ASSOCIATION OF CIRCULATING RENIN AND ALDOSTERONE WITH OSTEOCALCIN AND BONE MINERAL DENSITY IN AFRICAN ANCESTRY FAMILIES

PubMed Central

Kuipers, Allison L; Kammerer, Candace M; Howard Pratt, J; Bunker, Clareann H; Wheeler, Victor W; Patrick, Alan L; Zmuda, Joseph M

2016-01-01

Hypertension is associated with accelerated bone loss and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62; relative pairs: 1687). Participants underwent a clinical exam, dual energy x-ray absorptiometry, and quantitative computed tomography scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone to renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, co-morbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both p<0.01). There were also significant genetic correlations between renin activity and whole body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone to renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biologic mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. PMID:26975710

Aldosterone and renin in cardiac patients referred for catheterization.

PubMed

Erne, Paul; Müller, Andrea; Rossi, Gian Paolo; Seifert, Burkhardt; Stehlin, Fabrice; Redondo, Maurice; Bauer, Peter T; Kobza, Richard; Resink, Therese J; Radovanovic, Dragana

2017-06-01

Little is known regarding alterations of the renin-angiotensin system in patients referred for cardiac catheterization. Here, we measured plasma levels of active renin and aldosterone in patients referred for cardiac catheterization in order to determine the prevalence of elevated renin, aldosterone, and the aldosterone-renin ratio.A chemiluminescence assay was used to measure plasma aldosterone concentration (PAC) and active renin levels in 833 consecutive patients, after an overnight fasting and without any medication for least 12 hours. We evaluated associations of the hormonal elevations in relation to hypertension, atrial fibrillation (AF), hypertensive cardiomyopathy, coronary artery disease (CAD), valvular disease, impaired left ventricular ejection fraction (LVEF < 35%), and pulmonary hypertension (arterial pulmonary mean pressure >25 mm Hg).Hyperaldosteronism occurred in around one-third of all examined patients, without significant differences between patients with or without the named cardiac diseases. In a comparison between patients with or without any given cardiac disease condition, renin was significantly elevated in patients with either hypertension (36.4% vs 15.9%), CAD (33.9% vs 22.1%), or impaired LVEF (47.3% vs 24.8%). The angiotensin-renin ratio was elevated in AF patients and in patients with hypertensive cardiomyopathy. Patients with AF and coexisting hypertension had elevated renin more frequently than AF patients without coexisting hypertension (35.3% vs 16.5%; P  =  .005). Patients with persistent/permanent AF more frequently had elevated renin than patients with paroxysmal AF (34.1% vs 15.8%; P  =  .007).This prospective study of consecutive cardiac disease patients referred for cardiac catheterization has revealed distinct cardiac disease condition-associated differences in the frequencies of elevations in plasma renin, PAC, and the aldosterone-renin ratio.

Aldosterone and renin in cardiac patients referred for catheterization

PubMed Central

Erne, Paul; Müller, Andrea; Rossi, Gian Paolo; Seifert, Burkhardt; Stehlin, Fabrice; Redondo, Maurice; Bauer, Peter T.; Kobza, Richard; Resink, Therese J.; Radovanovic, Dragana

2017-01-01

Abstract Little is known regarding alterations of the renin-angiotensin system in patients referred for cardiac catheterization. Here, we measured plasma levels of active renin and aldosterone in patients referred for cardiac catheterization in order to determine the prevalence of elevated renin, aldosterone, and the aldosterone-renin ratio. A chemiluminescence assay was used to measure plasma aldosterone concentration (PAC) and active renin levels in 833 consecutive patients, after an overnight fasting and without any medication for least 12 hours. We evaluated associations of the hormonal elevations in relation to hypertension, atrial fibrillation (AF), hypertensive cardiomyopathy, coronary artery disease (CAD), valvular disease, impaired left ventricular ejection fraction (LVEF < 35%), and pulmonary hypertension (arterial pulmonary mean pressure >25 mm Hg). Hyperaldosteronism occurred in around one-third of all examined patients, without significant differences between patients with or without the named cardiac diseases. In a comparison between patients with or without any given cardiac disease condition, renin was significantly elevated in patients with either hypertension (36.4% vs 15.9%), CAD (33.9% vs 22.1%), or impaired LVEF (47.3% vs 24.8%). The angiotensin-renin ratio was elevated in AF patients and in patients with hypertensive cardiomyopathy. Patients with AF and coexisting hypertension had elevated renin more frequently than AF patients without coexisting hypertension (35.3% vs 16.5%; P  =  .005). Patients with persistent/permanent AF more frequently had elevated renin than patients with paroxysmal AF (34.1% vs 15.8%; P  =  .007). This prospective study of consecutive cardiac disease patients referred for cardiac catheterization has revealed distinct cardiac disease condition-associated differences in the frequencies of elevations in plasma renin, PAC, and the aldosterone-renin ratio. PMID:28640140

Calcium in the control of renin release.

PubMed

Park, C S; Malvin, R L

1978-07-01

The effect of Ca concentrations in the incubation medium and of estimated intracellular Ca concentrations on renin release was examined with use of pig renal cortical slices. In addition, the Ca requirement for the epinephrine stimulatory effect and for the ouabain inhibitory action on renin release was also tested. In mediums containing 5.9 mM K, variations in Ca concentration had no effect on renin release. In contrast, when the K concentration was 59 mM, a significant inhibition of renin release was attained with all concentrations of calcium. The inhibition of renin release in high K mediums by Ca was attributed to an increase in the intracellular Ca concentration. In addition, both the stimulatory effect of epinephrine and the inhibitory effect of ouabain on renin release required Ca in the medium. These results support the hypothesis that the control of renin secretion is mediated, in part, by changes in the intracellular concentration of Ca, most likely in the juxtaglomerular cells.

STUDIES ON THE MECHANISM OF EXPERIMENTAL PROTEINURIA INDUCED BY RENIN

PubMed Central

Deodhar, Sharad D.; Cuppage, Francis E.; Gableman, E.

1964-01-01

Renin-induced proteinuria in the rat was investigated, with special emphasis on the relationship between the enzymatic activity and the proteinuric effect of renin. The dependence of the proteinuric effect on the enzymatic activity was shown by using (a) renin preparations of widely varying purity and (b) chemically modified "active" and "inactive" renin derivatives. Angiotensin II, the pressor product of the enzymatic action of renin, also produced significant proteinuria. Adrenalectomy abolished the proteinuria induced by renin. Proteinuria, however, occurred as a result of pretreatment with DOCA, or aldosterone, or without treatment, 7 to 8 weeks after adrenalectomy. Electron microscopic studies of the kidney at the time of maximal proteinuria showed focal flattening and fusion of epithelial foot processes, as well as swelling and vesicle formation in endothelial and epithelial cells of the glomeruli. Studies with intravenously injected saccharated iron oxide showed increased permeability of the glomerular capillary basement membrane to these particles. These changes were transient and were not seen 24 hours after renin injection. Adrenalectomy prevented these changes. It is concluded that renin, acting through angiotensin, causes glomerular capillary damage with increased permeability of these structures to protein and resultant proteinuria. The adrenal glands participate in a permissive role in this phenomenon. PMID:14212126

Renin-secreting tumors.

PubMed

Roswell, R H

1990-02-01

Hypertension resulting from a renin-secreting tumor was first reported in 1967 by Robertson et al. Kihara and coworkers subsequently coined the term juxtaglomerular cell tumor for a similar tumor in a young woman with hyperreninemic hypertension. Since the description of these first two cases, it has become clear that renin-secreting tumors of both renal and nonrenal origin can cause surgically curable hypertension. Primary reninism has been suggested as a more appropriate term for the clinical syndrome associated with renin-secreting tumors, both renal and extrarenal, whether benign or malignant.

Reproduction and the renin-angiotensin system

NASA Technical Reports Server (NTRS)

Ganong, W. F.

1995-01-01

A unique aspect of the circulating renin-angiotensin system and the many independent tissue renin-angiotensin systems is their interactions at multiple levels with reproduction. These interactions, which have received relatively little attention, include effects of estrogens and possibly androgens on hepatic and renal angiotensinogen mRNA; effects of androgens on the Ren-2 gene and salivary renin in mice; the prorenin surge that occurs with but outlasts the LH surge during the menstrual cycle; the inhibitory effects of estrogens on thirst and water intake; the tissue renin-angiotensin systems in the brain, the anterior pituitary, and the ovaries and testes, that is, in all the components of the hypothalamo-pituitary-gonadal axis; the presence of some components of the renin-angiotensin system in the uterus and the fetoplacental unit; and the possible relation of renin and angiotensin to ovulation and fetal well-being. These interactions are described and their significance considered in this short review.

Classical Renin-Angiotensin System in Kidney Physiology

PubMed Central

Sparks, Matthew A.; Crowley, Steven D.; Gurley, Susan B.; Mirotsou, Maria; Coffman, Thomas M.

2014-01-01

The renin-angiotensin system has powerful effects in control of the blood pressure and sodium homeostasis. These actions are coordinated through integrated actions in the kidney, cardio-vascular system and the central nervous system. Along with its impact on blood pressure, the renin-angiotensin system also influences a range of processes from inflammation and immune responses to longevity. Here, we review the actions of the “classical” renin-angiotensin system, whereby the substrate protein angiotensinogen is processed in a two-step reaction by renin and angiotensin converting enzyme, resulting in the sequential generation of angiotensin I and angiotensin II, the major biologically active renin-angiotensin system peptide, which exerts its actions via type 1 and type 2 angiotensin receptors. In recent years, several new enzymes, peptides, and receptors related to the renin-angiotensin system have been identified, manifesting a complexity that was previously unappreciated. While the functions of these alternative pathways will be reviewed elsewhere in this journal, our focus here is on the physiological role of components of the “classical” renin-angiotensin system, with an emphasis on new developments and modern concepts. PMID:24944035

In Vitro Modulation of Renin-Angiotensin System Enzymes by Amaranth (Amaranthus hypochondriacus) Protein-Derived Peptides: Alternative Mechanisms Different from ACE Inhibition.

PubMed

Quiroga, Alejandra V; Aphalo, Paula; Nardo, Agustina E; Añón, María C

2017-08-30

Among the factors affecting the development of cardiovascular diseases, hypertension is one of the most important. Research done on amaranth proteins has demonstrated their hypotensive capacity in vivo and in vitro; nevertheless, the mechanism underlying this effect remains unclear. The aim of this study was to analyze in vitro the inhibition of peptides derived from an amaranth hydrolysate (AHH) on other RAS enzymes other than ACE. The chymase and renin activities were studied. AHH was not able to inhibit chymase activity, although a dose-response effect was found on renin activity (IC 50 0.6 mg/mL). To provide an approach to the renin inhibition mechanism, we analyzed AHH renin inhibition kinetics and performed a structural characterization of the peptides involved in the effect in terms of molecular size and hydrophobicity. Results suggest that amaranth peptides exhibit renin competitive inhibition behavior. Renin inhibition potency was directly related to peptide hydrophobicity. RP-HPLC separation of AHH and subsequent analysis of the peptide sequences showed 6 peptides belonging to 11S globulin (that can be grouped into 3 families) that would be responsible for renin inhibition. These results demonstrate that Amaranthus hypochondriacus seeds are an adequate source of peptides with renin inhibitory properties that could be used in functional food formulations.

Cathepsin B is not the processing enzyme for mouse prorenin.

PubMed

Mercure, Chantal; Lacombe, Marie-Josée; Khazaie, Khashayarsha; Reudelhuber, Timothy L

2010-05-01

Renin, an aspartyl protease that catalyzes the rate-limiting step in the renin-angiotensin system (RAS), is proteolytically activated by a second protease [referred to as the prorenin processing enzyme (PPE)] before its secretion from the juxtaglomerular cells of the kidney. Although several enzymes are capable of activating renin in vitro, the leading candidate for the PPE in the kidney is cathepsin B (CTSB) due to is colocalization with the renin precursor (prorenin) in juxtaglomerular cell granules and because of its site-selective activation of human prorenin both in vitro and in transfected tissue culture cell models. To verify the role of CTSB in prorenin processing in vivo, we tested the ability of CTSB-deficient (CTSB-/-) mice to generate active renin. CTSB-/- mice do not exhibit any overt symptoms (renal malformation, preweaning mortality) typical of an RAS deficiency and have normal levels of circulating active renin, which, like those in control animals, rise more than 15-fold in response to pharmacologic inhibition of the RAS. The mature renin enzyme detected in kidney lysates of CTSB-/- mice migrates at the same apparent molecular weight as that in control mice, and the processing to active renin is not affected by chloroquine treatment of the animals. Finally, the distribution and morphology of renin-producing cells in the kidney is normal in CTSB-/- mice. In conclusion, CTSB-deficient mice exhibit no differences compared with controls in their ability to generate active renin, and our results do not support CTSB as the PPE in mice.

Plasma renin and cardiovascular responses to the cold pressor test differ in black and white populations: The SABPA study.

PubMed

Gafane, L F; Schutte, R; Van Rooyen, J M; Schutte, A E

2016-05-01

Low plasma renin levels and augmented cardiovascular reactivity to stress are common in blacks and have been linked to the development of hypertension in this population. We (i) compared cardiovascular and plasma renin reactivity to a cold pressor test between a black and white population; and (ii) investigated the associations between cardiovascular and plasma renin reactivity within the black and white populations. Our population consisted of 153 black and 188 white men and women (age range, 20-65 years). We measured blood pressure (BP), heart rate (HR), stroke volume (SV), total peripheral resistance (TPR), Windkessel arterial compliance, and determined plasma renin levels at rest and during the cold pressor test. Reactivity was calculated for each participant as the percentage change from the resting value. We found lower renin and elevated BP in blacks compared with whites at rest and during stress (both, P<0.001). During stress, HR increased more in blacks (P<0.001), whereas SV (P<0.001) and arterial compliance (P=0.013) decreased more in blacks compared with whites. TPR reactivity was positively associated with renin reactivity in blacks only (β=0.17; P=0.041), while in whites diastolic BP reactivity was positively associated with renin reactivity (β=0.21; P=0.005). Although blacks had suppressed renin levels at rest and during acute stress, vascular resistance reactivity associated positively with renin reactivity only in the black population. These results suggest that low renin levels in blacks during rest and stress are linked to increased peripheral vascular responses to stress, which may contribute to elevated BP in blacks.

Evaluation of Vasopressin for Septic Shock in Patients on Chronic Renin-Angiotensin-Aldosterone System Inhibitors.

PubMed

Erwin, Beth L; Denaburg, Michael A; Barker, Andrew B; McArdle, Philip J; Windham, Samuel T; Morgan, Charity J

2017-12-01

To compare the hemodynamic response in septic shock patients receiving vasopressin who were on chronic renin-angiotensin-aldosterone system inhibitor therapy with those who were not. Single-center, retrospective cohort study. Medical and surgical ICUs at a 1,100-bed academic medical center. Medical and surgical ICU patients with septic shock who received vasopressin infusion added to at least one concomitant vasopressor agent between January 2014 and December 2015, then divided into two cohorts: 1) patients who were on chronic renin-angiotensin-aldosterone system inhibitor therapy as outpatients and 2) patients who were not on chronic renin-angiotensin-aldosterone system inhibitor therapy as outpatients. None. Mean arterial pressure at 6 hours was 72.2 mm Hg in the renin-angiotensin-aldosterone system inhibitor group versus 69.7 mm Hg in the non-renin-angiotensin-aldosterone system inhibitor group (p = 0.298). There was no difference in mean arterial pressure at 1, 24, or 48 hours between groups. Total concomitant vasopressor requirements, based on norepinephrine equivalents excluding vasopressin, were significantly lower at 24 hours in the renin-angiotensin-aldosterone system inhibitor group versus the non-renin-angiotensin-aldosterone system inhibitor group (10.7 vs 18.1 µg/min, respectively; p = 0.007), but no significant differences were seen at the other time points assessed. There were no significant differences in ICU or hospital length of stay or mortality. There was no significant difference in the primary outcome of 6-hour mean arterial pressure in septic shock patients receiving vasopressin who were on chronic renin-angiotensin-aldosterone system inhibitor therapy versus those receiving vasopressin who were not on chronic renin-angiotensin-aldosterone system inhibitor therapy. Renin-angiotensin-aldosterone system inhibitor patients had lower total concomitant vasopressor requirements at 24 hours compared with non-renin-angiotensin-aldosterone system inhibitor patients.

Renin knockout rat: control of adrenal aldosterone and corticosterone synthesis in vitro and adrenal gene expression

PubMed Central

Gehrand, Ashley; Bruder, Eric D.; Hoffman, Matthew J.; Engeland, William C.; Moreno, Carol

2014-01-01

The classic renin-angiotensin system is partly responsible for controlling aldosterone secretion from the adrenal cortex via the peptide angiotensin II (ANG II). In addition, there is a local adrenocortical renin-angiotensin system that may be involved in the control of aldosterone synthesis in the zona glomerulosa (ZG). To characterize the long-term control of adrenal steroidogenesis, we utilized adrenal glands from renin knockout (KO) rats and compared steroidogenesis in vitro and steroidogenic enzyme expression to wild-type (WT) controls (Dahl S rat). Adrenal capsules (ZG; aldosterone production) and subcapsules [zona reticularis/fasciculata (ZFR); corticosterone production] were separately dispersed and studied in vitro. Plasma renin activity and ANG II concentrations were extremely low in the KO rats. Basal and cAMP-stimulated aldosterone production was significantly reduced in renin KO ZG cells, whereas corticosterone production was not different between WT and KO ZFR cells. As expected, adrenal renin mRNA expression was lower in the renin KO compared with the WT rat. Real-time PCR and immunohistochemical analysis showed a significant decrease in P450aldo (Cyp11b2) mRNA and protein expression in the ZG from the renin KO rat. The reduction in aldosterone synthesis in the ZG of the renin KO adrenal seems to be accounted for by a specific decrease in P450aldo and may be due to the absence of chronic stimulation of the ZG by circulating ANG II or to a reduction in locally released ANG II within the adrenal gland. PMID:25394830

TRPV4 participates in pressure-induced inhibition of renin secretion by juxtaglomerular cells.

PubMed

Seghers, François; Yerna, Xavier; Zanou, Nadège; Devuyst, Olivier; Vennekens, Rudi; Nilius, Bernd; Gailly, Philippe

2016-12-15

Increase in blood pressure in the renal afferent arteriole is known to induce an increase in cytosolic calcium concentration ([Ca 2+ ] i ) of juxtaglomerular (JG) cells and to result in a decreased secretion of renin. Mechanical stimulation of As4.1 JG cells induces an increase in [Ca 2+ ] i that is inhibited by HC067047 and RN1734, two inhibitors of TRPV4, or by siRNA-mediated repression of TRPV4. Inhibition of TRPV4 impairs pressure-induced decrease in renin secretion. Compared to wild-type mice, Trpv4 -/- mice present increased resting plasma levels of renin and aldosterone and present a significantly altered pressure-renin relationship. We suggest that TRPV4 channel participates in mechanosensation at the juxtaglomerular apparatus. The renin-angiotensin system is a crucial blood pressure regulation system. It consists of a hormonal cascade where the rate-limiting enzyme is renin, which is secreted into the blood flow by renal juxtaglomerular (JG) cells in response to low pressure in the renal afferent arteriole. In contrast, an increase in blood pressure results in a decreased renin secretion. This is accompanied by a transitory increase in [Ca 2+ ] i of JG cells. The inverse relationship between [Ca 2+ ] i and renin secretion has been called the 'calcium paradox' of renin release. How increased pressure induces a [Ca 2+ ] i transient in JG cells, is however, unknown. We observed that [Ca 2+ ] i transients induced by mechanical stimuli in JG As4.1 cells were completely abolished by HC067047 and RN1734, two inhibitors of TRPV4. They were also reduced by half by siRNA-mediated repression of TRPV4 but not after repression or inhibition of TRPV2 or Piezo1 ion channels. Interestingly, the stimulation of renin secretion by the adenylate cyclase activator forskolin was totally inhibited by cyclic stretching of the cells. This effect was mimicked by stimulation with GSK1016790A and 4αPDD, two activators of TRPV4 and inhibited in the presence of HC067047. Moreover, in isolated perfused kidneys from Trpv4 -/- mice, the pressure-renin relationship was significantly altered. In vivo, Trpv4 -/- mice presented increased plasma levels of renin and aldosterone compared to wild-type mice. Altogether, our results suggest that TRPV4 is involved in the pressure-induced entry of Ca 2+ in JG cells, which inhibits renin release and allows the negative feedback regulation on blood pressure. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

2C.07: INVOLVEMENT OF THE RENIN-ANGIOTENSIN SYSTEM IN A PREMATURE AGING MOUSE MODEL.

PubMed

Van Thiel, B S; Ridwan, Y; Garrelds, I M; Vermeij, M; Groningen, M C Clahsen-Van; Danser, A H J; Essers, J; Van Der Pluijm, I

2015-06-01

Changes in the renin-angiotensin system (RAS), known for its critical role in the regulation of blood pressure and sodium homeostasis, may contribute to aging and age-related diseases. Here we characterized the RAS and kidney pathology in mice with genomic instability due to a defective nucleotide excision repair gene (Ercc1d/- mice). These mice display premature features of aging, including vascular dysfunction. Studies were performed in male and female Ercc1d/- mice and their wild type controls (Ercc1+/+) at the age of 12 or 18 weeks before and after treatment with losartan. The renin-activatable near-infrared fluorescent probe ReninSense 680™ was applied in vivo to allow non-invasive imaging of renin activity. Plasma renin concentrations (PRC) were additionally measured ex vivo by quantifying Ang I generation in the presence of excess angiotensinogen. Kidneys were harvested and examined for markers of aging, and albumin was determined in urine. Kidneys of 12-week old Ercc1d/- mice showed signs of aging, including tubular anisokaryosis, cell-senescence and increased apoptosis. This was even more pronounced at the age of 18 weeks. Yet, urinary albumin was normal at 12 weeks. The ReninSense 680™ probe showed increased intrarenal renin activity in Ercc1d/- mice versus Ercc1+/+ mice, both at 12 and 18 weeks of age, while PRC in these mice tended to be lower compared to Ercc1+/+ mice. Renin was higher in male than female mice, both in the kidney and in plasma, and losartan increased kidney and plasma renin in both Ercc1d/- and Ercc1+/+ mice. Rapidly aging Ercc1d/- mice display an activated intrarenal RAS, as evidenced by the increased fluorescence detected with the ReninSense 680™ probe. This increased RAS activity may contribute to the disturbed kidney pathology in these mice. The increased intrarenal activity detected with the ReninSense 680™ probe in male vs. female mice, as well as after losartan treatment, are in full agreement with the literature, and thus not only validate the specificity of the probe, but also support its use for longitudinal imaging of altered RAS signaling in aging.

Total renin after gonadotropin stimulation in polycystic ovarian disease.

PubMed

Matinlauri, I; Anttila, L; Jaatinen, T A; Koskinen, P; Aalto, M; Irjala, K; Nikkanen, V

1995-02-01

To examine the influence of polycystic ovarian disease (PCOD) on the levels of total renin in plasma and follicular fluid (FF) after stimulation with hMG. Comparative study of the plasma and FF concentrations of total renin in women with and without PCOD after stimulation with hMG. In vitro fertilization-embryo transfer program at the Department of Obstetrics and Gynecology, the University Central Hospital of Turku, Finland. Thirty-six women undergoing IVF-ET for infertility with (n = 10) or without (n = 26) ultrasonographically diagnosed PCOD. Of the latter group, 15 women had tubal infertility, and the rest suffered from an anovulatory infertility and reacted with PCO-like ovarian response to stimulation. The concentrations of total renin in plasma and FF, serum E2, and protein in FF. The concentrations of plasma total renin after the gonadotropin stimulation were significantly higher in the PCOD and PCO-like groups when compared with the tubal group. The concentration of total renin in FF and the ratio of total renin per protein in FF were higher in the PCOD and PCO-like groups than in the tubal group, but the differences did not reach statistical significance. Positive correlations were found between the plasma total renin and serum E2 concentrations in the PCO-like and in the tubal group and between plasma total renin concentrations and the number of mature follicles in all groups. Follicular fluid total renin did not correlate with FF protein in any group. All findings were independent of the total hMG dosage used and the body mass index of the patients. In the present study the concentrations of total renin in plasma were enhanced markedly after gonadotropin stimulation in women with PCOD compared with women having tubal infertility. The pattern of the hormonal secretions revealed a group of infertile patients reacting biochemically like women with PCOD.

Urinary Angiotensinogen and Renin Excretion are Associated with Chronic Kidney Disease.

PubMed

Juretzko, Annett; Steinbach, Antje; Hannemann, Anke; Endlich, Karlhans; Endlich, Nicole; Friedrich, Nele; Lendeckel, Uwe; Stracke, Sylvia; Rettig, Rainer

2017-01-01

Several studies sought to identify new biomarkers for chronic kidney disease (CKD). As the renal renin-angiotensin system is activated in CKD, urinary angiotensinogen or renin excretion may be suitable candidates. We tested whether urinary angiotensinogen or renin excretion is elevated in CKD and whether these parameters are associated with estimated glomerular filtration rate (eGFR). We further tested whether urinary angiotensinogen or renin excretion may convey additional information beyond that provided by albuminuria. We measured urinary and plasma angiotensinogen, renin, albumin and creatinine in 177 CKD patients from the Greifswald Approach to Individualized Medicine project and in 283 healthy controls from the Study of Health in Pomerania. The urinary excretion of specific proteins is given as protein-to-creatinine ratio. Receiver operating characteristic (ROC) curves, spearman correlation coefficients and linear regression models were calculated. Urinary angiotensinogen [2,511 (196-31,909) vs. 18.6 (8.3-44.0) pmol/g, *P<0.01] and renin excretion [0.311 (0.135-1.155) vs. 0.069 (0.045-0.148) pmol/g, *P<0.01] were significantly higher in CKD patients than in healthy controls. The area under the ROC curve was significantly larger when urinary angiotensinogen, renin and albumin excretion were combined than with urinary albumin excretion alone. Urinary angiotensinogen (ß-coefficient -2.405, standard error 0.117, P<0.01) and renin excretion (ß-coefficient -0.793, standard error 0.061, P<0.01) were inversely associated with eGFR. Adjustment for albuminuria, age, sex, systolic blood pressure and body mass index did not significantly affect the results. Urinary angiotensinogen and renin excretion are elevated in CKD patients. Both parameters are negatively associated with eGFR and these associations are independent of urinary albumin excretion. In CKD patients urinary angiotensinogen and renin excretion may convey additional information beyond that provided by albuminuria. © 2017 The Author(s)Published by S. Karger AG, Basel.

Association studies suggest a key role for endothelin-1 in the pathogenesis of preeclampsia and the accompanying renin-angiotensin-aldosterone system suppression.

PubMed

Verdonk, Koen; Saleh, Langeza; Lankhorst, Stephanie; Smilde, J E Ilse; van Ingen, Manon M; Garrelds, Ingrid M; Friesema, Edith C H; Russcher, Henk; van den Meiracker, Anton H; Visser, Willy; Danser, A H Jan

2015-06-01

Women with preeclampsia display low renin-angiotensin-aldosterone system activity and a high antiangiogenic state, the latter characterized by high levels of soluble Fms-like tyrosine kinase (sFlt)-1 and reduced placental growth factor levels. To investigate whether renin-angiotensin-aldosterone system suppression in preeclampsia is because of this disturbed angiogenic balance, we measured mean arterial pressure, creatinine, endothelin-1 (ET-1), and renin-angiotensin-aldosterone system components in pregnant women with a high (≥85; n=38) or low (<85; n=65) soluble Fms-like tyrosine kinase-1/placental growth factor ratio. Plasma ET-1 levels were increased in women with a high ratio, whereas their plasma renin activity and plasma concentrations of renin, angiotensinogen, and aldosterone were decreased. Plasma renin activity-aldosterone relationships were identical in both the groups. Multiple regression analysis revealed that plasma renin concentration correlated independently with mean arterial pressure and plasma ET-1. Plasma ET-1 correlated positively with soluble Fms-like tyrosine kinase-1 and negatively with plasma renin concentration, and urinary protein correlated with plasma ET-1 and mean arterial pressure. Despite the lower plasma levels of renin and angiotensinogen in the high-ratio group, their urinary levels of these components were elevated. Correction for albumin revealed that this was because of increased glomerular filtration. Subcutaneous arteries obtained from patients with preeclampsia displayed an enhanced, AT2 receptor-mediated response to angiotensin II. In conclusion, a high antiangiogenic state associates with ET-1 activation, which together with the increased mean arterial pressure may underlie the parallel reductions in renin and aldosterone in preeclampsia. Because ET-1 also was a major determinant of urinary protein, our data reveal a key role for ET-1 in the pathogenesis of preeclampsia. Finally, the enhanced angiotensin responsiveness in preeclampsia involves constrictor AT2 receptors. © 2015 American Heart Association, Inc.

The Spectrum of Subclinical Primary Aldosteronism and Incident Hypertension: A Cohort Study

PubMed Central

Brown, Jenifer M.; Robinson-Cohen, Cassianne; Fernandez, Miguel Angel Luque; Allison, Matthew A.; Baudrand, Rene; Ix, Joachim H.; Kestenbaum, Bryan; de Boer, Ian H.; Vaidya, Anand

2018-01-01

Background Primary aldosteronism is recognized as a severe form of “renin-independent aldosteronism” that results in excessive mineralocorticoid receptor (MR) activation. Objective To investigate whether there is a spectrum of subclinical renin-independent aldosteronism among normotensives that increases risk for hypertension. Design Cohort study. Setting National community-based study. Participants 850 untreated normotensive participants in the Multi-Ethnic Study of Atherosclerosis with measurements of serum aldosterone, plasma renin activity (PRA). Measurements Longitudinal analyses investigated whether aldosterone concentrations, in the context of physiologic PRA phenotypes (suppressed: ≤0.50; indeterminate: 0.51–0.99; unsuppressed: ≥1.0 μg/L/h), associated with incident hypertension, defined as SBP≥140, DBP≥90 mmHg, or initiation of anti-hypertensive medications. Cross-sectional analyses investigated associations of aldosterone with MR activity, assessed via serum potassium and urinary fractional excretion of potassium. Results A suppressed renin phenotype was associated with a higher rate of incident hypertension when compared to other PRA phenotypes (85.4 [73.4, 99.3] vs. 53.3 [42.8, 66.4] vs. 54.5 [41.8, 71.0] cases per 1000 person-years of follow-up). With renin suppression, higher aldosterone concentrations were independently associated with an increased risk for incident hypertension; whereas no association between aldosterone and hypertension was observed when renin was not suppressed. Higher aldosterone concentrations were associated with lower serum potassium and higher urinary excretion of potassium, but only when renin was suppressed. Limitations Measurements of sodium and potassium occurred several years before renin and aldosterone. Conclusions Suppression of renin, and higher aldosterone concentrations in the context of this renin suppression, associated with an increased risk for developing hypertension and possibly also with increased MR activity. These findings suggest a clinically-relevant spectrum of subclinical primary aldosteronism (renin-independent aldosteronism) in normotension. Funding National Institutes of Health PMID:29052707

Renin angiotensin aldosterone system altered in resistant hypertension in Sub-Saharan African diabetes patients without evidence of primary hyperaldosteronism.

