate at rest decreased and heart rate recovery improved after the procedure. (Renal Denervation With Uncontrolled Hypertension; [Symplicity HTN-2]; NCT00888433). Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Dynamic analysis of patterns of renal sympathetic nerve activity: implications for renal function.

PubMed

DiBona, Gerald F

2005-03-01

Methods of dynamic analysis are used to provide additional understanding of the renal sympathetic neural control of renal function. The concept of functionally specific subgroups of renal sympathetic nerve fibres conveying information encoded in the frequency domain is presented. Analog pulse modulation and pseudorandom binary sequence stimulation patterns are used for the determination of renal vascular frequency response. Transfer function analysis is used to determine the effects of non-renal vasoconstrictor and vasoconstrictor intensities of renal sympathetic nerve activity on dynamic autoregulation of renal blood flow.

Renal structure and function evaluation of rats from dams that received increased sodium intake during pregnancy and lactation submitted or not to 5/6 nephrectomy.

PubMed

Marin, Evelyn Cristina Santana; Balbi, Ana Paula Coelho; Francescato, Heloísa Della Coletta; Alves da Silva, Cleonice Giovanini; Costa, Roberto Silva; Coimbra, Terezila M

2008-01-01

Adult rats submitted to perinatal salt overload presented renin-angiotensin system (RAS) functional disturbances. The RAS contributes to the renal development and renal damage in a 5/6 nephrectomy model. The aim of the present study was to analyze the renal structure and function of offspring from dams that received a high-salt intake during pregnancy and lactation. We also evaluated the influence of the prenatal high-salt intake on the evolution of 5/6 nephrectomy in adult rats. A total of 111 sixty-day-old rat pups from dams that received saline or water during pregnancy and lactation were submitted to 5/6 nephrectomy (nephrectomized) or to a sham operation (sham). The animals were killed 120 days after surgery, and the kidneys were removed for immunohistochemical and histological analysis. Systolic blood pressure (SBP), albuminuria, and glomerular filtration rate (GFR) were evaluated. Increased SBP, albuminuria, and decreased GFR were observed in the rats from dams submitted to high-sodium intake before surgery. However, there was no difference in these parameters between the groups after the 5/6 nephrectomy. The scores for tubulointerstitial lesions and glomerulosclerosis were higher in the rats from the sham saline group compared to the same age control rats, but there was no difference in the histological findings between the groups of nephrectomized rats. In conclusion, our data showed that the high-salt intake during pregnancy and lactation in rats leads to structural changes in the kidney of adult offspring. However, the progression of the renal lesions after 5/6 nephrectomy was similar in both groups.

Consequences of advanced aging on renal function in chronic hyperandrogenemic female rat model: implications for aging women with polycystic ovary syndrome.

PubMed

Patil, Chetan N; Racusen, Lorraine C; Reckelhoff, Jane F

2017-11-01

Polycystic ovary syndrome (PCOS) is the most common endocrine and reproductive disorder in premenopausal women, characterized by hyperandrogenemia, metabolic syndrome, and inflammation. Women who had PCOS during their reproductive years remain hyperandrogenemic after menopause. The consequence of chronic hyperandrogenemia with advanced aging has not been studied to our knowledge. We have characterized a model of hyperandrogenemia in female rats and have aged them to 22-25 months to mimic advanced aging in hyperandrogenemic women, and tested the hypothesis that chronic exposure to hyperandrogenemia with aging has a deleterious effect on renal function. Female rats were chronically implanted with dihydrotestosterone pellets (DHT 7.5 mg/90 days) that were changed every 85 days or placebo pellets, and renal function was measured by clearance methods. Aging DHT-treated females had a threefold higher level of DHT with significantly higher body weight, mean arterial pressure, left kidney weight, proteinuria, and kidney injury molecule-1 (KIM-1), than did age-matched controls. In addition, DHT-treated-old females had a 60% reduction in glomerular filtration rate, 40% reduction in renal plasma flow, and significant reduction in urinary nitrate and nitrite excretion (UNOxV), an index of nitric oxide production. Morphological examination of kidneys showed that old DHT-treated females had significant focal segmental glomerulosclerosis, global sclerosis, and interstitial fibrosis compared to controls. Thus chronic hyperandrogenemia that persists into old age in females is associated with renal injury. These data suggest that women with chronic hyperandrogenemia such as in PCOS may be at increased risk for development of chronic kidney disease with advanced age. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

[Results of combined reconstructions of the renal arteries, abdominal aorta and its other branches in patients with atherosclerosis].

PubMed

Semenov, D V; Ignashov, A M; Turobova, E P; Martynenko, G I; Vakhitov, K M

2012-01-01

A comparative analysis was made of clinical indices and long-term survival in 20 patients (13 men and 7 women of mean age 62 +/- 2 years), having multifocal atherosclerosis of the renal arteries (RA), abdominal aorta and arteries of lower extremities (LE) (11 aneurysms, 7 occlusive lesions of the aorta and 3 of its unpaired branches) who underwent combined reconstructions, with patients having similar lesions, but not operated (12) or operated only on RA or on the arteries of LE (45). The groups of patients had no great differences except more pronounced renal dysfunction (RD) in the first of them. In spite of high postoperative lethality (20%) mainly due to acute renal failure (3), long-term survival proved to be significantly higher (14 from 16), than in not operated (3 from 12) (p = 0.00001) and had better tendency than in those operated on the same basin (35 from 45). In addition, the patients after combined operations had substantially decreased systolic and diastolic arterial pressure (159 +/- 13 vs. 132 +/- 9, p = 0.00001; 91 +/- 5 vs. 83 +/- 7, p = 0.010) and also stabilized renal function.

The Physiologic Effects of Pneumoperitoneum in the Morbidly Obese

PubMed Central

Nguyen, Ninh T.; Wolfe, Bruce M.

2005-01-01

Objective: To review the physiologic effects of carbon dioxide (CO2) pneumoperitoneum in the morbidly obese. Summary Background Data: The number of laparoscopic bariatric operations performed in the United States has increased dramatically over the past several years. Laparoscopic bariatric surgery requires abdominal insufflation with CO2 and an increase in the intraabdominal pressure up to 15 mm Hg. Many studies have demonstrated the adverse consequences of pneumoperitoneum; however, few studies have examined the physiologic effects of pneumoperitoneum in the morbidly obese. Methods: A MEDLINE search from 1994 to 2003 was performed using the key words morbid obesity, laparoscopy, bariatric surgery, pneumoperitoneum, and gastric bypass. The authors reviewed papers evaluating the physiologic effects of pneumoperitoneum in morbidly obese subjects undergoing laparoscopy. The topics examined included alteration in acid-base balance, hemodynamics, femoral venous flow, and hepatic, renal, and cardiorespiratory function. Results: Physiologically, morbidly obese patients have a higher intraabdominal pressure at 2 to 3 times that of nonobese patients. The adverse consequences of pneumoperitoneum in morbidly obese patients are similar to those observed in nonobese patients. Laparoscopy in the obese can lead to systemic absorption of CO2 and increased requirements for CO2 elimination. The increased intraabdominal pressure enhances venous stasis, reduces intraoperative portal venous blood flow, decreases intraoperative urinary output, lowers respiratory compliance, increases airway pressure, and impairs cardiac function. Intraoperative management to minimize the adverse changes include appropriate ventilatory adjustments to avoid hypercapnia and acidosis, the use of sequential compression devices to minimizes venous stasis, and optimize intravascular volume to minimize the effects of increased intraabdominal pressure on renal and cardiac function. Conclusions: Morbidly obese patients undergoing laparoscopic bariatric surgery are at risk for intraoperative complications relating to the use of CO2 pneumoperitoneum. Surgeons performing laparoscopic bariatric surgery should understand the physiologic effects of CO2 pneumoperitoneum in the morbidly obese and make appropriate intraoperative adjustments to minimize the adverse changes. PMID:15650630

Glucocorticoid-induced fetal programming alters the functional complement of angiotensin receptor subtypes within the kidney.

PubMed

Gwathmey, TanYa M; Shaltout, Hossam A; Rose, James C; Diz, Debra I; Chappell, Mark C

2011-03-01

We examined the impact of fetal programming on the functional responses of renal angiotensin receptors. Fetal sheep were exposed in utero to betamethasone (BMX; 0.17 mg/kg) or control (CON) at 80 to 81 days gestation with full-term delivery. Renal nuclear and plasma membrane fractions were isolated from sheep age 1.0 to 1.5 years for receptor binding and fluorescence detection of reactive oxygen species (ROS) or nitric oxide (NO). Mean arterial blood pressure and blood pressure variability were significantly higher in the BMX-exposed adult offspring versus CON sheep. The proportion of nuclear AT(1) receptors sensitive to losartan was 2-fold higher (67 ± 6% vs 27 ± 9%; P<0.01) in BMX compared with CON. In contrast, the proportion of AT(2) sites was only one third that of controls (BMX, 25 ± 11% vs CON, 78 ± 4%; P<0.01), with a similar reduction in sites sensitive to the Ang-(1-7) antagonist D-Ala7-Ang-(1-7) with BMX exposure. Functional studies revealed that Ang II stimulated ROS to a greater extent in BMX than in CON sheep (16 ± 3% vs 6 ± 4%; P<0.05); however, NO production to Ang II was attenuated in BMX (26 ± 7% vs 82 ± 14%; P<0.05). BMX exposure was also associated with a reduction in the Ang-(1-7) NO response (75 ± 8% vs 131 ± 26%; P<0.05). We conclude that altered expression of angiotensin receptor subtypes may be one mechanism whereby functional changes in NO- and ROS-dependent signaling pathways may favor the sustained increase in blood pressure evident in fetal programming.

Renal Hemodynamic and Morphological Changes after 7 and 28 Days of Leptin Treatment: The Participation of Angiotensin II via the AT1 Receptor

PubMed Central

Thieme, Karina; Oliveira-Souza, Maria

2015-01-01

The role of hyperleptinemia in cardiovascular diseases is well known; however, in the renal tissue, the exact site of leptin’s action has not been established. This study was conducted to assess the effect of leptin treatment for 7 and 28 days on renal function and morphology and the participation of angiotensin II (Ang II), through its AT1 receptor. Rats were divided into four groups: sham, losartan (10 mg/kg/day, s.c.), leptin (0.5 mg/kg/day for the 7 days group and 0.25 mg/kg/day for the 28 days group) and leptin plus losartan. Plasma leptin, Ang II and endothelin 1 (ET-1) levels were measured using an enzymatic immuno assay. The systolic blood pressure (SBP) was evaluated using the tail-cuff method. The renal plasma flow (RPF) and the glomerular filtration rate (GFR) were determined by p-aminohippuric acid and inulin clearance, respectively. Urinary Na+ and K+ levels were also analyzed. Renal morphological analyses, desmin and ED-1 immunostaining were performed. Proteinuria was analyzed by silver staining. mRNA expression of renin-angiotensin system (RAS) components, TNF-α and collagen type III was analyzed by quantitative PCR. Our results showed that leptin treatment increased Ang II plasma levels and progressively increased the SBP, achieving a pre-hypertension state. Rats treated with leptin 7 days showed a normal RPF and GFR, but increased filtration fraction (FF) and natriuresis. However, rats treated with leptin for 28 showed a decrease in the RPF, an increase in the FF and no changes in the GFR or tubular function. Leptin treatment-induced renal injury was demonstrated by: glomerular hypertrophy, increased desmin staining, macrophage infiltration in the renal tissue, TNF-α and collagen type III mRNA expression and proteinuria. In conclusion, our study demonstrated the progressive renal morphological changes in experimental hyperleptinemia and the interaction between leptin and the RAS on these effects. PMID:25793389

Predictors of Recoverability of Renal Function after Pyeloplasty in Adults with Ureteropelvic Junction Obstruction.

PubMed

Li, Xiao-Dong; Wu, Yu-Peng; Wei, Yong; Chen, Shao-Hao; Zheng, Qing-Shui; Cai, Hai; Xue, Xue-Yi; Xu, Ning

2018-01-01

This study aimed to identify factors predicting the recoverability of renal function after pyeloplasty in adult patients with ureteropelvic junction obstruction. We retrospectively reviewed 138 adults with unilateral renal obstruction-induced hydronephrosis and who underwent Anderson-Hynes dismembered pyeloplasty from January 2013 to January 2016. Hydronephrosis was classified preoperatively according to the Society for Fetal Urology (SFU) grading system. All patients underwent Doppler ultrasonography, excretory urography, computed tomography, and technetium-99m-diethylenetriamine pentaacetic acid radioisotope (99mTc DTPA) renography before and after surgery. Renal resistive index (RRI) and 99mTc DTPA renography were repeated at 1, 3, 6, and 12 months. Multivariate analysis identified age, renal pelvic type, SFU grade, preoperative RRI, decline of RRI, and renal parenchyma to hydronephrosis area ratio (PHAR) as independent predictors of renal function recoverability after pyeloplasty. However, preoperative RRI and RRI decline were not significantly associated with recoverability of renal function in patients aged >35 years. Lower preoperative RRI, greater decline in RRI, higher PHAR, lower SFU grade, and extrarenal pelvis were associated with greater improvements in postoperative renal function. Preoperative differential renal function cannot independently predict the recoverability of postoperative renal function in adult patients with unilateral renal obstruction-induced hydronephrosis. SFU grade, renal pelvic type, PHAR, preoperative RRI, and decline in RRI were significantly associated with the recoverability of renal function in adult patients aged <35 years, while only SFU grade, renal pelvic type, and PHAR were significantly associated with renal function recoverability in patients aged ≥35 years. Renal function recovery was better in patients younger than 35 years when compared with older patients. © 2018 S. Karger AG, Basel.