PubMed

Edinga-Melenge, Bertille Elodie; Ama Moor, Vicky J; Nansseu, Jobert Richie N; Nguetse Djoumessi, Romance; Mengnjo, Michel K; Katte, Jean-Claude; Noubiap, Jean Jacques N; Sobngwi, Eugene

2017-01-01

The renin-angiotensin-aldosterone system may be altered in patients with resistant hypertension. This study aimed to evaluate the relation between renin-angiotensin-aldosterone system activity and resistant hypertension in Cameroonian diabetes patients with resistant hypertension. We carried out a case-control study including 19 diabetes patients with resistant hypertension and 19 diabetes patients with controlled hypertension matched to cases according to age, sex and duration of hypertension since diagnosis. After collection of data, fasting blood was collected for measurement of sodium, potassium, chloride, active renin and plasma aldosterone of which the aldosterone-renin ratio was derived to assess the activity of renin-angiotensin-aldosterone system. Then, each participant received 2000 ml infusion of saline solution after which plasma aldosterone was re-assayed. Potassium levels were lower among cases compared to controls (mean: (4.10 ± 0.63 mmol/l vs. 4.47 ± 0.58 mmol/l), though nonsignificant (p = 0.065). Active renin, plasma aldosterone both before and after the dynamic test and aldosterone-renin ratio were comparable between cases and controls (all p values > 0.05). Plasma aldosterone significantly decreased after the dynamic test in both groups (p < 0.001), but no participant exhibited a post-test value>280 pmol/l. We found a significant negative correlation between potassium ion and plasma aldosterone (ρ = -0.324; p  = 0.047), the other correlations being weak and unsignificant. Although this study failed to show an association between RH and primary hyperaldosteronism in our context, there was a hyperactivity of renin-angiotensin-aldosterone system. Moreover, this study confirms the importance of potassium dosage when screening the renin-angiotensin-aldosterone system.

The pathogenesis of small arterial lesions in nephrectomized rats by the administration of renin.

PubMed Central

Kai, M.; Kanaide, H.; Yamamoto, H.; Kurozumi, T.; Tanaka, K.; Nakamura, M.

1981-01-01

Intraperitoneal injection of purified hog renal renin produced a marked and sustained elevation of arterial pressure and lesions of the "fibrinoid necrosis" type in the small arteries and arterioles of the pancreas, heart and mesentery, but not of the brain, in bilaterally nephrectomized rats. Both the elevation of arterial pressure and the production of arterial lesions were completely prevented by pretreatment with oral SQ14225. Plasma renin clearance in bilaterally nephrectomized rats was markedly slower than that in sham-nephrectomized rats. Pre-treatment with oral SQ14225 did not affect renin clearance. It is suggested that sustained high blood pressure due to the sustained high plasma renin concentration in bilaterally nephrectomized rat was responsible for the production by renin of lesions of the fibrinoid necrosis type in the arteries. Images Fig. 1 Fig. 4 PMID:7016159

Human prorenin structure sheds light on a novel mechanism of its autoinhibition and on its non-proteolytic activation by the (pro)renin receptor.

PubMed

Morales, Renaud; Watier, Yves; Böcskei, Zsolt

2012-08-03

Antibodies and prorenin mutants have long been used to structurally characterize prorenin, the inactive proenzyme form of renin. They were designed on the basis of homology models built using other aspartyl protease proenzyme structures since no structure was available for prorenin. Here, we present the first X-ray structure of a prorenin. The current structure of prorenin reveals that, in this zymogene, the active site of renin is blocked by the N-terminal residues of the mature version of the renin molecule, which are, in turn, covered by an Ω-shaped prosegment. This prevents access of substrates to the active site. The departure of the prosegment on activation induces an important global conformational change in the mature renin molecule with respect to prorenin: similar to other related enzymes such as pepsin or gastricsin, the segment that constitutes the N-terminal β-strand in renin is displaced from the renin active site by about 180° straight into the position that corresponds to the N-terminal β-strand of the prorenin prosegment. This way, the renin active site will become completely exposed and capable of carrying out its catalytic functions. A unique inactivation mechanism is also revealed, which does not make use of a lysine against the catalytic aspartates, probably in order to facilitate pH-independent activation [e.g., by the (pro)renin receptor]. Copyright © 2012 Elsevier Ltd. All rights reserved.

Design of potent substrate-analogue inhibitors of canine renin

NASA Technical Reports Server (NTRS)

Hui, K. Y.; Siragy, H. M.; Haber, E.

1992-01-01

Through a systematic study of structure-activity relationships, we designed potent renin inhibitors for use in dog models. In assays against dog plasma renin at neutral pH, we found that, as in previous studies of rat renin inhibitors, the structure at the P2 position appears to be important for potency. The substitution of Val for His at this position increases potency by one order of magnitude. At the P3 position, potency appears to depend on a hydrophobic side chain that does not necessarily have to be aromatic. Our results also support the approach of optimizing potency in a renin inhibitor by introducing a moiety that promotes aqueous solubility (an amino group) at the C-terminus of the substrate analogue. In the design of potent dog plasma renin inhibitors, the influence of the transition-state residue 4(S)-amino-3(S)-hydroxy-5-cyclohexylpentanoic acid (ACHPA)-commonly used as a substitute for the scissile-bond dipeptide to boost potency-is not obvious, and appears to be sequence dependent. The canine renin inhibitor Ac-paF-Pro-Phe-Val-statine-Leu-Phe-paF-NH2 (compound 15; IC50 of 1.7 nM against dog plasma renin at pH 7.4; statine, 4(S)-amino-3(S)-hydroxy-6-methylheptanoic acid; paF, para-aminophenylalanine) had a potent hypotensive effect when infused intravenously into conscious, sodium-depleted, normotensive dogs. Also, compound 15 concurrently inhibited plasma renin activity and had a profound diuretic effect.

The importance of the renin-angiotensin system in normal cardiovascular homeostasis

NASA Technical Reports Server (NTRS)

Haber, E.

1975-01-01

Studies were carried out on adult mongrel dogs (20 to 30 kilograms) to investigate the importance of the renin-angiotensin system. Results indicate that the renin-angiotensin system plays a major role in the maintenance of circulatory homeostasis when extracellular fluid volume is depleted. It was also found that angiotensin II concentration, in addition to renal perfusion pressure, is a factor in the regulation of renin release.

Budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme upon high-altitude exposure.

PubMed

Li, Hui-Jie; Zheng, Cheng-Rong; Chen, Guo-Zhu; Qin, Jun; Zhang, Ji-Hang; Yu, Jie; Zhang, En-Hao; Huang, Lan

2016-01-01

Inhaled budesonide is a novel approach to prevent acute mountain sickness (AMS). However, its mechanism is not completely understood. We aimed to investigate the effects of budesonide and dexamethasone on renin-angiotensin-aldosterone system in AMS prevention. Data were obtained from a randomised controlled trial including 138 participants. The participants were randomly assigned to receive budesonide, dexamethasone or placebo as prophylaxis before they travelled to 3450 m altitude from 400 m by car. Their plasma concentrations of renin, angiotensin-converting enzyme (ACE) and aldosterone were measured at both altitudes. All parameters were comparable among the three groups at 400 m. After high-altitude exposure of 3450, renin in all groups increased significantly; the ACE, aldosterone concentrations, as well as the aldosterone/renin ratio, rose markedly in the dexamethasone and placebo groups but not in the budesonide group. Moreover, the aldosterone/renin ratio correlated closely with ACE concentration. Upon acute high-altitude exposure, budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme. © The Author(s) 2016.

Role of the renin-angiotensin system in cardiac hypertrophy induced in rats by hyperthyroidism

PubMed Central

KOBORI, HIROYUKI; ICHIHARA, ATSUHIRO; SUZUKI, HIROMICHI; TAKENAKA, TSUNEO; MIYASHITA, YUTAKA; HAYASHI, MATSUHIKO; SARUTA, TAKAO

2008-01-01

This study was conducted to examine whether the renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy without involving the sympathetic nervous system. Sprague-Dawley rats were divided into control-innervated, control-denervated, hyperthyroid-innervated, and hyperthyroid-denervated groups using intraperitoneal injections of thyroxine and 6-hydroxydopamine. After 8 wk, the heart-to-body weight ratio increased in hyperthyroid groups (63%), and this increase was only partially inhibited by sympathetic denervation. Radioimmunoassays and reverse transcription-polymerase chain reaction revealed increased cardiac levels of renin (33%) and angiotensin II (53%) and enhanced cardiac expression of renin mRNA (225%) in the hyperthyroid groups. These increases were unaffected by sympathetic denervation or 24-h bilateral nephrectomy. In addition, losartan and nicardipine decreased systolic blood pressure to the same extent, but only losartan caused regression of thyroxine-induced cardiac hypertrophy. These results suggest that thyroid hormone activates the cardiac renin-angiotensin system without involving the sympathetic nervous system or the circulating renin-angiotensin system; the activated renin-angiotensin system contributes to cardiac hypertrophy in hyperthyroidism. PMID:9277473

Role of the renin-angiotensin system in cardiac hypertrophy induced in rats by hyperthyroidism.

PubMed

Kobori, H; Ichihara, A; Suzuki, H; Takenaka, T; Miyashita, Y; Hayashi, M; Saruta, T

1997-08-01

This study was conducted to examine whether the renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy without involving the sympathetic nervous system. Sprague-Dawley rats were divided into control-innervated, control-denervated, hyperthyroid-innervated, and hyperthyroid-denervated groups using intraperitoneal injections of thyroxine and 6-hydroxydopamine. After 8 wk, the heart-to-body weight ratio increased in hyperthyroid groups (63%), and this increase was only partially inhibited by sympathetic denervation. Radioimmunoassays and reverse transcription-polymerase chain reaction revealed increased cardiac levels of renin (33%) and angiotensin II (53%) and enhanced cardiac expression of renin mRNA (225%) in the hyperthyroid groups. These increases were unaffected by sympathetic denervation or 24-h bilateral nephrectomy. In addition, losartan and nicardipine decreased systolic blood pressure to the same extent, but only losartan caused regression of thyroxine-induced cardiac hypertrophy. These results suggest that thyroid hormone activates the cardiac renin-angiotensin system without involving the sympathetic nervous system or the circulating renin-angiotensin system; the activated renin-angiotensin system contributes to cardiac hypertrophy in hyperthyroidism.

Hypohydration and Heat Acclimation: Plasma Renin and Aldosterone during Exercise,

DTIC Science & Technology

1983-01-01

vasoconstriction in heat-stressed men: role of McGraw-Hill, 1964, p. 419-423. renin - angiotensin system . J. AppL PhysioL: Respirat. Environ. 13. LINDQUIST, E...AL.A137 365 HYPOHYDRATION AND HEAT ACCLIMATION: PLASMA RENIN AND I/ ALDOSTERONE DURING EXERCISE(U) ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE...heat acclimation:plasma renin dependent not only on the mode of exercise but also the and aldosterone during exercise. J. Appl. Physiol.: Respirat

Renal hemodynamics and renin-angiotensin system activity in humans with multifocal renal artery fibromuscular dysplasia.

PubMed

van Twist, Daan J L; Houben, Alphons J H M; de Haan, Michiel W; de Leeuw, Peter W; Kroon, Abraham A

2016-06-01

Fibromuscular dysplasia (FMD) is the second most common cause of renovascular hypertension. Nonetheless, knowledge on the renal microvasculature and renin-angiotensin system (RAS) activity in kidneys with FMD is scarce. Given the fairly good results of revascularization, we hypothesized that the renal microvasculature and RAS are relatively spared in kidneys with FMD. In 58 hypertensive patients with multifocal renal artery FMD (off medication) and 116 matched controls with essential hypertension, we measured renal blood flow (Xenon washout method) per kidney and drew blood samples from the aorta and both renal veins to determine renin secretion and glomerular filtration rate per kidney. We found that renal blood flow and glomerular filtration rate in FMD were comparable to those in controls. Although systemic renin levels were somewhat higher in FMD, renal renin secretion was not elevated. Moreover, in patients with unilateral FMD, no differences between the affected and unaffected kidney were observed with regard to renal blood flow, glomerular filtration rate, or renin secretion. In men, renin levels and renin secretion were higher as compared with women. The renal blood flow response to RAS modulation (by intrarenal infusion of angiotensin II, angiotensin-(1-7), an angiotensin II type 1 receptor blocker, or a nitric oxide synthase blocker) was also comparable between FMD and controls. Renal blood flow, glomerular filtration, and the response to vasoactive substances in kidneys with multifocal FMD are comparable to patients with essential hypertension, suggesting that microvascular function is relatively spared. Renin secretion was not increased and the response to RAS modulation was not affected in kidneys with FMD.

Heterogeneous Downregulation of Angiotensin II AT1-A and AT1-B Receptors in Arterioles in STZ-Induced Diabetic Rat Kidneys

PubMed Central

Razga, Zsolt; Talapka, Petra; Nyengaard, Jens Randel

2014-01-01

Introduction. The renin granulation of kidney arterioles is enhanced in diabetes despite the fact that the level of angiotensin II in the diabetic kidney is elevated. Therefore, the number of angiotensin II AT1-A and AT1-B receptors in afferent and efferent arteriole's renin-positive and renin-negative smooth muscle cells (SMC) was estimated. Method. Immunohistochemistry at the electron microscopic level was combined with 3D stereological sampling techniques. Results. In diabetes the enhanced downregulation of AT1-B receptors in the renin-positive than in the renin-negative SMCs in both arterioles was resulted: the significant difference in the number of AT1 (AT1-A + AT1-B) receptors between the two types of SMCs in the normal rats was further increased in diabetes and in contrast with the significant difference observed between the afferent and efferent arterioles in the normal animals, there was no such difference in diabetes. Conclusions. The enhanced downregulation of the AT1-B receptors in the renin-negative SMCs in the efferent arterioles demonstrates that the regulation of the glomerular filtration rate by the pre- and postglomerular arterioles is changed in diabetes. The enhanced downregulation of the AT1-B receptors in the renin-positive SMCs in the arterioles may result in an enhanced level of renin granulation in the arterioles. PMID:24587998

Neural mechanisms by which gravitational stimuli and stress affect the secretion of renin and other hormones

NASA Technical Reports Server (NTRS)

Ganong, William F.

1987-01-01

The present goal is to determine by the production of discrete lesions the parts of the hypothalamus and brainstem that are involved in serotonin-mediated increases in renin secretion. A variety of stimuli which act in different ways to increase renin stimuli were developed and standardized. The experiments with p-chloroamphetamine (PCA) demonstrated that there is a serotonergic pathway which projects from the dorsal raphe nuclei to the paraventricular nuclei and the vetromedial nuclei of the hypothalamus; that projection from paraventricular nuclei to the brainstem and spinal cord may be oxytocinergic; and that the pathway from the spinal cord to the renin secreting cells is sympathetic. The demonstration that paraventicular lesions lower circulating renin substrate is important because it raises the possibility that substrate secretion is under neural control, either via the pituitary or by direct neural pathways. The discovery that lesions of the ventromedial nuclei appear to abolish the increase in renin secretion produced by many different stimuli without affecting the concentration of renin substrate in the plasma makes the position of the hypothalamus in the regulation of fluid and electrolyte balance more prominent than previously suspected.

Inhibition of the renin-angiotensin-aldosterone system: is there room for dual blockade in the cardiorenal continuum?

PubMed

Volpe, Massimo; Danser, A H Jan; Menard, Joël; Waeber, Bernard; Mueller, Dominik N; Maggioni, Aldo P; Ruilope, Luis M

2012-04-01

Antagonism of renin-angiotensin-aldosterone system is exerted through angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, renin inhibitors and mineralocorticoid receptor antagonists. These drugs have been successfully tested in numerous trials and in different clinical settings. The original indications of renin-angiotensin-aldosterone system blockers have progressively expanded from the advanced stages to the earlier stages of cardiorenal continuum. To optimize the degree of blockade of renin-angiotensin-aldosterone system, dose uptitrations of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists or the use of a dual blockade, initially identified with the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists, have been proposed. The data from the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) study do not support this specific dual blockade approach. However, the dual blockade of angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists with direct renin inhibitors is currently under investigation while that based on an aldosterone blocker with any of the previous three drugs requires more evidence beyond heart failure. In this review, we revisited potential advantages of dual blockade of renin-angiotensin-aldosterone system in arterial hypertension and diabetes.

Neuron-specific (pro)renin receptor knockout prevents the development of salt-sensitive hypertension

PubMed Central

Li, Wencheng; Peng, Hua; Mehaffey, Eamonn P.; Kimball, Christie D.; Grobe, Justin L.; van Gool, Jeanette M.G.; Sullivan, Michelle N.; Earley, Scott; Danser, A.H. Jan; Ichihara, Atsuhiro; Feng, Yumei

2013-01-01

The (pro)renin receptor, which binds both renin and prorenin, is a newly discovered component of the renin angiotensin system that is highly expressed in the central nervous system. The significance of brain PRRs in mediating local angiotensin II formation and regulating blood pressure remains unclear. The current study was performed to test the hypothesis that PRR-mediated, non-proteolytic activation of prorenin is the main source of angiotensin II in the brain. Thus, PRR knockout in the brain is expected to prevent angiotensin II formation and development of deoxycorticosterone acetate salt induced hypertension. A neuron-specific PRR (ATP6AP2) knockout mouse model was generated using the Cre-LoxP system. Physiological parameters were recorded by telemetry. (Pro)renin receptor expression, detected by immunostaining and RT-PCR, was significantly decreased in the brains of knockout compared with wide-type mice. Intracerebroventricular infusion of mouse prorenin increased blood pressure and angiotensin II formation in wild type mice. This hypertensive response was abolished in (pro)renin receptor knockout mice in association with a reduction in angiotensin II levels. Deoxycorticosterone acetate salt increased (pro)renin receptor expression and angiotensin II formation in the brains of wild-type mice, an effect that was attenuated in (pro)renin receptor knockout mice. (Pro)renin receptor knockout in neurons prevented the development of Deoxycorticosterone acetate salt-induced hypertension as well as activation of cardiac and vasomotor sympathetic tone. In conclusion, non-proteolytic activation of prorenin through binding to the PRR mediates angiotensin II formation in the brain. Neuron-specific PRR knockout prevents the development of deoxycorticosterone acetate salt-induced hypertension, possibly through diminished angiotensin II formation. PMID:24246383

PEP-on-DEP: A competitive peptide-based disposable electrochemical aptasensor for renin diagnostics.

PubMed

Biyani, Manish; Kawai, Keiko; Kitamura, Koichiro; Chikae, Miyuki; Biyani, Madhu; Ushijima, Hiromi; Tamiya, Eiichi; Yoneda, Takashi; Takamura, Yuzuru

2016-10-15

Antibody-based immunosensors are relatively less accessible to a wide variety of unreachable targets, such as low-molecular-weight biomarkers that represent a rich untapped source of disease-specific diagnostic information. Here, we present a peptide aptamer-based electrochemical sensor technology called 'PEP-on-DEP' to detect less accessible target molecules, such as renin, and to improve the quality of life. Peptide-based aptamers represent a relatively smart class of affinity binders and show great promise in biosensor development. Renin is involved in the regulation of arterial blood pressure and is an emerging biomarker protein for predicting cardiovascular risk and prognosis. To our knowledge, no studies have described aptamer molecules that can be used as new potent probes for renin. Here, we describe a portable electrochemical biosensor platform based on the newly identified peptide aptamer molecules for renin. We constructed a randomized octapeptide library pool with diversified sequences and selected renin specific peptide aptamers using cDNA display technology. We identified a few peptide aptamer sequences with a KD in the µM binding affinity range for renin. Next, we grafted the selected peptide aptamers onto gold nanoparticles and detected renin in a one-step competitive assay using our originally developed DEP (Disposable Electrochemical Printed) chip and a USB powered portable potentiostat system. We successfully detected renin in as little as 300ngmL(-1) using the PEP-on-DEP method. Thus, the generation and characterization of novel probes for unreachable target molecules by merging a newly identified peptide aptamer with electrochemical transduction allowed for the development of a more practical biosensor that, in principle, can be adapted to develop a portable, low-cost and mass-producible biosensor for point-of-care applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Intrarenal and Intravenous Infusion of the Phosphodiesterase 3 Inhibitor Milrinone on Renin Secretion

NASA Technical Reports Server (NTRS)

Kumagai, Kazuhiro; Reid, Ian A.

1994-01-01

We have reported that administration of the phosphodiesterase III inhibitor milrinone increases renin secretion in conscious rabbits. The aim of the present study was to determine if the increase in renin secretion results from a direct renal action of milrinone, or from an indirect extrarenal effect of the drug. This was accomplished by comparing the effects of intrarenal and intravenous infusion of graded doses of milrinone on plasma renin activity in unilaterally nephrectomized conscious rabbits. Milrinone was infused into the renal artery in doses of 0.01, 0.1 and 1.0 micro-g/kg/min, and intravenously in the same rabbits in doses of 0.01, 0.1, 1.0 and 10 micro-g/kg/min. Each dose was infused for 15 min. No intrarenal dose of milrinone altered plasma renin activity or arterial pressure, although at the highest dose, there was a small increase in heart rate. Intravenous infusion of milrinone at 1.0 micro-g/kg/min increased plasma renin activity to 176 +/- 55% of the control value (P less than 0.05). Heart rate increased but arterial pressure did not change. Intravenous infusion of milrinone at 1O micro-g/kg/min increased plasma renin activity to 386 +/- 193% of control in association with a decrease in arterial pressure and an increase in heart rate. These results confirm that milrinone increases renin secretion, and indicate that the stimulation is due to an extrarenal effect of the drug.

Sequential changes in the human renin-angiotensin system following therapeutic termination of pregnancy.

PubMed

Broughton Pipkin, F; Oats, J J; Hunter, J C; Craven, D J; Symonds, E M

1979-04-01

Plasma renin and angiotensin II levels were measured in nine patients immediately before and at half-hourly intervals in the four hours following therapeutic termination of pregnancy. There was a small fall in renin and angiotensin II levels over the first 1 to 2 hours, followed by a slight increase. The magnitude of these effects was much smaller than those previously seen following normal delivery. It is concluded that in early pregnancy maternal, rather than feto-placental, factors are controlling the renin-angiotensin system.

Molecular cardiology: the beat goes on

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

Bialy, H.

1987-06-01

Recombination DNA techniques have given cardiac physiologists their first access to the genes, proteins, and chemical signals that regulate the human heart. Scientists have been investigating the molecular biology of the angiotensinogen converting enzyme, renin, and of atrial natriuretic factor (ANF), an important cardiac-peptide hormone with a wide range of physiologic activities. Renin initiates a regulatory cascade that eventually produces angiotensin II, a potent hypertensive agent. By studying renin's genetic organization, and protein chemistry, scientists hope to be able to design a rational therapeutic to specifically inhibit this aspartyl protease. To determine if renin is endogenously produced or if itmore » makes its way to these cells through the circulation. A combination of fluorescent-labeled antibodies and radio-labeled nucleic acid probes derived from renin cDNA were used.« less

New approaches to hyperkalemia in patients with indications for renin angiotensin aldosterone inhibitors: Considerations for trial design and regulatory approval.

PubMed

Zannad, Faiez; Rossignol, Patrick; Stough, Wendy Gattis; Epstein, Murray; Alonso Garcia, Maria de Los Angeles; Bakris, George L; Butler, Javed; Kosiborod, Mikhail; Berman, Lance; Mebazaa, Alexandre; Rasmussen, Henrik S; Ruilope, Luis M; Stockbridge, Norman; Thompson, Aliza; Wittes, Janet; Pitt, Bertram

2016-08-01

Hyperkalemia is a common clinical problem, especially in patients with chronic kidney disease, diabetes mellitus, or heart failure. Treatment with renin angiotensin aldosterone system inhibitors exacerbates the risk of hyperkalemia in these patients. Concern about hyperkalemia can result in the failure to initiate, suboptimal dosing, or discontinuation of renin angiotensin aldosterone system inhibitor therapy in patients; effective treatments for hyperkalemia might mitigate such undertreatment. New treatments for hyperkalemia in development may offer better efficacy, tolerability and safety profiles than do existing approved treatments. These compounds might enable more eligible patients to receive renin angiotensin aldosterone system inhibitor therapy or to receive renin angiotensin aldosterone system inhibitors at target doses. The evidence needed to support a treatment claim (reduction in serum potassium) differs from that needed to support a prevention claim (preventing hyperkalemia to allow renin angiotensin aldosterone system inhibitor treatment). Thus, several issues related to clinical trial design and drug development need to be considered. This paper summarizes and expands upon a discussion at the Global Cardiovascular Clinical Trialists 2014 Forum and examines methodologic considerations for trials of new potassium binders for the prevention and management of hyperkalemia in patients with renin angiotensin aldosterone system inhibitor indications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characteristics of renin release from isolated superfused glomeruli in vitro.

PubMed Central

Blendstrup, K; Leyssac, P P; Poulsen, K; Skinner, S L

1975-01-01

1. A method is described for studying renin release from superfused rat glomeruli following their rapid isolation by a magnetic iron-oxide technique. 2. Microscopically selected glomeruli were free of tubular components. Some possessed vascular pole protrusions of up to 20 mum, unrelated to renin content. 3. Renin content of 102 batches, each of 400 glomeruli, was 1.34 plus or minus 0.08 times 10-4 Goldblatt hog units per 100 glomeruli (plus or minus S.E. of mean). Different osmolarities (305, 355 and 400 m-osmole/1.), sodium concentrations (110 and 135 mM) and buffer compositions of the preparation solution did not alter this value. Renin content per glomerulus in intact kidney was 100-fold higher. 4. At 30 degrees C the contained juxtaglomerular cells released renin at consistent but decreasing rates over 4-6 hr. Initial release rate in 110 mM sodium, 305 m-osmole/1. solutions were 0.86 plus or minus 0.068 times 10-6 units per 100 glomeruli per 30 min (plus or minus S.E. of mean, n = 42) or 0.546 plus or minus 0.046 percent of content per 30 min. In 135 mM sodium, 305 m-osmole/1. solutions, release was 2.4-fold higher (P less than 0.001) and remained elevated for at least 3 hr. When related to renin content per glomerulus resting release rate in vitro was higher by at most one order of magnitude than calculated in vivo values. 5. Release was augmented by gentle physical agitation of the glomeruli. 6. Release rate was inversely ralated to temperature. On reducing temperature from 30 degrees C, release increased 2.6-fold at 20 degrees C and 6.7-fold at 10 degrees C (P less than 0.001, n = 11). The response was reversible. 7. 3 mM sodium cyanide plus 3 mM sodium iodoacetate caused a variable release of renin associated with depletion of content within 4 hr. The response was progressive and reached a peak after 60 min. 8. Sensitivity of renin release to temperature and metabolic blockade indicates that energy is required for retention of renin by the cell. This, together with the release observed with increased sodium concentration at constant osmolarity, suggests a dependence of renin release upon the mechanism controlling the volume of the juxtaglomerular cell or its organelles. PMID:1133791

Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

NASA Technical Reports Server (NTRS)

Reid, Ian A.

1994-01-01

Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric oxide donors in vitro and in vivo has variable effects on vasopressin secretion, but the most common one is inhibition. Blockade of nitric oxide synthesis has been reported to increase vasopressin secretion, but again variable results have been obtained. An attractive working hypothesis is that nitric oxide serves a neuromodulatory role as an inhibitor of vasopressin secretion.

Analysis of postoperative biochemical values and clinical outcomes after adrenalectomy for primary aldosteronism.

PubMed

Swearingen, Andrew J; Kahramangil, Bora; Monteiro, Rosebel; Krishnamurthy, Vikram; Jin, Judy; Shin, Joyce; Siperstein, Allan; Berber, Eren

2018-04-01

Primary aldosteronism causes hypertension and hypokalemia and is often surgically treatable. Diagnosis includes elevated plasma aldosterone, suppressed plasma renin activity, and elevated aldosterone renin ratio. Adrenalectomy improves hypertension and hypokalemia. Postoperative plasma aldosterone and plasma renin activity may be useful in documenting cure or failure. A retrospective analysis of patients who underwent adrenalectomy for primary aldosteronism from 2010 to 2016 was performed, analyzing preoperative and postoperative plasma aldosterone, plasma renin activity, hypertension, and hypokalemia. The utility of postoperative testing was assessed. Clinical cure was defined as improved hypertension control and resolution of potassium loss. Biochemical cure was defined as aldosterone renin ratio reduction to <23.6. Forty-four patients were included; 20 had plasma aldosterone and plasma renin activity checked on postoperative day 1. In the study, 40/44 (91%) were clinically cured. All clinical failures had of biochemical failure at follow-up. Postoperative day 1aldosterone renin ratio <23.6 had PPV of 95% for clinical cure. Cured patients had mean plasma aldosterone drop of 33.1 ng/dL on postoperative day 1; noncured patient experienced 3.9 ng/dL increase. A cutoff of plasma aldosterone decrease of 10 ng/dL had high positive predictive value for clinical cure. Changes in plasma aldosterone and plasma renin activity after adrenalectomy correlate with improved hypertension and hypokalemia. The biochemical impact of adrenalectomy manifests as early as postoperative day 1. We propose a plasma aldosterone decrease of 10 ng/dL as a criterion to predict clinical cure. Copyright © 2017 Elsevier Inc. All rights reserved.