Renal dopamine containing nerves. What is their functional significance?

PubMed

DiBona, G F

1990-06-01

Biochemical and morphological studies indicate that there are nerves within the kidney that contain dopamine and that various structures within the kidney contain dopamine receptors. However, the functional significance of these renal dopamine containing nerves in relation to renal dopamine receptors is unknown. The functional significance could be defined by demonstrating that an alteration in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves is dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors. Thus, the hypothesis becomes: reflex or electrical activation of efferent renal nerves causes alterations in renal function (eg, renal blood flow, water and solute handling) that are inhibited by specific and selective dopamine receptor antagonists. As reviewed herein, the published experimental data do not support the hypothesis. Therefore, the view that alterations in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves are dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors remains unproven.

Angiotensin II AT2 receptor decreases AT1 receptor expression and function via nitric oxide/cGMP/Sp1 in renal proximal tubule cells from Wistar–Kyoto rats

PubMed Central

Yang, Jian; Chen, Caiyu; Ren, Hongmei; Han, Yu; He, Duofen; Zhou, Lin; Hopfer, Ulrich; Jose, Pedro A.; Zeng, Chunyu

2013-01-01

Background The renin–angiotensin (Ang) system controls blood pressure, in part, by regulating renal tubular sodium transport. In the kidney, activation of the angiotensin II type 1 (AT1) receptor increases renal sodium reabsorption, whereas the angiotensin II type 2 (AT2) receptor produces the opposite effect. We hypothesized that the AT2 receptor regulates AT1 receptor expression and function in the kidney. Methods and results In immortalized renal proximal tubule (RPT) cells from Wistar–Kyoto rats, CGP42112, an AT2 receptor agonist, decreased AT1 receptor mRNA and protein expression (P < 0.05), as assessed by reverse transcriptase-polymerase chain reaction and immunoblotting. The inhibitory effect of the AT2 receptor on AT1 receptor expression was blocked by the AT2 receptor antagonist, PD123319 (10−6 mol/l), the nitric oxide synthase inhibitor Nw-nitro-l-arginine methyl ester (10−4 mol/l), or the nitric oxide-dependent soluble guanylate cyclase inhibitor 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (10−5 mol/l), indicating that both nitric oxide and cyclic guanosine monophosphate (cGMP) were involved in the signaling pathway. Furthermore, CGP42112 decreased Sp1 serine phosphorylation and reduced the binding of Sp1 to AT1 receptor DNA. Stimulation with Ang II (10−11 mol/l per 30 min) enhanced Na+-K+-ATPase activity in RPT cells, which was prevented by pretreatment with CGP42112 (10−7 mol/l per 24 h) (P < 0.05). The above-mentioned results were confirmed in RPT cells from AT2 receptor knockout mice; AT1 receptor expression and Ang II-stimulated Na+-K+-ATPase activity were greater in these cells than in RPT cells from wild-type mice (P < 0.05). AT1/AT2 receptors co-localized and co-immunoprecipitated in RPT cells; short-term CGP42112 (10−7 mol/l per 30 min) treatment increased AT1/AT2 receptor co-immunoprecipitation (P < 0.05). Conclusions These results indicate that the renal AT2 receptor, via nitric oxide/cGMP/Sp1 pathway, regulates AT1 receptor expression and function, which may be important in the regulation of sodium excretion and blood pressure. PMID:22504846

Renal sympathetic denervation using an externally irrigated radiofrequency ablation catheter for treatment of resistant hypertension - Acute safety and short term efficacy.

PubMed

Yalagudri, Sachin; Raju, Narayana; Das, Bharati; Daware, Ashwin; Maiya, Shreesha; Jothiraj, Kannan; Ravikishore, A G

2015-01-01

This study was conducted to assess the acute safety and short term efficacy of renal sympathetic denervation (RSDN) using solid tip radiofrequency ablation (RFA) catheter and saline irrigation through the renal guiding catheter to achieve effective denervation. RSDN using a specialized solid-tip RFA catheter has recently been demonstrated to safely reduce systemic blood pressure in patients with refractory hypertension, the limitation being inadequate power delivery in renal arteries. So, we used solid-tip RFA catheter along with saline irrigation for RSDN. Nine patients with resistant hypertension underwent CT and conventional renal angiography, followed by bilateral or unilateral RSDN using 5F RFA catheter with saline irrigation through renal guiding catheter. Repeat renal angiography was performed at the end of the procedure. In all patients, pre- and post-procedure serum creatinine was measured. Over 1-month period: 1) the systolic/diastolic blood pressure decreased by -57 ± 20/-25 ± 7.5 mm Hg; 2) all patients experienced a decrease in systolic blood pressure of at least -36 mm Hg (range 36-98 mm Hg); 3) there was no evidence of renal artery injury immediate post-procedure. There was no significant change in serum creatinine level. This data shows the acute procedural safety and short term efficacy of RSDN using modified externally irrigated solid tip RFA catheter. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

[Effect of Cordyceps sinensis powder on renal oxidative stress and mitochondria functions in 5/6 nephrectomized rats].

PubMed

Zhang, Ming-hui; Pan, Ming-ming; Ni, Hai-feng; Chen, Jun-feng; Xu, Mn; Gong, Yu-xiang; Chen, Ping-sheng; Liu, Bi-cheng

2015-04-01

To observe the effect of Cordyceps sinensis (CS) powder on renal oxidative stress and mitochondria functions in 5/6 nephrectomized rats, and to primarily explore its possible mechanisms. Totally 30 male Sprague-Dawley rats were divided into the sham-operation group, the model group, and the treatment group by random digit table, 10 in each group. A chronic kidney disease (CKD) rat model was prepared by one step 5/6 nephrectomy. Rats in the treatment group were intragastrically administered with CS powder solution at the daily dose of 2 g/kg, once per day. Equal volume of double distilled water was intragastrically administered to rats in the sham-operation group and the model group. All medication lasted for 12 weeks. The general condition of rats, their body weight, blood pressure, 24 h proteinuria, urinary N-acetyl-β-D-glucosaminidase (NAG), serum creatinine (SCr) , and blood urea nitrogen (BUN) were assessed before surgery, at week 2, 4, 6, 8, 10, and 10 after surgery. Pathological changes of renal tissues were observed under light microscope. Morphological changes of mitochondria in renal tubular epithelial cells were observed under transmission electron microscope. Activities of antioxidant enzymes including reduced glutathione (GSH), manganese superoxide dismutase (MnSOD), and malondialdehyde (MDA) in fresh renal tissue homogenate were detected. Mitochondria of renal tissues were extracted to detect levels of mitochondrial membrane potential and changes of reactive oxygen species (ROS). And expressions of cytochrome-C (Cyto-C) and prohibitin in both mitochondria and cytoplasm of the renal cortex were also measured by Western blot. (1) Compared with the sham-operation group, body weight was significantly decreased at week 2 (P <0. 01), but blood pressure increased at week 4 (P <0. 05) in the model group. Compared with the model group, body weight was significantly increased at week 12 (P <0. 01), but blood pressure decreased at week 8 (P < 0. 01) in the treatment group. (2) Compared with the sham-operation group, 24 h proteinuria, urinary NAG, blood SCr and BUN significantly increased in the model group (all P <0. 01). Compared with the model group, blood and urinary biochemical indices all significantly decreased in the treatment group (all P <0. 01). (3) Results of pathological renal scoring: Glomerular sclerosis index, scoring for tubulointerstitial fibrosis, degree of tubulointerstitial inflammatory infiltration were all obviously higher in the model group than in the sham-operation group (all P <0. 01). All the aforesaid indices were more obviously improved in the treatment group than in the model group (all P <0. 01). (4) Compared with the sham-operation group, activities of MnSOD and GSH-Px were significantly reduced, but MDA contents obviously increased in the renal cortex of the model group (all P <0. 01). Compared with the model group, activities of MnSOD and GSH-Px obviously increased (P <0. 05, P <0. 01), but MDA contents obviously decreased in the renal cortex of the treatment group (P <0. 01). (5) Compared with the sham-operation group, the mitochondrial membrane potential significantly decreased, but ROS levels significantly increased in the model group (all P <0.01). Compared with the model group, mitochondrial transmembrane potential increased in the treatment group, thereby inhibiting the tendency of increased production of ROS (both P < 0. 01). (6) Results of Western blot showed that, compared with the sham-operation group, expression levels of mitochondrial Cyto-C and Prohibitin were significantly reduced in the renal cortex (P <0. 01), but significantly elevated in the cytoplasm of the model group (P <0. 01). Compared with the model group, each index was obviously improved in the treatment group with statistical difference (P <0. 05, P <0. 01). CS powder had renal protection, and its mechanism might partially depend on in- hibition of oxidative stress and protection for mitochondria.

Denervation of nerve terminals in renal arteries: one-year follow-up of interventional treatment of arterial hypertension.

PubMed

Bartuś, Krzysztof; Sadowski, Jerzy; Kapelak, Bogusław; Litwinowicz, Radosław; Zajdel, Wojciech; Godlewski, Jacek; Bartuś, Magdalena; Zmudka, Krzysztof; Chrapusta, Anna; Konstanty-Kalandyk, Janusz; Węgrzyn, Piotr; Sobotka, Paul A

2014-01-01

Arterial hypertension is the most common cardiovascular system disease, affecting nearly one billion people worldwide. Despite the widespread use of antihypertensive medications, in some groups of patients an optimal blood pressure (BP) cannot be achieved. To assess BP reduction in patients with resistant hypertension after a catheter-based renal sympathetic denervation procedure and to report vascular and kidney safety in one-year follow-up. Twenty eight patients with diagnosed resistant hypertension (median age 52.02 years, range 42-72) underwent percutaneous catheter-based renal denervation of nerve terminals in renal arteries. Arterial angiography and procedure of ablation was performed by Symplicity catheters and generator provided by Ardian (currently Medtronic Inc., USA). Mean BP value before ablation was [mm Hg]: systolic 176.6, diastolic 100.28 and pulse pressure 73.4. After the procedure, reductions in the value of BP were reported [mm Hg]: systolic 154.8/152.54; diastolic 90.2/89.8, pulse pressure 64.66/62.73, respectively in nine-month and one-year follow-up. All results were statistically significant. No complications during one year observation were observed. Percutaneous renal artery ablation procedure effectively reduces systolic BP, diastolic BP, and pulse pressure. No vascular or renal complications in any of the patients were observed. The results of a Polish research group showed no significant differences compared to the results obtained in the international studies Symplicity I and Symplicity II.

Global- and renal-specific sympathoinhibition in aldosterone hypertension.

PubMed

Lohmeier, Thomas E; Liu, Boshen; Hildebrandt, Drew A; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

2015-06-01

Recent technology for chronic electric activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12 μg/kg per day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ≈40% and arterial pressure by 16±2 mm Hg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mm Hg) was diminished (≈55%) during aldosterone hypertension when compared with control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. © 2015 American Heart Association, Inc.

Global and Renal-Specific Sympathoinhibition in Aldosterone Hypertension

PubMed Central

Lohmeier, Thomas E.; Liu, Boshen; Hildebrandt, Drew A.; Cates, Adam W.; Georgakopoulos, Dimitrios; Irwin, Eric D.

2015-01-01

Recent technology for chronic electrical activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12µg/kg/day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ~ 40% and arterial pressure by 16±2 mmHg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mmHg) was diminished (~ 55%) during aldosterone hypertension as compared to control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. PMID:25895584

Randomized comparison of renal denervation versus intensified pharmacotherapy including spironolactone in true-resistant hypertension: six-month results from the Prague-15 study.

PubMed

Rosa, Ján; Widimský, Petr; Toušek, Petr; Petrák, Ondřej; Čurila, Karol; Waldauf, Petr; Bednář, František; Zelinka, Tomáš; Holaj, Robert; Štrauch, Branislav; Šomlóová, Zuzana; Táborský, Miloš; Václavík, Jan; Kociánová, Eva; Branny, Marian; Nykl, Igor; Jiravský, Otakar; Widimský, Jiří

2015-02-01

This prospective, randomized, open-label multicenter trial evaluated the efficacy of catheter-based renal denervation (Symplicity, Medtronic) versus intensified pharmacological treatment including spironolactone (if tolerated) in patients with true-resistant hypertension. This was confirmed by 24-hour ambulatory blood pressure monitoring after excluding secondary hypertension and confirmation of adherence to therapy by measurement of plasma antihypertensive drug levels before enrollment. One-hundred six patients were randomized to renal denervation (n=52), or intensified pharmacological treatment (n=54) with baseline systolic blood pressure of 159±17 and 155±17 mm Hg and average number of drugs 5.1 and 5.4, respectively. A significant reduction in 24-hour average systolic blood pressure after 6 months (-8.6 [95% cofidence interval: -11.8, -5.3] mm Hg; P<0.001 in renal denervation versus -8.1 [95% cofidence interval: -12.7, -3.4] mm Hg; P=0.001 in pharmacological group) was observed, which was comparable in both groups. Similarly, a significant reduction in systolic office blood pressure (-12.4 [95% cofidence interval: -17.0, -7.8] mm Hg; P<0.001 in renal denervation versus -14.3 [95% cofidence interval: -19.7, -8.9] mm Hg; P<0.001 in pharmacological group) was present. Between-group differences in change were not significant. The average number of antihypertensive drugs used after 6 months was significantly higher in the pharmacological group (+0.3 drugs; P<0.001). A significant increase in serum creatinine and a parallel decrease of creatinine clearance were observed in the pharmacological group; between-group difference were borderline significant. The 6-month results of this study confirmed the safety of renal denervation. In conclusion, renal denervation achieved reduction of blood pressure comparable with intensified pharmacotherapy. © 2014 American Heart Association, Inc.