Controlled treatment of primary hypertension with propranolol and spironolactone. A crossover study with special reference to initial plasma renin activity.

PubMed

Karlberg, B E; Kågedal, B; Tegler, L; Tolagen, K; Bergman, B

1976-03-31

Twenty-seven patients with hypertension were randomly allocated to a 10 month crossover study. Treatment consisted of spironolactone (200 mg/day for 2 months), propranolol (320 mg/day for 2 months) and combined administration of both drugs at half the dosage. Between treatment periods placebo was given for 2 months. Fourteen patients were previously untreated. The average pretreatment blood pressure for the entire group was 188/114 +/- 16/7(mean +/- standard deviation) mm Hg supine and 188/118 +/- 20/9 mm Hg standing. Both spironolactone and propranolol reduced blood pressure significantly in both the supine and standing positions. Upright plasma renin activity was determined by radioimmunoassay of angiotensin I. The average initial level was 1.9 +/- 1.2 (range 0.4 to 5.0) ng/ml/hr. There was a close correlation between plasma renin activity and the effects of the drugs: With increasing renin level the response to propranolol was better whereas the opposite was true for spironolactone. The combination of spironolactone and propranolol decreased the blood pressure still further in the supine and standing positions, irrespective of initial plasma renin activity. All patients achieved a normal supine pressure. Blood pressure and plasma renin activity returned toward pretreatment values during placebo administration. It is concluded that pretreatment levels of plasma renin activity can predict the antihypertensive response to propranolol and spironolactone. The combination of the two drugs, which have different modes of action, will effectively reduce blood pressure in hypertension. The results support the concept that the renin-angiotensin-aldo-sterone system may be involved in primary hypertension.

Studies on the Release of Renin by Direct and Reflex Activation of Renal Sympathetic Nerves.

ERIC Educational Resources Information Center

Donald, David E.

1979-01-01

Presents data on release of renin during direct and indirect stimulation of renal nerves. Conclusions show that renin release is influenced by change in activity of carotid and cardiopulmonary baroreceptor systems, and excitation of discrete areas of brain and hypothalamus by changes in renal sympathetic nerve. (Author/SA)

Current laboratory requirements for adrenocorticotropic hormone and renin/aldosterone sample handling are unnecessarily restrictive.

PubMed

Chakera, Ali J; McDonald, Timothy J; Knight, Bridget A; Vaidya, Bijay; Jones, Angus G

2017-02-01

Samples for adrenocorticotropic hormone (ACTH) and aldosterone/renin analysis usually require rapid transport to the receiving laboratory for immediate separation and freezing. In practice, this means assessment is limited to hospital settings and many samples are rejected. We examined whether these requirements are necessary by assessing the stability of ACTH, aldosterone and renin over 48 hours in whole blood collected in serum gel and EDTA plasma from 31 participants. Our results show that ACTH collected into EDTA plasma is stable at room temperature for at least 6 hours, mean change at 6 hours -2.6% (95% CI -9.7 to 4.5). Both aldosterone and renin were stable collected on serum gel at room temperature for at least 6 hours: mean change aldosterone +0.2% (95% CI -3.6 to 4.0), renin -1.9% (95% CI -7.0 to3.2). Therefore, by using appropriate preservatives, ACTH and aldosterone/renin can be measured on samples collected at room temperature and processed within 6 hours. This would facilitate outpatient and emergency room assessment of these analytes. © Royal College of Physicians 2017. All rights reserved.

Evolution and Variation of Renin Genes in Mice

PubMed Central

Dickinson, Douglas P.; Gross, Kenneth W.; Piccini, Nina; Wilson, Carol M.

1984-01-01

Inbred strains of mice carry Ren-1, a gene encoding the thermostable Renin-1 isozyme. Ren-1 is expressed at relatively low levels in mouse submandibular gland and kidney. Some strains also carry Ren-2, a gene encoding the thermolabile Renin-2 isozyme. Ren-2 is expressed at high levels in the mouse submandibular gland and at very low levels, if at all, in the kidney. Ren-1 and Ren-2 are closely linked on mouse chromosome 1, show extensive homology in coding and noncoding regions and provide a model for studying the regulation of gene expression. An investigation of renin genes and enzymatic activity in wild-derived mice identified several restriction site polymorphisms as well as putative variants in renin gene expression and protein structure. The number of renin genes carried by different subpopulations of wild-derived mice is consistent with the occurrence of a gene duplication event prior to the divergence of M. spretus (2.75–5.5 million yr ago). This conclusion is in agreement with a prior estimate based upon comparative sequence analysis of Ren-1 and Ren-2 from inbred laboratory mice. PMID:6389258

Budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme upon high-altitude exposure

PubMed Central

Li, Hui-Jie; Zheng, Cheng-Rong; Chen, Guo-Zhu; Qin, Jun; Zhang, Ji-Hang; Yu, Jie; Zhang, En-Hao; Huang, Lan

2016-01-01

Introduction: Inhaled budesonide is a novel approach to prevent acute mountain sickness (AMS). However, its mechanism is not completely understood. We aimed to investigate the effects of budesonide and dexamethasone on renin–angiotensin–aldosterone system in AMS prevention. Materials and methods: Data were obtained from a randomised controlled trial including 138 participants. The participants were randomly assigned to receive budesonide, dexamethasone or placebo as prophylaxis before they travelled to 3450 m altitude from 400 m by car. Their plasma concentrations of renin, angiotensin-converting enzyme (ACE) and aldosterone were measured at both altitudes. Results: All parameters were comparable among the three groups at 400 m. After high-altitude exposure of 3450, renin in all groups increased significantly; the ACE, aldosterone concentrations, as well as the aldosterone/renin ratio, rose markedly in the dexamethasone and placebo groups but not in the budesonide group. Moreover, the aldosterone/renin ratio correlated closely with ACE concentration. Conclusions: Upon acute high-altitude exposure, budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme. PMID:27317302

The evolution of renin-angiotensin blockade: angiotensin-converting enzyme inhibitors as the starting point.

PubMed

Sica, Domenic A

2010-04-01

The renin-angiotensin system has been a target in the treatment of hypertension for close to three decades. Several medication classes that block specific aspects of this system have emerged as useful therapies, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and, most recently, direct renin inhibitors. There has been a natural history to the development of each of these three drug classes, starting with their use as antihypertensive agents; thereafter, in each case they have been employed as end-organ protective agents. To date, there has been scant evidence to favor angiotensin receptor blockers or direct renin inhibitors over angiotensin-converting enzyme inhibitors in treating hypertension or in affording end-organ protection; thus, angiotensin-converting enzyme inhibitors remain the standard of care when renin-angiotensin system blockade is warranted.

Effect of Blockade of Nitric Oxide Synthesis on the Renin Secretory Response to Frusemide in Conscious Rabbits

NASA Technical Reports Server (NTRS)

Reid, Ian A.; Chou, Lance

1995-01-01

The enzyme nitric oxide synthase is present in the macula densa and may participate in the control of renin secretion by the adjacent juxtagiomerular cells. In the present study, we investigated the effect of inhibiting nitric oxide synthase on the renin secretory response to frusemide, which stimulates renin secretion by blocking Na(+)-K(+)-2Cl(-) co-transport in the macula densa. Injection of frusemide in 12 conscious rabbits elicited a transient increase in mean arterial pressure from 84 +/- 2 to 92 +/-3 mm Hg at 5 min (P less than 0.01) and a sustained increase in heart rate from 246 +/- 6 to 281 +/- 10 beats/min at 45 min (P less than 0.01). Plasma renin activity increased from 8.0 +/- 1.2 to 14.3 +/- 1.8, 12.4 +/- 1.6 and 11.6 +/- 1.5 pmol/2h ml at 15, 30 and 45min respectively (P less than 0.01). There were no changes in plasma sodium and potassium concentrations or osmoiality. Inhibition of nitric oxide synthase with N(sup G)-nitro-L- arginine methyl ester increased mean arterial pressure by 9 mm Hg, decreased heart rate and plasma renin activity, and markedly suppressed the renin response to frusemide (from 4.6 +/- 0.7 to 7.6 +/- 1.7, 4.7 +/- 1.0 and 4.6 +/- 0.7pmol/2h ml at 15, 30 and 45 min respectively). By contrast, infusion of an equipressor dose of phenylephrine did not suppress the renin response to frusemide. Histochemical studies with the NADPH diaphorase technique confirmed the presence of nitric oxide synthase in the macula densa, and suggested that enzyme activity is increased by treatment with frusemide. These results are consistent with a role for the L- arginine-nitric oxide pathway in the modulation of renin secretion by the macula densa.

Calcium-dependent phosphodiesterase 1C inhibits renin release from isolated juxtaglomerular cells

PubMed Central

Ortiz-Capisano, M. Cecilia; Liao, Tang-Dong; Ortiz, Pablo A.

2009-01-01

Renin release from the juxtaglomerular (JG) cell is stimulated by the second messenger cAMP and inhibited by calcium. We previously showed JG cells contain a calcium sensing receptor (CaSR), which, when stimulated, decreases cAMP formation and inhibits renin release. We hypothesize CaSR activation decreases cAMP and renin release, in part, by stimulating a calcium calmodulin-activated phosphodiesterase 1 (PDE1). We incubated our primary culture of JG cells with two selective PDE1 inhibitors [8-methoxymethil-IBMX (8-MM-IBMX; 20 μM) and vinpocetine (40 μM)] and the calmodulin inhibitor W-7 (10 μM) and measured cAMP and renin release. Stimulation of the JG cell CaSR with the calcimimetic cinacalcet (1 μM) resulted in decreased cAMP from a basal of 1.13 ± 0.14 to 0.69 ± 0.08 pM/mg protein (P < 0.001) and in renin release from 0.89 ± 0.16 to 0.38 ± 0.08 μg ANG I/ml·h−1·mg protein−1 (P < 0.001). However, the addition of 8-MM-IBMX with cinacalcet returned both cAMP (1.10 ± 0.19 pM/mg protein) and renin (0.57 ± 0.16 μg ANG I/ml·h−1·mg protein−1) to basal levels. Similar results were obtained with vinpocetine, and also with W-7. Combining 8-MM-IBMX and W-7 had no additive effect. To determine which PDE1 isoform is involved, we performed Western blot analysis for PDE1A, B, and C. Only Western blot analysis for PDE1C showed a characteristic band apparent at 80 kDa. Immunofluorescence showed cytoplasmic distribution of PDE1C and renin in the JG cells. In conclusion, PDE1C is expressed in isolated JG cells, and contributes to calcium's inhibitory modulation of renin release from JG cells. PMID:19741056

Associations of aldosterone and renin concentrations with inflammation-the Study of Health in Pomerania and the German Conn's Registry.

PubMed

Grotevendt, A; Wallaschofski, H; Reincke, M; Adolf, C; Quinkler, M; Nauck, M; Hoffmann, W; Rettig, R; Hannemann, A

2017-08-01

Chronic inflammation is an age-independent and body mass index-independent contributor to the development of multi-morbidity. Alterations of the renin-angiotensin-aldosterone system are observed within the context of proinflammatory states. We assessed circulating aldosterone, renin, and inflammatory biomarker concentrations in healthy, normotensive subjects and patients with primary aldosteronism. We included 1177 normotensive individuals from the population-based Study of Health in Pomerania (first follow-up, Study of Health in Pomerania-1) and 103 primary aldosteronism patients from the German Conn's Registry. A 1:1 matching for sex, age, body mass index, smoking status, diabetes mellitus, and the estimated glomerular filtration rate was performed to determine whether primary aldosteronism patients exhibit higher inflammatory biomarker concentrations than normotensive controls. The associations of plasma aldosterone concentration or plasma renin concentration with circulating fibrinogen concentrations, white blood cell count, and high sensitive C-reactive protein concentrations in the normotensive sample were determined with multivariable linear and logistic regression analyses. 1:1 matched primary aldosteronism patients demonstrated significantly (p < 0.01) higher plasma aldosterone concentration (198 vs. 47 ng/l), lower plasma renin concentration (3.1 vs. 7.7 ng/l) and higher high sensitive C-reactive protein concentrations (1.5 vs. 1.0 mg/l) than normotensive controls. Within the normotensive cohort, plasma renin concentration but not plasma aldosterone concentration was positively associated with fibrinogen concentrations and white blood cell count. Further, a J-shaped association between plasma renin concentration and high sensitive C-reactive protein concentrations was detected. High plasma aldosterone concentration in a primary aldosteronism cohort and high plasma renin concentration in normotensive subjects are associated with increased concentrations of inflammatory biomarkers. This suggests a link between the renin-angiotensin-aldosterone system and inflammatory processes in patients with primary aldosteronism and even in normotensive subjects.

Bovine ovarian cells have (pro)renin receptors and prorenin induces resumption of meiosis in vitro.

PubMed

Dau, Andressa Minussi Pereira; da Silva, Eduardo Pradebon; da Rosa, Paulo Roberto Antunes; Bastiani, Felipe Tusi; Gutierrez, Karina; Ilha, Gustavo Freitas; Comim, Fabio Vasconcellos; Gonçalves, Paulo Bayard Dias

2016-07-01

The discovery of a receptor that binds prorenin and renin in human endothelial and mesangial cells highlights the possible effect of renin-independent prorenin in the resumption of meiosis in oocytes that was postulated in the 1980s.This study aimed to identify the (pro)renin receptor in the ovary and to assess the effect of prorenin on meiotic resumption. The (pro)renin receptor protein was detected in bovine cumulus-oocyte complexes, theca cells, granulosa cells, and in the corpus luteum. Abundant (pro)renin receptor messenger ribonucleic acid (mRNA) was detected in the oocytes and cumulus cells, while prorenin mRNA was identified in the cumulus cells only. Prorenin at concentrations of 10(-10), 10(-9), and 10(-8)M incubated with oocytes co-cultured with follicular hemisections for 15h caused the resumption of oocyte meiosis. Aliskiren, which inhibits free renin and receptor-bound renin/prorenin, at concentrations of 10(-7), 10(-5), and 10(-3)M blocked this effect (P<0.05). To determine the involvement of angiotensin II in prorenin-induced meiosis resumption, cumulus-oocyte complexes and follicular hemisections were treated with prorenin and with angiotensin II or saralasin (angiotensin II antagonist). Prorenin induced the resumption of meiosis independently of angiotensin II. Furthermore, cumulus-oocyte complexes cultured with forskolin (200μM) and treated with prorenin and aliskiren did not exhibit a prorenin-induced resumption of meiosis (P<0.05). Only the oocytes' cyclic adenosine monophosphate levels seemed to be regulated by prorenin and/or forskolin treatment after incubation for 6h. To the best of our knowledge, this is the first study to identify the (pro)renin receptor in ovarian cells and to demonstrate the independent role of prorenin in the resumption of oocyte meiosis in cattle. Copyright © 2016 Elsevier Inc. All rights reserved.

Peripheral and central interactions between the renin-angiotensin system and the renal sympathetic nerves in control of renal function.

PubMed

DiBona, G F

2001-06-01

Increases in renal sympathetic nerve activity (RSNA) regulate the functions of the nephron, the vasculature, and the renin-containing juxtaglomerular granular cells. As increased activity of the renin-angiotensin system can also influence nephron and vascular function, it is important to understand the interactions between RSNA and the renin-angiotensin system in the control of renal function. These interactions can be intrarenal, that is, the direct (via specific innervation) and indirect (via angiotensin II) contributions of increased RSNA to the regulation of renal function. The effects of increased RSNA on renal function are attenuated when the activity of the renin-angiotensin system is suppressed or antagonized with angiotensin-converting enzyme inhibitors or angiotensin II-type AT1 receptor antagonists. The effects of intrarenal administration of angiotensin II are attenuated following renal denervation. These interactions can also be extrarenal, that is, in the central nervous system, wherein RSNA and its arterial baroreflex control are modulated by changes in activity of the renin-angiotensin system. In addition to the circumventricular organs, the permeable blood-brain barrier of which permits interactions with circulating angiotensin II, there are interactions at sites behind the blood-brain barrier that depend on the influence of local angiotensin II. The responses to central administration of angiotensin II type AT1 receptor antagonists, into the ventricular system or microinjected into the rostral ventrolateral medulla, are modulated by changes in activity of the renin-angiotensin system produced by physiological changes in dietary sodium intake. Similar modulation is observed in pathophysiological models wherein activity of both the renin-angiotensin and sympathetic nervous systems is increased (e.g., congestive heart failure). Thus, both renal and extrarenal sites of interaction between the renin-angiotensin system and RSNA are involved in influencing the neural control of renal function.

Nervous kidney. Interaction between renal sympathetic nerves and the renin-angiotensin system in the control of renal function.

PubMed

DiBona, G F

2000-12-01

Increases in renal sympathetic nerve activity regulate the functions of the nephron, the vasculature, and the renin-containing juxtaglomerular granular cells. Because increased activity of the renin-angiotensin system can also influence nephron and vascular function, it is important to understand the interactions between the renal sympathetic nerves and the renin-angiotensin system in the control of renal function. These interactions can be intrarenal, for example, the direct (by specific innervation) and indirect (by angiotensin II) contributions of increased renal sympathetic nerve activity to the regulation of renal function. The effects of increased renal sympathetic nerve activity on renal function are attenuated when the activity of the renin-angiotensin system is suppressed or antagonized with ACE inhibitors or angiotensin II-type AT(1)-receptor antagonists. The effects of intrarenal administration of angiotensin II are attenuated after renal denervation. These interactions can also be extrarenal, for example, in the central nervous system, wherein renal sympathetic nerve activity and its arterial baroreflex control are modulated by changes in activity of the renin-angiotensin system. In addition to the circumventricular organs, whose permeable blood-brain barrier permits interactions with circulating angiotensin II, there are interactions at sites behind the blood-brain barrier that depend on the influence of local angiotensin II. The responses to central administration of angiotensin II-type AT(1)-receptor antagonists into the ventricular system or microinjected into the rostral ventrolateral medulla are modulated by changes in activity of the renin-angiotensin system produced by physiological changes in dietary sodium intake. Similar modulation is observed in pathophysiological models wherein activity of both the renin-angiotensin and sympathetic nervous systems is increased (eg, congestive heart failure). Thus, both renal and extrarenal sites of interaction between the renin-angiotensin system and renal sympathetic nerve activity are involved in influencing the neural control of renal function.

Genome-Wide Meta-Analyses of Plasma Renin Activity and Concentration Reveal Association with the Kininogen 1 and Prekallikrein Genes

PubMed Central

Lieb, Wolfgang; Chen, Ming-Huei; Teumer, Alexander; de Boer, Rudolf A.; Lin, Honghuang; Fox, Ervin R.; Musani, Solomon K.; Wilson, James G.; Wang, Thomas J.; Völzke, Henry; Petersen, Ann-Kristin; Meisinger, Christine; Nauck, Matthias; Schlesinger, Sabrina; Li, Yong; Menard, Jöel; Hercberg, Serge; Wichmann, H.-Erich; Völker, Uwe; Rawal, Rajesh; Bidlingmaier, Martin; Hannemann, Anke; Dörr, Marcus; Rettig, Rainer; van Gilst, Wiek H.; van Veldhuisen, Dirk J.; Bakker, Stephan J.L.; Navis, Gerjan; Wallaschofski, Henri; Meneton, Pierre; van der Harst, Pim; Reincke, Martin; Vasan, Ramachandran S.; Consortium, CKDGen

2015-01-01

Background The renin-angiotensin-aldosterone-system (RAAS) is critical for regulation of blood pressure and fluid balance and influences cardiovascular remodeling. Dysregulation of the RAAS contributes to cardiovascular and renal morbidity. The genetic architecture of circulating RAAS components is incompletely understood. Methods and Results We meta-analyzed genome-wide association data for plasma renin activity (n=5,275), plasma renin concentrations (n=8,014) and circulating aldosterone (n=13,289) from up to four population-based cohorts of European and European-American ancestry, and assessed replication of the top results in an independent sample (n=6,487). Single nucleotide polymorphisms (SNPs) in two independent loci displayed associations with plasma renin activity atgenome-wide significance (p<5×10-8). A third locus was close to this threshold (rs4253311 in kallikrein B [KLKB1], p=5.5×10-8). Two of these loci replicated in an independent sample for both plasma renin and aldosterone concentrations (SNP rs5030062 in kininogen 1 [KNG1]: p=0.001 for plasma renin, p=0.024 for plasma aldosterone concentration; rs4253311 with p<0.001 for both plasma renin and aldosterone concentration). SNPs in the NEBL gene reached genome-wide significance for plasma renin concentration in the discovery sample (top SNP rs3915911, p= 8.81×10-9), but did not replicate (p=0.81). No locus reached genome-wide significance for aldosterone. SNPs rs5030062 and rs4253311 were not related to blood pressure or renal traits; in a companion study, variants in the kallikrein B locus were associated with B-type natriuretic peptide concentrations in African-Americans. Conclusions We identified two genetic loci (kininogen 1 and kallikrein B) influencing key components of the RAAS, consistent with the close interrelation between the kallikrein-kinin system and the RAAS. PMID:25477429

A novel interaction between sympathetic overactivity and aberrant regulation of renin by miR-181a in BPH/2J genetically hypertensive mice.

PubMed

Jackson, Kristy L; Marques, Francine Z; Watson, Anna M D; Palma-Rigo, Kesia; Nguyen-Huu, Thu-Phuc; Morris, Brian J; Charchar, Fadi J; Davern, Pamela J; Head, Geoffrey A

2013-10-01

Genetically hypertensive mice (BPH/2J) are hypertensive because of an exaggerated contribution of the sympathetic nervous system to blood pressure. We hypothesize that an additional contribution to elevated blood pressure is via sympathetically mediated activation of the intrarenal renin-angiotensin system. Our aim was to determine the contribution of the renin-angiotensin system and sympathetic nervous system to hypertension in BPH/2J mice. BPH/2J and normotensive BPN/3J mice were preimplanted with radiotelemetry devices to measure blood pressure. Depressor responses to ganglion blocker pentolinium (5 mg/kg i.p.) in mice pretreated with the angiotensin-converting enzyme inhibitor enalaprilat (1.5 mg/kg i.p.) revealed a 2-fold greater sympathetic contribution to blood pressure in BPH/2J mice during the active and inactive period. However, the depressor response to enalaprilat was 4-fold greater in BPH/2J compared with BPN/3J mice, but only during the active period (P=0.01). This was associated with 1.6-fold higher renal renin messenger RNA (mRNA; P=0.02) and 0.8-fold lower abundance of micro-RNA-181a (P=0.03), identified previously as regulating human renin mRNA. Renin mRNA levels correlated positively with depressor responses to pentolinium (r=0.99; P=0.001), and BPH/2J mice had greater renal sympathetic innervation density as identified by tyrosine hydroxylase staining of cortical tubules. Although there is a major sympathetic contribution to hypertension in BPH/2J mice, the renin-angiotensin system also contributes, doing so to a greater extent during the active period and less during the inactive period. This is the opposite of the normal renin-angiotensin system circadian pattern. We suggest that renal hyperinnervation and enhanced sympathetically induced renin synthesis mediated by lower micro-RNA-181a contributes to hypertension in BPH/2J mice.

Lack of effect of vasopressin replacement on renin hypersecretion in Brattleboro rats

NASA Technical Reports Server (NTRS)

Golin, Raffaello M. A.; Gotoh, Eiji; Keil, Lanny C.; Shackelford, Roy L.; Ganong, William F.

1989-01-01

The congenital vasopressin deficiency in homozygous Brattleboro rats with diabetes insipidus is associated with elevated plasma renin activity at rest and supernormal responses to stimuli that increase renin secretion. The mechanism underlying this phenomenon was investigated by infusing homozygous and heterozygous Brattleboro rats with a dose of arginine vasopressin that restored plasma vasopressin to normal in the homozygous animals. The resulting data indicate that increased renin secretion in homozygous rats results from increased sympathetic activity. Because circulating vasopressin does not cross the blood-brain barrier, it seems likely that the increased sympathetic activity is central in origin.

Prorenin induces ERK activation in endothelial cells to enhance neovascularization independently of the renin-angiotensin system

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

Uraoka, Maki; Ikeda, Koji, E-mail: ikedak@koto.kpu-m.ac.jp; Nakagawa, Yusuke

Prorenin is an enzymatically inactive precursor of renin, and its biological function in endothelial cells (ECs) is unknown despite its relevance with the incidence of diabetic microvascular complications. Recently, (pro)renin receptor was identified, and the receptor-associated prorenin system has been discovered, whereas its expression as well as function in ECs remain unclear. In the present study, we found that ECs express the (pro)renin receptor, and that prorenin provoked ERK activation through (pro)renin receptor independently of the renin-angiotensin system (RAS). Prorenin stimulated the proliferation, migration and tube-formation of ECs, while it inhibited endothelial apoptosis induced by serum and growth factor depletion.more » MEK inhibitor abrogated these proangiogenic effects of prorenin, while AT1 receptor antagonist or angiotensin-converting enzyme inhibitor failed to block them. In vivo neovascularization in the Matrigel-plugs implanted into mouse flanks was significantly enhanced by prorenin, in which significant ERK activation was detected in ECs. Furthermore, tumor xenografts stably transfected with prorenin demonstrated the significantly accelerated growth rate concomitantly with enhanced intratumoral neovascularization. Our data demonstrated that the RAS-independent (pro)renin receptor-mediated signal transduction plays a pivotal role in the regulation of ECs function as well as in the neovascularization, and thus prorenin is potentially involved in the pathophysiology of diabetic microvascular complications as well as cancers.« less

Different antihypertensive effect of beta-blocking drugs in low and normal-high renin hypertension.

PubMed

Kralberg, B E; Tolagen, K

1976-05-31

The treatment response to beta-adrenoceptor blocking drugs was compared in two groups of patients with primary (essential) hypertension and different renin levels. Each group consisted of 25 patients and was equally distributed regarding age, severity and stage of hypertension. In the first group (group 1), the mean upright plasma renin activity was 0.8 ng ml-1h-1 (range 0.3 to 1.5) and the patients were considered to have low renin hypertension. In the other group (group 2) the patients had a mean plasma renin activity of 2.1 ng ml-1h-1 (range 1.1 to 5.1) and were considered to have normal to high renin hypertension. In both groups the patients were initially treated with beta-blocking drugs; in group 1 with a beta-blocker corresponding to an average dose of 311 mg propranolol a day for at least eight weeks and in group 2 with propranolol 320 mg a day in a fixed dose for eight weeks. The hypotensive response differed significantly between the two groups (p less than 0.001). In group 1 the pretreatment blood pressure was 197/117 mm Hg supine and 198/120 mm Hg standing. During treatment blood pressure decreased only 5/3 mm Hg supine and 9/5 mm Hg standing. The pretreatment blood pressure in group 2 was 187/114 mm Hg supine and 186/117 mm Hg standing. Beta-blocking therapy reduced blood pressure 36/23 and 34/18 mm Hg, respectively (both p less than 0.001). Pulse rates fell significantly in the two groups, both in the lying and standing positions. In 17 patients with low renin hypertension (group 1), a volume-depleting drug was added (spironolactone, 14 patients; thiazides, 3 patients) and this achieved a marked fall in blood pressure levels of 38/16 mm Hg supine and 37/19 mm Hg standing (both p less than 0.001). These results suggest the following: (1) Most patients with normal to high plasma renin activity respond well to moderate doses of propranolol. (2) Propranolol given in the same doses is almost without antihypertensive effect in patients with low renin hypertension. (3) A volume factor may be operating in patients with low renin hypertension since a hypotensive effect is demonstrated after the addition of volume-depleting drugs. (4) Determination of plasma renin activity with adequate methods can predict the treatment response to hypotensive agents.

Screening for primary aldosteronism--normal ranges for aldosterone and renin in three South African population groups.

PubMed

Rayner, B L; Myers, J E; Opie, L H; Trinder, Y A; Davidson, J S

2001-07-01

To establish normal ranges for plasma aldosterone, renin and aldosterone/renin (A/R) ratio in South African normotensives under typical outpatient conditions, and to estimate the prevalence of primary aldosteronism (PA) among hypertensives in primary care settings. One hundred and thirty-six normotensive subjects and 154 sex- and age-matched hypertensives at three primary care clinics had measurements of blood pressure, plasma creatinine, K+, aldosterone, plasma renin activity, and spot urine for urinary Na+/creatinine ratio. Medication was not withdrawn before testing. Mean plasma renin activity in black normotensive subjects (0.95 +/- 1.25 ng/ml/h, mean +/- standard deviation (SD)) was significantly lower than in white (2.09 +/- 1.12 ng/ml/h; P < 0.0001) and coloured (1.81 +/- 1.86 ng/ml/h, P = 0.013) normotensives. Mean plasma aldosterone in black normotensives (306 +/- 147 pmol/l) was also significantly lower than in white (506 +/- 324 pmol/l, P = 0.0002) and coloured (418 +/- 304 pmol/l, P = 0.0148) normotensives. In hypertensives, there were no significant differences in renin or aldosterone levels between the three population groups. Urinary Na+/creatinine ratios, an index of Na+ intake, were not significantly different in the three population groups. None of the normotensives had an A/R ratio > or = 1,000 plus aldosterone > or = 750, while 7.1% of hypertensives exceeded these levels, suggesting that they are appropriate criteria for screening for PA. A large fraction of black normotensive subjects had low renin and aldosterone levels compared with whites, suggesting a salt-retaining tendency in black subjects. These results have important implications for the interpretation of plasma renin and aldosterone levels in hypertensive patients. In primary care settings, 7.1% of hypertensives had biochemical results indicating the need for investigation of PA.

The Prorenin and (Pro)renin Receptor: New Players in the Brain Renin-Angiotensin System?