Effects of a human recombinant alkaline phosphatase on renal hemodynamics, oxygenation and inflammation in two models of acute kidney injury.

PubMed

Peters, Esther; Ergin, Bülent; Kandil, Asli; Gurel-Gurevin, Ebru; van Elsas, Andrea; Masereeuw, Rosalinde; Pickkers, Peter; Ince, Can

2016-12-15

Two small clinical trials indicated that administration of bovine intestinal alkaline phosphatase (AP) improves renal function in critically ill patients with sepsis-associated acute kidney injury (AKI), for which the mechanism of action is not completely understood. Here, we investigated the effects of a newly developed human recombinant AP (recAP) on renal oxygenation and hemodynamics and prevention of kidney damage and inflammation in two in vivo AKI models. To induce AKI, male Wistar rats (n=18) were subjected to renal ischemia (30min) and reperfusion (I/R), or sham-operated. In a second model, rats (n=18) received a 30min infusion of lipopolysaccharide (LPS; 2.5mg/kg), or saline, and fluid resuscitation. In both models, recAP (1000U/kg) was administered intravenously (15min before reperfusion, or 90min after LPS). Following recAP treatment, I/R-induced changes in renal blood flow, renal vascular resistance and oxygen delivery at early, and cortical microvascular oxygen tension at late reperfusion were no longer significantly affected. RecAP did not influence I/R-induced effects on mean arterial pressure. During endotoxemia, recAP treatment did not modulate the LPS-induced changes in systemic hemodynamics and renal oxygenation. In both models, recAP did exert a clear renal protective anti-inflammatory effect, demonstrated by attenuated immunostaining of inflammatory, tubular injury and pro-apoptosis markers. Whether this renal protective effect is sufficient to improve outcome of patients suffering from sepsis-associated AKI is being investigated in a large clinical trial. Copyright © 2016. Published by Elsevier Inc.

Protective response in renal transplantation: no clinical or molecular differences between open and laparoscopic donor nephrectomy

PubMed Central

Machado, Christiano; Malheiros, Denise Maria Avancini Costa; Adamy, Ari; Santos, Luiz Sergio; da Silva Filho, Agenor Ferreira; Nahas, William Carlos; Lemos, Francine Brambate Carvalhinho

2013-01-01

OBJECTIVE: Prolonged warm ischemia time and increased intra-abdominal pressure caused by pneumoperitoneum during a laparoscopic donor nephrectomy could enhance renal ischemia reperfusion injury. For this reason, laparoscopic donor nephrectomy may be associated with a slower graft function recovery. However, an adequate protective response may balance the ischemia reperfusion damage. This study investigated whether laparoscopic donor nephrectomy modified the protective response of renal tissue during kidney transplantation. METHODS: Patients undergoing live renal transplantation were prospectively analyzed and divided into two groups based on the donor nephrectomy approach used: 1) the control group, recipients of open donor nephrectomy (n = 29), and 2) the study group, recipients of laparoscopic donor nephrectomy (n = 26). Graft biopsies were obtained at two time points: T-1 = after warm ischemia time and T+1 = 45 minutes after kidney reperfusion. The samples were analyzed by immunohistochemistry for the Bcl-2 and HO-1 proteins and by real-time polymerase chain reaction for the mRNA expression of Bcl-2, HO-1 and vascular endothelial growth factor. RESULTS: The area under the curve for creatinine and delayed graft function were similar in both the laparoscopic and open groups. There was no difference in the protective gene expression between the laparoscopic donor nephrectomy and open donor nephrectomy groups. The protein expression of HO-1 and Bcl-2 were similar between the open and laparoscopic groups. Furthermore, the gene expression of B-cell lymphoma 2 correlated with the warm ischemia time in the open group (p = 0.047) and that of vascular endothelial growth factor with the area under the curve for creatinine in the laparoscopic group (p = 0.01). CONCLUSION: The postoperative renal function and protective factor expression were similar between laparoscopic donor nephrectomy and open donor nephrectomy. These findings ensure laparoscopic donor nephrectomy utilization in renal transplantation. PMID:23778338

The renal effects of droxidopa are maintained in propranolol treated cirrhotic rats.

PubMed

Rodríguez, Sarai; Raurell, Imma; Ezkurdia, Nahia; Augustin, Salvador; Esteban, Rafael; Genescà, Joan; Martell, María

2015-02-01

Droxidopa improves hemodynamic and renal alterations of cirrhotic rats without changing portal pressure. We aimed to evaluate the effects of a combined treatment with droxidopa and non-selective beta-blockers or statins in order to decrease portal pressure, while maintaining droxidopa beneficial effects. Acute studies combining droxidopa with carvedilol, propranolol or atorvastatin in four-week bile-duct ligated (BDL) rats and a chronic study combining propranolol and droxidopa for 5 days in CCl4 -cirrhotic rats were performed. Hemodynamic values were registered and biochemical parameters from blood and urine samples analyzed. Bile-duct ligated rats treated with carvedilol + droxidopa showed no changes in mean arterial pressure (MAP) and portal pressure (PP) compared to vehicles. Atorvastatin + droxidopa combination also failed to reduce PP, but maintained the beneficial increase in MAP and superior mesenteric artery resistance (SMAR) and decrease in blood flow (SMABF) caused by droxidopa. In contrast, the acute administration of propranolol + droxidopa significantly reduced PP maintaining a mild increase in MAP and improving, in an additive way, the decrease in SMABF and increase in SMAR caused by droxidopa. This combination also preserved droxidopa diuretic effect. When chronically administered to CCl4 -cirrhotic rats, propranolol + droxidopa caused a decrease in PP, a significant reduction in SMABF and an increase in SMAR. The combination did not alter liver function and droxidopa diuretic and natriuretic effect, and even improved free water clearance. Droxidopa could be effective for the renal alterations of cirrhotic patients on propranolol therapy and the combination of both drugs may balance the adverse effects of each treatment. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Renal function following three distinct weight loss dietary strategies during 2 years of a randomized controlled trial.

PubMed

Tirosh, Amir; Golan, Rachel; Harman-Boehm, Ilana; Henkin, Yaakov; Schwarzfuchs, Dan; Rudich, Assaf; Kovsan, Julia; Fiedler, Georg M; Blüher, Matthias; Stumvoll, Michael; Thiery, Joachim; Stampfer, Meir J; Shai, Iris

2013-08-01

This study addressed the long-term effect of various diets, particularly low-carbohydrate high-protein, on renal function on participants with or without type 2 diabetes. In the 2-year Dietary Intervention Randomized Controlled Trial (DIRECT), 318 participants (age, 51 years; 86% men; BMI, 31 kg/m(2); mean estimated glomerular filtration rate [eGFR], 70.5 mL/min/1.73 m(2); mean urine microalbumin-to-creatinine ratio, 12:12) with serum creatinine <176 μmol/L (eGFR ≥ 30 mL/min/1.73 m(2)) were randomized to low-fat, Mediterranean, or low-carbohydrate diets. The 2-year compliance was 85%, and the proportion of protein intake significantly increased to 22% of energy only in the low-carbohydrate diet (P < 0.05 vs. low-fat and Mediterranean). We examined changes in urinary microalbumin and eGFR, estimated by Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration formulas. Significant (P < 0.05 within groups) improvements in eGFR were achieved in low-carbohydrate (+5.3% [95% CI 2.1-8.5]), Mediterranean (+5.2% [3.0-7.4]), and low-fat diets (+4.0% [0.9-7.1]) with similar magnitude (P > 0.05) across diet groups. The increased eGFR was at least as prominent in participants with (+6.7%) or without (+4.5%) type 2 diabetes or those with lower baseline renal function of eGFR <60 mL/min/1.73 m(2) (+7.1%) versus eGFR ≥ 60 mL/min/1.73 m(2) (+3.7%). In a multivariable model adjusted for age, sex, diet group, type 2 diabetes, use of ACE inhibitors, 2-year weight loss, and change in protein intake (confounders and univariate predictors), only a decrease in fasting insulin (β = -0.211; P = 0.004) and systolic blood pressure (β = -0.25; P < 0.001) were independently associated with increased eGFR. The urine microalbumin-to-creatinine ratio improved similarly across the diets, particularly among participants with baseline sex-adjusted microalbuminuria, with a mean change of -24.8 (P < 0.05). A low-carbohydrate diet is as safe as Mediterranean or low-fat diets in preserving/improving renal function among moderately obese participants with or without type 2 diabetes, with baseline serum creatinine <176 μmol/L. Potential improvement is likely to be mediated by weight loss-induced improvements in insulin sensitivity and blood pressure.

Renal Function Following Three Distinct Weight Loss Dietary Strategies During 2 Years of a Randomized Controlled Trial

PubMed Central

Tirosh, Amir; Golan, Rachel; Harman-Boehm, Ilana; Henkin, Yaakov; Schwarzfuchs, Dan; Rudich, Assaf; Kovsan, Julia; Fiedler, Georg M.; Blüher, Matthias; Stumvoll, Michael; Thiery, Joachim; Stampfer, Meir J.; Shai, Iris

2013-01-01

OBJECTIVE This study addressed the long-term effect of various diets, particularly low-carbohydrate high-protein, on renal function on participants with or without type 2 diabetes. RESEARCH DESIGN AND METHODS In the 2-year Dietary Intervention Randomized Controlled Trial (DIRECT), 318 participants (age, 51 years; 86% men; BMI, 31 kg/m2; mean estimated glomerular filtration rate [eGFR], 70.5 mL/min/1.73 m2; mean urine microalbumin-to-creatinine ratio, 12:12) with serum creatinine <176 μmol/L (eGFR ≥30 mL/min/1.73 m2) were randomized to low-fat, Mediterranean, or low-carbohydrate diets. The 2-year compliance was 85%, and the proportion of protein intake significantly increased to 22% of energy only in the low-carbohydrate diet (P < 0.05 vs. low-fat and Mediterranean). We examined changes in urinary microalbumin and eGFR, estimated by Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration formulas. RESULTS Significant (P < 0.05 within groups) improvements in eGFR were achieved in low-carbohydrate (+5.3% [95% CI 2.1–8.5]), Mediterranean (+5.2% [3.0–7.4]), and low-fat diets (+4.0% [0.9–7.1]) with similar magnitude (P > 0.05) across diet groups. The increased eGFR was at least as prominent in participants with (+6.7%) or without (+4.5%) type 2 diabetes or those with lower baseline renal function of eGFR <60 mL/min/1.73 m2 (+7.1%) versus eGFR ≥60 mL/min/1.73 m2 (+3.7%). In a multivariable model adjusted for age, sex, diet group, type 2 diabetes, use of ACE inhibitors, 2-year weight loss, and change in protein intake (confounders and univariate predictors), only a decrease in fasting insulin (β = −0.211; P = 0.004) and systolic blood pressure (β = −0.25; P < 0.001) were independently associated with increased eGFR. The urine microalbumin-to-creatinine ratio improved similarly across the diets, particularly among participants with baseline sex-adjusted microalbuminuria, with a mean change of −24.8 (P < 0.05). CONCLUSIONS A low-carbohydrate diet is as safe as Mediterranean or low-fat diets in preserving/improving renal function among moderately obese participants with or without type 2 diabetes, with baseline serum creatinine <176 μmol/L. Potential improvement is likely to be mediated by weight loss–induced improvements in insulin sensitivity and blood pressure. PMID:23690533

Lower Blood Pressure-Induced Renal Hypoperfusion Promotes Cisplatin-Induced Nephrotoxicity.

PubMed

Mizuno, Tomohiro; Hayashi, Takahiro; Shimabukuro, Yuka; Murase, Maho; Hayashi, Hiroki; Ishikawa, Kazuhiro; Takahashi, Kazuo; Yuzawa, Yukio; Yamada, Shigeki; Nagamatsu, Tadashi

2016-01-01

Cisplatin-induced nephrotoxicity primarily occurs in the proximal tubules, and tubular injuries reduce glomerular filtration rates. Lower blood pressure causes renal hypoperfusion, which promotes ischemic acute kidney injury (AKI). Our study examined the relationship between lower blood pressure-induced renal hypoperfusion and cisplatin-induced nephrotoxicity. The relationship between cisplatin use and hypoalbuminemia is not clear. This study consisted of Japanese patients who received cisplatin as the first-line chemotherapy at Fujita Health University Hospital from April 2006 to December 2012. Hypoalbuminemia was defined as serum albumin levels ≤3.5 mg/dl. Patients who experienced lower blood pressure during chemotherapy were included in the lower blood pressure group (n = 229), and those who did not were included in the normal blood pressure group (n = 743). Total cisplatin dose in the normal blood pressure and lower blood pressure groups was 58.9 ± 23.8 and 55.0 ± 20.4 mg/m2, respectively. The rate of severe nephrotoxicity was higher and overall survival was shorter in the lower blood pressure group than in the normal blood pressure group. In a multivariable analysis, lower blood pressure significantly correlated with hypoalbuminemia. To prevent ischemic AKI, nutrition and cachexia controlling are important parts of cancer treatment. © 2016 S. Karger AG, Basel.

Association between pulmonary function and renal function: findings from China and Australia.

PubMed

Yu, Dahai; Chen, Tao; Cai, Yamei; Zhao, Zhanzheng; Simmons, David

2017-05-01

The relationship between obstructive lung function and impaired renal function is unclear. This study investigated the dose-response relationship between obstructive lung function and impaired renal function. Two independent cross-sectional studies with representative sampling were applied. 1454 adults from rural Victoria, Australia (1298 with normal renal function, 156 with impaired renal function) and 5824 adults from Nanjing, China (4313 with normal renal function, 1511 with impaired renal function). Pulmonary function measurements included forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Estimated glomerular filtration rate (eGFR), and impaired renal function marked by eGFR <60 mL/min/1.73m 2 were used as outcome. eGFR increased linearly with FEV1 in Chinese participants and with FVC in Australians. A non-linear relationship with peaked eGFR was found for FEV1 at 2.65 L among Australians and for FVC at 2.78 L among Chinese participants, respectively. A non-linear relationship with peaked eGFR was found for the predicted percentage value of forced expiratory volume in 1 s (PFEV1) at 81-82% and for the predicted percentage value of forced vital capacity (PFVC) at 83-84% among both Chinese and Australian participants, respectively. The non-linear dose-response relationships between lung capacity measurements (both for FEV1 and FVC) and risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 3.05 L both for FEV1 and FVC, respectively. The non-linear relationship between PFEV and PVC and the risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 76-77% for PFEV1 and 79-80% for PFVC, respectively. In both Australian and Chinese populations, the risk of impaired renal function increased both with FEV1 and FVC below 3.05 L, with PFEV1 below 76-77% or with PFVC below 79-80%, respectively. Obstructive lung function was associated with increased risk of reduced renal function. The screen for impaired renal function in patients with obstructive lung disease might be useful to ensure there was no impaired renal function before the commencement of potentially nephrotoxic medication where indicated (eg diuretics).

Contribution of anemia and hypertension to left ventricular hypertrophy during the initial 2 years after renal transplantation.

PubMed

Ibernon, M; Moreso, F; Ruiz-Majoral, A; Sarrias, X; Sarrias, M; Grinyó, J M; Serón, D

2011-01-01

Cardiovascular disease is the main cause of mortality after renal transplantation. Left ventricular hypertrophy (LVH) is considered to be an independent predictor of cardiovascular events. The main risk factors for LVH after renal transplantation are anemia and hypertension. In hypertensive and renal transplant patients, ambulatory blood pressure monitoring (ABPM) has been demonstrated to be more closely related to LVH than office blood pressure. The aim of this study has to evaluate LVH after renal transplantation, particularly its association with measures derived from ABPM and cardiovascular risk factors. Between March 2005 and October 2006, we recruited 101 consecutive kidney transplant patients to calculate left ventricular mass index (LVMI) by echocardiography at 3, 12, and 24 months. Hypertension was evaluated by office blood pressure measurements at 3, 12, and 24 months and also by ABPM at 3 months. Clinical and laboratory data were recorded during the study. From 3 to 24 months LVMI was reduced from 129 ± 29 g/m(2) to 121 ± 34 g/m(2) (P = .0089). Multivariate stepwise regression analysis showed independent predictors of LVMI at 3 months to be hemoglobin at 1 month, day systolic blood pressure (SBP) derived from ABPM and donor age (R = .50, P < .001). The independent predictors of LVMI at 12 months were day SBP derived from ABPM, hemoglobin at 1 month, and proteinuria at 12 months (R = .55, P < .001). Office SBP at 12 months, proteinuria at 24 months, patient age and night diastolic blood pressure derived from ABPM at 3 months were independent predictors of LVMI at 24 months (R = .71, P < .001). We observed a significant reduction in LVMI after renal transplantation. The main contributors to LVMI were anemia and elevated blood pressures measured by ABPM. Copyright © 2011 Elsevier Inc. All rights reserved.

Arterial stiffness, body fat compartments, central hemodynamics, renal function and left atrial size.

PubMed

Katulska, Katarzyna; Milewska, Agata; Wykretowicz, Mateusz; Krauze, Tomasz; Przymuszala, Dagmara; Piskorski, Jaroslaw; Stajgis, Marek; Guzik, Przemyslaw; Wysocki, Henryk; Wykrętowicz, Andrzej

2013-10-01

Left atrial (LA) size is an important predictor of stroke, death, and atrial fibrillation. It was demonstrated recently that body fat, arterial stiffness and renal functions are associated with LA diameter. However, data are lacking for comprehensive assessments of all these risk factors in a single population. Therefore, the aim of the present study was to investigate the association between LA size and different fat descriptors, central hemodynamics, arterial stiffness, and renal function in healthy subjects. To this end, body fat percentage, abdominal, subcutaneous fat, and general descriptors of body fat were estimated in 162 healthy subjects (mean age 51 years). Echocardiography was performed to assess LA diameter. Arterial stiffness and peripheral and central hemodynamics were estimated by digital volume pulse analysis and pulse wave analysis. Glomerular filtration rate was estimated by MDRD formula. There were significant (p < 0.05) bivariate correlations between LA diameter and all descriptors of body fat (except subcutaneous fat). Arterial stiffness and estimated glomerular filtration rate (eGFR) were also significantly correlated with LA size. Multiple regression analysis including all significant confounders, such as sex, mean arterial pressure, arterial stiffness, eGFR and body fat descriptors, explained 35% of variance in LA diameter. In conclusion, the present study reveals significant, independent relationships between body fat, arterial stiffness, and LA size.

Novel RAAS agonists and antagonists: clinical applications and controversies.

PubMed

Romero, Cesar A; Orias, Marcelo; Weir, Matthew R

2015-04-01

The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure homeostasis and vascular injury and repair responses. The RAAS was originally thought to be an endocrine system critically important in regulating blood pressure homeostasis. Yet, important local forms of the RAAS have been described in many tissues, which are mostly independent of the systemic RAAS. These systems have been associated with diverse physiological functions, but also with inflammation, fibrosis and target-organ damage. Pharmacological modulation of the RAAS has brought about important advances in preventing morbidity and mortality associated with cardiovascular disease. Yet, traditional RAAS blockers such as angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) only reduce the risk of disease progression in patients with established cardiovascular or renal disease by ∼20% compared with other therapies. As more components of the RAAS are described, other potential therapeutic targets emerge, which could provide improved cardiovascular and renal protection beyond that provided by an ACE inhibitor or ARB. This Review summarizes the present and future pharmacological manipulation of this important system.

Increased release of norepinephrine and dopamine from canine kidney during bilateral carotid occlusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, T.; Hjemdahl, P.; DiBona, G.F.

1987-02-01

The renal overflow of norepinephrine (NE) and dopamine (DA) to plasma from the innervated kidney was studied at rest and during sympathetic nervous system activation by bilateral carotid artery occlusion (BCO) in vagotomized dogs under barbiturate or barbiturate/nitrous oxide anesthesia. BCO elevated arterial pressure and the arterial plasma concentration of NE, DA, and epinephrine (Epi). Renal vascular resistance (renal arterial pressure kept constant) increased by 15 +/- 7% and the net renal venous outflows (renal veno-arterial concentration difference x renal plasma flow) of NE and DA were enhanced. To obtain more correct estimates of the renal contribution to the renalmore » venous catecholamine outflow, they corrected for the renal extraction of arterial catecholamines, assessed as the extractions of (/sup 3/H)NE, (/sup 3/H)DA, or endogenous Epi. The (/sup 3/H)NE corrected renal NE overflow to plasma increased from 144 +/- 40 to 243 +/- 64 pmol-min/sup -1/ during BCO, which, when compared with a previous study of the (/sup 3/H)NE corrected renal NE overflow to plasma evoked by electrical renal nerve stimulation, corresponds to a 40% increase in nerve impulse frequency from approx. 0.6 Hz. If the renal catecholamine extraction was not taken into account the effect of BCO was underestimated. The renal DA overflow to plasma was about one-fifth of the NE overflow both at rest and during BCO, indicating that there was no preferential activation of noradrenergic or putative dopaminergic nerves by BCO.« less

Renal biopsy practice: What is the gold standard?

PubMed

Brachemi, Soumeya; Bollée, Guillaume

2014-11-06

Renal biopsy (RB) is useful for diagnosis and therapy guidance of renal diseases but incurs a risk of bleeding complications of variable severity, from transitory haematuria or asymptomatic hematoma to life-threatening hemorrhage. Several risk factors for complications after RB have been identified, including high blood pressure, age, decreased renal function, obesity, anemia, low platelet count and hemostasis disorders. These should be carefully assessed and, whenever possible, corrected before the procedure. The incidence of serious complications has become low with the use of automated biopsy devices and ultrasound guidance, which is currently the "gold standard" procedure for percutaneous RB. An outpatient biopsy may be considered in a carefully selected population with no risk factor for bleeding. However, controversies persist on the duration of observation after biopsy, especially for native kidney biopsy. Transjugular RB and laparoscopic RB represent reliable alternatives to conventional percutaneous biopsy in patients at high risk of bleeding, although some factors limit their use. This aim of this review is to summarize the issues of complications after RB, assessment of hemorrhagic risk factors, optimal biopsy procedure and strategies aimed to minimize the risk of bleeding.

Intrarenal hemodynamic changes following acute partial renal arterial occlusion.

DOT National Transportation Integrated Search

1965-10-01

Both an increase and a decrease in total renal vascular resistance, following a period of total renal artery occlusion, have been reported from this laboratory. The duration of the occlusive period and height of the perfusion pressure were found to p...

Renal Function Descriptors in Neonates: Which Creatinine-Based Formula Best Describes Vancomycin Clearance?

PubMed

Bhongsatiern, Jiraganya; Stockmann, Chris; Yu, Tian; Constance, Jonathan E; Moorthy, Ganesh; Spigarelli, Michael G; Desai, Pankaj B; Sherwin, Catherine M T

2016-05-01

Growth and maturational changes have been identified as significant covariates in describing variability in clearance of renally excreted drugs such as vancomycin. Because of immaturity of clearance mechanisms, quantification of renal function in neonates is of importance. Several serum creatinine (SCr)-based renal function descriptors have been developed in adults and children, but none are selectively derived for neonates. This review summarizes development of the neonatal kidney and discusses assessment of the renal function regarding estimation of glomerular filtration rate using renal function descriptors. Furthermore, identification of the renal function descriptors that best describe the variability of vancomycin clearance was performed in a sample study of a septic neonatal cohort. Population pharmacokinetic models were developed applying a combination of age-weight, renal function descriptors, or SCr alone. In addition to age and weight, SCr or renal function descriptors significantly reduced variability of vancomycin clearance. The population pharmacokinetic models with Léger and modified Schwartz formulas were selected as the optimal final models, although the other renal function descriptors and SCr provided reasonably good fit to the data, suggesting further evaluation of the final models using external data sets and cross validation. The present study supports incorporation of renal function descriptors in the estimation of vancomycin clearance in neonates. © 2015, The American College of Clinical Pharmacology.

Prognostic Significance of Creatinine Increases During an Acute Heart Failure Admission in Patients With and Without Residual Congestion: A Post Hoc Analysis of the PROTECT Data.

PubMed

Metra, Marco; Cotter, Gad; Senger, Stefanie; Edwards, Christopher; Cleland, John G; Ponikowski, Piotr; Cursack, Guillermo C; Milo, Olga; Teerlink, John R; Givertz, Michael M; O'Connor, Christopher M; Dittrich, Howard C; Bloomfield, Daniel M; Voors, Adriaan A; Davison, Beth A

2018-05-01

The importance of a serum creatinine increase, traditionally considered worsening renal function (WRF), during admission for acute heart failure has been recently debated, with data suggesting an interaction between congestion and creatinine changes. In post hoc analyses, we analyzed the association of WRF with length of hospital stay, 30-day death or cardiovascular/renal readmission and 90-day mortality in the PROTECT study (Placebo-Controlled Randomized Study of the Selective A1 Adenosine Receptor Antagonist Rolofylline for Patients Hospitalized With Acute Decompensated Heart Failure and Volume Overload to Assess Treatment Effect on Congestion and Renal Function). Daily creatinine changes from baseline were categorized as WRF (an increase of 0.3 mg/dL or more) or not. Daily congestion scores were computed by summing scores for orthopnea, edema, and jugular venous pressure. Of the 2033 total patients randomized, 1537 patients had both available at study day 14. Length of hospital stay was longer and 30-day cardiovascular/renal readmission or death more common in patients with WRF. However, these were driven by significant associations in patients with concomitant congestion at the time of assessment of renal function. The mean difference in length of hospital stay because of WRF was 3.51 (95% confidence interval, 1.29-5.73) more days ( P =0.0019), and the hazard ratio for WRF on 30-day death or heart failure hospitalization was 1.49 (95% confidence interval, 1.06-2.09) times higher ( P =0.0205), in significantly congested than nonsignificantly congested patients. A similar trend was observed with 90-day mortality although not statistically significant. In patients admitted for acute heart failure, WRF defined as a creatinine increase of ≥0.3 mg/dL was associated with longer length of hospital stay, and worse 30- and 90-day outcomes. However, effects were largely driven by patients who had residual congestion at the time of renal function assessment. URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00328692 and NCT00354458. © 2018 American Heart Association, Inc.