PubMed Central

Li, Wencheng; Peng, Hua; Seth, Dale M.; Feng, Yumei

2012-01-01

It is well known that the brain renin-angiotensin (RAS) system plays an essential role in the development of hypertension, mainly through the modulation of autonomic activities and vasopressin release. However, how the brain synthesizes angiotensin (Ang) II has been a debate for decades, largely due to the low renin activity. This paper first describes the expression of the vasoconstrictive arm of RAS components in the brain as well as their physiological and pathophysiological significance. It then focus on the (pro)renin receptor (PRR), a newly discovered component of the RAS which has a high level in the brain. We review the role of prorenin and PRR in peripheral organs and emphasize the involvement of brain PRR in the pathogenesis of hypertension. Some future perspectives in PRR research are heighted with respect to novel therapeutic target for the treatment of hypertension and other cardiovascular diseases. PMID:23316344

Is renin a risk factor?

PubMed Central

Kirkendall, W. M.; Overturf, M. L.; Druilhet, R. E.

1981-01-01

1. These results show that elevated blood pressure and a hyperlipidemic diet exacerbate atherogenesis in the two kidney, one-clip hypertensive rabbit. Elevated PRA activity was not essential for the hypertension and did not exacerbate atherogenesis. 2. In addition, the experimentally induced, low renin state following DOC-saline did not result in a protective effect on cardiovascular lesions in rabbits fed an atherogenic diet when compared to normal renin controls. 3. Thus, in these experiments neither an increase in plasma renin accelerated atherogenesis, nor did a decrease in PRA slow the rate of production of atherosclerosis in the rabbit. 4. These observations lend no support to the thesis that renin is an independent risk factor when it is generated within the body in response to these stimuli. Indeed, it suggests that in this setting other factors, not PRA, are responsible for both hypertension in the two-kidney, one-clip rabbit and the arterial damage which occurs in this hypercholesterolemic model. PMID:7025426

Renin-angiotensin-aldosterone system inhibition: overview of the therapeutic use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, mineralocorticoid receptor antagonists, and direct renin inhibitors.

PubMed

Mercier, Kelly; Smith, Holly; Biederman, Jason

2014-12-01

Angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy in hypertensive diabetic patients with macroalbuminuria, microalbuminuria, or normoalbuminuria has been repeatedly shown to improve cardiovascular mortality and reduce the decline in glomerular filtration rate. Renin-angiotensin-aldosterone system (RAAS) blockade in normotensive diabetic patients with normoalbuminuria or microalbuminuria cannot be advocated at present. Dual RAAS inhibition with ACE inhibitors plus ARBs or ACE inhibitors plus direct renin inhibitors has failed to improve cardiovascular or renal outcomes but has predisposed patients to serious adverse events. Copyright © 2014 Elsevier Inc. All rights reserved.

Aldosterone to Renin Ratio as a Screening Instrument for Primary Aldosteronism in a Middle-Aged Population with Atrial Fibrillation.

PubMed

Mourtzinis, Georgios; Ebrahimi, Ahmad; Gustafsson, Helena; Johannsson, Gudmundur; Manhem, Karin

2017-11-01

Atrial fibrillation seems to be overrepresented among patients with primary aldosteronism. The aim of this study was to determine the usefulness of aldosterone to renin ratio as a screening instrument for primary aldosteronism in an atrial fibrillation population with relatively low cardiovascular risk profile. A total of 149 patients <65 years and with history of AF were screened for primary aldosteronism using aldosterone to renin ratio. Pathologically increased aldosterone to renin ratio (>65 pmol/mIU) was found in 15 participants (10.1%). Further investigation of the positive screened participants and confirmatory saline infusion test resulted in a diagnosis of primary aldosteronism in four individuals out of 149 (2.6%). Three out of the four individuals with primary aldosteronism had previously been diagnosed with hypertension, but only one out of the four had uncontrolled blood pressure, that is, >140/90 mmHg. All participants had normal potassium levels. Individuals with increased aldosterone to renin ratio had significantly higher mean systolic and diastolic blood pressure in comparison to participants with normal aldosterone to renin ratio (136 vs. 126 mmHg, p=0.02 and 84 vs. 78 mmHg, p=0.02). These findings suggest that assessment of aldosterone to renin ratio can be useful for identification of underlying primary aldosteronism in patients with diagnosed atrial fibrillation and hypertension in spite of well controlled blood pressure and normokalemia. © Georg Thieme Verlag KG Stuttgart · New York.

Bimodal Aldosterone Distribution in Low-Renin Hypertension

PubMed Central

2013-01-01

BACKGROUND In low-renin hypertension (LRH), serum aldosterone levels are higher in those subjects with primary aldosteronism and may be lower in those with non-aldosterone mineralocorticoid excess or primary renal sodium retention. We investigated the hypothesis that the frequency distribution of aldosterone in LRH is bimodal. METHODS Of the 3,532 attendees at the sixth examination cycle of the Framingham Offspring Study, 1,831 were included in this cross-sectional analysis after we excluded those with conditions or taking medications such as antihypertensive drugs that might affect renin or aldosterone. RESULTS Three hundred three subjects (17%) had untreated hypertension (SBP ≥140mm Hg or DBP ≥90mm Hg). LRH, defined as plasma renin ≤5 mU/L, was present in 93 of those 303 hypertensive subjects (31%). Aldosterone values were adjusted statistically for age, sex, and the urinary sodium/creatinine ratio. In the subjects with LRH, the adjusted aldosterone distribution was bimodal (dip test for unimodality, P = 0.008). The adjusted aldosterone distribution was unimodal in the normal subjects (P = 0.98) and in the hypertensive subjects with normal plasma renin (P = 0.94). CONCLUSIONS In this community-based sample of white subjects, those with low-renin hypertension had a bimodal adjusted aldosterone distribution. Subjects with normal-renin hypertension and subjects with normal blood pressure had unimodal adjusted aldosterone distributions. These findings suggest 2 pathophysiological variants of LRH, one that is aldosterone-dependent and one that is non-aldosterone-dependent. PMID:23757402

Optimization of orally bioavailable alkyl amine renin inhibitors

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

Xu, Zhenrong; Cacatian, Salvacion; Yuan, Jing

2010-09-17

Structure-guided drug design led to new alkylamine renin inhibitors with improved in vitro and in vivo potency. Lead compound 21a, has an IC{sub 50} of 0.83 nM for the inhibition of human renin in plasma (PRA). Oral administration of 21a at 10 mg/kg resulted in >20 h reduction of blood pressure in a double transgenic rat model of hypertension.

Anthology of the renin-angiotensin system: a one hundred reference approach to angiotensin II antagonists.

PubMed

Ménard, J

1993-04-01

To provide a historical overview of the renin-angiotensin system as a guide to the introduction of a new therapeutic pathway, non-peptide inhibition of a angiotensin II. One hundred references were selected as a personal preference, for their originality or for their potential impact on medicine. This review raises the following questions for future research. (1) Will the long-term cardiovascular effects of angiotensin converting enzyme (ACE) inhibition, angiotensin II antagonism and renin inhibition be similar or not, and dependent or independent of blood pressure levels? (2) What are the local-regional interactions between vasoconstrictor and vasodilator systems, and does the renin-angiotensin system synchronize these regional hemodynamic regulatory mechanisms? (3) If hypertension is the result of an interaction between genetic and environmental factors, do proteins secreted through constitutive pathways contribute to the genetic abnormality (prorenin, angiotensinogen, ACE) while regulated secretion (renin) and other regulatory mechanisms (angiotensin II receptors) provide biological support for the environmental effects?

Elevated renin levels in patients with liver cirrhosis and hepatocellular carcinoma.

PubMed

Lotfy, Mahmoud; El-Kenawy, Ayman El-Meghawry; Abdel-Aziz, Mohamed M; El-Kady, Ibrahim; Talaat, Ayman

2010-01-01

Liver fibrosis is the common consequence of chronic liver injury of any etiology, disrupting the normal architecture,and causing hepatocellular dysfunction and portal hypertension. Since the renin-angiotensin system (RAS) may be involved in chronic liver diseases, in the present study we assayed renin levels using ELISA in groups of Egyptian patients with liver cirrhosis (N=32) and hepatocellular carcinoma (HCC) (N=67), for comparison with twenty five healthy controls. The results showed significant differences between the control and liver cirrhosis patients (P<0.001) and also the controls and HCC patients (P<0.001), without significant variation between the patient groups. Furthermore, in HCC patients, it was found that the renin levels negatively correlated with serum albumin and prothrombin time (P=0.003 for each) and positively with α-fetoprotein (P=0.04). Thus, it is concluded that renin levels are elevated in patients with liver cirrhosis and HCC and suitable medical intervention should be placed for management of such alteration. Moreover, further studies are warranted to explore its prognostic significance.

Iminopyrimidinones: A novel pharmacophore for the development of orally active renin inhibitors

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

McKittrick, Brian A.; Caldwell, John P.; Bara, Thomas

2015-04-01

The development of renin inhibitors with favorable oral pharmacokinetic profiles has been a longstanding challenge for the pharmaceutical industry. As part of our work to identify inhibitors of BACE1, we have previously developed iminopyrimidinones as a novel pharmacophore for aspartyl protease inhibition. In this letter we describe how we modified substitution around this pharmacophore to develop a potent, selective and orally active renin inhibitor.

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

Matsumura, Yasuo; Kawazoe, Shinka; Ichihara, Toshio

Extracellular high potassium inhibits renin release in vitro by increasing calcium concentrations in the juxtaglomerular cells. The authors found that the decreased response of renin release from rat kidney cortical slices in high potassium solution changed to a strikingly increased one in the presence of nifedipine at doses over 10{sup {minus}6} M. They then examined the stimulatory effect of extracellular high potassium in the presence of nifedipine on renin release. The enhancement of release was significantly suppressed either by propranolol or by metoprolol but not by prazosin. High potassium plus nifedipine-induced increase in renin release was markedly attenuated by renalmore » denervation. The enhancing effect was not observed when the slices were incubated in calcium-free medium. Divalent cations such as Cd{sup 2+}, Co{sup 2+}, and Mn{sup 2+} blocked this enhancement in a concentration-dependent manner. High potassium elicited an increase in {sup 3}H efflux from the slices preloaded with ({sup 3}H)-norepinephrine. The increasing effect was not influenced by nifedipine but was abolished by the removal of extracellular calcium or by the addition of divalent cations. These observations suggest to us that the high potassium plus nifedipine-induced increase in renin release from the slices is mediated by norepinephrine derived from renal sympathetic nerves and that this neuronally released norepinephrine stimulates renin release via activation of {beta}-adrenoceptors.« less

Elucidation of the binding mechanism of renin using a wide array of computational techniques and biological assays.

PubMed

Tzoupis, Haralambos; Leonis, Georgios; Avramopoulos, Aggelos; Reis, Heribert; Czyżnikowska, Żaneta; Zerva, Sofia; Vergadou, Niki; Peristeras, Loukas D; Papavasileiou, Konstantinos D; Alexis, Michael N; Mavromoustakos, Thomas; Papadopoulos, Manthos G

2015-11-01

We investigate the binding mechanism in renin complexes, involving three drugs (remikiren, zankiren and enalkiren) and one lead compound, which was selected after screening the ZINC database. For this purpose, we used ab initio methods (the effective fragment potential, the variational perturbation theory, the energy decomposition analysis, the atoms-in-molecules), docking, molecular dynamics, and the MM-PBSA method. A biological assay for the lead compound has been performed to validate the theoretical findings. Importantly, binding free energy calculations for the three drug complexes are within 3 kcal/mol of the experimental values, thus further justifying our computational protocol, which has been validated through previous studies on 11 drug-protein systems. The main elements of the discovered mechanism are: (i) minor changes are induced to renin upon drug binding, (ii) the three drugs form an extensive network of hydrogen bonds with renin, whilst the lead compound presented diminished interactions, (iii) ligand binding in all complexes is driven by favorable van der Waals interactions and the nonpolar contribution to solvation, while the lead compound is associated with diminished van der Waals interactions compared to the drug-bound forms of renin, and (iv) the environment (H2O/Na(+)) has a small effect on the renin-remikiren interaction. Copyright © 2015 Elsevier Inc. All rights reserved.

Investigating the association of vitamin D with blood pressure and the renin-angiotensin-aldosterone system in hypertensive subjects: a cross-sectional prospective study.

PubMed

Cremer, Antoine; Tambosco, Chloé; Corcuff, Jean-Benoît; Boulestreau, Romain; Gaillard, Prune; Lainé, Marion; Papaioannou, Georgios; Gosse, Philippe

2018-02-01

The hypothesis that vitamin D (25(OH)D) insufficiency plays a role in occurring of various disease has led to a rise in requests of dosages and to an increase of health-care costs. 25(OH)D insufficiency is associated with increased risk of cardiovascular disease and hypertension in many studies. Animal studies demonstrated that 25(OH)D insufficiency activates renin angiotensin system but corresponding humans data are limited. The aim of the study was to document relationship between 25(OH)D, blood pressure, and renin angiotensin system in hypertensive subjects. In all, 248 hypertensive individuals, 46.8 years (±14), were hospitalized for an etiological assessment of hypertension in this cross-sectional study over two calendar years. 25(OH)D, plasma renin activity, and aldosterone were determined in stringent conditions and blood pressure was measure. Statistical analyses were carried out to analyze the association between 25(OH)D, blood pressure, and renin angiotensin system using linear and logistic regressions with adjustments on relevant variables. In all, 80% of the studied population had a 25(OH)D insufficiency. There were no significant association between 25(OH)D and levels of systolic or diastolic blood pressure, plasma renin activity, and aldosterone whatever the statiscal method used after adjustment. 25(OH)D is not associated with blood pressure and renin angiontensin component in hypertensive subjects. These results corroborate the interventional studies which are for a large majority negatives. A new definition of the 25(OH)D insufficiency in general population is necessary.

Clinical pharmacokinetics and efficacy of renin inhibitors.

PubMed

Rongen, G A; Lenders, J W; Smits, P; Thien, T

1995-07-01

The successful introduction of angiotensin converting enzyme (ACE) inhibitors in the treatment of patients with essential hypertension or heart failure has increased interest in the (patho)physiological role of the renin-angiotensin system (RAS). ACE is not only involved in the formation of angiotensin II from angiotensin I, but also inactivates vasoactive substances such as bradykinin and substance P. Accumulation of these substances during treatment with ACE inhibitors may contribute to both their therapeutic action and certain adverse effects associated with their use, such as cough and angioneurotic oedema. Renin inhibitors offer an alternative approach to inhibit the RAS. The major advantage of these, still experimental, drugs is their high specificity for the RAS since angiotensinogen is the only known substrate of renin. The currently available renin inhibitors are pseudopeptides that are rapidly taken up by the liver and excreted in the bile. Consequently, these drugs are subjected to a considerable first pass effect which limits their oral bioavailability. Additionally, plasma elimination half-life times are short and the duration of action is limited. Despite these shortcomings, single oral or intravenous administration results in a 80 to 90% inhibition of plasma renin activity and a slight reduction in blood pressure in patients with hypertension. The extent of blood pressure reduction is dependent on the patient's salt balance. After 1 week of oral treatment with the renin inhibitor remikiren, the antihypertensive effect was reduced in salt-repleted hypertensive patients. Subsequent intravenous administration of the drug did not further affect blood pressure, indicating that it was not the first pass effect that was limiting the efficacy of remikiren.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of adrenal vein sampling performed during concurrent mineralocorticoid receptor antagonist therapy.

PubMed

Haase, Matthias; Riester, Anna; Kröpil, Patric; Hahner, Stefanie; Degenhart, Christoph; Willenberg, Holger S; Reincke, Martin

2014-12-01

Pharmacological inhibition of mineralocorticoid receptor (MR) signaling in patients with primary aldosteronism (PA) reestablishes aldosterone synthesis by nondiseased zona glomerulosa cells through activation of the renin-angiotensin-aldosterone system. In this context, current guidelines recommend discontinuing MR blockade for diagnostic procedures, including adrenal vein sampling (AVS). Discontinuation of MR blockade in high-risk patients may be harmful because of uncontrolled hypertension and severe hypokalemia. We hypothesize that MR antagonist therapy can be continued during AVS as long as renin levels remain suppressed. The objective of this study was to assess the validity of AVS results in the context of MR antagonistic therapy. We retrospectively analyzed all AVS studies in Munich (since 2008) and Düsseldorf (since 2011) and identified four of 237 (1.7%) patients with PA who underwent AVS while treated with an MR antagonist. Adrenalectomy was recommended based on the results of AVS in all four patients. After adrenalectomy, follow-up data were obtained to confirm improvement or remission of PA. Main outcome measures included blood pressure values, daily defined doses of antihypertensive medication, as well as levels of aldosterone, renin, and potassium, and the aldosterone/renin ratio. In all patients, renin remained low or suppressed during AVS despite MR antagonist treatment. AVS clearly demonstrated unilateral aldosterone excess in each case. After adrenalectomy, all patients showed remission of PA as demonstrated by blood pressure values, potassium levels, and the aldosterone/renin ratio. In selected cases of PA, MR antagonist therapy might be continued during AVS, provided that renin values remain low.

Renin inhibitor aliskiren exerts beneficial effect on trabecular bone by regulating skeletal renin-angiotensin system and kallikrein-kinin system in ovariectomized mice.

PubMed

Zhang, Y; Wang, L; Song, Y; Zhao, X; Wong, M S; Zhang, W

2016-03-01

The skeletal renin-angiotensin system contributes to the development of osteoporosis. The renin inhibitor aliskiren exhibited beneficial effects on trabecular bone of osteoporotic mice, and this action might be mediated through angiotensin and bradykinin receptor pathways. This study implies the potential application of renin inhibitor in the management for postmenopausal osteoporosis. The skeletal renin-angiotensin system plays key role in the pathological process of osteoporosis. The present study is designed to elucidate the effect of renin inhibitor aliskiren on trabecular bone and its potential action mechanism in ovariectomized (OVX) mice. The OVX mice were treated with low dose (5 mg/kg) or high dose (25 mg/kg) of aliskiren or its vehicle for 8 weeks. The bone turnover markers were measured by ELISA. The structural parameters of trabecular bone at lumbar vertebra (LV) and distal femoral metaphysis were measured by micro-CT. The expression of messenger RNA (mRNA) and protein was studied by RT-PCR and immunoblotting, respectively. Aliskiren treatment reduced urinary excretion of calcium and serum level of tartrate-resistant acid phosphatase in OVX mice. The treatment with aliskiren significantly increased bone volume (BV/TV) and connectivity density (Conn.D) of trabecular bone at LV-2 and LV-5 as well as dramatically enhanced BV/TV, Conn.D, bone mineral density (BMD/BV) and decreased bone surface (BS/BV) at the distal femoral end. Aliskiren significantly down-regulated the expression of angiotensinogen, angiotensin II (Ang II), Ang II type 1 receptor, bradykinin receptor (BR)-1, and osteocytic-specific gene sclerostin as well as the osteoclast-specific genes, including carbonic anhydrase II, matrix metalloproteinase-9, and cathepsin K. This study revealed that renin inhibitor aliskiren exhibited the beneficial effects on trabecular bone of ovariectomy-induced osteoporotic mice, and the underlying mechanism for this action might be mediated through Ang II and BR signaling pathways in bone.

'Decoy peptide' region (RIFLKRMPSI) of prorenin prosegment plays a crucial role in prorenin binding to the (pro)renin receptor.

PubMed

Nabi, A H M Nurun; Biswas, Kazal Boron; Nakagawa, Tsutomu; Ichihara, Atsuhiro; Inagami, Tadashi; Suzuki, Fumiaki

2009-07-01

This study investigated a role of decoy peptide region (R10PIFLKRMPSI19P) in prorenin prosegment for prorenin binding to the (pro)renin receptor using the surface plasmon resonance technique. Three kinds of anti-receptor antibodies labeled as anti-107/121, anti-221/235 and anti-His tag antibody were prepared. The respective antigens D107SVANSIHSLFSEET121 (close to the N-terminal side of receptor), E221IGKRYGEDSEQFRD235 (N-terminal side of the transmembrane part of receptor) and 10xHis sequence (C-terminus) were designed based on the sequence of the receptor. These antibodies were immobilized on the CM5 sensor chip by amine coupling and allowed to bind to the receptor. Human prorenin, renin and the decoy bound to the receptor associated with antibodies. Their association (ka) and dissociation (kd) rate constants were measured and the dissociation constants (KD) were determined using Langmuir 1:1 kinetic binding model. The KD for interaction of prorenin and receptor associated to anti-107/121, anti-221/235 and anti-His tag antibodies were 2.9, 1.2 and 7.8 nM, respectively and for renin they were 9.3, 4.4 and 7.1 nM. The decoy bound to the respective immobilized receptor-antibody complexes at KD's of 6.2, 3.5 and 15.2 nM. Prorenin, renin and decoy had lower KD at the nanomolar ranges compared to those of L1PPTD4P in the prorenin prosegment and A248KKRLFDYVV257 in the C-domain of mature renin. The decoy reduced the binding of not only prorenin but also renin to (P)RR. These data are direct evidence that prorenin, renin and the peptides bind to (P)RR and the decoy reduces prorenin binding, supporting our hypothesis that decoy peptide region has a crucial role in prorenin binding.

Factors Influencing Renal Vasculature during Anesthesia, Trauma, and Oliguric Renal Failure States in Man

DTIC Science & Technology

1980-03-01

striking influence of prior sodium intake on the pathogenesis of acute renal failure, raising the possibility that the renin - angiotensin system was...the product of the renin - angiotensin system , is the most powerful renal vasoconstrictor agent yet identified. These observations, viewed in the light of... angiotensin and, when they became available, to a detailed study of agents suitable for pharmacologic interruption of the renin - angiotensin system . We showed

Responses of Plasma Atrial Natriuretic Peptide to High Intensity Submaximal Exercise in the Heat,

DTIC Science & Technology

1987-06-01

atrial natriuretic factor on blood pressure and renin - angiotensin - aldosterone system . Federation Proc 45: 2115-2121. Blain EH (1986) Atrial...acclimation adaptations. Conversely, plasma aldosterone (ALDO). renin activity (PRA) and cortisol (COR) all increased (p’O.05) pre-to post- exercise on each...Words: Atrial natriuretic peptide,-cortisol. plasma renin activity. aldosterone .- heat, males. Accession For -TIS ORA&I DTIC TAB 0 mnUnannounced 0

Histamine H4-Receptors Inhibit Mast Cell Renin Release in Ischemia/Reperfusion via Protein Kinase Cε-Dependent Aldehyde Dehydrogenase Type-2 Activation

PubMed Central

Aldi, Silvia; Takano, Ken-ichi; Tomita, Kengo; Koda, Kenichiro; Chan, Noel Y.-K.; Marino, Alice; Salazar-Rodriguez, Mariselis; Thurmond, Robin L.

2014-01-01

Renin released by ischemia/reperfusion (I/R) from cardiac mast cells (MCs) activates a local renin-angiotensin system (RAS) causing arrhythmic dysfunction. Ischemic preconditioning (IPC) inhibits MC renin release and consequent activation of this local RAS. We postulated that MC histamine H4-receptors (H4Rs), being Gαi/o-coupled, might activate a protein kinase C isotype–ε (PKCε)–aldehyde dehydrogenase type-2 (ALDH2) cascade, ultimately eliminating MC-degranulating and renin-releasing effects of aldehydes formed in I/R and associated arrhythmias. We tested this hypothesis in ex vivo hearts, human mastocytoma cells, and bone marrow–derived MCs from wild-type and H4R knockout mice. We found that activation of MC H4Rs mimics the cardioprotective anti-RAS effects of IPC and that protection depends on the sequential activation of PKCε and ALDH2 in MCs, reducing aldehyde-induced MC degranulation and renin release and alleviating reperfusion arrhythmias. These cardioprotective effects are mimicked by selective H4R agonists and disappear when H4Rs are pharmacologically blocked or genetically deleted. Our results uncover a novel cardioprotective pathway in I/R, whereby activation of H4Rs on the MC membrane, possibly by MC-derived histamine, leads sequentially to PKCε and ALDH2 activation, reduction of toxic aldehyde-induced MC renin release, prevention of RAS activation, reduction of norepinephrine release, and ultimately to alleviation of reperfusion arrhythmias. This newly discovered protective pathway suggests that MC H4Rs may represent a new pharmacologic and therapeutic target for the direct alleviation of RAS-induced cardiac dysfunctions, including ischemic heart disease and congestive heart failure. PMID:24696042

Combined use of nonsteroidal anti-inflammatory drugs with diuretics and/or renin-angiotensin system inhibitors in the community increases the risk of acute kidney injury.

PubMed

Dreischulte, Tobias; Morales, Daniel R; Bell, Samira; Guthrie, Bruce

2015-08-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with an increased risk of acute kidney injury (AKI) when used in triple combination with renin-angiotensin system inhibitors and diuretics, but previous research reported that NSAIDs in dual combinations with either renin-angiotensin system inhibitors or diuretics alone were not. However, earlier studies relied on hospital coding to define AKI, which may underestimate true risk. This nested case-control study characterized the risk of community-acquired AKI associated with NSAID use among 78,379 users of renin-angiotensin system inhibitors and/or diuretics, where AKI was defined as a 50% or greater increase in creatinine from baseline. The AKI incidence was 68/10,000 person-years. The relative increase in AKI risk was similar for NSAID use in both triple (adjusted rate ratio 1.64 (95% CI 1.25-2.14)) and dual combinations with either renin-angiotensin system inhibitors (1.60 (1.18-2.17)) or diuretics (1.64 (1.17-2.29)). However, the absolute increase in AKI risk was higher for NSAIDs used in triple versus dual combinations with renin-angiotensin system inhibitors or diuretics alone (numbers needed to harm for 1 year treatment with NSAID of 158 vs. over 300). AKI risk was highest among users of loop diuretic/aldosterone antagonist combinations, in those over 75 years of age, and in those with renal impairment. Thus, the nephrotoxic potential of both dual and triple combinations of NSAIDs with renin-angiotensin system inhibitors and/or diuretics yields a higher incidence of AKI than previously thought.

Retinal vasculopathy is reduced by dietary salt restriction: involvement of Glia, ENaCα, and the renin-angiotensin-aldosterone system.

PubMed

Deliyanti, Devy; Armani, Roksana; Casely, David; Figgett, William A; Agrotis, Alex; Wilkinson-Berka, Jennifer L

2014-09-01

Neovascularization and vaso-obliteration are vision-threatening events that develop by interactions between retinal vascular and glial cells. A high-salt diet is causal in cardiovascular and renal disease, which is linked to modulation of the renin-angiotensin-aldosterone system. However, it is not known whether dietary salt influences retinal vasculopathy and if the renin-angiotensin-aldosterone system is involved. We examined whether a low-salt (LS) diet influenced vascular and glial cell injury and the renin-angiotensin-aldosterone system in ischemic retinopathy. Pregnant Sprague Dawley rats were fed LS (0.03% NaCl) or normal salt (0.3% NaCl) diets, and ischemic retinopathy was induced in the offspring. An LS diet reduced retinal neovascularization and vaso-obliteration, the mRNA and protein levels of the angiogenic factors, vascular endothelial growth factor, and erythropoietin. Microglia, which influence vascular remodeling in ischemic retinopathy, were reduced by LS as was tumor necrosis factor-α. Macroglial Müller cells maintain the integrity of the blood-retinal barrier, and in ischemic retinopathy, LS reduced their gliosis and also vascular leakage. In retina, LS reduced mineralocorticoid receptor, angiotensin type 1 receptor, and renin mRNA levels, whereas, as expected, plasma levels of aldosterone and renin were increased. The aldosterone/mineralocorticoid receptor-sensitive epithelial sodium channel alpha (ENaCα), which is expressed in Müller cells, was increased in ischemic retinopathy and reduced by LS. In cultured Müller cells, high salt increased ENaCα, which was prevented by mineralocorticoid receptor and angiotensin type 1 receptor blockade. Conversely, LS reduced ENaCα, angiotensin type 1 receptor, and mineralocorticoid receptor expression. An LS diet reduced retinal vasculopathy, by modulating glial cell function and the retinal renin-angiotensin-aldosterone system. © 2014 American Heart Association, Inc.

[Renin-angiotensin-aldosterone system activity during head-up tilt testing in patients with vasovagal syncope].

PubMed

Gajek, Jacek; Zyśko, Dorota; Mazurek, Walentyna

2005-08-01

The stimulation of renin-angiotensin-aldosterone (RAA) system during tilt table test is caused by sympathetic nervous system activation by orthostatic stress and a serotonin release as well. In healthy individuals increase of plasma renin activity during test with maximal values on the peak of the test was described. The aim of the study was to assess the activation of RAAS in patients with neurally mediated syncope during the tilt table test by means of plasma renin activity and serum aldosterone levels. The study was carried out in 31 patients aged 39.4 +/- 15.0 years (18 women and 13 men) with neurally mediated syncope during tilt test. Plasma renin activity was assessed in the baseline conditions, immediately after the test and 10 minutes after the test using radioenzymatic assay. Aldosterone concentrations were measured radioimmunologically, twice: after 30 minutes supine rest and after the syncope. Plasma renin activity during supine rest was 2.2 +/- 2.4 ng/ml/h, rose after the syncope 2.5-fold to 5.2 +/- 4.5 ng/ml/h (p < 0.001 comparing to baseline) stayed on similar level approximately for the next 10 minutes--4.9 +/- 5.5 ng/ml/h (p = n.s.). In 11 patients (35%) 10 minutes after the test even further increase of PRA was observed. Serum aldosterone level increased significantly immediately after tilt test (90.0 +/- 72.9 vs 178.8 +/- 150.1 pg/ml, p < 0.01). Authors showed, that in patients with NMS plasma renin activity increases and this increase lasts for 10 minutes after the syncope and the concentration of aldosterone increases immediately after tilt test.

Hypovolemia in syncope and orthostatic intolerance role of the renin-angiotensin system

NASA Technical Reports Server (NTRS)

Jacob, G.; Robertson, D.; Mosqueda-Garcia, R.; Ertl, A. C.; Robertson, R. M.; Biaggioni, I.

1997-01-01

PURPOSE: Orthostatic intolerance is the cause of significant disability in otherwise normal patients. Orthostatic tachycardia is usually the dominant hemodynamic abnormality, but symptoms may include dizziness, visual changes, discomfort in the head or neck, poor concentration, fatigue, palpitations, tremulousness, anxiety and, in some cases, syncope. It is the most common disorder of blood pressure regulation after essential hypertension. There is a predilection for younger rather than older adults and for women more than men. Its cause is unknown; partial sympathetic denervation or hypovolemia has been proposed. METHODS AND MATERIALS: We tested the hypothesis that reduced plasma renin activity, perhaps from defects in sympathetic innervation of the kidney, could underlie a hypovolemia, giving rise to these clinical symptoms. Sixteen patients (14 female, 2 male) ranging in age from 16 to 44 years were studied. Patients were enrolled in the study if they had orthostatic intolerance, together with a raised upright plasma norepinephrine (> or = 600 pg/mL). Patients underwent a battery of autonomic tests and biochemical determinations. RESULTS: There was a strong positive correlation between the blood volume and plasma renin activity (r = 0.84, P = 0.001). The tachycardic response to upright posture correlated with the severity of the hypovolemia. There was also a correlation between the plasma renin activity measured in these patients and their concomitant plasma aldosterone level. CONCLUSIONS: Hypovolemia occurs commonly in orthostatic intolerance. It is accompanied by an inappropriately low level of plasma renin activity. The degree of abnormality of blood volume correlates closely with the degree of abnormality in plasma renin activity. Taken together, these observations suggest that reduced plasma renin activity may be an important pathophysiologic component of the syndrome of orthostatic intolerance.

Acute change in glomerular filtration rate with inhibition of the renin-angiotensin system does not predict subsequent renal and cardiovascular outcomes.

PubMed

Clase, Catherine M; Barzilay, Joshua; Gao, Peggy; Smyth, Andrew; Schmieder, Roland E; Tobe, Sheldon; Teo, Koon K; Yusuf, Salim; Mann, Johannes F E

2017-03-01

Initiation of blockade of the renin-angiotensin system may cause an acute decrease in glomerular filtration rate (GFR): the prognostic significance of this is unknown. We did a post hoc analysis of patients with, or at risk for, vascular disease, in two randomized controlled trials: Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) and the Telmisartan Randomized AssessmeNt Study in ACE iNtolerant participants with cardiovascular Disease (TRANSCEND), whose median follow-up was 56 months. In 9340 patients new to renin-angiotensin system blockade, who were then randomized to renin-angiotensin system blockade, a fall in GFR of 15% or more at 2 weeks after starting renin-angiotensin system blockade was seen in 1480 participants (16%), with persistence at 8 weeks in 700 (7%). Both acute increases and decreases in GFR after initiation of renin-angiotensin system blockade were associated with tendencies, mostly not statistically significant, to increased risk of cardiovascular outcomes, which occurred in 1280 participants, and of microalbuminuria, which occurred in 864. Analyses of creatinine-based outcomes were suggestive of regression to the mean. In more than 3000 patients randomized in TRANSCEND to telmisartan or placebo, there was no interaction between acute change in GFR and renal or cardiovascular benefit from telmisartan. Thus, both increases and decreases in GFR on initiation of renin-angiotensin system blockade are common, and may be weakly associated with increased risk of cardiovascular and renal outcomes. Changes do not predict increased benefit from therapy. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Sodium butyrate suppresses angiotensin II-induced hypertension by inhibition of renal (pro)renin receptor and intrarenal renin-angiotensin system.

PubMed

Wang, Lei; Zhu, Qing; Lu, Aihua; Liu, Xiaofen; Zhang, Linlin; Xu, Chuanming; Liu, Xiyang; Li, Haobo; Yang, Tianxin

2017-09-01

Butyrate, a short-chain fatty acid, is the end product of the fermentation of complex carbohydrates by the gut microbiota. Recently, sodium butyrate (NaBu) has been found to play a protective role in a number of chronic diseases. However, it is still unclear whether NaBu has a therapeutic potential in hypertension. The present study was aimed to investigate the role of NaBu in angiotensin II (Ang II)-induced hypertension and to further explore the underlying mechanism. Ang II was infused into uninephrectomized Sprague-Dawley rats with or without intramedullary infusion of NaBu for 14 days. Mean arterial blood pressure was recorded by the telemetry system. Renal tissues, serum samples, and 24-h urine samples were collected to examine renal injury and the regulation of the (pro)renin receptor (PRR) and renin. Intramedullary infusion of NaBu in Sprague-Dawley rats lowered the Ang II-induced mean arterial pressure from 129 ± 6 mmHg to 108 ± 4 mmHg (P < 0.01). This corresponded with an improvement in Ang II-induced renal injury, including urinary albumin, glomerulosclerosis, and renal fibrosis, as well as the expression of inflammatory mediators tumor necrosis factor α, interleukin 6. The renal expression of PRR, angiotensinogen, angiotensin I-converting enzyme and the urinary excretion of soluble PRR, renin, and angiotensinogen were all increased by Ang II infusion but decreased by NaBu treatment. In cultured innermedullary collecting duct cells, NaBu treatment attenuated Ang II-induced expression of PRR and renin. These results demonstrate that NaBu exerts an antihypertensive action, likely by suppressing the PRR-mediated intrarenal renin-angiotensin system.

Excessively low salt diet damages the heart through activation of cardiac (pro) renin receptor, renin-angiotensin-aldosterone, and sympatho-adrenal systems in spontaneously hypertensive rats.

PubMed

Okamoto, Chihiro; Hayakawa, Yuka; Aoyama, Takuma; Komaki, Hisaaki; Minatoguchi, Shingo; Iwasa, Masamitsu; Yamada, Yoshihisa; Kanamori, Hiromitsu; Kawasaki, Masanori; Nishigaki, Kazuhiko; Mikami, Atsushi; Minatoguchi, Shinya

2017-01-01

A high salt intake causes hypertension and leads to cardiovascular disease. Therefore, a low salt diet is now recommended to prevent hypertension and cardiovascular disease. However, it is still unknown whether an excessively low salt diet is beneficial or harmful for the heart. Wistar Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) received normal salt chow (0.9% salt diet) and excessively low salt chow (0.01% salt diet referred to as saltless diet) for 8 weeks from 8 to 16 weeks of age. The effects of the excessively low salt diet on the cardiac (pro) renin receptor, renin-angiotensin-aldosterone, and sympatho-adrenal systems were investigated. The excessively low salt diet did not affect the systolic blood pressure but significantly increased the heart rate both in WKYs and SHRs. The excessively low salt diet significantly elevated plasma renin activity, plasma angiotensin I, II and aldosterone concentrations, and plasma noradrenaline and adrenaline concentrations both in WKYs and SHRs. Cardiac expressions of renin, prorenin, (P)RR, angiotensinogen, and angiotensin II AT1 receptor and phosphorylated (p)-ERK1/2, p-HSP27, p-38MAPK, and TGF-ß1 were significantly enhanced by the excessively low salt diet in both WKYs and SHRs. The excessively low salt diet accelerated cardiac interstitial and perivascular fibrosis and increased the cardiomyocyte size and interventricular septum thickness in WKYs and SHRs but the extent was greater in SHRs. An excessively low salt diet damages the heart through activation of plasma renin-angiotensin-aldosterone and sympatho-adrenal systems and activation of cardiac (P)RR and angiotensin II AT1 receptor and their downstream signals both in WKYs and SHRs.

Natriuretic peptides buffer renin-dependent hypertension.

PubMed

Demerath, Theo; Staffel, Janina; Schreiber, Andrea; Valletta, Daniela; Schweda, Frank

2014-06-15

The renin-angiotensin-aldosterone system and cardiac natriuretic peptides [atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP)] are opposing control mechanisms for arterial blood pressure. Accordingly, an inverse relationship between plasma renin concentration (PRC) and ANP exists in most circumstances. However, PRC and ANP levels are both elevated in renovascular hypertension. Because ANP can directly suppress renin release, we used ANP knockout (ANP(-/-)) mice to investigate whether high ANP levels attenuate the increase in PRC in response to renal hypoperfusion, thus buffering renovascular hypertension. ANP(-/-) mice were hypertensive and had reduced PRC compared with that in wild-type ANP(+/+) mice under control conditions. Unilateral renal artery stenosis (2-kidney, 1-clip) for 1 wk induced similar increases in blood pressure and PRC in both genotypes. Unexpectedly, plasma BNP concentrations in ANP(-/-) mice significantly increased in response to two-kidney, one-clip treatment, potentially compensating for the lack of ANP. In fact, in mice lacking guanylyl cyclase A (GC-A(-/-) mice), which is the common receptor for both ANP and BNP, renovascular hypertension was markedly augmented compared with that in wild-type GC-A(+/+) mice. However, the higher blood pressure in GC-A(-/-) mice was not caused by disinhibition of the renin system because PRC and renal renin synthesis were significantly lower in GC-A(-/-) mice than in GC-A(+/+) mice. Thus, natriuretic peptides buffer renal vascular hypertension via renin-independent effects, such as vasorelaxation. The latter possibility is supported by experiments in isolated perfused mouse kidneys, in which physiological concentrations of ANP and BNP elicited renal vasodilatation and attenuated renal vasoconstriction in response to angiotensin II. Copyright © 2014 the American Physiological Society.

The Role of Neural Reflexes in Control of the Cardiovascular System during Stress.

DTIC Science & Technology

1984-02-01

cold block increase arterial pressure but did not alter plasma renin activity or renin secretory rate in dogs with normal or high sodium diet...also found that these afferents may play a keen role in the regulation of renin scretoary rate during conditions which may alter cardiopulmonary blood ...important hormone in -. the regulation of arterial pressure . However, the role of the nervous system in controlling the release of vasopressin has not been

Renal sodium transport in renin-deficient Dahl salt-sensitive rats

PubMed Central

Pavlov, Tengis S; Levchenko, Vladislav; Ilatovskaya, Daria V; Moreno, Carol; Staruschenko, Alexander

2016-01-01

Objective: The Dahl salt-sensitive rat is a well-established model of salt-sensitive hypertension. The goal of this study was to assess the expression and activity of renal sodium channels and transporters in the renin-deficient salt-sensitive rat. Methods: Renin knockout (Ren−/−) rats created on the salt-sensitive rat background were used to investigate the role of renin in the regulation of ion transport in salt-sensitive hypertension. Western blotting and patch-clamp analyses were utilized to assess the expression level and activity of Na+ transporters. Results: It has been described previously that Ren−/− rats exhibit severe kidney underdevelopment, polyuria, and lower body weight and blood pressure compared to their wild-type littermates. Here we found that renin deficiency led to decreased expression of sodium-hydrogen antiporter (NHE3), the Na+/H+ exchanger involved in Na+ absorption in the proximal tubules, but did not affect the expression of Na-K-Cl cotransporter (NKCC2), the main transporter in the loop of Henle. In the distal nephron, the expression of sodium chloride cotransporter (NCC) was lower in Ren−/− rats. Single-channel patch clamp analysis detected decreased ENaC activity in Ren−/− rats which was mediated via changes in the channel open probability. Conclusion: These data illustrate that renin deficiency leads to significant dysregulation of ion transporters. PMID:27443990

Plasma renin is increased in young rats exposed to lead in utero and during nursing

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

Victery, W.; Vander, A.J.; Schoeps, P.

Rats were exposed continuously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 5, 25, 100, or 500 ppm Pb (as Pb acetate); they were sacrificed at 1 month of age, at which time their mean blood Pb concentrations were, respectively, approximately 3, 9, 19, 30, and 70 ..mu..g/dl. All Pb-exposed groups sacrificed by decapitation had elevated mean plasma renin activities (PRA), relative to controls. Pentobarbital-anesthesia and laparotomy markedly increased PRA in the 0, 100, and 500 ppm groups, but the increase was significantly less in the 100 ppm group.more » Renal renin concentration was normal in the 5 and 25 ppm groups, but was significantly increased in the 100 and 500 ppm groups. The ratio of plasma angiotensin II to PRA was normal in the 100 ppm group but significantly reduced in the 500 ppm group. We conclude that exposure of rats to those generally present in human populations stimulates basal renin secretion in 1-month-old rats, but partially inhibits the response to renin-releasing stimuli. The highest dose reduces plasma angiotensin II at any given PRA. These results, taken with previous publications, emphasize that the effects of lead on plasma renin even within a single species are greatly affected by the timing of the exposure.« less

[Estimation of the renin-angiotensin-aldosterone system, water and electrolyte imbalance and endothelial function in newborns of women with chronic hypertension].

PubMed

Chistiakova, G N; Gazieva, I A; Rmizova, I I

2015-01-01

The aim of this study was to evaluate the parameters of renin-angiotensin-aldosterone system, natriuretic peptides, and markers of endothelial function in the early neonatal period and at the age of 3 months in 83 full-term infants of women with chronic hypertension, there were: 60 newborns from women with chronic hypertension of mild to moderate severity (main group) and 23 newborns from women without hypertension (comparison group). The levels of the renin angiotensin-II, aldosterone, natriuretic peptides, endothelin-1, in cord and peripheral blood were determined by immunoassay, the metabolites of stable oxide nitric--by Griess method. The newborn of women with chronic hypertension showed a significant elevation of renin, angiotensin II and brain natriuretic peptide at birth. A statistically significant increase in concentration of atrial natriuretic peptide (aANP1-28) was determined to the 3-5 days of life. Significantly high levels of renin, angiotensin II, endothelin-1 and decreased levels of endogenous nitrite at the age of 3 months of life was found. The results findings suggest that prenatal activation of the renin-angiotensin-aldosterone system of the fetus, continuing to be in the newborn of women with chronic hypertension during the first three months of life. The same infants have the violation of endothelial function to 3 months of age.

Antihypertensive effect of caffeic acid and its analogs through dual renin-angiotensin-aldosterone system inhibition.

PubMed

Bhullar, Khushwant S; Lassalle-Claux, Grégoire; Touaibia, Mohamed; Rupasinghe, H P Vasantha

2014-05-05

Hypertension is a crucial risk factor for cardiovascular diseases and contributes to one third of global mortality. In addition to conventional antihypertensive drugs such as captopril, naturally occurring phytochemicals and their analogs are used for reducing the risk and occurrence of hypertension. Herein, we demonstrate the possible use of caffeic acid and its derivatives in the treatment of hypertension through multi-target modulation of renin-angiotensin-aldosterone system (RAAS). Caffeic acid along with its nineteen novel derivatives, chlorogenic acid, quercetin and captopril were all investigated for the inhibition of renin and angiotensin converting enzyme (ACE) activities and production of aldosterone. Compound 22 with CH2CH(Ph)2 moiety exhibited the strongest renin inhibition (IC50=229µM) among all compounds tested (P≤0.05). Caffeic acid was the weakest renin inhibitor (IC50=5704µM) among all the compounds assayed. Similar to renin inhibition, compound 22 (IC50=9.1µM) also exhibited about 47 times stronger ACE inhibition compared to the parent compound. Analysis of aldosterone revealed that compound 8 with n-Pr moiety was the strongest modulator of aldosterone production among all the derivatives (P≤0.05). Toxicity analysis using human fibroblasts (WI-38 cells) confirmed the non-toxic manifestations of caffeic acid and its derivatives in comparison to clinically used drug captopril. Copyright © 2014 Elsevier B.V. All rights reserved.

Hyperpotassemia and bradycardia in a bedridden elderly woman with selective hypoaldosteronism associated with low renin activity.

PubMed

Inada, Mitsuo; Iwasaki, Keiko; Imai, Chihiro; Hashimoto, Satoshi

2010-01-01

A bedridden 85-year-old woman had hyperpotassemia (7.7 mEq/L) and bradycardia (30/min). Endocrinologic findings revealed a decrease in the renin-aldosterone system and normal adrenoglucocorticoid function. The results were consistent with the abnormalities seen in selective hypoaldosteronism with low renin activity. In addition, 9 of 11 patients, selected randomly from 72 bedridden elderly patients with normal serum sodium and potassium levels in our hospital, had diminished plasma renin activity (PRA) and plasma aldosterone concentration (PAC). The present patient was prescribed nonsteroidal anti-inflammatory drug (NSAID). NSAID reduces renal potassium excretion through the inhibition of renal prostaglandin synthesis. Therefore, the use of NSAID in bedridden elderly patients might intensify the underlying asymptomatic hypoaldosteronism and cause life-threatening hyperpotassemia.

Connexin 40 is dispensable for vascular renin cell recruitment but is indispensable for vascular baroreceptor control of renin secretion.

PubMed

Machura, Katharina; Neubauer, Bjoern; Müller, Hanna; Tauber, Philipp; Kurtz, Armin; Kurtz, Lisa

2015-08-01

Defects of the gap junction protein connexin 40 (Cx40) in renin-secreting cells (RSCs) of the kidney lead to a shift of the localization of RSCs from the media layer of afferent arterioles to the periglomerular interstitium. The dislocation of RSCs goes in parallel with elevated plasma renin levels, impaired pressure control of renin secretion, and hypertension. The reasons for the extravascular shift of RSCs and the blunted pressure regulation of renin secretion caused by the absence of Cx40 are still unclear. We have therefore addressed the question if Cx40 is essential for the metaplastic transformation of preglomerular vascular smooth muscle cells (SMCs) into RSCs and if Cx40 is essential for the pressure control of renin secretion from RSCs located in the media layer of afferent arterioles. For our study, we used mice lacking the angiotensin II type 1A (AT1A) receptors, which display a prominent and reversible salt-sensitive metaplastic transformation of SMCs into RSCs. This mouse line was crossed with Cx40-deficient mice to obtain AT1A and Cx40 double deleted mice. The kidneys of AT1A (-/-)Cx40(-/-) mice kept on normal salt (0.3 %) displayed RSCs both in the inner media layer of preglomerular vessels and in the periglomerular interstitium. In contrast to hypotensive AT1A (-/-) (mean bp syst 112 mmHg) and hypertensive Cx40(-/-) (mean bp syst 160 mmHg) mice AT1A (-/-)Cx40(-/-) mice were normotensive(mean bp syst 130 mmHg). Pressure regulation of renin secretion from isolated kidneys was normal in AT1A (-/-) mice, but was absent in AT1A (-/-)Cx40(-/-) mice alike in Cx40(-/-) mice. Low-salt diet (0.02 %) increased RSC numbers in the media layer, whilst high-salt diet (4 %) caused disappearance of RSCs in the media layer but not in the periglomerular interstitium. Blood pressure was clearly salt sensitive both in AT1A (-/-) and in AT1A (-/-)Cx40(-/-) mice but was shifted to higher pressure values in the latter genotype. Our data indicate that Cx40 is not a requirement for intramural vascular localization of RSCs nor for reversible metaplastic transformation of SMCs into RSCs. Therefore, the ectopic localization of RSCs in Cx40(-/-) kidneys is more likely due to a disturbed intercellular communication rather than being the result of chronic overactivation of the renin-angiotensin-aldosterone system or hypertension. Moreover, our findings suggest that Cx40 is a requirement for the pressure control of renin secretion irrespective of the localization of RSCs.

Renin blood test

MedlinePlus

... pressure , your doctor may order a renin and aldosterone test to help determine the cause of your ... due to: Adrenal glands that release too much aldosterone hormone ( hyperaldosteronism ) High blood pressure that is salt- ...

Renin Gene Polymorphisms in Bangladeshi Hypertensive Population

PubMed Central

Afruza, Rownock; Islam, Laila N; Banerjee, Sajal; Hassan, Md. Mahbub; Suzuki, Fumiaki; Nabi, AHM Nurun

2014-01-01

Objective: Linkages of renin gene polymorphisms with hypertension have been implicated in several populations with contrasting results. Present study aims to assess the pattern of renin gene polymorphisms in Bangladeshi hypertensive individuals. Methodology: Introns 1, 9 of renin gene and 4063 bases upstream of promoter sequence of renin gene were amplified from the genomic DNA of the total 124 (hypertensive and normotensive) subjects using respective primers. Polymerase chain reaction-based restriction fragment length polymorphisms were performed using BglI, MboI and TaqI restriction enzymes. Results: Homozygosity was common in renin gene regarding BglI (bb=48.4%, Bb=37.9%, BB=13.7%, χ2 =1.91, P>0.05), TaqI (TT=81.5%, Tt=14.5%, tt=4.0%, χ2 =7.50, P<0.01) and MboI (mm=63.7%, Mm=32.3%, MM=4.0%, χ2=0.00, P>0.05) polymorphisms among total study population. For BglI and TaqI genotype distribution, hypertensive subjects (BglI: χ2 =6.66, P<0.05; TaqI: χ2 = 10.28, P<0.005) significantly deviate from Hardy-Weinberg Equilibrium law compared to normotensive subjects (BglI: χ2=0.51, P>0.05; TaqI: χ2=0.20, P>0.05). On the other hand, with respect to MboI polymorphisms of renin gene, only normotensive subjects deviate from the law (patients: χ2=1.28, P>0.05; vs controls: χ2=6.81, P<0.01). In the context of allelic frequency, common T allele was clearly prevalent (T frequency=0.86, t frequency = 0.14) for TaqI, but rare alleles b and m were more frequent for both BglI (b frequency=0.69, B frequency=0.31) and MboI (m frequency=0.80 M frequency=0.20) polymorphisms, respectively. Conclusion: Thus, we report that Bangladeshi hypertensive subjects did not show any distinct pattern of renin gene polymorphisms compared to their healthy control subjects with regard to their genotypic and allelic frequencies. PMID:25057323

Treatment with patiromer decreases aldosterone in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors.

PubMed

Weir, Matthew R; Bakris, George L; Gross, Coleman; Mayo, Martha R; Garza, Dahlia; Stasiv, Yuri; Yuan, Jinwei; Berman, Lance; Williams, Gordon H

2016-09-01

Elevated serum aldosterone can be vasculotoxic and facilitate cardiorenal damage. Renin-angiotensin system inhibitors reduce serum aldosterone levels and/or block its effects but can cause hyperkalemia. Patiromer, a nonabsorbed potassium binder, decreases serum potassium in patients with chronic kidney disease on renin-angiotensin system inhibitors. Here we examined the effect of patiromer treatment on serum aldosterone, blood pressure, and albuminuria in patients with chronic kidney disease on renin-angiotensin system inhibitors with hyperkalemia (serum potassium 5.1-6.5 mEq/l). We analyzed data from the phase 3 OPAL-HK study (4-week initial treatment phase of 243 patients; 8-week randomized withdrawal phase of 107 patients). In the treatment phase, the (mean ± standard error) serum potassium was decreased concordantly with the serum aldosterone (-1.99 ± 0.51 ng/dl), systolic/diastolic blood pressure (-5.64 ± 1.04 mm Hg/-3.84 ± 0.69 mm Hg), and albumin-to-creatinine ratio (-203.7 ± 54.7 mg/g), all in a statistically significant manner. The change in the plasma renin activity (-0.44 ± 0.63 μg/l/hr) was not significant. In the withdrawal phase, mean aldosterone levels were sustained with patiromer (+0.23 ± 1.07 ng/dl) and significantly increased with placebo (+2.78 ± 1.25 ng/dl). Patients on patiromer had significant reductions in mean systolic/diastolic blood pressure (-6.70 ± 1.59/-2.15 ± 1.06 mm Hg), whereas those on placebo did not (-1.21 ± 1.89 mm Hg/+1.72 ± 1.26 mm Hg). Significant changes in plasma renin activity were found only in the placebo group (-3.90 ± 1.41 μg/l/hr). Thus, patiromer reduced serum potassium and aldosterone levels independent of plasma renin activity in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Cholecalciferol treatment downregulates renin-angiotensin system and improves endothelial function in essential hypertensive patients with hypovitaminosid D.

PubMed

Carrara, Davide; Bruno, Rosa Maria; Bacca, Alessandra; Taddei, Stefano; Duranti, Emiliano; Ghiadoni, Lorenzo; Bernini, Giampaolo

2016-11-01

Vitamin D deficiency is related to an increased prevalence of cardiovascular disease. Renin-angiotensin-aldosterone system suppression and vascular dysfunction are considered among the main mechanisms implicated in this association. However, interventional studies demonstrating that vitamin D replacement reduces circulating renin-angiotensin-aldosterone components and improves vascular function in humans are still lacking. Thirty-three consecutive patients with essential hypertension and hypovitaminosis D underwent therapy with cholecalciferol 50 000 IU/week orally for 8 weeks. Thirty-three hypertensive patients with normal vitamin D levels and 20 normotensive individuals were also enrolled as control groups. At baseline and at the end of the study, we evaluated plasma renin activity, circulating renin, angiotensin II, aldosterone and plasma vitamin D levels. Endothelial function [flow-mediated dilation (FMD)], carotid-femoral pulse wave velocity and augmentation index, peripheral and central blood pressure were also acquired. After 8-week cholecalciferol administration, all treated patients normalized plasma 25(OH)D values. Furthermore, a reduction in plasma levels of plasma renin activity (1.17 ± 0.3 vs 1.51 ± 0.4 ng/ml per h, P = 0.02), renin (13.4 ± 1.7 vs 19.2 ± 2.9 pg/ml, P < 0.001), angiotensin II (11.6 ± 1.6 vs 15.8 ± 2.7 pg/ml, P = 0.02) was observed at the end of the study. FMD was significantly increased after cholecalciferol treatment (4.4 ± 2.6 vs 3.3 ± 2.1%, P < 0.05), in the absence of changes of brachial artery diameter and endothelium-independent vasodilation. Carotid-femoral pulse wave velocity and augmentation index were not modified, as well peripheral and central blood pressure. The restoration of normal vitamin D levels after 8-week cholecalciferol treatment is able to inhibit peripheral renin-angiotensin system and improve FMD in essential hypertensive patients with hypovitaminosis D.

Endocrine concomitants of sweating and sweat depression.

PubMed

Candas, V; Brandenberger, G; Lutz-Bucher, B; Follenius, M; Libert, J P

1984-01-01

The effect of humid heat (Ta = 43 degrees C, Pa = 32 Torr) on sweat rate, plasma renin activity and plasma levels of aldosterone and antidiuretic hormone (ADH) was studied in four male subjects before and after repeated heat exposures. Over-sweating and sweat drippage followed by hidromeiosis were observed in three subjects during initial heat exposure. With repeated humid heat exposures increased sweat rates were accompanied by a more intense sweat depression (hidromeiosis) in all four subjects. In our conditions, no changes in plasma levels of aldosterone and ADH or plasma renin activity were observed with hidromeiosis. Plasma renin activity was slightly depressed by repeated exposures, whereas plasma volumes were enhanced, with no significant changes in plasma Na or K. The results suggest that neither ADH nor the components of the renin-angiotensin aldosterone system are involved in the hidromeiotic phenomenon.

Bilateral adrenal phaeochromocytomas associated with unilateral renal artery stenosis.

PubMed Central

Burns, A. P.; O'Connell, P. R.; Murnaghan, D. J.; Brady, M. P.

1989-01-01

A 21 year old male was discovered to be severely hypertensive. He was found to have bilateral adrenal phaeochromocytomas and a single renal artery stenosis. More than 40 cases of coexisting renal artery stenosis and phaeochromocytomas have been reported. The aetiology of renal artery stenosis in association with phaeochromocytoma maybe multifactorial and the radiographic appearances are not always clear-cut. Renin levels in this patient were elevated prior to the removal of the phaeochromocytomas but the renal vein renin ratio did not suggest that the renal artery stenosis contributed significantly to his hypertension. The patient's hypertension resolved following successful removal of the phaeochromocytomas despite persistence of the renal artery stenosis. Thus, though renin levels may be misleading in these cases, renal vein renin ratios may still be helpful in deciding on patient management. Images Figure 1 Figure 2 PMID:2694147

[Renin-angiotensin-aldosteron system: evolution of views from renin discovery to nowadays. Perspectives of therapeutic block].

PubMed

Shestakova, M V

2011-01-01

Recent revolution in the knowledge about structure, physiological and pathophysiological effects of renin-angiotensin-aldosteron system (RAAS) took place recently when it was discovered that local synthesis of all the RAAS components occurs in target organs and their tissues (the heart, kidneys, vessels, brain tissues). It was found that besides classic RAAS acting via activation of angiotensin II (Ang-II) and its receptors, there is an alternative RAAS opposed to atherogenic potential of Ang-II. Renin and prorenin are shown to have both enzymatic and hormonal activities. Wider understanding appeared of extrarenal effects of aldosteron, its non-genomic activity. The above discoveries open new opportunities for pharmacological regulation of RAAS activity, which enables more effectively correct overactivity of this system in organs at risk of negativeAng-II impact.

Conditional deletion of p53 and Rb in the renin-expressing compartment of the pancreas leads to a highly penetrant metastatic pancreatic neuroendocrine carcinoma

PubMed Central

Glenn, Sean T.; Jones, Craig A.; Sexton, Sandra; LeVea, Charles M.; Caraker, Susan M.; Hajduczok, George; Gross, Kenneth W.

2014-01-01

Efforts to model human pancreatic neuroendocrine tumors (PanNET) in animals have been moderately successful, with minimal evidence for glucagonomas or metastatic spread. The renin gene while classically associated with expression in the kidney is also expressed in many other extra-renal tissues including the pancreas. To induce tumorigenesis within renin specific tissues, floxed alleles of p53 and Rb were selectively abrogated using Cre-recombinase driven by the renin promoter. The primary neoplasm generated is a highly metastatic islet cell carcinoma of the pancreas. Lineage tracing identifies descendants of renin-expressing cells as pancreatic alpha cells despite a lack of active renin expression in the mature pancreas. Both primary and metastatic tumors express high levels of glucagon, furthermore an increased level of glucagon is found in the serum identifying the pancreatic cancer as a functional glucagonoma. This new model is highly penetrant and exhibits robust frequency of metastases to lymph nodes and liver, mimicking human disease and provides a useful platform for better understanding pancreatic endocrine differentiation and development, as well as islet cell carcinogenesis. The use of fluorescent reporters for lineage tracing of the cells contributing to disease initiation and progression provides a unique opportunity to dissect the timeline of disease, examining mechanisms of the metastatic process, as well as recovering primary and metastatic cells for identifying co-operating mutations that are necessary for progression of disease. PMID:24292676

High maternal sodium intake alters sex-specific renal renin-angiotensin system components in newborn Wistar offspring.