Assessment of the relationship between renal volume and renal function after minimally-invasive partial nephrectomy: the role of computed tomography and nuclear renal scan.

PubMed

Bertolo, Riccardo; Fiori, Cristian; Piramide, Federico; Amparore, Daniele; Barrera, Monica; Sardo, Diego; Veltri, Andrea; Porpiglia, Francesco

2018-05-14

To evaluate the correlation between the loss of renal function as assessed by Tc99MAG-3 renal scan and the loss of renal volume as calculated by volumetric assessment on CT-scan in patients who underwent minimally-invasive partial nephrectomy (PN). PN prospectively-maintained database was retrospectively queried for patients who underwent minimally-invasive PN (2012-2017) for renal mass

Does the serum uric acid level have any relation to arterial stiffness or blood pressure in adults with congenital renal agenesis and/or hypoplasia?

PubMed

Yazici, Raziye; Guney, İbrahim; Altintepe, Lutfullah; Yazici, Mehmet

2017-01-01

The relationship between serum uric acid and arterial stiffness or blood pressure is not clear. The serum uric acid level and its association with cardiovascular risk is not well known in patients with reduced renal mass. We aimed to investigate the relation between serum uric acid levels and arterial stiffness and also blood pressure in patients with congenital renal agenesis and/or hypoplasia. In this single center, cross-sectional study, a total of 55 patients (39 (% 70.9) with unilateral small kidney and 16 (%29.1) with renal agenesis) were included. The median age was 35 (21-50) years. The study population was divided into tertiles of serum uric acid (according to 2.40-3.96, 3.97-5.10, and 5.11-9.80 mg/dl cut-off values of serum uric acid levels). Official and 24-h ambulatory non-invasive blood pressures of all patients were measured. The arterial stiffness was assessed by pulse wave velocity (PWV). PWV values were increased from first to third tertile (5.5 ± 0.6, 5.7 ± 0.8, 6.1 ± 0.7, respectively), but this gradual increase between tertiles did not reach significance. Linear regression analyses showed a positive correlation between serum uric acid levels and PWV (β = 0.40, p = 0.010), but no correlation was found between uric acid and daytime systolic blood pressure (β = 0.24, p = 0.345). In congenital renal agenesis/hypoplasia, the serum uric acid level was positively correlated with arterial stiffness, but there was no correlation with blood pressure.

CNS sites activated by renal pelvic epithelial sodium channels (ENaCs) in response to hypertonic saline in awake rats.

PubMed

Goodwill, Vanessa S; Terrill, Christopher; Hopewood, Ian; Loewy, Arthur D; Knuepfer, Mark M

2017-05-01

In some patients, renal nerve denervation has been reported to be an effective treatment for essential hypertension. Considerable evidence suggests that afferent renal nerves (ARN) and sodium balance play important roles in the development and maintenance of high blood pressure. ARN are sensitive to sodium concentrations in the renal pelvis. To better understand the role of ARN, we infused isotonic or hypertonic NaCl (308 or 500mOsm) into the left renal pelvis of conscious rats for two 2hours while recording arterial pressure and heart rate. Subsequently, brain tissue was analyzed for immunohistochemical detection of the protein Fos, a marker for neuronal activation. Fos-immunoreactive neurons were identified in numerous sites in the forebrain and brainstem. These areas included the nucleus tractus solitarius (NTS), the lateral parabrachial nucleus, the paraventricular nucleus of the hypothalamus (PVH) and the supraoptic nucleus (SON). The most effective stimulus was 500mOsm NaCl. Activation of these sites was attenuated or prevented by administration of benzamil (1μM) or amiloride (10μM) into the renal pelvis concomitantly with hypertonic saline. In anesthetized rats, infusion of hypertonic saline but not isotonic saline into the renal pelvis elevated ARN activity and this increase was attenuated by simultaneous infusion of benzamil or amiloride. We propose that renal pelvic epithelial sodium channels (ENaCs) play a role in activation of ARN and, via central visceral afferent circuits, this system modulates fluid volume and peripheral blood pressure. These pathways may contribute to the development of hypertension. Copyright © 2016 Elsevier B.V. All rights reserved.

Dietary Sodium and Health: More Than Just Blood Pressure

PubMed Central

Farquhar, William B.; Edwards, David G.; Jurkovitz, Claudine T.; Weintraub, William S.

2016-01-01

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt-sensitivity of BP varies widely, but certain subgroups tend to be more salt-sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood, but may involve alterations in renal function, fluid volume, fluid regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, we address these issues and the epidemiological literature relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. We also provide information and strategies for reducing dietary sodium. PMID:25766952

Mechanism of postarrhythmic renal vasoconstriction in the anesthetized dog.

PubMed

Katholi, R E; Oparil, S; Urthaler, F; James, T N

1979-07-01

The mechanism of postarrhythmic renal vasoconstriction was studied in 28 dogs anesthetized with pentobarbital sodium (30 mg/kg i.v.). Rapid atrial or ventricular pacing or induction of atrial fibrilation were used to produce at least 20% prompt decrease in cardiac output and mean arterial blood pressure. Return to control cardiac output and blood pressure occurred within 3 minutes after cessation of the arrhythmia, but renal blood flow remained significantly decreased (26%) with gradual recovery by 17.7 +/- 6.6 min. Infusion of phentolamine (0.25 mg/min) into the renal artery, intravenous hexamethonium (l mg/kg), adrenal demedullation, or cooling the cervical vagi prevented postarrhythmic renal vasoconstriction. In contrast, renal denervation, intravenous bretylium (10 mg/kg), intravenous atropine (0.5 mg/kg) or intrarenal SQ 20881 (0.20 mg/min) has no effect on postarrhythmic renal vasoconstriction. Intravenous propranolol (0.5 mg/kg) intensified postarrhythmic renal vasoconstriction. These data suggested that the postarrhythmic renal vasoconstrictive response required intact vagi and was due to alpha adrenergic stimulation by adrenal catecholamines. However, femoral arterial catecholamine levels were not elevated above control during postarrhythmic renal vasoconstriction. We therefore sought local vascular pathways by which catecholamines might reach the kidneys. An adrenorenal vascular network was found in each dog. Collection of catecholamines from these vessels during postarrhythmic renal vasoconstriction in six dogs revealed catecholamine concentrations threefold higher than simultaneously collected femoral arterial catecholamines levels. Because ligation of these vessels abolished postarrhythmic renal vasoconstriction in each dog, we conclude that postarrhythmic renal vasconstriction is due to adrenal catecholamines reaching the kidneys through an adreno-renal vascular network and that the response requires intact vagi.

Protective effect of Euterpe oleracea Mart (açaí) extract on programmed changes in the adult rat offspring caused by maternal protein restriction during pregnancy.

PubMed

de Bem, Graziele Freitas; da Costa, Cristiane Aguiar; de Oliveira, Paola Raquel Braz; Cordeiro, Viviane Silva Cristino; Santos, Izabelle Barcellos; de Carvalho, Lenize Costa Reis Marins; Souza, Marcelo Augusto Vieira; Ognibene, Dayane Texeira; Daleprane, Julio Beltrame; Sousa, Pergentino José Cunha; Resende, Angela Castro; de Moura, Roberto Soares

2014-09-01

This study examined the effect of açaí (Euterpe oleracea Mart.) seed extract (ASE) on cardiovascular and renal alterations in adult offspring, whose mothers were fed a low-protein (LP) diet during pregnancy. Four groups of rats were fed: control diet (20% protein); ASE (200 mg/kg per day); and LP (6% protein); LP + ASE (6% protein + ASE) during pregnancy. After weaning, all male offspring were fed a control diet and sacrificed at 4 months old. We evaluated the blood pressure, vascular function, serum and urinary parameters, plasma and kidney oxidative damage, and antioxidant activity and renal structural changes. Hypertension and the reduced acetylcholine-induced vasodilation in the LP group were prevented by ASE. Serum levels of urea, creatinine and fractional excretion of sodium were increased in LP and reduced in LP + ASE. ASE improved nitrite levels and the superoxide dismutase and glutathione peroxidase activity in LP, with a corresponding decrease of malondialdehyde and protein carbonyl levels. Kidney volume and glomeruli number were reduced and glomerular volume was increased in LP. These renal alterations were prevented by ASE. Treatment of protein-restricted dams with ASE provides protection from later-life hypertension, oxidative stress, renal functional and structural changes, probably through a vasodilator and antioxidant activity. © 2014 Royal Pharmaceutical Society.

Renal transplantation in Indo-Asian patients in the UK.

PubMed

Dooldeniya, M D; Dupont, P J; He, X; Johnson, R J; Joshi, T; Basra, R; Johnston, A; Warrens, A N

2006-04-01

Membership of some ethnic groups has an effect on renal transplant outcome but little is known about the impact of Indo-Asian ethnicity, despite this group's high incidence of renal disease. We compared outcomes in Indo-Asians and Caucasians at the Hammersmith Hospital (Indo-Asians, N = 46; Caucasians, N = 90), in the Long-Term Efficacy and Safety Surveillance (LOTESS) database of cyclosporin-treated renal transplant recipients (Indo-Asians, N = 254; Caucasians, N = 4262) and the National Transplant Database held by UK Transplant (Indo-Asians, N = 459; Caucasians, N = 4831). The baseline demographic and co-morbid characteristics of the two ethnic groups were comparable, save for more diabetes in the Indo-Asian community. Following transplantation, the incidence of delayed graft function and steroid-resistant acute rejection were also comparable, as were graft and patient survival (out to 5 years) and graft function. In addition, post-transplant blood pressure, levels of cholesterol and triglycerides and exposure to corticosteroids and cyclosporin were comparable. However, when patients who were not diabetic before transplantation were studied separately, there was an increased incidence of diabetes in the Indo-Asian community (Hammersmith data: Indo-Asians 10.9% vs. Caucasians 3.3%, p = 0.02; LOTESS data Indo-Asians 5.5% vs. Caucasians 1.6%, p < 0.0001). Subsequent management of this group should pursue immunosuppressive regimens less likely to impair post-transplant glucose tolerance.

Role of angiotensin II in dynamic renal blood flow autoregulation of the conscious dog

PubMed Central

Just, Armin; Ehmke, Heimo; Wittmann, Uwe; Kirchheim, Hartmut R

2002-01-01

The influence of angiotensin II (ANGII) on the dynamic characteristics of renal blood flow (RBF) was studied in conscious dogs by testing the response to a step increase in renal artery pressure (RAP) after a 60 s period of pressure reduction (to 50 mmHg) and by calculating the transfer function between physiological fluctuations in RAP and RBF. During the RAP reduction, renal vascular resistance (RVR) decreased and upon rapid restoration of RAP, RVR returned to baseline with a characteristic time course: within the first 10 s, RVR rose rapidly by 40 % of the initial change (first response, myogenic response). A second rise began after 20–30 s and reached baseline after an overshoot at 40 s (second response, tubuloglomerular feedback (TGF)). Between both responses, RVR rose very slowly (plateau). The transfer function had a low gain below 0.01 Hz (high autoregulatory efficiency) and two corner frequencies at 0.026 Hz (TGF) and at 0.12 Hz (myogenic response). Inhibition of angiotensin converting enzyme (ACE) lowered baseline RVR, but not the minimum RVR at the end of the RAP reduction (autoregulation-independent RVR). Both the first and second response were reduced, but the normalised level of the plateau (balance between myogenic response, TGF and possible slower mechanisms) and the transfer gain below 0.01 Hz were not affected. Infusion of ANGII after ramipril raised baseline RVR above the control condition. The first and second response and the transfer gain at both corner frequencies were slightly augmented, but the normalised level of the plateau was not affected. It is concluded that alterations of plasma ANGII within a physiological range do not modulate the relative contribution of the myogenic response to the overall short-term autoregulation of RBF. Consequently, it appears that ANGII augments not only TGF, but also the myogenic response. PMID:11773325

The effect of obesity and type 1 diabetes on renal function in children and adolescents.