PubMed

Maia, D R R; Lopes, K L; Heimann, J C; Furukawa, L N S

2016-01-28

This study aimed to evaluate the systemic and renal renin-angiotensin-aldosterone system (RAAS) at birth in male and female offspring and in mothers fed a high sodium diet (HSD) before and during gestation. Female Wistar rats were fed a HSD (8.0% NaCl) or a normal sodium diet (1.3% NaCl) from 8 weeks of age until delivery of their first litter. Maternal body weight, tail blood pressure, and food and water intake were evaluated. The litter sizes were assessed, and the body and kidney weights of the offspring were measured. Both mothers and offspring were euthanized immediately following the birth of the pups to evaluate plasma renin activity (PRA), renal renin content (RRC), renal angiotensin-converting enzyme (ACE) activity, renal angiotensin (Ang) II content, serum aldosterone (ALDO) levels, and renal cortical and medullary renin messenger RNA expression. In mothers in the HSD group, water intake and kidney mass were higher, whereas renal ACE activity, Ang II, PRA, ALDO and RRC were decreased. In the offspring of HSD-fed dams, the body and kidney mass were lower in both genders, renal ACE activity was lower in females and renal Ang II was lower in males. PRA, RRC, renin gene expression and ALDO levels did not differ between the groups of offspring. The data presented herein showed that a maternal HSD during pregnancy induces low birth weight and a sex-specific response in the RAAS in offspring.

Tagging SNPs in REN, AGTR1 and AGTR2 genes and response of renin activity, angiotensin II and aldosterone concentrations to antihypertensive treatment in Kazakans.

PubMed

Yan, Weili; Zhang, Yuanming; Shan, Zimei; Wang, Qian; Huang, Yongdi; Wang, Chenchen; Yan, Kai

2011-12-01

Polymorphisms of REN, AGTR1 and AGTR2 may be associated with responses of renin-angiotensin-aldosterone system (RAAS) activity phenotypes to angiotensin-converting enzyme inhibitor (ACEI) antihypertensive treatment. A total of 400 first diagnosed Kazak hypertensives were randomly allocated to two groups and received a 3-week course of either captopril and atenolol as monotherapy under double blinding. Genotype-phenotype association analyses were performed by covariance analyses between baseline level and responses of blood pressure, renin, angiotensin II and aldosterone concentrations with tagging single nucleotide polymorphisms (SNPs) in REN, AGTR1 and AGTR2 genes. A false discovery rate method was used to adjust multiple testing. After adjustment for multiple testing, we found that the G allele of rs6676670 (T/G) in intron 1 of REN was significantly associated with higher baseline aldosterone concentrations (p < 0.0001, explained variance (EV) = 2.3%). Significant associations after adjustments were also found between the A allele of rs2887284, with higher baseline renin activity (p = 0.022, EV = 1.0%), higher responses of renin (p = 0.018 EV = 5.4%), and higher responses of angiotensin II (p = 0.0255, EV = 3.13%) to the treatment of ACEI. The carriers of the A allele of rs2887284 appeared to be more sensitive to the ACEI treatment. rs2887284 in intron 9 of REN is associated with the response of renin and angiotensin II levels to ACEI treatment.

Complement 3 activates the renal renin-angiotensin system by induction of epithelial-to-mesenchymal transition of the nephrotubulus in mice.

PubMed

Zhou, Xueli; Fukuda, Noboru; Matsuda, Hiroyuki; Endo, Morito; Wang, Xiaofei; Saito, Kosuke; Ueno, Takahiro; Matsumoto, Taro; Matsumoto, Koichi; Soma, Masayoshi; Kobayashi, Naohiko; Nishiyama, Akira

2013-10-01

We have demonstrated that mesenchymal cells from spontaneously hypertensive rats genetically express complement 3 (C3). Mature tubular epithelial cells can undergo epithelial-to-mesenchymal transition (EMT) that is linked to the pathogenesis of renal fibrosis and injury. In this study, we investigated the contribution of C3 in EMT and in the renal renin-angiotensin (RA) systems associated with hypertension. C3a induced EMT in mouse TCMK-1 epithelial cells, which displayed increased expression of renin and Krüppel-like factor 5 (KLF5) and nuclear localization of liver X receptor α (LXRα). C3 and renin were strongly stained in the degenerated nephrotubulus and colocalized with LXRα and prorenin receptor in unilateral ureteral obstruction (UUO) kidneys from wild-type mice. In C3-deficient mice, hydronephrus and EMT were suppressed, with no expression of renin and C3. After UUO, systolic blood pressure was increased in wild-type but not C3-deficient mice. In wild-type mice, intrarenal angiotensin II (ANG II) levels were markedly higher in UUO kidneys than normal kidneys and decreased with aliskiren. There were no increases in intrarenal ANG II levels after UUO in C3-deficient mice. Thus C3 induces EMT and dedifferentiation of epithelial cells, which produce renin through induction of LXRα. These data indicate for the first time that C3 may be a primary factor to activate the renal RA systems to induce hypertension.

Exercise training hypotension - Implications for plasma volume, renin, and vasopressin

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Sciaraffa, D.; Shvartz, E.; Keil, L. C.; Brock, P. J.

1981-01-01

The relation of changes in plasma volume, plasma renin activity and arginine vasopressin to changes in resting blood pressure during exercise training is investigated. Resting supine, sitting, and standing systolic and fifth-phase diastolic blood pressures were measured in ten men before and after an eight-day training period on a cycle ergometer in either a hot (39.8 C) or cool (23.8 C) environment, and compared with plasma volume, renin and vasopressin levels, heart rates, maximal oxygen uptakes, rectal temperatures and sweat rates. Following acclimatization, resting supine and sitting diastolic pressures are observed to decrease by 6 and 9 mm Hg, respectively, while no significant changes are found in the diastolic pressures of the control group or the systolic pressures of either group. Resting plasma volume is found to increase by 12.2% in the controls and by 17.6% after acclimatization following the exercise training. Results suggest that the resting hypotension produced is not attributable to changes in resting plasma volume, renin or vasopressin, although heat acclimatization, which leads to large decreases in plasma volume and increases in vasopressin and renin activity, may be useful in the treatment of hypertension.

[Pharmacological differences between inhibitor drugs of the renin-angiotensin aldosterone system].

PubMed

Méndez-Durán, Antonio

2011-01-01

The activation of the renin-angiotensin-aldosterone cascade is a mechanism that generates high blood pressure. The structure has been identified and can be blocked through specific enzymatic pathways or receptors. We have a diversity of medications that act on this system. It is useful to develop the skill in clinical practice for selecting a drug from a wide variety. Renin-angiotensin system inhibitors share many pharmacological and pharmacokinetic characteristics but not all them are equivalent. Knowledge based on scientific evidence allows the clinician to choose the ideal drug for each patient.

Human renin 5'-flanking DNA to nucleotide-2750.

PubMed

Smith, D L; Jeyapalan, S; Lang, J A; Guo, X H; Sigmund, C D; Morris, B J

1995-01-01

Renin is one of the most important factors in blood pressure and electrolyte regulation in mammals and the renin locus has been implicated in hypertension. To assist studies of promoter control we therefore determined the 5'-flanking sequence of the human gene (REN) to residue -2750 relative to the transcription start site (+1). Sites of homology to consensus sequences for binding of trans-acting factors involved in transcriptional control of other genes were identified, and functionality for two of these (a CRE and Pit-1 site) have so far been demonstrated.

Prediction of response to medical therapy by serum soluble (pro)renin receptor levels in Graves’ disease

PubMed Central

Kimura, Shihori; Takano, Noriyoshi; Yamashita, Kaoru; Seki, Yasufumi; Bokuda, Kanako; Yatabe, Midori; Yatabe, Junichi; Watanabe, Daisuke; Ando, Takashi

2018-01-01

Antithyroid drugs are generally selected as the first-line treatment for Graves’ Disease (GD); however, the existence of patients showing resistance or severe side effects to these drugs is an important issue to be solved. The (pro)renin receptor [(P)RR] is a multi-functional protein that activates the tissue renin-angiotensin system and is an essential constituent of vacuolar H+-ATPase, necessary for the autophagy-lysosome pathway. (P)RR is cleaved to soluble (s)(P)RR, which reflects the status of (P)RR expression. In this retrospective study, we aimed to investigate whether serum s(P)RR concentration can be used as a biomarker to predict the outcome of antithyroid drug treatment in GD patients. Serum s(P)RR levels were measured in 54 untreated GD patients and 47 control participants. Effects of medical treatment with antithyroid drugs on these levels were investigated in GD patients. Serum s(P)RR levels were significantly higher in patients with Graves’ disease than in control subjects (P<0.005) and were significantly reduced after medical treatment for Graves’ disease. High serum s(P)RR levels were associated with resistance to antithyroid drug treatment, suggesting that serum s(P)RR concentration can be used as a useful biomarker to predict the outcome of antithyroid drug treatment in these patients. Patients with Graves’ disease with low body mass index showed higher levels of serum soluble (pro)renin receptor levels than those with high body mass index. In addition, in patients with Graves’ disease, serum triglyceride levels were negatively correlated with serum soluble (pro)renin receptor levels. All these data indicated an association between low nutrient condition due to hyperthyroidism and increased (pro)renin receptor expression in these patients, suggesting that (pro)renin receptor expression could be increased in the process of stimulating intracellular energy production via activating autophagy function to compensate energy loss. PMID:29621332

Prediction of response to medical therapy by serum soluble (pro)renin receptor levels in Graves' disease.

PubMed

Mizuguchi, Yuki; Morimoto, Satoshi; Kimura, Shihori; Takano, Noriyoshi; Yamashita, Kaoru; Seki, Yasufumi; Bokuda, Kanako; Yatabe, Midori; Yatabe, Junichi; Watanabe, Daisuke; Ando, Takashi; Ichihara, Atsuhiro

2018-01-01

Antithyroid drugs are generally selected as the first-line treatment for Graves' Disease (GD); however, the existence of patients showing resistance or severe side effects to these drugs is an important issue to be solved. The (pro)renin receptor [(P)RR] is a multi-functional protein that activates the tissue renin-angiotensin system and is an essential constituent of vacuolar H+-ATPase, necessary for the autophagy-lysosome pathway. (P)RR is cleaved to soluble (s)(P)RR, which reflects the status of (P)RR expression. In this retrospective study, we aimed to investigate whether serum s(P)RR concentration can be used as a biomarker to predict the outcome of antithyroid drug treatment in GD patients. Serum s(P)RR levels were measured in 54 untreated GD patients and 47 control participants. Effects of medical treatment with antithyroid drugs on these levels were investigated in GD patients. Serum s(P)RR levels were significantly higher in patients with Graves' disease than in control subjects (P<0.005) and were significantly reduced after medical treatment for Graves' disease. High serum s(P)RR levels were associated with resistance to antithyroid drug treatment, suggesting that serum s(P)RR concentration can be used as a useful biomarker to predict the outcome of antithyroid drug treatment in these patients. Patients with Graves' disease with low body mass index showed higher levels of serum soluble (pro)renin receptor levels than those with high body mass index. In addition, in patients with Graves' disease, serum triglyceride levels were negatively correlated with serum soluble (pro)renin receptor levels. All these data indicated an association between low nutrient condition due to hyperthyroidism and increased (pro)renin receptor expression in these patients, suggesting that (pro)renin receptor expression could be increased in the process of stimulating intracellular energy production via activating autophagy function to compensate energy loss.

Chronic renin inhibition lowers blood pressure and reduces upright muscle sympathetic nerve activity in hypertensive seniors

PubMed Central

Okada, Yoshiyuki; Jarvis, Sara S; Best, Stuart A; Bivens, Tiffany B; Adams-Huet, Beverley; Levine, Benjamin D; Fu, Qi

2013-01-01

Cardiovascular risk remains high in patients with hypertension even with adequate blood pressure (BP) control. One possible mechanism may be sympathetic activation via the baroreflex. We tested the hypothesis that chronic inhibition of renin reduces BP without sympathetic activation, but diuresis augments sympathetic activity in elderly hypertensives. Fourteen patients with stage-I hypertension (66 ± 5 (SD) years) were treated with a direct renin inhibitor, aliskiren (n= 7), or a diuretic, hydrochlorothiazide (n= 7), for 6 months. Muscle sympathetic nerve activity (MSNA), BP, direct renin and aldosterone were measured during supine and a graded head-up tilt (HUT; 5 min 30° and 20 min 60°), before and after treatment. Sympathetic baroreflex sensitivity (BRS) was assessed. Both groups had similar BP reductions after treatment (all P < 0.01), while MSNA responses were different between hydrochlorothiazide and aliskiren (P= 0.006 pre/post × drug). Both supine and upright MSNA became greater after hydrochlorothiazide treatment (supine, 72 ± 18 post vs. 64 ± 15 bursts (100 beats)−1 pre; 60° HUT, 83 ± 10 vs. 78 ± 13 bursts (100 beats)−1; P= 0.002). After aliskiren treatment, supine MSNA remained unchanged (69 ± 13 vs. 64 ± 8 bursts (100 beats)−1), but upright MSNA was lower (74 ± 15 vs. 85 ± 10 bursts (100 beats)−1; P= 0.012 for pre/post × posture). Direct renin was greater after both treatments (both P < 0.05), while upright aldosterone was greater after hydrochlorothiazide only (P= 0.002). The change in upright MSNA by the treatment was correlated with the change of aldosterone (r= 0.74, P= 0.002). Upright sympathetic BRS remained unchanged after either treatment. Thus, chronic renin inhibition may reduce upright MSNA through suppressed renin activity, while diuresis may evoke sympathetic activation via the upregulated renin–angiotensin–aldosterone system, without changing intrinsic sympathetic baroreflex function in elderly hypertensive patients. PMID:24060993

Expression of genes of the cardiac and renal renin-angiotensin systems in preterm piglets: is this system a suitable target for therapeutic intervention?

PubMed

Kim, Eleanor; Eiby, Yvonne; Lumbers, Eugenie; Boyce, Amanda; Gibson, Karen; Lingwood, Barbara

2015-10-01

The newborn circulating, cardiac and renal renin-angiotensin systems (RASs) are essential for blood pressure control, and for cardiac and renal development. If cardiac and renal RASs are immature this may contribute to cardiovascular compromise in preterm infants. This study measured mRNA expression of cardiac and renal RAS components in preterm, glucocorticoid (GC) exposed preterm, and term piglets. Renal and cardiac RAS mRNA levels were measured using real-time polymerase chain reaction (PCR). Genes studied were: (pro)renin receptor, renin, angiotensinogen, angiotensin converting enzyme (ACE), ACE2, angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R). All the genes studied were expressed in the kidney; neither renin nor AT2R mRNA were detected in the heart. There were no gestational changes in (pro)renin receptor, renin, ACE or AT1R mRNA levels. Right ventricular angiotensinogen mRNA levels in females were lower in preterm animals than at term, and GC exposure increased levels in male piglets. Renal angiotensinogen mRNA levels in female term piglets were lower than females from both preterm groups, and lower than male term piglets. Left ventricular ACE2 mRNA expression was lower in GC treated preterm piglets. Renal AT2R mRNA abundance was highest in GC treated preterm piglets, and the AT1R/AT2R ratio was increased at term. Preterm cardiac and renal RAS mRNA levels were similar to term piglets, suggesting that immaturity of these RASs does not contribute to preterm cardiovascular compromise. Since preterm expression of both renal and cardiac angiotensin II-AT1R is similar to term animals, cardiovascular dysfunction in the sick preterm human neonate might be effectively treated by agents acting on their RASs. © The Author(s), 2015.

Common genetic variations of the renin-angiotensin-aldosterone system and response to acute angiotensin I-converting enzyme inhibition in essential hypertension.

PubMed

Hannila-Handelberg, Tuula; Kontula, Kimmo K; Paukku, Kirsi; Lehtonen, Jukka Y; Virtamo, Jarmo; Tikkanen, Ilkka; Hiltunen, Timo P

2010-04-01

In order to get insight into possible genetic determinants of antihypertensive drug action, we analysed the relations between polymorphisms of the genes of the renin-angiotensin-aldosterone system and acute effects of ACE inhibition on blood pressure as well as circulating renin and aldosterone levels in hypertensive patients. A total of 315 hypertensive patients referred for problems in drug treatment were given a single 50 mg dose of captopril. Plasma renin and aldosterone were measured before and 60 min after the drug administration. Four DNA variants, including angiotensin type I receptor (AGTR1) 1166 A/C, angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T and AGT -217 G/A, were genotyped in the patients and normotensive men (n = 175). A replication study on the relation between AGTR1 1166 A/C and plasma renin and aldosterone levels was carried out in the 244 hypertensive men of the pharmacogenetic GENRES Study. Referred hypertensive patients with the AGTR1 CC genotype had higher aldosterone at baseline (P = 0.02) and after 60 min of captopril administration (P = 0.01) compared with the AA genotype. Replicate analysis in the GENRES patients showed a similar trend. When the two studies were combined (315 and 244 patients, respectively), plasma aldosterone level (P = 0.007) as well as aldosterone/renin ratio (P = 0.04) were significantly higher in the CC genotype (n = 13) than in the AA genotype (n = 370). Transfection studies in cultured HEK293 cells indicated that the 1166C allele was associated with higher mRNA levels than the 1166A allele. The AGTR1 1166C allele when present in homozygous form may be associated with a form of essential hypertension characterized by high plasma aldosterone and low plasma renin levels, possibly due to increased AGTR1 mRNA levels and augmented angiotensin II action.

A Continuum of Renin-Independent Aldosteronism in Normotension

PubMed Central

Baudrand, Rene; Guarda, Francisco J.; Fardella, Carlos; Hundemer, Gregory; Brown, Jenifer; Williams, Gordon; Vaidya, Anand

2017-01-01

Primary aldosteronism (PA) is a severe form of autonomous aldosteronism. Milder forms of autonomous and renin-independent aldosteronism may be common, even in normotension. We characterized aldosterone secretion in 210 normotensives who had suppressed plasma renin activity (PRA<1.0 ng/mL/h), completed an oral sodium suppression test, received an infusion of angiotensin II (AngII), and had measurements of blood pressure (BP) and renal plasma flow (RPF). Continuous associations between urinary aldosterone excretion rate (AER), renin, and potassium handling were investigated. Severe autonomous aldosterone secretion that was consistent with confirmed PA was defined based on accepted criteria of an AER >12 mcg/24h with urinary sodium excretion >200 mmol/24h. Across the population, there were strong and significant associations between higher AER and higher urinary potassium excretion, higher AngII-stimulated aldosterone, and lower PRA, suggesting a continuum of renin-independent aldosteronism and mineralocorticoid receptor activity. Autonomous aldosterone secretion that fulfilled confirmatory criteria for PA was detected in 29 participants (14%). Normotensives with evidence suggestive of confirmed PA had higher 24h urinary AER (20.2±12.2 vs. 6.2±2.9 mcg/24h, P<0.001) as expected, but also higher AngII-stimulated aldosterone (12.4±8.6 vs. 6.6±4.3 ng/dL, P<0.001) and lower 24h urinary sodium-to-potassium excretion (2.69±0.65 vs. 3.69±1.50 mmol/mmol, P=0.001); however, there were no differences in age, aldosterone-to-renin ratio, BP, or RPF between the two groups. These findings indicate a continuum of renin-independent aldosteronism and mineralocorticoid receptor activity in normotension that ranges from subtle to overtly dysregulated and autonomous. Longitudinal studies are needed to determine whether this spectrum of autonomous aldosterone secretion contributes to hypertension and cardiovascular disease. PMID:28289182

Local bone marrow renin-angiotensin system in the genesis of leukemia and other malignancies.

PubMed

Haznedaroglu, I C; Malkan, U Y

2016-10-01

The existence of a local renin-angiotensin system (RAS) specific to the hematopoietic bone marrow (BM) microenvironment had been proposed two decades ago. Most of the RAS molecules including ACE, ACE2, AGT, AGTR1, AGTR2, AKR1C4, AKR1D1, ANPEP, ATP6AP2, CMA1, CPA3, CTSA, CTSD, CTSG, CYP11A1, CYP11B1, CYP11B2, CYP17A1, CYP21A2, DPP3, EGFR, ENPEP, GPER, HSD11B1, HSD11B2, IGF2R, KLK1, LNPEP, MAS1, MME, NR3C1, NR3C2, PREP, REN, RNPEP, and THOP1 are locally present in the BM microenvironment. Local BM RAS peptides control the hematopoietic niche, myelopoiesis, erythropoiesis, thrombopoiesis and the development of other cellular lineages. Local BM RAS is important in hematopoietic stem cell biology and microenvironment. Angiotensin II regulates the proliferation, differentiation, and engraftment of hematopoietic stem cells. Activation of Mas receptor or ACE2 promotes proliferation of CD34+ cells. BM contains a progenitor that expresses renin throughout development. Angiotensin II attenuates the migration and proliferation of CD34+ Cells and promotes the adhesion of both MNCs and CD34+ cells. Renin cells in hematopoietic organs are precursor B cells. The renin cell requires RBP-J to differentiate. Mutant renin-expressing hematopoietic precursors can cause leukemia. Deletion of RBP-J in the renin-expressing progenitors enriches the precursor B-cell gene programme. Mutant cells undergo a neoplastic transformation, and mice develop a highly penetrant B-cell leukemia with multi-organ infiltration and early death. Many biological conditions during the development and function of blood cells are mediated by RAS, such as apoptosis, cellular proliferation, intracellular signaling, mobilization, angiogenesis, and fibrosis. The aim of this paper is to review recent developments regarding the actions of local BM RAS in the genesis of leukemia and other malignancies molecules.

Renin stimulation by passive tilting: the influence of an anti-gravity suit on postural changes in plasma renin activity, plasma noradrenaline concentration and kidney function in normal man.

PubMed

Hesse, B; Ring-Larsen, H; Nielsen, I; Christensen, N J

1978-04-01

Plasma renin activity (PRA), plasma noradrenaline concentration, heart rate, blood pressure, and clearances of para-aminohippurate and inulin were measured in twelve normal subjects (clearances in only three subjects) before and after 40 min of 60 degrees upright tilting. The tilting experiments were repeated after inflation of an anti-gravity suit to 60 mmHg on the lower extremities. Inflation of the anti-gravity suit caused an abolition of the postural PRA increase, a marked reduction of the postural increases in plasma noradrenaline and heart rate, and elimination of the decreases in pulse pressure, inulin and para-aminohippurate clearances and sodium excretion. The results suggest a decisive role of the sympathetic nervous system for postural renin increase, probably mainly activated by stretch receptors in the low-pressure cardiopulmoanry area.

NEW RENIN INHIBITORS - STABILITY AND ACTIVITY DETERMINATION. PART IV.

PubMed

Marszalek, Dorota; Goldnik, Anna; Winiecka, Iwona; Jaworsk, Pawel; Mazurek Aleksander P

2017-03-01

A series of new seven potential renin inhibitors containing pseudodipeptides were synthesized. Stability for all compounds (1-7) in homogenates of liver, kidney, lung and in serum, gastric, intestinal juice and in the presence of α-chymotrypsin was determined. Compound 1 was unstable in all determined mediums. Compounds 2, 4, 5 and 7 were unstable, compound 3 was stable, compound 6 was unstable only in α-chy-motrypsin solution. Inhibitory activity of the compounds was measured in vitro by HPLC determination of low-ering concentration of substrate (angiotensinogen) in the presence of renin and the potential renin inhibitor (compounds 1-7). Compounds 1, 2, 4, 5, 6 and 7 showed inhibitory activity (1.12 x 10⁻⁷, 0.96 x 10⁻⁶, 1.58 x10⁻⁷,1.68 x 10⁻⁶, 1.30 x 10⁻⁶, 0.96 x 10⁻⁷M, respectively).

RETRACTED: Association of the ACE I/D gene polymorphism with sepsis susceptibility and sepsis progression.

PubMed

Yang, Chun-Hua; Zhou, Tian-Biao

2015-12-01

This article has been included in a multiple retraction: Chun-Hua Yang and Tian-Biao Zhou Association of the ACE I/D gene polymorphism with sepsis susceptibility and sepsis progression Journal of Renin-Angiotensin-Aldosterone System 1470320314568521, first published on February 3, 2015 doi: 10.1177/1470320314568521 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10.1177/1470320314566019 Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 Chun-Hua Yang and Tian-Biao Zhou Relationship between the angiotensinogen A1166C gene polymorphism and the risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314566221, first published on February 1, 2015 doi: 10.1177/1470320314566221 Chun-Hua Yang and Tian-Biao Zhou Association of the ACE I/D gene polymorphism with sepsis susceptibility and sepsis progression Journal of Renin-Angiotensin-Aldosterone System 1470320314568521, first published on February 3, 2015 doi: 10.1177/1470320314568521 Articles published in an issue Guohui Liu, Tian-Biao Zhou, Zongpei Jiang, and Dongwen Zheng Association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in a Caucasian population Journal of Renin-Angiotensin-Aldosterone System March 2015 16: 165-171, first published on November 14, 2014 doi: 10.1177/1470320314557849 Weiqiang Zhong, Zhongliang Huang, Yong Wu, Zongpei Jiang, and Tian-Biao Zhou Association of aldosterone synthase (CYP11B2) gene polymorphism with IgA nephropathy risk and progression of IgA nephropathy Journal of Renin-Angiotensin-Aldosterone System September 2015 16: 660-665, first published on August 20, 2014 doi: 10.1177/1470320314524011.

RETRACTED: Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population.

PubMed

Zhou, Tian-Biao; Guo, Xue-Feng; Jiang, Zongpei; Li, Hong-Yan

2015-12-01

The following article has been included in a multiple retraction: Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10.1177/1470320314566019 Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 Chun-Hua Yang and Tian-Biao Zhou Relationship between the angiotensinogen A1166C gene polymorphism and the risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314566221, first published on February 1, 2015 doi: 10.1177/1470320314566221 Chun-Hua Yang and Tian-Biao Zhou Association of the ACE I/D gene polymorphism with sepsis susceptibility and sepsis progression Journal of Renin-Angiotensin-Aldosterone System 1470320314568521, first published on February 3, 2015 doi: 10.1177/1470320314568521 Articles published in an issue Guohui Liu, Tian-Biao Zhou, Zongpei Jiang, and Dongwen Zheng Association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in a Caucasian population Journal of Renin-Angiotensin-Aldosterone System March 2015 16: 165-171, first published on November 14, 2014 doi: 10.1177/1470320314557849 Weiqiang Zhong, Zhongliang Huang, Yong Wu, Zongpei Jiang, and Tian-Biao Zhou Association of aldosterone synthase (CYP11B2) gene polymorphism with IgA nephropathy risk and progression of IgA nephropathy Journal of Renin-Angiotensin-Aldosterone System September 2015 16: 660-665, first published on August 20, 2014 doi: 10.1177/1470320314524011.

RETRACTED: Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population.

PubMed

Zhong, Weiqiang; Jiang, Zongpei; Zhou, Tian-Biao

2015-12-01

This article has been included in a multiple retraction: Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10.1177/1470320314566019 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January 26, 2015 doi: 10.1177/1470320314566019 Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 Chun-Hua Yang and Tian-Biao Zhou Relationship between the angiotensinogen A1166C gene polymorphism and the risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314566221, first published on February 1, 2015 doi: 10.1177/1470320314566221 Chun-Hua Yang and Tian-Biao Zhou Association of the ACE I/D gene polymorphism with sepsis susceptibility and sepsis progression Journal of Renin-Angiotensin-Aldosterone System 1470320314568521, first published on February 3, 2015 doi: 10.1177/1470320314568521 Articles published in an issue Guohui Liu, Tian-Biao Zhou, Zongpei Jiang, and Dongwen Zheng Association of ACE I/D gene polymorphism with T2DN susceptibility and the risk of T2DM developing into T2DN in a Caucasian population Journal of Renin-Angiotensin-Aldosterone System March 2015 16: 165-171, first published on November 14, 2014 doi: 10.1177/1470320314557849 Weiqiang Zhong, Zhongliang Huang, Yong Wu, Zongpei Jiang, and Tian-Biao Zhou Association of aldosterone synthase (CYP11B2) gene polymorphism with IgA nephropathy risk and progression of IgA nephropathy Journal of Renin-Angiotensin-Aldosterone System September 2015 16: 660-665, first published on August 20, 2014 doi: 10.1177/1470320314524011.

The impact of obstructive sleep apnea syndrome on renin and aldosterone.

PubMed

Lykouras, D; Theodoropoulos, K; Sampsonas, F; Lagiou, O; Lykouras, M; Spiropoulou, A; Flordellis, C; Alexandrides, T; Karkoulias, K; Spiropoulos, K

2015-11-01

Obstructive Sleep Apnoea Syndrome (OSAS) is a respiratory disorder characterized by recurrent airflow obstruction caused by total or partial collapse of the upper airway. OSAS is an established independent factor of cardiovascular risk together with other risk factors such as smoking and increased lipids. The aim of our study was to measure serum levels of aldosterone and renin in OSAS patients that did not suffer from arterial hypertension and compare them to matched healthy subjects in order to reveal the impact of chronic intermittent hypoxia on the renin-angiotensin-aldosterone system. The patients that enrolled in this study were 19 OSAS patients who had undergone overnight polysomnography and had an Apnoea Hypopnoea Index (AHI) greater than 10 events/hour. They were compared to 20 healthy non-OSAS closely matched controls. Serum aldosterone and direct renin concentration were measured by radioimmunoassay. Aldosterone concentration follows a diurnal variation; therefore, all blood samples were obtained at the same time (6 AM). There were no significant differences in serum aldosterone levels between the two studied groups of OSAS patients and the healthy subjects group (140.6 pg/ml ± 25.2 vs. 133.2 pg/ml ± 18.5 with p = 0.223). Similar were the results for the renin levels (25.0 ± 6.9 vs. 24.9 ± 4.4 with p = 0.360). Our study suggests that patients with OSAS, but without existing hypertension have aldosterone and renin levels similar to healthy subjects. According to our findings a direct connection between OSAS and the development of arterial hypertension may not be established via sympathetic system activation.

Renal Atp6ap2/(Pro)renin Receptor Is Required for Normal Vacuolar H+-ATPase Function but Not for the Renin-Angiotensin System.

PubMed

Trepiccione, Francesco; Gerber, Simon D; Grahammer, Florian; López-Cayuqueo, Karen I; Baudrie, Véronique; Păunescu, Teodor G; Capen, Diane E; Picard, Nicolas; Alexander, R Todd; Huber, Tobias B; Chambrey, Regine; Brown, Dennis; Houillier, Pascal; Eladari, Dominique; Simons, Matias

2016-11-01

ATPase H + -transporting lysosomal accessory protein 2 (Atp6ap2), also known as the (pro)renin receptor, is a type 1 transmembrane protein and an accessory subunit of the vacuolar H + -ATPase (V-ATPase) that may also function within the renin-angiotensin system. However, the contribution of Atp6ap2 to renin-angiotensin-dependent functions remains unconfirmed. Using mice with an inducible conditional deletion of Atp6ap2 in mouse renal epithelial cells, we found that decreased V-ATPase expression and activity in the intercalated cells of the collecting duct impaired acid-base regulation by the kidney. In addition, these mice suffered from marked polyuria resistant to desmopressin administration. Immunoblotting revealed downregulation of the medullary Na + -K + -2Cl - cotransporter NKCC2 in these mice compared with wild-type mice, an effect accompanied by a hypotonic medullary interstitium and impaired countercurrent multiplication. This phenotype correlated with strong autophagic defects in epithelial cells of medullary tubules. Notably, cells with high accumulation of the autophagosomal substrate p62 displayed the strongest reduction of NKCC2 expression. Finally, nephron-specific Atp6ap2 depletion did not affect angiotensin II production, angiotensin II-dependent BP regulation, or sodium handling in the kidney. Taken together, our results show that nephron-specific deletion of Atp6ap2 does not affect the renin-angiotensin system but causes a combination of renal concentration defects and distal renal tubular acidosis as a result of impaired V-ATPase activity. Copyright © 2016 by the American Society of Nephrology.

Unsuccessfully Treated Hypertension: A Major Public Health Problem With a Potential Solution.

PubMed

Furberg, Curt D; Sealey, Jean E; Blumenfeld, Jon D

2017-09-01

About one-half of all hypertensive adults do not have their blood pressure controlled. They are often prescribed medications that conform to national guidelines but they continue to have elevated blood pressure. This public health problem might be improved by applying plasma renin guided therapy. A contributor to the public health problem of unsuccessfully treated hypertension is that the circulating renin-angiotensin system (RAS) is not recognized in treatment guidelines as clinically relevant for the treatment of hypertension or as important as the body salt status for determining blood pressure levels. Another contributor to the problem is the lack of specificity in the package inserts for antihypertensive drugs. They do not specifically state under the heading "Indications" that RAS blockers are primarily most effective in hypertensive subjects with medium and high plasma renin levels; by contrast, natriuretic drugs are most effective in those with low plasma renin levels. Literature review. To address the problem of unsuccessfully treated hypertension, we recommend that the "Indications" section of package inserts for antihypertensive drugs be more specific. The primary indication for RAS blockers ought to be hypertension with medium and high plasma renin levels, and natriuretic agents for those with low plasma renin levels. Similar language ought to be added to treatment guidelines. Additionally, 3 other reasons for lack of blood pressure control also need to be addressed-failure to prescribe antihypertensive drugs to hypertensive subjects, failure of patients to fill prescriptions, and low drug adherence. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Erythropoietin alleviates post-resuscitation myocardial dysfunction in rats potentially through increasing the expression of angiotensin II receptor type 2 in myocardial tissues

PubMed Central

Zhou, Hourong; Huang, Jia; Zhu, Li; Cao, Yu

2018-01-01

Activation of renin-angiotensin system (RAS) is one of the pathological mechanisms associated with myocardial ischemia-reperfusion injury following resuscitation. The present study aimed to determine whether erythropoietin (EPO) improves post-resuscitation myocardial dysfunction and how it affects the renin-angiotensin system. Sprague-Dawley rats were randomly divided into sham, vehicle, epinephrine (EP), EPO and EP + EPO groups. Excluding the sham group, all groups underwent cardiopulmonary resuscitation (CPR) 4 min after asphyxia-induced cardiac arrest (CA). EP and/or EPO was administrated by intravenous injection when CPR began. The results demonstrated that the vehicle group exhibited lower mean arterial pressure, left ventricular systolic pressure, maximal ascending rate of left ventricular pressure during left ventricular isovolumic contraction and maximal descending rate of left ventricular pressure during left ventricular isovolumic relaxation (+LVdP/dt max and -LVdP/dt max, respectively), and higher left ventricular end-diastolic pressure, compared with the sham group following return of spontaneous circulation (ROSC). Few significant differences were observed concerning the myocardial function between the vehicle and EP groups; however, compared with the vehicle group, EPO reversed myocardial function indices following ROSC, excluding-LVdP/dt max. Serum renin and angiotensin (Ang) II levels were measured by ELISA. The serum levels of renin and Ang II were significantly increased in the vehicle group compared with the sham group, which was also observed for the myocardial expression of renin and Ang II receptor type 1 (AT1R), as determined by reverse transcription-quantitative polymerase chain reaction and western blotting. EPO alone did not significantly reduce the high serum levels of renin and Ang II post-resuscitation, but changed the protein levels of renin and AT1R expression in myocardial tissues. However, EPO enhanced the myocardial expression of Ang II receptor type 2 (AT2R) following ROSC. In conclusion, the present study confirmed that CA resuscitation activated the renin-Ang II-AT1R signaling pathway, which may contribute to myocardial dysfunction in rats. The present study confirmed that EPO treatment is beneficial for protecting cardiac function post-resuscitation, and the roles of EPO in alleviating post-resuscitation myocardial dysfunction may potentially be associated with enhanced myocardial expression of AT2R. PMID:29393490

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

The unique response of renin and aldosterone to dietary sodium intervention in sodium sensitivity.

PubMed

Shin, Sung Joon; Lim, ChiYeon; Oh, Sang Woo; Rhee, Moo-Yong

2014-06-01

Sodium sensitivity (SS) is a phenomenon in which significant changes in blood pressure (BP) are observed based on sodium intake. The renin-angiotensin-aldosterone system plays a critical role in sodium handling and hypertension. We identified the specific responses of renin and aldosterone based on dietary sodium intake and revealed the relationship between these hormonal changes and dietary sodium intake in patients with SS. In total, 61 subjects were available to analyze full data including plasma renin activity (PRA) and aldosterone. Participants were given a low-sodium DASH diet (LSD) for 7 days and a high-sodium DASH diet (HSD) for the following 7 days. SS was found in five (14.71%) in normotensives, and 14 (51.85%) in hypertensives. In sodium-resistant (SR) subjects, both PRA and aldosterone decreased significantly after consuming HSD. Moreover, a significant correlation was observed between PRA and aldosterone in SR subjects. In contrast, only hypertensive subjects showed a marked fall in PRA after consuming HSD (1.299 ± 0.904 vs. 0.593 ± 0.479) among SS subjects. This study demonstrated the different responses of renin and aldosterone in SS and SR subjects based on dietary sodium intake whether or not they had hypertension. © The Author(s) 2014.

Correlations of plasma renin activity and aldosterone concentration with ambulatory blood pressure responses to nebivolol and valsartan, alone and in combination, in hypertension.

PubMed

Giles, Thomas D; Bakris, George; Oparil, Suzanne; Weber, Michael A; Li, Huiling; Mallick, Madhuja; Bharucha, David B; Chen, ChunLin; Ferguson, William G

2015-11-01

After demonstration of the antihypertensive efficacy of the combination of the beta-blocker nebivolol and the angiotensin receptor blocker valsartan in an 8-week, randomized, placebo-controlled trial (N = 4161), we now report the effects of this treatment on the renin-angiotensin-aldosterone system in a substudy (n = 805). Plasma renin activity increased with valsartan (54%-73%) and decreased with nebivolol (51%-65%) and the combination treatment (17%-39%). Plasma aldosterone decreased with individual treatments (valsartan, 11%-22%; nebivolol, 20%-26%), with the largest reduction (35%) observed with maximum combination dose (20 mg nebivolol/320 mg valsartan). Baseline ln(plasma renin activity) correlated with the 8-week reductions in 24-hour systolic and diastolic BP following treatments with the combination (all doses combined, P = .003 and P < .001) and nebivolol (both, P < .001), but not with valsartan. Baseline ln(aldosterone) correlated with 24-hour systolic and diastolic BP reductions following combination treatment only (P < .001 and P = .005). The implications of the renin-angiotensin-aldosterone system effects of this beta blocker-angiotensin receptor blocker combination should be explored further. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Excessive Catecholamine Secretion and the Activation of the Renin-Angiotensin-Aldosterone-System in Patients with Pheochromocytoma: A Single Center Experience and Overview of the Literature.

PubMed

Haase, Matthias; Dringenberg, Till; Allelein, Stephanie; Willenberg, Holger S; Schott, Matthias

2017-10-01

Catecholamines stimulate renin-secretion in the juxtaglomerular cells of the kidney and a number of case reports suggest an association between pheochromocytoma and activation of the RAAS. Therefore, it could be asked whether patients suffering from pheochromocytoma with high concentrations of circulating catecholamines present with oversecretion of renin and aldosterone. We identified twelve patients with excessive catecholamine secretion due to pheochromocytoma and compared them to a group of twelve patients with essential hypertension (EH) with regard to the activation of the renin-angiotensin-aldosterone-system (RAAS). The PubMed database was screened for studies that investigate the association between pheochromocytoma and activation of the RAAS. The plasma concentrations of metanephrines (19.9-fold) and normetanephrines (29.5-fold) were significantly higher in the pheochromocytoma group than in the EH group. Renin and aldosterone levels were 1.3-fold and 1.6-fold higher, respectively, as compared to the EH group, whereas the differences were not statistically significant. There was no significant correlation between plasma metanephrine or normetanephrine levels and the plasma renin concentration (r s =0.077, r s =0.049, respectively) in our patients. The data from our institution and from review of literature suggest that an association between pheochromocytoma in the context of high plasma catecholamine levels and activation of the RAAS is present. However, results have not been consistent. Thus, other causes of RAAS-activation should be considered also in the presence of pheochromocytoma or reinvestigation for aldosteronism should be offered to such patients after removal of the catecholamine-producing tumour. © Georg Thieme Verlag KG Stuttgart · New York.

Regulation of Renin Secretion and Arterial Pressure During Prolonged Baroreflex Activation: Influence of Salt Intake

PubMed Central

Hildebrandt, Drew A.; Irwin, Eric D.; Cates, Adam W.; Lohmeier, Thomas E.

2014-01-01

Chronic electrical activation of the carotid baroreflex produces sustained reductions in sympathetic activity and arterial pressure and is currently being evaluated as antihypertensive therapy for patients with resistant hypertension. However, the influence of variations in salt intake on blood pressure lowering during baroreflex activation has not been determined. As sensitivity of arterial pressure to salt intake is linked to the responsiveness of renin secretion, we determined steady-state levels of arterial pressure and neurohormonal responses in 6 dogs on low, normal, and high salt intakes ( 5, 40, 450 mmol/day, respectively) under control conditions and during a 7-day constant level of baroreflex activation. Under control conditions, there was no difference in mean arterial pressure at low (92±1) and normal (92±2 mmHg) sodium intakes, but pressure increased 9 ±2 mmHg during high salt. Plasma renin activity (2.01±0.23, 0.93±0.20, 0.01±0.01 ng ANGI/mL/hr) and plasma aldosterone (10.3±1.9, 3.5±0.5, 1.7±0.1ng/dL) were inversely related to salt intake, whereas there were no changes in plasma norepinephrine. Although mean arterial pressure (19-22 mmHg) and norepinephrine (20-40%) were lower at all salt intakes during baroreflex activation, neither the changes in pressure nor the absolute values for plasma renin activity or aldosterone in response to salt were different from control conditions. These findings demonstrate that suppression of sympathetic activity by baroreflex activation lowers arterial pressure without increasing renin release and indicate that changes in sympathetic activity are not primary mediators of the effect of salt on renin secretion. Consequently, blood pressure lowering during baroreflex activation is independent of salt intake. PMID:24935941

Effect of postural changes on aldosterone to plasma renin ratio in patients with suspected secondary hypertension.

PubMed

Barigou, M; Ah-Kang, F; Orloff, E; Amar, J; Chamontin, B; Bouhanick, B

2015-06-01

To study the influence of postural changes on aldosterone to renin ratio (ARR) in patients with suspected secondary hypertension and to evaluate the sensitivity and specificity of the recommended seated ARR compared to supine and upright ARR for primary aldosteronism screening. Fifty-three hypertensive patients were prospectively hospitalized for secondary hypertension exploration (age: 51 ± 12, 66% males). After withdrawal of drugs interfering with renin angiotensin system, plasma aldosterone and direct renin concentration were measured in the morning, at bed after an overnight supine position, then out of bed after 1 hour of upright position and finally 2 hours later after 15 minutes of seating. Minimal renin value was set at 5 μUI/mL. Referring to ARR cut-off of 23 pg/μUI, the sensitivity of seated ARR was 57.1% and specificity was 92.3%. The negative and positive predictive values were 95.1% and 45.2% respectively. Compared to these results, a cut-off of 19 improved sensitivity to 85.7% with a specificity of 89.7%. Negative and positive predictive values were 98.3% and 41.1% respectively. Seated ARR mean value was lower than supine and upright ARR mean values, due to an overall increase in renin at seating compared to the supine position by factor 1.9 while aldosterone just slightly increased by factor 1.2. Seated ARR correlated to supine and upright ARR: correlation coefficients (r) 0.90 and 0.93 respectively (P<0.001). Current recommended measurement of ARR in the seating position is fairly correlated to supine and upright ARR. A suggested cut-off value of 19 instead of 23 pg/μUI increased the discriminating power of this test. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Characterization of renin-angiotensin system enzyme activities in cultured mouse podocytes.

PubMed

Velez, Juan Carlos Q; Bland, Alison M; Arthur, John M; Raymond, John R; Janech, Michael G

2007-07-01

Intraglomerular ANG II has been linked to glomerular injury. However, little is known about the contribution of podocytes (POD) to intraglomerular ANG II homeostasis. The aim of the present study was to examine the processing of angiotensin substrates by cultured POD. Our approach was to use matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry for peptide determination from conditioned cell media and customized AQUA peptides for quantification. Immortalized mouse POD were incubated with 1-2 microM ANG I, ANG II, or the renin substrate ANG-(1-14) for different time intervals and coincubated in parallel with various inhibitors. Human mesangial cells (MES) were used as controls. POD incubated with 1 microM ANG I primarily formed ANG-(1-9) and ANG-(1-7). In contrast, MES incubated with ANG I primarily generated ANG II. In POD, ANG-(1-7) was the predominant product, and its formation was inhibited by a neprilysin inhibitor. Modest angiotensin-converting enzyme (ACE) activity was also detected in POD, although only after cells were incubated with 2 microM ANG I. In addition, we observed that POD degraded ANG II into ANG III and ANG-(1-7). An aminopeptidase A inhibitor inhibited ANG III formation, and an ACE2 inhibitor led to ANG II accumulation. Furthermore, we found that POD converted ANG-(1-14) to ANG I and ANG-(1-7). This conversion was inhibited by a renin inhibitor. These findings demonstrate that POD express a functional intrinsic renin-angiotensin system characterized by neprilysin, aminopeptidase A, ACE2, and renin activities, which predominantly lead to ANG-(1-7) and ANG-(1-9) formation, as well as ANG II degradation. These findings may reflect a specific role of POD in maintenance of intraglomerular renin-angiotensin system balance.

Local renin–angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy

PubMed Central

Kobori, H; Ichihara, A; Miyashita, Y; Hayashi, M; Saruta, T

2008-01-01

We have reported previously that thyroid hormone activates the circulating and tissue renin–angiotensin systems without involving the sympathetic nervous system, which contributes to cardiac hypertrophy in hyperthyroidism. This study examined whether the circulating or tissue renin–angiotensin system plays the principal role in hyperthyroidism-induced cardiac hypertrophy. The circulating renin–angiotensin system in Sprague–Dawley rats was fixed by chronic angiotensin II infusion (40 ng/ min, 28 days) via mini-osmotic pumps. Daily i.p. injection of thyroxine (0·1 mg/kg per day, 28 days) was used to mimic hyperthyroidism. Serum free tri-iodothyronine, plasma renin activity, plasma angiotensin II, cardiac renin and cardiac angiotensin II were measured with RIAs. The cardiac expression of renin mRNA was evaluated by semiquantitative reverse transcriptase-polymerase chain reaction. Plasma renin activity and plasma angiotensin II were kept constant in the angiotensin II and angiotensin II+thyroxine groups (0·12 ± 0·03 and 0·15 ± 0·03 μg/h per liter, 126 ± 5 and 130 ± 5 ng/l respectively) (means ± s.e.m.). Despite stabilization of the circulating renin–angiotensin system, thyroid hormone induced cardiac hypertrophy (5·0 ± 0·5 vs 3·5 ± 0·1 mg/g) in conjunction with the increases in cardiac expression of renin mRNA, cardiac renin and cardiac angiotensin II (74 ± 2 vs 48 ± 2%, 6·5 ± 0·8 vs 3·8 ± 0·4 ng/h per g, 231 ± 30 vs 149 ± 2 pg/g respectively). These results indicate that the local renin–angiotensin system plays the primary role in the development of hyperthyroidism-induced cardiac hypertrophy. PMID:9854175

Obstructive Sleep Apnea and Aldosterone

PubMed Central

Svatikova, Anna; Olson, Lyle J.; Wolk, Robert; Phillips, Bradley G.; Adachi, Taro; Schwartz, Gary L.; Somers, Virend K.

2009-01-01

Background: Obstructive sleep apnea (OSA) is a major risk factor for hypertension and has been associated with increased risk for cardiovascular morbidity. A dysregulated renin-angiotensin-aldosterone system may contribute to excess sodium retention and hypertension and may be activated in OSA. We tested the hypothesis that serum levels of aldosterone and plasma renin activity (PRA) are increased by apneic sleep in subjects without cardiovascular disease, compared to healthy control subjects. Methods and Results: Plasma aldosterone level was measured in 21 subjects with moderate to severe OSA and was compared to 19 closely matched healthy subjects. Plasma renin activity (PRA) was measured in 19 OSA patients and in 20 healthy controls. Aldosterone and PRA were measured before sleep (9pm), after 5 hrs of untreated OSA (2am) and in the morning after awakening (6am). There were no baseline (9pm) differences in serum aldosterone levels and PRA between the healthy controls and OSA patients (aldosterone: 55.2 ± 9 vs 56.0 ± 9 pg/mL; PRA: 0.99 ± 0.15 vs 1.15 ± 0.15 ng/mL/hr). Neither several hours of untreated severe OSA nor CPAP treatment affected aldosterone levels and PRA in OSA patients. Diurnal variation of both aldosterone and PRA was observed in both groups, in that morning renin and aldosterone levels were higher than those measured at night before sleep. Conclusions: Our study shows that patients with moderate to severe OSA without co-existing cardiovascular disease have plasma aldosterone and renin levels similar to healthy subjects. Neither untreated OSA nor CPAP treatment acutely affect plasma aldosterone or renin levels. Citation: Svatikova A; Olson LJ; Wolk R; Phillips BG; Adachi T; Schwartz GL; Somers VK. Obstructive sleep apnea and aldosterone. SLEEP 2009;32(12):1589-1592. PMID:20041594

Living alone and activation of the renin-angiotensin-aldosterone-system: Differential effects depending on alexithymic personality features.

PubMed

Terock, Jan; Hannemann, Anke; Janowitz, Deborah; Völzke, Henry; Nauck, Matthias; Freyberger, Harald-Jürgen; Wallaschofski, Henri; Grabe, Hans Jörgen

2017-05-01

Living alone is considered as a chronic stress factor predicting different health conditions and particularly cardiovascular disease (CVD). Alexithymia is associated with increased psychological distress, less social skills and fewer close relationships, making alexithymic subjects particularly susceptible to chronic stress imposed by "living alone". Only few studies investigated the renin-angiotensin-aldosterone-system (RAAS) activity in response to chronic stress. We aimed at evaluating the effects of "living alone" as a paradigm for chronic stress on RAAS activity and putatively differential effects depending on alexithymic personality features. Alexithymia and serum concentrations of renin and aldosterone were measured in 944 subjects from the population-based SHIP-1 study. Subgroups were formed using the median of the Toronto Alexithymia Scale-20 (TAS-20) and a cohabitation status of "living alone" or "living together". Analyses were adjusted for various psychosocial, behavioral and metabolic risk factors. "Living alone" was associated with elevated plasma renin (p<0.01, β=0.138) but not aldosterone concentrations in the total sample. On subgroup level, we found associations of "living alone" and elevated renin concentrations only in subjects low in TAS-20 scores (p<0.01, β=0.219). Interactional effects of alexithymia×cohabitation status were found for the aldosterone-to-renin ratio (p=0.02, β=-0.234). The association of chronic stress imposed by "living alone" with increased RAAS activity contributes to explain the relationship of this psychosocial stress condition and increased risk for CVD. In contrast, alexithymic subjects may be less affected by the deleterious effects of "living alone". Copyright © 2017 Elsevier Inc. All rights reserved.

Methylglyoxal, a reactive glucose metabolite, increases renin angiotensin aldosterone and blood pressure in male Sprague-Dawley rats.

PubMed

Dhar, Indu; Dhar, Arti; Wu, Lingyun; Desai, Kaushik M

2014-03-01

The majority of people with diabetes develop hypertension along with increased activity of the renin-angiotensin system. Methylglyoxal, a reactive glucose metabolite, is elevated in diabetic patients. We investigated the effects of methylglyoxal on the renin-angiotensin system and blood pressure. Male Sprague-Dawley rats were treated with a continuous infusion of methylglyoxal with a minipump for 4 weeks. Organs/tissues and cultured vascular smooth muscle cells (VSMCs) were used for molecular studies. High-performance liquid chromatography, Western blotting, and quantitative real-time polymerase chain reaction were used to measure methylglyoxal, proteins, and mRNA, respectively. Small interfering RNA for angiotensinogen and the receptor for advanced glycation endproducts (RAGE) were used to study mechanisms. Methylglyoxal-treated rats developed a significant increase in blood pressure and plasma levels of aldosterone, renin, angiotensin, and catecholamines. Methylglyoxal level and protein and mRNA for angiotensin, AT1 receptor, adrenergic α1D receptor, and renin were significantly increased in the aorta and/or kidney of methylglyoxal-treated rats, a novel finding. Alagebrium attenuated the above effects of methylgloyxal. Treatment of cultured VSMCs with methylglyoxal or high glucose (25 mM) significantly increased cellular methylglyoxal and protein and mRNA for nuclear factor kappa B (NF-κB), angiotensin, AT1 receptor, and α1D receptor, which were prevented by inhibition of NF-κB, and by alagebrium. Silencing of mRNA for RAGE prevented the increase in NF-kB induced by methylglyoxal. Silencing of mRNA for angiotensinogen prevented the increase in NF-κB, angiotensin, AT1 receptor, and α1D receptor. Methylglyoxal activates NF-κB through RAGE and thereby increases renin-angiotensin levels, a novel finding, and a probable mechanism of increase in blood pressure.

Increase of plasma renin activity in male and female rabbits subjected to dysbaric conditions

NASA Technical Reports Server (NTRS)

Chryssanthou, C.; Kircikoglu, H.; Strugar, J.

1985-01-01

The renin-angiotensin-aldosterone system may be implicated in hemodynamic alterations occurring in dysbaric disorders. This report concerns changes in plasma renin activity (PRA) induced by exposure of rabbits to a compression-decompression schedule that does not normally produce clinical manifestations of decompression sickness. The results revealed a significant increase in PRA in 19 of 23 animals following dysbaric exposure. Mean PRA rose from 1.18 ng ang I/ml hr (preexposure) to 2.40 ng ang I/ml hr (postexposure). The increase was particularly pronounced in female animals (217 percent). Asymptomatic intravascular gas bubbles (silent bubbles) were detected by gross or microscopic examination in the majority of the animals. Renin elaboration and secretion in asymptomatic dysbaric exposures may be mediated by bradykinin and/or prostaglandins released or activated in a chain reaction triggered by silent gas bubbles. This hypothesis is also applicable to increased PRA in altitude decompression. Alternatively elevation of PRA may result from decreased renal perfusion when dysbaric disorders are complicated by significant hypovolemia.

Aldosterone, Renin, and Diabetes Mellitus in African Americans: The Jackson Heart Study.

PubMed

Joseph, Joshua J; Echouffo-Tcheugui, Justin B; Kalyani, Rita R; Yeh, Hsin-Chieh; Bertoni, Alain G; Effoe, Valery S; Casanova, Ramon; Sims, Mario; Correa, Adolfo; Wu, Wen-Chih; Wand, Gary S; Golden, Sherita H

2016-04-01

Previous research has suggested that activation of the renin-angiotensin-aldosterone system may promote insulin resistance and β-cell dysfunction, but the association with incident diabetes in African Americans is unknown. We examined the association of aldosterone and renin with insulin resistance, β-cell function, and incident diabetes in a large African American cohort. The Jackson Heart Study is a prospective study of the development and progression of cardiovascular disease in African Americans. Participants were recruited from the tricounty area of metropolitan Jackson, Mississippi. A total of 5301 African American adults, aged 21–94 years, were assessed at baseline and through 12 years of follow-up. Data on aldosterone, renin, and risk factors were collected at baseline (2000–2004). Diabetes (fasting glucose ≥ 126 mg/dL, physician diagnosis, use of diabetes drugs, or glycated hemoglobin ≥ 6.5%) was assessed at baseline and through 12 years of follow-up. Participants were excluded for missing data on baseline covariates or diabetes follow-up. Cox regression was used to estimate hazard ratios (HR) for incident diabetes using sequential modeling adjusting for age, sex, education, occupation, systolic blood pressure, current smoking, physical activity, dietary intake, and body mass index. Aldosterone, renin, and diabetes risk factors were measured. Outcomes included the homeostatic model assessment of insulin resistance (HOMA-IR) and incident diabetes. Among 3234 participants over a median of 8.0 years of follow-up, there were 554 cases of incident diabetes. Every 1% increase in log-transformed aldosterone was associated with a 0.18% higher log-transformed HOMA-IR in cross-sectional analyses of nondiabetic participants (P < .001). Log-transformed aldosterone and renin levels in the fifth vs first quintile were associated with a 78% (HR 1.78, 95% confidence interval 1.35–2.34) and 35% (HR 1.35, 95% confidence interval 1.06–1.72) increase in diabetes risk, respectively, in fully adjusted models. Activation of the renin-angiotensin-aldosterone system may play a significant role in the development of insulin resistance and diabetes in African Americans.

Aldosterone, Renin, and Diabetes Mellitus in African Americans: The Jackson Heart Study

PubMed Central

Joseph, Joshua J.; Echouffo-Tcheugui, Justin B.; Kalyani, Rita R.; Yeh, Hsin-Chieh; Bertoni, Alain G.; Effoe, Valery S.; Casanova, Ramon; Sims, Mario; Correa, Adolfo; Wu, Wen-Chih; Wand, Gary S.

2016-01-01

Context: Previous research has suggested that activation of the renin-angiotensin-aldosterone system may promote insulin resistance and β-cell dysfunction, but the association with incident diabetes in African Americans is unknown. Objective: We examined the association of aldosterone and renin with insulin resistance, β-cell function, and incident diabetes in a large African American cohort. Design: The Jackson Heart Study is a prospective study of the development and progression of cardiovascular disease in African Americans. Setting: Participants were recruited from the tricounty area of metropolitan Jackson, Mississippi. Participants: A total of 5301 African American adults, aged 21–94 years, were assessed at baseline and through 12 years of follow-up. Data on aldosterone, renin, and risk factors were collected at baseline (2000–2004). Diabetes (fasting glucose ≥ 126 mg/dL, physician diagnosis, use of diabetes drugs, or glycated hemoglobin ≥ 6.5%) was assessed at baseline and through 12 years of follow-up. Participants were excluded for missing data on baseline covariates or diabetes follow-up. Cox regression was used to estimate hazard ratios (HR) for incident diabetes using sequential modeling adjusting for age, sex, education, occupation, systolic blood pressure, current smoking, physical activity, dietary intake, and body mass index. Exposures: Aldosterone, renin, and diabetes risk factors were measured. Outcomes: Outcomes included the homeostatic model assessment of insulin resistance (HOMA-IR) and incident diabetes. Results: Among 3234 participants over a median of 8.0 years of follow-up, there were 554 cases of incident diabetes. Every 1% increase in log-transformed aldosterone was associated with a 0.18% higher log-transformed HOMA-IR in cross-sectional analyses of nondiabetic participants (P < .001). Log-transformed aldosterone and renin levels in the fifth vs first quintile were associated with a 78% (HR 1.78, 95% confidence interval 1.35–2.34) and 35% (HR 1.35, 95% confidence interval 1.06–1.72) increase in diabetes risk, respectively, in fully adjusted models. Conclusions: Activation of the renin-angiotensin-aldosterone system may play a significant role in the development of insulin resistance and diabetes in African Americans. PMID:26908112

Validated low-volume immunoassay for the reliable determination of direct renin especially valuable for pediatric investigations.

PubMed

Schaefer, J; Burckhardt, B B; Tins, J; Bartel, A; Laeer, S

2017-01-01

The pharmacotherapy of pediatric patients suffering from heart failure is extrapolated from adults due to missing data in children. Development and validation of a low-volume immunoassay for the reliable determination of renin. The immunoassay was validated according to international guidelines. The assay allows the reliable determination of renin in 40 μL plasma within a calibration range of 4-128 pg/mL. Between-run accuracy varied from -3.3 to +3.0% (relative error), while between-run precision ranged from 4.9 to 11.3% (coefficient of variation). The low-volume immunoassay facilitates the reliable collection of pharmacodynamic data in children.

Possible contribution of (pro)renin receptor to development of gestational diabetes mellitus.