PubMed

Franchini, Simone; Savino, Alessandra; Marcovecchio, M Loredana; Tumini, Stefano; Chiarelli, Francesco; Mohn, Angelika

2015-09-01

Early signs of renal complications can be common in youths with type 1 diabetes (T1D). Recently, there has been an increasing interest in potential renal complications associated with obesity, paralleling the epidemics of this condition, although there are limited data in children. Obese children and adolescents present signs of early alterations in renal function similar to non-obese peers with T1D. Eighty-three obese (age: 11.6 ± 3.0 yr), 164 non-obese T1D (age: 12.4 ± 3.2 yr), and 71 non-obese control (age: 12.3 ± 3.2 yr) children and adolescents were enrolled in the study. Anthropometric parameters and blood pressure were measured. Renal function was assessed by albumin excretion rate (AER), serum cystatin C, creatinine and estimated glomerular filtration rate (e-GFR), calculated using the Bouvet's formula. Obese and non-obese T1D youths had similar AER [8.9(5.9-10.8) vs. 8.7(5.9-13.1) µg/min] and e-GFR levels (114.8 ± 19.6 vs. 113.4 ± 19.1 mL/min), which were higher than in controls [AER: 8.1(5.9-8.7) µg/min, e-GFR: 104.7 ± 18.9 mL/min]. Prevalence of microalbuminuria and hyperfiltration was similar between obese and T1D youths and higher than their control peers (6.0 vs. 8.0 vs. 0%, p = 0.02; 15.9 vs. 15.9 vs. 4.3%, p = 0.03, respectively). Body mass index (BMI) z-score was independently related to e-GFR (r = 0.328; p < 0.001), and AER (r = 0.138; p = 0.017). Hemoglobin A1c (HbA1c) correlated with AER (r = 0.148; p = 0.007) but not with eGFR (r = 0.041; p = 0.310). Obese children and adolescents show early alterations in renal function, compared to normal weight peers, and they have similar renal profiles than age-matched peers with T1D. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Systolic hypertension: an increasing clinical challenge in Asia

PubMed Central

Park, Jeong Bae; Kario, Kazuomi; Wang, Ji-Guang

2015-01-01

Systolic hypertension, the predominant form of hypertension in patients aged over 50–60 years, is a growing health issue as the Asian population ages. Elevated systolic blood pressure is mainly caused by arterial stiffening, resulting from age-related vascular changes. Elevated systolic pressure increases the risk of cardiovascular disease, mortality and renal function decline, and this risk may increase at lower systolic pressure levels in Asian than Western subjects. Hence, effective systolic pressure lowering is particularly important in Asians yet blood pressure control remains inadequate despite the availability of numerous antihypertensive medications. Reasons for poor blood pressure control include low awareness of hypertension among health-care professionals and patients, under-treatment, and tolerability problems with antihypertensive drugs. Current antihypertensive treatments also lack effects on the underlying vascular pathology of systolic hypertension, so novel drugs that address the pathophysiology of arterial stiffening are needed for optimal management of systolic hypertension and its cardiovascular complications. PMID:25503845

The effects of medicinal plants on renal function and blood pressure in diabetes mellitus.

PubMed

Musabayane, C T

2012-09-01

Diabetes mellitus is one of the most common chronic global diseases affecting children and adolescents in both the developed and developing nations. The major types of diabetes mellitus are type 1 and type 2, the former arising from inadequate production of insulin due to pancreatic β-cell dysfunction, and the latter from reduced sensitivity to insulin in the target tissues and/or inadequate insulin secretion. Sustained hyperglycaemia is a common result of uncontrolled diabetes and, over time, can damage the heart, eyes, kidneys and nerves, mainly through deteriorating blood vessels supplying the organs. Microvascular (retinopathy and nephropathy) and macrovascular (atherosclerotic) disorders are the leading causes of morbidity and mortality in diabetic patients. Therefore, emphasis on diabetes care and management is on optimal blood glucose control to avert these adverse outcomes. Studies have demonstrated that diabetic nephropathy is associated with increased cardiovascular mortality. In general, about one in three patients with diabetes develops end-stage renal disease (ESRD) which proceeds to diabetic nephropathy (DN), the principal cause of significant morbidity and mortality in diabetes. Hypertension, a well-established major risk factor for cardiovascular disease contributes to ESRD in diabetes. Clinical evidence suggests that there is no effective treatment for diabetic nephropathy and prevention of the progression of diabetic nephropathy. However, biomedical evidence indicates that some plant extracts have beneficial effects on certain processes associated with reduced renal function in diabetes mellitus. On the other hand, other plant extracts may be hazardous in diabetes, as reports indicate impairment of renal function. This article outlines therapeutic and pharmacological evidence supporting the potential of some medicinal plants to control or compensate for diabetes-associated complications, with particular emphasis on kidney function and hypertension.

Mechanisms for renal blood flow control early in diabetes as revealed by chronic flow measurement and transfer function analysis.

PubMed

Bell, Tracy D; DiBona, Gerald F; Wang, Ying; Brands, Michael W

2006-08-01

The purpose of this study was to establish the roles of the myogenic response and the TGF mechanism in renal blood flow (RBF) control at the very earliest stages of diabetes. Mean arterial pressure (MAP) and RBF were measured continuously, 18 h/d, in uninephrectomized control and diabetic rats, and transfer function analysis was used to determine the dynamic autoregulatory efficiency of the renal vasculature. During the control period, MAP averaged 91 +/- 0.5 and 89 +/- 0.4 mmHg, and RBF averaged 8.0 +/- 0.1 and 7.8 +/- 0.1 ml/min in the control and diabetic groups, respectively. Induction of diabetes with streptozotocin caused a marked and progressive increase in RBF in the diabetic rats, averaging 10 +/- 6% above control on day 1 of diabetes and 22 +/- 3 and 34 +/- 1% above control by the end of diabetes weeks 1 and 2. MAP increased approximately 9 mmHg during the 2 wk in the diabetic rats, and renal vascular resistance decreased. Transfer function analysis revealed significant increases in gain to positive values over the frequency ranges of both the TGF and myogenic mechanisms, beginning on day 1 of diabetes and continuing through day 14. These very rapid increases in RBF and transfer function gain suggest that autoregulation is impaired at the very onset of hyperglycemia in streptozotocin-induced type 1 diabetes and may play an important role in the increase in RBF and GFR in diabetes. Together with previous reports of decreases in chronically measured cardiac output and hindquarter blood flow, this suggests that there may be differential effects of diabetes on RBF versus nonrenal BF control.

Chronic kidney disease and poor outcomes in ischemic stroke: is impaired cerebral autoregulation the missing link?

PubMed

Castro, Pedro; Azevedo, Elsa; Rocha, Isabel; Sorond, Farzaneh; Serrador, Jorge M

2018-03-02

Chronic kidney disease increases stroke incidence and severity but the mechanisms behind this cerebro-renal interaction are mostly unexplored. Since both vascular beds share similar features, microvascular dysfunction could be the possible missing link. Therefore, we examined the relationship between renal function and cerebral autoregulation in the early hours post ischemia and its impact on outcome. We enrolled 46 ischemic strokes (middle cerebral artery). Dynamic cerebral autoregulation was assessed by transfer function (coherence, phase and gain) of spontaneous blood pressure oscillations to blood flow velocity within 6 h from symptom-onset. Estimated glomerular filtration rate (eGFR) was calculated. Hemorrhagic transformation (HT) and white matter lesions (WML) were collected from computed tomography performed at presentation and 24 h. Outcome was evaluated with modified Rankin Scale at 3 months. High gain (less effective autoregulation) was correlated with lower eGFR irrespective of infarct side (p < 0.05). Both lower eGFR and higher gain correlated with WML grade (p < 0.05). Lower eGFR and increased gain, alone and in combination, progressively reduced the odds of a good functional outcome [ipsilateral OR = 4.39 (CI95% 3.15-25.6), p = 0.019; contralateral OR = 8.15 (CI95% 4.15-15.6), p = 0.002] and increased risk of HT [ipsilateral OR = 3.48 (CI95% 0.60-24.0), p = 0.132; contralateral OR = 6.43 (CI95% 1.40-32.1), p = 0.034]. Lower renal function correlates with less effective dynamic cerebral autoregulation in acute ischemic stroke, both predicting a bad outcome. The evaluation of serum biomarkers of renal dysfunction could have interest in the future for assessing cerebral microvascular risk and relationship with stroke complications.

Significance of mast cell renal infiltration in patients with anti-GBM nephritis.

PubMed

Wu, Xiao-Mei; Zhang, Yi-Yan; Zhang, Ming-Chao; Zhang, Li-Hua; Zeng, Cai-Hong; Liu, Zhi-Hong; Tang, Zheng

2016-07-01

To investigate the role of mast cells (MCs) renal infiltration in the progression of human anti-GBM nephritis, 38 patients diagnosed with anti-GBM nephritis were enrolled. Renal biopsies were performed. Immunohistochemistry was conducted to detect MCs in renal tissues. Patients were divided into group 1 (MCs <50 mm(-2), n = 18) and group 2 (MCs ≥50 mm(-2), n = 20) according to the infiltrating renal MC count. The clinical-pathological indices were compared. And, correlation between MCs and the clinical-pathological indices was analyzed. Patients of group 2 had more severe renal dysfunctions, expressed as higher levels of serum creatinine (SCr 8.95 ± 3.66 vs. 4.75 ± 2.73 mg/dL, p < 0.001), urine retinol-binding protein (RBP 29.8 ± 13.9 vs. 15.7 ± 11.5 mg/dL, p = 0.005), and lower urinary osmotic pressure. Pathologically, patients of group 2 had a higher percentage of fibrous/fibrocellular crescents (66.7 ± 21.9 vs. 47.0 ± 33.6%, p = 0.037) but a lower percentage of cellular crescents. More CD8 (268 mm(-2) vs. 180 mm(-2), p = 0.045) and CD68 (268 mm(-2) vs. 180 mm(-2), p = 0.045) positive cells infiltrating the interstitium were observed in group 2. Furthermore, renal MCs correlated significantly with the total number of crescents and the tubular interstitial CD8 and CD68 positive cells. And, the number of MCs was associated with the histological types. The renal function was significantly different between the two groups at presentation. However, at 3 and 6 month follow-up, the patient outcome was associated with the histological types. Our study showed that MC infiltrations were associated with chronic lesions in anti-GBM nephritis and may be involved in the loss of renal function with pathological changes.

The renal blood flow reserve in healthy humans and patients with atherosclerotic renovascular disease measured by positron emission tomography using [15O]H2O.

PubMed

Päivärinta, Johanna; Koivuviita, Niina; Oikonen, Vesa; Iida, Hidehiro; Liukko, Kaisa; Manner, Ilkka; Löyttyniemi, Eliisa; Nuutila, Pirjo; Metsärinne, Kaj

2018-06-11

Microvascular function plays an important role in ARVD (atherosclerotic renovascular disease). RFR (renal flow reserve), the capacity of renal vasculature to dilate, is known to reflect renal microvascular function. In this pilot study, we assessed PET (positron emission tomography)-based RFR values of healthy persons and renal artery stenosis patients. Seventeen patients with ARVD and eight healthy subjects were included in the study. Intravenous enalapril 1 mg was used as a vasodilatant, and the maximum response (blood pressure and RFR) to it was measured at 40 min. Renal perfusion was measured by means of oxygen-15-labeled water PET. RFR was calculated as a difference of stress flow and basal flow and was expressed as percent [(stress blood flow - basal blood flow)/basal blood flow] × 100%. RFR of the healthy was 22%. RFR of the stenosed kidneys of bilateral stenosis patients (27%) was higher than that of the stenosed kidneys of unilateral stenosis patients (15%). RFR of the contralateral kidneys of unilateral stenosis patients was 21%. There was no difference of statistical significance between RFR values of ARVD subgroups or between ARVD subgroups and the healthy. In the stenosed kidneys of unilateral ARVD patients, stenosis grade of the renal artery correlated negatively with basal (p = 0.04) and stress flow (p = 0.02). Dispersion of RFR values was high. This study is the first to report [ 15 O]H 2 O PET-based RFR values of healthy subjects and ARVD patients in humans. The difference between RFR values of ARVD patients and the healthy did not reach statistical significance perhaps because of high dispersion of RFR values. [ 15 O]H 2 O PET is a valuable non-invasive and quantitative method to evaluate renal blood flow though high dispersion makes imaging challenging. Larger studies are needed to get more information about [ 15 O]H 2 O PET method in evaluation of renal blood flow.

Effect of high protein vs high carbohydrate intake on insulin sensitivity, body weight, hemoglobin A1c, and blood pressure in patients with type 2 diabetes mellitus.

PubMed

Sargrad, Karin R; Homko, Carol; Mozzoli, Maria; Boden, Guenther

2005-04-01

Extremely low carbohydrate/high protein diets are popular methods of weight loss. Compliance with these diets is poor and long-term effectiveness and the safety of these diets for patients with type 2 diabetes is not known. The objective of the current study was to evaluate effects of less extreme changes in carbohydrate or protein diets on weight, insulin sensitivity, glycemic control, cardiovascular risk factors (blood pressure, lipid levels), and renal function in obese inner-city patients with type 2 diabetes. Study patients were admitted to the General Clinical Research Center for 24 hours for initial tests including a hyperinsulinemic-euglycemic clamp (for measurement of insulin sensitivity), bioelectrical impedance analysis (BIA) and anthropometric measurements (for assessment of body composition), indirect calorimetry (for measurement of REE), electronic blood pressure monitoring, and blood chemistries to measure blood lipids levels along with renal and hepatic functions. Six patients with type 2 diabetes (five women and one man) were randomly assigned to the high-protein diet (40% carbohydrate, 30% protein, 30% fat) and six patients (four women and two men) to the high-carbohydrate diet (55% carbohydrate, 15% protein, 30% fat). All patients returned to the General Clinical Research Center weekly for monitoring of food records; dietary compliance; and measurements of body weight, blood pressure, and blood glucose. After 8 weeks on these diets, all patients were readmitted to the General Clinical Research Center for the same series of tests. Twelve study patients were taught to select either the high-protein or high-carbohydrate diet and were followed for 8 weeks. Insulin sensitivity, hemoglobin A1c, weight, and blood pressure were measured. Statistical significance was assessed using two-tailed Student's t tests and two-way repeated measures analysis of variance. Both the high-carbohydrate and high-protein groups lost weight (-2.2+/-0.9 kg, -2.5+/-1.6 kg, respectively, P <.05) and the difference between the groups was not significant (P =.9). In the high-carbohydrate group, hemoglobin A1c decreased (from 8.2% to 6.9%, P <.03), fasting plasma glucose decreased (from 8.8 to 7.2 mmol/L, P <.02), and insulin sensitivity increased (from 12.8 to 17.2 micromol/kg/min, P <.03). No significant changes in these parameters occurred in the high-protein group, instead systolic and diastolic blood pressures decreased (-10.5+/-2.3 mm Hg, P =.003 and -18+/-9.0 mm Hg, P <.05, respectively). After 2 months on these hypocaloric diets, each diet had either no or minimal effects on lipid levels (total cholesterol, low-density lipoprotein, high-density lipoprotein), renal (blood urea nitrogen, serum creatinine), or hepatic function (aspartate aminotransferase, alanine aminotransferase, bilirubin).

Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats.

PubMed

Li, Peng; Huang, Pei-Pei; Yang, Yun; Liu, Chi; Lu, Yan; Wang, Fang; Sun, Wei; Kong, Xiang-Qing

2017-01-01

Li P, Huang P, Yang Y, Liu C, Lu Y, Wang F, Sun W, Kong X. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats. J Appl Physiol 122: 121-129, 2017. First published October 14, 2016; doi:10.1152/japplphysiol.01019.2015-Sympathetic activity is enhanced in patients with essential or secondary hypertension, as well as in various hypertensive animal models. Therapeutic targeting of sympathetic activation is considered an effective antihypertensive strategy. We hypothesized that renal sympathetic denervation (RSD) attenuates hypertension and improves vascular remodeling and renal disease in the 2-kidney, 1-clip (2K1C) rat model. Rats underwent 2K1C modeling or sham surgery; then rats underwent RSD or sham surgery 4 wk later, thus resulting in four groups (normotensive-sham, normotensive-RSD, 2K1C-sham, and 2K1C-RSD). Norepinephrine was measured by ELISA. Echocardiography was used to assess heart function. Fibrosis and apoptosis were assessed by Masson and TUNEL staining. Changes in mean arterial blood pressure in response to hexamethonium and plasma norepinephrine levels were used to evaluate basal sympathetic nerve activity. The 2K1C modeling success rate was 86.8%. RSD reversed the elevated systolic blood pressure induced by 2K1C, but had no effect on body weight. Compared with rats in the 2K1C-sham group, rats in the 2K1C-RSD group showed lower left ventricular mass/body weight ratio, interventricular septal thickness in diastole, left ventricular end-systolic diameter, and left ventricular posterior wall thickness in systole, whereas fractional shortening and ejection fraction were higher. Right kidney apoptosis and left kidney hypertrophy were not changed by RSD. Arterial fibrosis was lower in animals in the 2K1C-RSD group compared with those in the 2K1C-sham group. RSD reduced plasma norepinephrine and basal sympathetic activity in rats in the 2K1C-RSD group compared with rats in the 2K1C-sham group. These results suggest a possible clinical efficacy of RSD for renovascular hypertension. The effects of renal sympathetic denervation (RSD) on hypertension, cardiac function, vascular fibrosis, and renal apoptosis were studied in the 2K1C rat model. Results showed that RSD attenuated hypertension, improved vascular remodeling, and reduced vascular fibrosis through decreased sympathetic activity in the 2K1C rat model, but it did not change the kidney size, renal apoptosis, or renal caspase-3 expression. These results could suggest possible clinical efficacy of RSD for renovascular hypertension. Copyright © 2017 the American Physiological Society.

Presence of transient hydronephrosis immediately after surgery has a limited influence on renal function 1 year after ileal neobladder construction.

PubMed

Narita, Takuma; Hatakeyama, Shingo; Koie, Takuya; Hosogoe, Shogo; Matsumoto, Teppei; Soma, Osamu; Yamamoto, Hayato; Yoneyama, Tohru; Tobisawa, Yuki; Yoneyama, Takahiro; Hashimoto, Yasuhiro; Ohyama, Chikara

2017-08-31

Urinary tract obstruction and postoperative hydronephrosis are risk factor for renal function deterioration after orthotopic ileal neobladder construction. However, reports of relationship between transient hydronephrosis and renal function are limited. We assess the influence of postoperative transient hydronephrosis on renal function in patients with orthotopic ileal neobladder construction. Between January 2006 and June 2013, we performed radical cystectomy in 164 patients, and 101 received orthotopic ileal neobladder construction. This study included data available from 64 patients with 128 renal units who were enrolled retrospectively. The hydronephrosis grade of each renal unit scored 0-4. The patients were divided into 4 groups according to the grade of hydronephrosis: control, low, intermediate, and high. The grade of postoperative hydronephrosis was compared with renal function 1 month and 1 year after surgery. There were no significant differences in renal function before surgery between groups. One month after surgery, the presence of hydronephrosis was significantly associated with decreased renal function. However, 1 year after urinary diversion hydronephrosis grades were improved significantly, and renal function was comparable between groups. Postoperative hydronephrosis at 1 month had no significant influence on renal function 1 year after ileal neobladder construction. Limitations include retrospective design, short follow-up periods, and a sample composition. The presence of transient hydronephrosis immediately after surgery may have limited influence on renal function 1 year after ileal neobladder construction.

M‐Atrial Natriuretic Peptide and Nitroglycerin in a Canine Model of Experimental Acute Hypertensive Heart Failure: Differential Actions of 2 cGMP Activating Therapeutics

PubMed Central

McKie, Paul M.; Cataliotti, Alessandro; Ichiki, Tomoko; Sangaralingham, S. Jeson; Chen, Horng H.; Burnett, John C.

2014-01-01

Background Systemic hypertension is a common characteristic in acute heart failure (HF). This increasingly recognized phenotype is commonly associated with renal dysfunction and there is an unmet need for renal enhancing therapies. In a canine model of HF and acute vasoconstrictive hypertension we characterized and compared the cardiorenal actions of M‐atrial natriuretic peptide (M‐ANP), a novel particulate guanylyl cyclase (pGC) activator, and nitroglycerin, a soluble guanylyl cyclase (sGC) activator. Methods and Results HF was induced by rapid RV pacing (180 beats per minute) for 10 days. On day 11, hypertension was induced by continuous angiotensin II infusion. We characterized the cardiorenal and humoral actions prior to, during, and following intravenous M‐ANP (n=7), nitroglycerin (n=7), and vehicle (n=7) infusion. Mean arterial pressure (MAP) was reduced by M‐ANP (139±4 to 118±3 mm Hg, P<0.05) and nitroglycerin (137±3 to 116±4 mm Hg, P<0.05); similar findings were recorded for pulmonary wedge pressure (PCWP) with M‐ANP (12±2 to 6±2 mm Hg, P<0.05) and nitroglycerin (12±1 to 6±1 mm Hg, P<0.05). M‐ANP enhanced renal function with significant increases (P<0.05) in glomerular filtration rate (38±4 to 53±5 mL/min), renal blood flow (132±18 to 236±23 mL/min), and natriuresis (11±4 to 689±37 mEq/min) and also inhibited aldosterone activation (32±3 to 23±2 ng/dL, P<0.05), whereas nitroglycerin had no significant (P>0.05) effects on these renal parameters or aldosterone activation. Conclusions Our results advance the differential cardiorenal actions of pGC (M‐ANP) and sGC (nitroglycerin) mediated cGMP activation. These distinct renal and aldosterone modulating actions make M‐ANP an attractive therapeutic for HF with concomitant hypertension, where renal protection is a key therapeutic goal. PMID:24385449

M-atrial natriuretic peptide and nitroglycerin in a canine model of experimental acute hypertensive heart failure: differential actions of 2 cGMP activating therapeutics.

PubMed

McKie, Paul M; Cataliotti, Alessandro; Ichiki, Tomoko; Sangaralingham, S Jeson; Chen, Horng H; Burnett, John C

2014-01-02

Systemic hypertension is a common characteristic in acute heart failure (HF). This increasingly recognized phenotype is commonly associated with renal dysfunction and there is an unmet need for renal enhancing therapies. In a canine model of HF and acute vasoconstrictive hypertension we characterized and compared the cardiorenal actions of M-atrial natriuretic peptide (M-ANP), a novel particulate guanylyl cyclase (pGC) activator, and nitroglycerin, a soluble guanylyl cyclase (sGC) activator. HF was induced by rapid RV pacing (180 beats per minute) for 10 days. On day 11, hypertension was induced by continuous angiotensin II infusion. We characterized the cardiorenal and humoral actions prior to, during, and following intravenous M-ANP (n=7), nitroglycerin (n=7), and vehicle (n=7) infusion. Mean arterial pressure (MAP) was reduced by M-ANP (139 ± 4 to 118 ± 3 mm Hg, P<0.05) and nitroglycerin (137 ± 3 to 116 ± 4 mm Hg, P<0.05); similar findings were recorded for pulmonary wedge pressure (PCWP) with M-ANP (12 ± 2 to 6 ± 2 mm Hg, P<0.05) and nitroglycerin (12 ± 1 to 6 ± 1 mm Hg, P<0.05). M-ANP enhanced renal function with significant increases (P<0.05) in glomerular filtration rate (38 ± 4 to 53 ± 5 mL/min), renal blood flow (132 ± 18 to 236 ± 23 mL/min), and natriuresis (11 ± 4 to 689 ± 37 mEq/min) and also inhibited aldosterone activation (32 ± 3 to 23 ± 2 ng/dL, P<0.05), whereas nitroglycerin had no significant (P>0.05) effects on these renal parameters or aldosterone activation. Our results advance the differential cardiorenal actions of pGC (M-ANP) and sGC (nitroglycerin) mediated cGMP activation. These distinct renal and aldosterone modulating actions make M-ANP an attractive therapeutic for HF with concomitant hypertension, where renal protection is a key therapeutic goal.

Renal denervation with a percutaneous bipolar radiofrequency balloon catheter in patients with resistant hypertension: 6-month results from the REDUCE-HTN clinical study.

PubMed

Sievert, Horst; Schofer, Joachim; Ormiston, John; Hoppe, Uta C; Meredith, Ian T; Walters, Darren L; Azizi, Michel; Diaz-Cartelle, Juan; Cohen-Mazor, Meital

2015-02-01

To evaluate the safety and efficacy of the balloon-based bipolar Vessix Renal Denervation System in treating patients with resistant hypertension. In this prospective, multicentre, single-arm study, 146 patients (age 58.6±10.5 years; 61% men) with office systolic blood pressure (BP) ≥160 mmHg despite ≥3 antihypertensive medications at maximally tolerated doses were treated with the Vessix System. Efficacy endpoints were reductions in office and 24-hour ambulatory systolic and diastolic BPs at six months. Acute and long-term safety, with a focus on the renal artery and estimated glomerular filtration rate (eGFR), were assessed. Baseline office and ambulatory BPs were 182.4±18.4/100.2±14.0 mmHg and 153.0±15.1/87.5±13.2 mmHg, respectively. No acute renal artery injury requiring intervention or serious periprocedural cardiovascular events occurred. At six months, office BP was reduced by 24.7±22.1/10.3±12.7 mmHg (p<0.0001) and ambulatory BP was reduced by 8.4±14.4/5.9±9.1 mmHg (N=69; p<0.0001). Twenty-six patients (18%) achieved an office systolic BP <140 mmHg. One patient had renal artery stenosis which required stenting. Mean eGFR remained stable. Renal artery denervation with the Vessix System reduced both office and ambulatory BP at six months in patients with resistant hypertension. Renal artery safety and renal function results are favourable.

Chronic treatment with atrial natriuretic peptide in spontaneously hypertensive rats: beneficial renal effects and sex differences.

PubMed

Romero, Mariana; Caniffi, Carolina; Bouchet, Gonzalo; Costa, María A; Elesgaray, Rosana; Arranz, Cristina; Tomat, Analía L

2015-01-01

The aim of this study was to investigate the effects of chronic treatment with atrial natriuretic peptide (ANP) on renal function, nitric oxide (NO) system, oxidative stress, collagen content and apoptosis in kidneys of spontaneously hypertensive rats (SHR), as well as sex-related differences in the response to the treatment. 10 week-old male and female SHR were infused with ANP (100 ng/h/rat) or saline (NaCl 0.9%) for 14 days (subcutaneous osmotic pumps). Systolic blood pressure (SBP) was recorded and diuresis and natriuresis were determined. After treatment, renal NO synthase (NOS) activity and eNOS expression were evaluated. Thiobarbituric acid-reactive substances (TBARS), glutathione concentration and glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were determined in the kidney. Collagen was identified in renal slices by Sirius red staining and apoptosis by Tunel assay. Female SHR showed lower SBP, oxidative stress, collagen content and apoptosis in kidney, and higher renal NOS activity and eNOS protein content, than males. ANP lowered SBP, increased diuresis, natriuresis, renal NOS activity and eNOS expression in both sexes. Renal response to ANP was more marked in females than in males. In kidney, ANP reduced TBARS, renal collagen content and apoptosis, and increased glutathione concentration and activity of GPx and SOD enzymes in both sexes. Female SHR exhibited less organ damage than males. Chronic ANP treatment would ameliorate hypertension and end-organ damage in the kidney by reducing oxidative stress, increasing NO-system activity, and diminishing collagen content and apoptosis, in both sexes.

Chronic Treatment with Atrial Natriuretic Peptide in Spontaneously Hypertensive Rats: Beneficial Renal Effects and Sex Differences

PubMed Central

Romero, Mariana; Caniffi, Carolina; Bouchet, Gonzalo; Costa, María A.; Elesgaray, Rosana; Arranz, Cristina; Tomat, Analía L.

2015-01-01

Objective The aim of this study was to investigate the effects of chronic treatment with atrial natriuretic peptide (ANP) on renal function, nitric oxide (NO) system, oxidative stress, collagen content and apoptosis in kidneys of spontaneously hypertensive rats (SHR), as well as sex-related differences in the response to the treatment. Methods 10 week-old male and female SHR were infused with ANP (100 ng/h/rat) or saline (NaCl 0.9%) for 14 days (subcutaneous osmotic pumps). Systolic blood pressure (SBP) was recorded and diuresis and natriuresis were determined. After treatment, renal NO synthase (NOS) activity and eNOS expression were evaluated. Thiobarbituric acid-reactive substances (TBARS), glutathione concentration and glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were determined in the kidney. Collagen was identified in renal slices by Sirius red staining and apoptosis by Tunel assay. Results Female SHR showed lower SBP, oxidative stress, collagen content and apoptosis in kidney, and higher renal NOS activity and eNOS protein content, than males. ANP lowered SBP, increased diuresis, natriuresis, renal NOS activity and eNOS expression in both sexes. Renal response to ANP was more marked in females than in males. In kidney, ANP reduced TBARS, renal collagen content and apoptosis, and increased glutathione concentration and activity of GPx and SOD enzymes in both sexes. Conclusions Female SHR exhibited less organ damage than males. Chronic ANP treatment would ameliorate hypertension and end-organ damage in the kidney by reducing oxidative stress, increasing NO-system activity, and diminishing collagen content and apoptosis, in both sexes. PMID:25774801

Ansys Fluent versus Sim Vascular for 4-D patient-specific computational hemodynamics in renal arteries

NASA Astrophysics Data System (ADS)

Mumbaraddi, Avinash; Yu, Huidan (Whitney); Sawchuk, Alan; Dalsing, Michael

2015-11-01

The objective of this clinical-need driven research is to investigate the effect of renal artery stenosis (RAS) on the blood flow and wall shear stress in renal arteries through 4-D patient-specific computational hemodynamics (PSCH) and search for possible critical RASs that significantly alter the pressure gradient across the stenosis by manually varying the size of RAS from 50% to 95%. The identification of the critical RAS is important to understand the contribution of RAS to the overall renal resistance thus appropriate clinical therapy can be determined in order to reduce the hypertension. Clinical CT angiographic data together with Doppler Ultra sound images of an anonymous patient are used serving as the required inputs of the PSCH. To validate the PSCH, we use both Ansys Fluent and Sim Vascular and compare velocity, pressure, and wall-shear stress under identical conditions. Renal Imaging Technology Development Program (RITDP) Grant.

Impact of pretransplant renal function on survival after liver transplantation.

PubMed

Gonwa, T A; Klintmalm, G B; Levy, M; Jennings, L S; Goldstein, R M; Husberg, B S

1995-02-15

To determine the effect of pretransplant liver function on survival following orthotopic liver transplantation and to quantify the effects of cyclosporine administration on long-term renal function in patients undergoing liver transplant, we performed an analysis of a prospectively maintained database. Data from 569 consecutive patients undergoing liver transplantation alone who were treated with CsA for immunosuppression were used for this study. Actuarial graft and patient survival rates were calculated using Kaplan-Meier statistics. Glomerular filtration rates, serum creatinine, and the use of various immunosuppressives were analyzed for this study. The initial analysis demonstrated that patients presenting for liver transplant with hepatorenal syndrome have a significantly decreased acturial patient survival after liver transplant at 5 years compared with patients without hepatorenal syndrome (60% vs. 68%, P < 0.03). Patients with hepatorenal syndrome recovered their renal function after liver transplant. Patients who had hepatorenal syndrome were sicker and required longer stays in the intensive care unit, longer hospitalizations, and more dialysis treatments after transplantation compared with patients who did not have hepatorenal syndrome. The incidence of end-stage renal disease after liver transplantation in patients who had hepatorenal syndrome was 7%, compared with 2% in patients who did not have hepatorenal syndrome. To more fully examine the effect of pretransplant renal function on posttransplant survival, the non-hepatorenal syndrome patients were divided into quartiles depending upon their pretransplant renal function. The patients with the lowest pretransplant renal function had the same survival as the patients with the highest pretransplant renal function. In addition, there was no increased incidence of acute or chronic rejection in any of the groups. The patients with the lower pretransplant renal function were treated with more azathioprine to maintain renal function and had a negligible decrease in glomerular filtration rate following transplant. Conversely, patients with the highest level of renal function pretransplant had a 40% decline in renal function in the first year, but maintained stable renal function up to 4 years after transplant. We conclude that pretransplant renal function other than hepato-renal syndrome has no effect on patient survival after orthotopic liver transplant. Renal function after liver transplant is stable after an initial decline, despite continued administration of CsA.(ABSTRACT TRUNCATED AT 400 WORDS)

[Atherosclerotic renovascular hypertension: clinical findings and results of treatment over 15 years].

PubMed

Alfonzo, J P; Rosario, M N; Ugarte, C; Banasco, J; Fraxedas, R; Lahera, J

2003-01-01

The aim of this study was to present our clinical experience and results of different treatments in 83 atherosclerotic renovascular hypertensive patients treated in the last 15 years in the Instituto de nefrologia in Havana. Regardless of the type of treatment the patients were divided in two groups. Group I: 52 (62.3%) cases with standard oral hypotensive drugs alone and control of other cardiovascular risk factors (mean age 53 years old, sex m/f 50/50%, race white/no-white 75/25%, mean known hypertension follow-up 10.2 +/- 10 years, mean SBP 208 +/- 30 mmHg, mean DBP 123 +/- 17 mmHg, mean serum creatinina 1.62 mg/dl and increase peripheral plasma renin value in 61.6% of patients) and group II: 31 (37.7%) cases treated with revascularización procedures (PTA or surgery) or nephrectomy in selected patients (mean age 50 years old, sex m/f 68/32%, race white/no-white 16/84%, mean known hypertension follow-up 8.5 +/- 8.6 years, mean SBP 214 +/- 32 mmHg, mean DBP 1.31 +/- 16 mmHg, mean serum creatinina 1.85 mg/dl and increase peripheral plasma renin value 78.3% of patients). As end point for treatment results we selected: 1) hypertension cure or control, 2) evolution of the serum creatinine value and 3) kidney and patients survival. In those cases with a follow up for more than one year, in 82.9% the blood pressure was cure (21.4%) or controlled (61.4%). The proportion of failed was superior in group I (20.9%) than in group II (11.1%). All 18 cases treated by PTA with a follow up period longer than a year, blood pressure cure in 10 (55.6%), ameliorate in 5 (27.8%) and in 3 (16.6%) was unchanged (one patient lost of follow up). Nine patients were treated by surgery (3 revascularization and 6 nephrectomy), 5 (55.5%) cases cured and 4 (44.5%) ameliorate his blood pressure. Patients in group II maintain normal renal function in more cases than in group I (48.4% vs 30.8%). Both group had similar percentage of normal-normal + pathology-normal renal function (G I: 65.4% vs G II: 77.4%) p = 0.29. When chronic renal function was present at the base line study none of the revascularization procedure were superior. Patient and Kidney actuarial survivals rate do not showed superiority for any treatment procedure after 10 years of follow up. In atherosclerosis renovascular hypertension patients treated with intervention procedure had better BP control than those treated by hypotensive drugs. Not significant different between intervention procedures and drugs treatment in renal function preservation or in patient and kidney actuarial survival rate were found in these patients.

Extracorporeal shock wave therapy does not improve hypertensive nephropathy.

PubMed

Caron, Jonathan; Michel, Pierre-Antoine; Dussaule, Jean-Claude; Chatziantoniou, Christos; Ronco, Pierre; Boffa, Jean-Jacques

2016-06-01

Low-energy extracorporeal shock wave therapy (SWT) has been shown to improve myocardial dysfunction, hind limb ischemia, erectile function, and to facilitate cell therapy and healing process. These therapeutic effects were mainly due to promoting angiogenesis. Since chronic kidney diseases are characterized by renal fibrosis and capillaries rarefaction, they may benefit from a proangiogenic treatment. The objective of our study was to determine whether SWT could ameliorate renal repair and favor angiogenesis in L-NAME-induced hypertensive nephropathy in rats. SWT was started when proteinuria exceeded 1 g/mmol of creatinine and 1 week after L-NAME removal. SWT consisted of implying 0.09 mJ/mm(2) (400 shots), 3 times per week. After 4 weeks of SWT, blood pressure, renal function and urinary protein excretion did not differ between treated (LN + SWT) and untreated rats (LN). Histological lesions including glomerulosclerosis and arteriolosclerosis scores, tubular dilatation and interstitial fibrosis were similar in both groups. In addition, peritubular capillaries and eNOS, VEGF, VEGF-R, SDF-1 gene expressions did not increase in SWT-treated compared to untreated animals. No procedural complications or adverse effects were observed in control (C + SWT) and hypertensive rats (LN + SWT). These results suggest that extracorporeal kidney shock wave therapy does not induce angiogenesis and does not improve renal function and structure, at least in the model of hypertensive nephropathy although the treatment is well tolerated. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Organ damage changes in patients with resistant hypertension randomized to renal denervation or spironolactone: The DENERVHTA (Denervación en Hipertensión Arterial) study.

PubMed

Oliveras, Anna; Armario, Pedro; Sans, Laia; Clarà, Albert; Vázquez, Susana; Molina, Luis; Pareja, Júlia; de la Sierra, Alejandro; Pascual, Julio

2018-01-01

Renal denervation and spironolactone have both been proposed for the treatment of resistant hypertension, but their effects on preclinical target organ damage have not been compared. Twenty-four patients with 24-hour systolic blood pressure ≥140 mm Hg despite receiving three or more full-dose antihypertensive drugs, one a diuretic, were randomized to receive spironolactone or renal denervation. Changes in 24-hour blood pressure, urine albumin excretion, arterial stiffness, carotid intima-media thickness, and left ventricular mass index were evaluated at 6 months. Mean baseline-adjusted difference between the two groups (spironolactone vs renal denervation) at 6 months in 24-hour systolic blood pressure was -17.9 mm Hg (95% confidence interval [CI], -30.9 to -4.9; P = .01). Mean baseline-adjusted change in urine albumin excretion was -87.2 (95% CI, -164.5 to -9.9) and -23.8 (95% CI, -104.5 to 56.9), respectively (P = .028). Mean baseline-adjusted variation of 24-hour pulse pressure was -13.5 (95% CI, -18.8 to -8.2) and -2.1 (95% CI, -7.9 to 3.7), respectively (P = .006). The correlation of change in 24-hour systolic blood pressure with change in log-transformed urine albumin excretion was r = .713 (P < .001). At 6 months there was a reduction in albuminuria in patients with resistant hypertension treated with spironolactone as compared with renal denervation. ©2018 Wiley Periodicals, Inc.

Effects of a human recombinant alkaline phosphatase on renal hemodynamics, oxygenation and inflammation in two models of acute kidney injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Esther, E-mail: esther.peters@radboudumc.n

Two small clinical trials indicated that administration of bovine intestinal alkaline phosphatase (AP) improves renal function in critically ill patients with sepsis-associated acute kidney injury (AKI), for which the mechanism of action is not completely understood. Here, we investigated the effects of a newly developed human recombinant AP (recAP) on renal oxygenation and hemodynamics and prevention of kidney damage and inflammation in two in vivo AKI models. To induce AKI, male Wistar rats (n = 18) were subjected to renal ischemia (30 min) and reperfusion (I/R), or sham-operated. In a second model, rats (n = 18) received a 30 minmore » infusion of lipopolysaccharide (LPS; 2.5 mg/kg), or saline, and fluid resuscitation. In both models, recAP (1000 U/kg) was administered intravenously (15 min before reperfusion, or 90 min after LPS). Following recAP treatment, I/R-induced changes in renal blood flow, renal vascular resistance and oxygen delivery at early, and cortical microvascular oxygen tension at late reperfusion were no longer significantly affected. RecAP did not influence I/R-induced effects on mean arterial pressure. During endotoxemia, recAP treatment did not modulate the LPS-induced changes in systemic hemodynamics and renal oxygenation. In both models, recAP did exert a clear renal protective anti-inflammatory effect, demonstrated by attenuated immunostaining of inflammatory, tubular injury and pro-apoptosis markers. Whether this renal protective effect is sufficient to improve outcome of patients suffering from sepsis-associated AKI is being investigated in a large clinical trial. - Highlights: • Human recombinant alkaline phosphatase (recAP) is a potential new therapy for sepsis-associated acute kidney injury (AKI). • RecAP can modulate renal oxygenation and hemodynamics immediately following I/R-induced AKI. • RecAP did not modulate endotoxemia-induced changes in systemic hemodynamics and renal oxygenation. • RecAP did exert a clear renal protective anti-inflammatory effect in both models.« less