PubMed

Bokuda, Kanako; Ichihara, Atsuhiro

2014-12-15

(Pro)renin receptor [(P)RR], a receptor for renin and prorenin, was first cloned in 2002. Since then, the pathophysiological roles of (P)RR have been growing concerns. (P)RR binds renin and prorenin, with two important consequences, nonproteolytic activation of prorenin, leading to the tissue renin-angiotensin system activation and the intracellular signalings. It is now also known to play an important role as vacuolar H(+)-ATPase associated protein, involving in Wnt signaling, main component of embryonic development. Extracellular domain of full-length (P)RR is cleaved in golgi-complex forming soluble (P)RR [s(P)RR]. The s(P)RR is now possible to be measured in human blood and urine. It is now measured in different pathophysiological states, and recent study showed that elevated plasma s(P)RR levels in the early stage of pregnancies are associated with higher incidence of gestational diabetes mellitus later in the pregnancies. Plasma s(P)RR levels of neonates are known to be higher than that of adults. It was also shown that, increased s(P)RR concentrations in cord blood, associated with a lower small for gestational age birth likelihood. These data suggests the involvement of (P)RR in embryo's growth. In this review article, we attempt to figure out the possible pathophysiological roles of the (P)RR in maternal glucose intolerance and embryo's growth, through reviewing previous studies.

High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells.

PubMed

Xu, Chuanming; Fang, Hui; Zhou, Li; Lu, Aihua; Yang, Tianxin

2016-10-01

(Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release.

Azilsartan, aliskiren, and combination antihypertensives utilizing renin-angiotensin-aldosterone system antagonists.

PubMed

Lanier, Gregg; Sankholkar, Kedar; Aronow, Wilbert S

2014-01-01

Health care providers managing hypertension (HTN) have a large selection of pharmacologic agents to choose from, including several different classes of drugs and many similar drugs within each class. Antagonism of the renin-angiotensin-aldosterone system has been shown to be very effective for HTN, especially in patients with cardiovascular disease, diabetes, and heart failure. Within this group, there have been 2 new agents recently introduced to the US market and approved by the Food and Drug Administration. It is important for the HTN specialist to be familiar with the merits of these 2 drugs: the angiotensin receptor blocker Edarbi (azilsartan) and the renin inhibitor Tekturna (aliskiren). Additionally, there have been several new, fixed-dose combination antihypertensives introduced to the market since 2006 that use a renin-angiotensin-aldosterone antagonist. Seven of these combine 2 drugs together in a single pill: Edarbyclor (azilsartan/chlorthalidone), Exforge (amlodipine/valsartan), Azor (olmesartan/amlodipine), Twynsta (amlodipine/telmisartan), Tekturna HCT [aliskiren/hydrochlorothiazide (HCTZ)], Valturna (aliskiren/valsartan), Tekamlo (aliskiren/amlodipine). Three triple-drug combination medications have also been introduced recently: Exforge HCT (amlodipine/valsartan/HCTZ), Tribenzor (olmesartan/amlodipine/HCTZ), and Amturnide (aliskiren/amlodipine/hydrocholorothiazide). This review will summarize the trial data and important pharmacologic merits of these 2 new renin-angiotensin-aldosterone antagonists and the advantages of initiating treatment with one of the new fixed-dose, combination drugs approved over the last 5 years.

Evolving concepts on regulation and function of renin in distal nephron

PubMed Central

Prieto, Minolfa C.; Gonzalez, Alexis A.

2012-01-01

Sustained stimulation of the intrarenal/intratubular renin–angiotensin system in a setting of elevated arterial pressure elicits renal vasoconstriction, increased sodium reabsorption, proliferation, fibrosis, and eventual renal injury. Activation of luminal AT1 receptors in proximal and distal nephron segments by local Ang II formation stimulates various transport systems. Augmented angiotensinogen (AGT) production by proximal tubule cells increases AGT secretion contributing to increased proximal Ang II levels and leading to spillover of AGT into the distal nephron segments, as reflected by increased urinary AGT excretion. The increased distal delivery of AGT provides substrate for renin, which is expressed in principal cells of the collecting tubule and collecting ducts, and is also stimulated by AT1 receptor activation. Renin and prorenin are secreted into the tubular lumen and act on the AGT delivered from the proximal tubule to form more Ang I. The catalytic actions of renin and or prorenin may be enhanced by binding to prorenin receptors on the intercalated cells or soluble prorenin receptor secreted into the tubular fluid. There is also increased luminal angiotensin converting enzyme in collecting ducts facilitating Ang II formation leading to stimulation of sodium reabsorption via sodium channel and sodium/chloride co-transporter. Thus, increased collecting duct renin contributes to Ang II-dependent hypertension by augmenting distal nephron intra-tubular Ang II formation leading to sustained stimulation of sodium reabsorption and progression of hypertension. PMID:22990760

High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells

PubMed Central

Xu, Chuanming; Fang, Hui; Zhou, Li; Lu, Aihua

2016-01-01

(Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release. PMID:27534754

LINEAGE TRACING AGED MOUSE KIDNEYS SHOWS LOWER NUMBER OF CELLS OF RENIN LINEAGE AND REDUCED RESPONSIVENESS TO RAAS INHIBITION.

PubMed

Hamatani, Hiroko; Eng, Diana G; Kaverina, Natalya V; Gross, Kenneth W; Freedman, Benjamin; Pippin, Jeffrey W; Shankland, Stuart J

2018-02-07

Blocking the renin-angiotensin-aldosterone system (RAAS) remains a mainstay of therapy in hypertension and glomerular diseases. With the population aging, our understanding of renin producing cells in kidneys with advanced age is more critical than ever. Accordingly, we administered tamoxifen to Ren1cCreERxRs-tdTomato-R mice to permanently fate map cells of renin lineage (CoRL). The number of Td-tomato labeled CoRL decreased significantly in aged mice (24m of age) compared to young mice (3.5m of age), as did renin mRNA levels. To determine if aged CoRL responded less to RAAS blockade, enalapril and losartan were administered over 25d following uninephrectomy in young and aged mice. The number of CoRL increased in young mice in response to enalapril and losartan. However, this was significantly lower in aged mice compared to young mice due to limited proliferation, but not recruitment. Gene expression analysis of laser captured CoRL showed a substantial increase in mRNA levels for pro-apoptotic and pro-senescence genes, and an increase in a major pro-senescence protein on immunostaining. These results show that CoRL are lower in aged mice, and do not respond to RAAS inhibition to the same extent as young mice.

Effects of aqueous extract of Hibiscus sabdariffa on the renin-angiotensin-aldosterone system of Nigerians with mild to moderate essential hypertension: A comparative study with lisinopril.

PubMed

Nwachukwu, Daniel Chukwu; Aneke, Eddy Ikemefuna; Obika, Leonard Fidelis; Nwachukwu, Nkiru Zuada

2015-01-01

The present study investigated the effects of aqueous extract of Hibiscus sabdariffa (HS) on the three basic components of renin-angiotensin-aldosterone system: Plasma renin, serum angiotensin-converting enzyme (ACE), and plasma aldosterone (PA) in mild to moderate essential hypertensive Nigerians and compared with that of lisinopril, an ACE inhibitor. A double-blind controlled randomized clinical study was used. Seventy-eight newly diagnosed but untreated mild to moderate hypertensive subjects attending Medical Outpatients Clinic of Enugu State University Teaching Hospital, Enugu were recruited for the study. Those in Group A received placebo (150 mg/kg/day), Group B were given lisinopril (10 mg once daily) while those in Group C received aqueous extract of HS (150 mg/kg/day). After 4 weeks of treatment, the levels of plasma renin, serum ACE, and PA were determined. HS and lisinopril significantly (P < 0.001) reduced PA compared to placebo by 32.06% and 30.01%, respectively. Their effects on serum ACE and plasma renin activity (PRA) were not significant compared to placebo; they reduced ACE by 6.63% and 5.67% but increased plasma PRA by 2.77% and 5.36%, respectively. HS reduced serum ACE and PA in mild to moderate hypertensive Nigerians with equal efficacy as lisinopril. These actions are possibly due to the presence of anthocyanins in the extract.

Some Comparative Aspects of the Renin-Angiotensin System.

ERIC Educational Resources Information Center

Malvin, Richard L.

1984-01-01

The renin-angiotensin system (RAS) maintains salt and water balance. Discusses functions of the RAS as defined in mammalian species, considering how the system arose and what its original function was. Also discusses where some of the changes occurred in the system (and why) as well as other topics. (JN)

The Renal Renin-Angiotensin System

ERIC Educational Resources Information Center

Harrison-Bernard, Lisa M.

2009-01-01

The renin-angiotensin system (RAS) is a critical regulator of sodium balance, extracellular fluid volume, vascular resistance, and, ultimately, arterial blood pressure. In the kidney, angiotensin II exerts its effects to conserve salt and water through a combination of the hemodynamic control of renal blood flow and glomerular filtration rate and…

21 CFR 862.1085 - Angiotensin I and renin test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Angiotensin I and renin test system. 862.1085 Section 862.1085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

21 CFR 862.1085 - Angiotensin I and renin test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Angiotensin I and renin test system. 862.1085 Section 862.1085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

21 CFR 862.1085 - Angiotensin I and renin test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Angiotensin I and renin test system. 862.1085 Section 862.1085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

21 CFR 862.1085 - Angiotensin I and renin test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Angiotensin I and renin test system. 862.1085 Section 862.1085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

21 CFR 862.1085 - Angiotensin I and renin test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Angiotensin I and renin test system. 862.1085 Section 862.1085 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

The (pro)renin receptor and body fluid homeostasis

PubMed Central

Cao, Theresa

2013-01-01

The renin-angiotensin system (RAS) has long been established as one of the major mechanisms of hypertension through the increased levels of angiotensin (ANG) II and its resulting effect on the sympathetic nerve activity, arterial vasoconstriction, water reabsorption, and retention, etc. In the central nervous system, RAS activation affects body fluid homeostasis through increases in sympathetic nerve activity, water intake, food intake, and arginine vasopressin secretion. Previous studies, however, have shown that ANG II can be made in the brain, and it could possibly be through a new component called the (pro)renin receptor. This review intends to summarize the central and peripheral effects of the PRR on body fluid homeostasis. PMID:23678024

[Primary hyperaldosteronism: problems of diagnostic approaches].

PubMed

Widimský, Jiří

2015-05-01

Primary hyperaldosteronism (PH) is common cause of endocrine/secondary hypertension with autonomous aldosterone overproduction by adrenal cortex. PH is typically characterized by hypertension, hypokalemia, high plasma aldosterone/renin ratio, high aldosterone, suppressed renin and nonsupressibilty of aldosterone during confirmatory tests. Diagnosis of PH can be difficult since hypokalemia is found only in 50 % of cases and measurement of the parameters of renin-angiotensin-aldosterone system can be influenced by several factors. Morphological dia-gnosis requires in majority of cases adrenal venous sampling. Early diagnostic and therapeutic measures are very important due to high prevalence of PH and potential cure. Patients with suspicion to PH should be investigated in experienced hypertensive centers due to relatively difficult laboratory and morphological diagnostic approaches.

Neural Mechanism by which Gravitational Stimuli and Stress Affect the Secretion of Renin and Other Hormones

NASA Technical Reports Server (NTRS)

Ganong, W. F.; Gotoh, E.; Alper, R. H.

1985-01-01

The serotonin-releasing drug p-chloroamphetamine (PCA), as well as L-propranolol and chloriasondamine were used in a study which established that the pathway from the hypothalamus to the kidneys is sympathetic. Which hypothalamic nuclei mediate the response to PCA is being investigated experiments are being conducted to determine a readily reproducible psychological stimulus to renin secretion that can be used in rats. The effects of equithesin, urethane, and inactin on plasma renin activity were examined in preparation for tilting experiments. The relation of vasopressin-secreting neurons in the brain sem to PCA response was explored in Brattleboro rats that are congenitally unable to produce vasopressin in their hypothalami.

Local Renin Angiotensin Aldosterone Systems and Cardiovascular Diseases.

PubMed

De Mello, Walmor C

2017-01-01

The presence of local renin angiotensin aldosterone systems (RAAS) in the cardiovascular and renal tissues and their influence in cardiovascular and renal diseases are described. The fundamental role of ACE/Ang II/AT1 receptor axis activation as well the counterregulatory role of ACE2/Ang (1-7)/Mas receptor activation on cardiovascular and renal physiology and pathology are emphasized. The presence of a local RAS and its influence on hypertension is discussed, and finally, the hypothesis that epigenetic factors change the RAAS in utero and induce the expression of renin or Ang II inside the cells of the cardiovascular system is presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Development of Sensitive and Direct Methods for Measuring Plasma Aldosterone and Catecholamine Concentrations

NASA Technical Reports Server (NTRS)

Haber, E.

1972-01-01

Radioimmunoassays for renin activity, angiotensin 1, and angiotensin 2 in the study of vasomotor regulation give new insight into the role of the renin system in maintaining postural homeostatsis. Similar laboratory procedures for specific assays of aldosterone and catecholamines achieve accurate determinations in small human blood samples.

Plasma volume, osmolality, vasopressin, and renin activity during graded exercise in man

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Keil, L. C.; Bernauer, E. M.; Greenleaf, J. E.

1981-01-01

The influence of work intensity on plasma volume, osmolality, vasopressin and renin activity and the interrelationships between these responses are investigated. Plasma volume, renin activity and osmotic, sodium and arginine vasopressin concentrations were measured in venous blood samples taken from 15 healthy male subjects before and after six minutes of bicycle ergometer exercise at 100, 175 and 225 W. Plasma volume is found to decrease significantly with increasing work intensity, while increases in Na(+) concentration, osmolality and vasopressin are only observed to be significant when the work intensity exceeds 40% maximal aerobic capacity and plasma resin activity increased linearly at all work levels. In addition, significant correlations are observed between plasma volume and osmolality and sodium changes, and between vasopressin and osmolality and sodium content changes. Data thus support the hypotheses that (1) vasopressin may be the primary controlling endocrine for fluid and electrolyte levels following exercise; (2) an exercise intensity greater than 40% maximal aerobic capacity is required to stimulate vasopressin release through changes in plasma osmolality; and (3) the stimulation of the renin-angiotensin system is a more general stress response.

Succinate receptor GPR91 provides a direct link between high glucose levels and renin release in murine and rabbit kidney

PubMed Central

Toma, Ildikó; Kang, Jung Julie; Sipos, Arnold; Vargas, Sarah; Bansal, Eric; Hanner, Fiona; Meer, Elliott; Peti-Peterdi, János

2008-01-01

Diabetes mellitus is the most common and rapidly growing cause of end-stage renal disease in developed countries. A classic hallmark of early diabetes mellitus includes activation of the renin-angiotensin system (RAS), which may lead to hypertension and renal tissue injury, but the mechanism of RAS activation is elusive. Here we identified a paracrine signaling pathway in the kidney in which high levels of glucose directly triggered the release of the prohypertensive hormone renin. The signaling cascade involved the local accumulation of succinate and activation of the kidney-specific G protein–coupled metabolic receptor, GPR91, in the glomerular endothelium as observed in rat, mouse, and rabbit kidney sections. Elements of signal transduction included endothelial Ca2+, the production of NO and prostaglandin (PGE2), and their paracrine actions on adjacent renin-producing cells. This GPR91 signaling cascade may serve to modulate kidney function and help remove metabolic waste products through renal hyperfiltration, and it could also link metabolic diseases, such as diabetes, or metabolic syndrome with RAS overactivation, systemic hypertension, and organ injury. PMID:18535668

Renin Angiotensin Aldosterone System Inhibitors in Hypertension: Is There Evidence for Benefit Independent of Blood Pressure Reduction?

PubMed

Bavishi, Chirag; Bangalore, Sripal; Messerli, Franz H

The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in the pathogenesis of hypertension (HTN). Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are first line anti-HTN drug classes that are potent, effective and largely safe. Direct renin inhibitors (DRIs) have shown similar blood pressure (BP) reduction but more side effects. The efficacy of ACEIs and ARBs (for cardiovascular, cerebrovascular and renal protection) has been promoted to extend beyond what could be explained by BP reduction alone. In the current review, we will briefly discuss the (1) pathophysiology of renin-angiotensin-aldosterone system (RAAS) system, (2) clinical evidence for ACEIs, ARBs and DRIs in HTN, (3) comparison of ACEIs vs. ARBs and combination therapy, (4) role of RAAS inhibitors in specific patient populations, (5) safety profile of RAAS inhibitors, and (6) guideline recommendations and future perspectives. Closer scrutiny of outcome data shows little, if any, evidence that the efficacy of RAAS blockers in HTN extends beyond BP reduction. Copyright © 2016 Elsevier Inc. All rights reserved.

The Renin Angiotensin Aldosterone System and Insulin Resistance in Humans

PubMed Central

Underwood, Patricia C

2012-01-01

Alterations in the renin angiotensin aldosterone system (RAAS) contribute to the underlying pathophysiology of insulin resistance in humans; however, individual differences in the treatment response of insulin resistance to RAAS blockade persist. Thus, understanding inter-individual differences in the relationship between the RAAS and insulin resistance may provide insights into improved personalized treatments and improved outcomes. The effects of the systemic RAAS on blood pressure regulation and glucose metabolism have been studied extensively; however, recent discoveries on the influence of local tissue RAAS in the skeletal muscle, heart, vasculature, adipocytes, and pancreas have led to an improved understanding of how activated tissue RAAS influences the development of insulin resistance and diabetes in humans. Angiotensin II (ANGII) is the predominant RAAS component contributing to insulin resistance; however, other players such as aldosterone, renin, and ACE2 are also involved. This review examines the role of local ANGII activity on insulin resistance development in skeletal muscle, adipocytes, and pancreas, followed by a discussion of the other RAAS components implicated in insulin resistance, including ACE2, Ang1-7, renin, and aldosterone. PMID:23242734

Effect of paricalcitol on renin and albuminuria in non-diabetic stage III-IV chronic kidney disease: a randomized placebo-controlled trial

PubMed Central

2013-01-01

Background Vitamin D receptor activators reduce albuminuria, and may improve survival in chronic kidney disease (CKD). Animal studies suggest that these pleiotropic effects of vitamin D may be mediated by suppression of renin. However, randomized trials in humans have yet to establish this relationship. Methods In a randomized, placebo-controlled, double-blinded crossover study, the effect of oral paricalcitol (2 μg/day) was investigated in 26 patients with non-diabetic, albuminuric stage III-IV CKD. After treatment, plasma concentrations of renin (PRC), angiotensin II (AngII) and aldosterone (Aldo) were measured. GFR was determined by 51Cr-EDTA clearance. Assessment of renal NO dependency was performed by infusion of NG-monomethyl-L-arginine (L-NMMA). Albumin excretion rate (AER) was analyzed in 24-h urine and during 51Cr-EDTA clearance. Results Paricalcitol did not alter plasma levels of renin, AngII, Aldo, or urinary excretion of sodium and potassium. A modest reduction of borderline significance was observed in AER, and paricalcitol abrogated the albuminuric response to L-NMMA. Conclusions In this randomized, placebo-controlled trial paricalcitol only marginally decreased AER and did not alter circulating levels of renin, AngII or Aldo. The abrogation of the rise in albumin excretion by paricalcitol during NOS blockade may indicate that favourable modulation of renal NO dependency could be involved in mediating reno-protection and survival benefits in CKD. Trial registration ClinicalTrials.gov identifier: NCT01136564 PMID:23889806

Low Response of Renin-Angiotensin System to Sodium Intake Intervention in Chinese Hypertensive Patients.

PubMed

Feng, Weijing; Cai, Qingqing; Yuan, Woliang; Liu, Yu; Bardeesi, Adham Sameer A; Wang, Jingfeng; Chen, Jie; Huang, Hui

2016-02-01

The interactions of sodium balance and response of renin-angiotensin-aldosterone system are important for maintaining the hemodynamic stability in physiological conditions. However, the influence of short-term sodium intake intervention in the response of renin-angiotensin system (RAS) on hypertensive patients is still unclear. Thus, we conducted a clinical trial to investigate the effects of short-term sodium intake intervention on the response of RAS in hypertensive patients.One hundred twenty-five primary Chinese hypertensive patients were divided into high, moderate, and low sodium groups by 24-hour urinary sodium excretion (UNa). All the patients received a 10-day dietary sodium intake intervention with standardized sodium (173.91mmol/day) and potassium (61.53mmol/day). Blood pressure, urinary sodium, urinary potassium, plasma sodium, potassium, creatinine, the levels of plasma renin activity, plasma angiotensin II concentrations (AT-II), and plasma aldosterone concentrations were detected before and after the intervention.Before the intervention, no differences were found in blood pressure and RAS among 3 groups. After standardized dietary sodium intake intervention, both UNa excretion and systolic pressure decreased in high-sodium group, while they increased in moderate and low-sodium groups. Intriguingly, there were no changes in the levels of plasma renin activity, AT-II, and plasma aldosterone concentrations among 3 groups during the intervention.The present study demonstrated that the influenced sodium excretion and blood pressure by short-term sodium intake intervention were independent of RAS quick response in Chinese hypertensive patients.

Conditional deletion of p53 and Rb in the renin-expressing compartment of the pancreas leads to a highly penetrant metastatic pancreatic neuroendocrine carcinoma.

PubMed

Glenn, S T; Jones, C A; Sexton, S; LeVea, C M; Caraker, S M; Hajduczok, G; Gross, K W

2014-12-11

Efforts to model human pancreatic neuroendocrine tumors (PanNETs) in animals have been moderately successful, with minimal evidence for glucagonomas or metastatic spread. The renin gene, although classically associated with expression in the kidney, is also expressed in many other extrarenal tissues including the pancreas. To induce tumorigenesis within rennin-specific tissues, floxed alleles of p53 and Rb were selectively abrogated using Cre-recombinase driven by the renin promoter. The primary neoplasm generated is a highly metastatic islet cell carcinoma of the pancreas. Lineage tracing identifies descendants of renin-expressing cells as pancreatic alpha cells despite a lack of active renin expression in the mature pancreas. Both primary and metastatic tumors express high levels of glucagon; furthermore, an increased level of glucagon is found in the serum, identifying the pancreatic cancer as a functional glucagonoma. This new model is highly penetrant and exhibits robust frequency of metastases to the lymph nodes and the liver, mimicking human disease, and provides a useful platform for better understanding pancreatic endocrine differentiation and development, as well as islet cell carcinogenesis. The use of fluorescent reporters for lineage tracing of the cells contributing to disease initiation and progression provides an unique opportunity to dissect the timeline of disease, examining mechanisms of the metastatic process, as well as recovering primary and metastatic cells for identifying cooperating mutations that are necessary for progression of disease.

Renin inhibition improves metabolic syndrome, and reduces angiotensin II levels and oxidative stress in visceral fat tissues in fructose-fed rats.

PubMed

Chou, Chu-Lin; Lin, Heng; Chen, Jin-Shuen; Fang, Te-Chao

2017-01-01

Renin-angiotensin system in visceral fat plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. However, the effects of renin inhibition on visceral adiposity in metabolic syndrome are not fully investigated. We investigated the effects of renin inhibition on visceral adiposity in fructose-fed rats. Male Wistar-Kyoto rats were divided into 4 groups for 8-week experiments: Group Con (standard chow diet), Group Fru (high-fructose diet; 60% fructose), Group FruA (high-fructose diet and concurrent aliskiren treatment; 100 mg/kg body weight [BW] per day), and Group FruB (high-fructose diet and subsequent, i.e. 4 weeks after initiating high-fructose feeding, aliskiren treatment; 100 mg/kg BW per day). The high-fructose diet induced metabolic syndrome, increased visceral fat weights and adipocyte sizes, and augmented angiotensin II (Ang II), NADPH oxidase (NOX) isoforms expressions, oxidative stress, and dysregulated production of adipocytokines from visceral adipose tissues. Concurrent and subsequent aliskiren administration ameliorated metabolic syndrome, dysregulated adipocytokines, and visceral adiposity in high fructose-fed hypertensive rats, and was associated with reducing Ang II levels, NOX isoforms expressions and oxidative stress in visceral fat tissues. Therefore, this study demonstrates renin inhibition could improve metabolic syndrome, and reduce Ang II levels and oxidative stress in visceral fat tissue in fructose-fed rats, and suggests that visceral adipose Ang II plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats.

Effects of aqueous extract of Hibiscus sabdariffa on the renin-angiotensin-aldosterone system of Nigerians with mild to moderate essential hypertension: A comparative study with lisinopril

PubMed Central

Nwachukwu, Daniel Chukwu; Aneke, Eddy Ikemefuna; Obika, Leonard Fidelis; Nwachukwu, Nkiru Zuada

2015-01-01

Objectives: The present study investigated the effects of aqueous extract of Hibiscus sabdariffa (HS) on the three basic components of renin-angiotensin-aldosterone system: Plasma renin, serum angiotensin-converting enzyme (ACE), and plasma aldosterone (PA) in mild to moderate essential hypertensive Nigerians and compared with that of lisinopril, an ACE inhibitor. Materials and Methods: A double-blind controlled randomized clinical study was used. Seventy-eight newly diagnosed but untreated mild to moderate hypertensive subjects attending Medical Outpatients Clinic of Enugu State University Teaching Hospital, Enugu were recruited for the study. Those in Group A received placebo (150 mg/kg/day), Group B were given lisinopril (10 mg once daily) while those in Group C received aqueous extract of HS (150 mg/kg/day). After 4 weeks of treatment, the levels of plasma renin, serum ACE, and PA were determined. Results: HS and lisinopril significantly (P < 0.001) reduced PA compared to placebo by 32.06% and 30.01%, respectively. Their effects on serum ACE and plasma renin activity (PRA) were not significant compared to placebo; they reduced ACE by 6.63% and 5.67% but increased plasma PRA by 2.77% and 5.36%, respectively. Conclusion: HS reduced serum ACE and PA in mild to moderate hypertensive Nigerians with equal efficacy as lisinopril. These actions are possibly due to the presence of anthocyanins in the extract. PMID:26600645

Interaction of renin-angiotensin system and adenosine monophosphate-activated protein kinase signaling pathway in renal carcinogenesis of uninephrectomized rats.

PubMed

Yang, Ke-Ke; Sui, Yi; Zhou, Hui-Rong; Zhao, Hai-Lu

2017-05-01

Renin-angiotensin system and adenosine monophosphate-activated protein kinase signaling pathway both play important roles in carcinogenesis, but the interplay of renin-angiotensin system and adenosine monophosphate-activated protein kinase in carcinogenesis is not clear. In this study, we researched the interaction of renin-angiotensin system and adenosine monophosphate-activated protein kinase in renal carcinogenesis of uninephrectomized rats. A total of 96 rats were stratified into four groups: sham, uninephrectomized, and uninephrectomized treated with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Renal adenosine monophosphate-activated protein kinase and its downstream molecule acetyl coenzyme A carboxylase were detected by immunohistochemistry and western blot at 10 months after uninephrectomy. Meanwhile, we examined renal carcinogenesis by histological transformation and expressions of Ki67 and mutant p53. During the study, fasting lipid profiles were detected dynamically at 3, 6, 8, and 10 months. The results indicated that adenosine monophosphate-activated protein kinase expression in uninephrectomized rats showed 36.8% reduction by immunohistochemistry and 89.73% reduction by western blot. Inversely, acetyl coenzyme A carboxylase expression increased 83.3% and 19.07% in parallel to hyperlipidemia at 6, 8, and 10 months. The histopathology of carcinogenesis in remnant kidneys was manifested by atypical proliferation and carcinoma in situ, as well as increased expressions of Ki67 and mutant p53. Intervention with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker significantly prevented the inhibition of adenosine monophosphate-activated protein kinase signaling pathway and renal carcinogenesis in uninephrectomized rats. In conclusion, the novel findings suggest that uninephrectomy-induced disturbance in adenosine monophosphate-activated protein kinase signaling pathway resulted in hyperlipidemia and carcinogenesis in tubular epithelial cells, which may be largely attenuated by renin-angiotensin system blockade, implying the interaction of renin-angiotensin system and adenosine monophosphate-activated protein kinase signaling pathway in renal carcinogenesis of uninephrectomized rats.

Direct renin inhibitor ameliorates insulin resistance by improving insulin signaling and oxidative stress in the skeletal muscle from post-infarct heart failure in mice.

PubMed

Fukushima, Arata; Kinugawa, Shintaro; Takada, Shingo; Matsumoto, Junichi; Furihata, Takaaki; Mizushima, Wataru; Tsuda, Masaya; Yokota, Takashi; Matsushima, Shouji; Okita, Koichi; Tsutsui, Hiroyuki

2016-05-15

Insulin resistance can occur as a consequence of heart failure (HF). Activation of the renin-angiotensin system (RAS) may play a crucial role in this phenomenon. We thus investigated the effect of a direct renin inhibitor, aliskiren, on insulin resistance in HF after myocardial infarction (MI). MI and sham operation were performed in male C57BL/6J mice. The mice were divided into 4 groups and treated with sham-operation (Sham, n=10), sham-operation and aliskiren (Sham+Aliskiren; 10mg/kg/day, n=10), MI (n=11), or MI and aliskiren (MI+Aliskiren, n=11). After 4 weeks, MI mice showed left ventricular dilation and dysfunction, which were not affected by aliskiren. The percent decrease of blood glucose after insulin load was significantly smaller in MI than in Sham (14±5% vs. 36±2%), and was ameliorated in MI+Aliskiren (34±5%) mice. Insulin-stimulated serine-phosphorylation of Akt and glucose transporter 4 translocation were decreased in the skeletal muscle of MI compared to Sham by 57% and 69%, and both changes were ameliorated in the MI+Aliskiren group (91% and 94%). Aliskiren administration in MI mice significantly inhibited plasma renin activity and angiotensin II (Ang II) levels. Moreover, (pro)renin receptor expression and local Ang II production were upregulated in skeletal muscle from MI and were attenuated in MI+Aliskiren mice, in tandem with a decrease in superoxide production and NAD(P)H oxidase activities. In conclusion, aliskiren ameliorated insulin resistance in HF by improving insulin signaling in the skeletal muscle, at least partly by inhibiting systemic and (pro)renin receptor-mediated local RAS activation, and subsequent NAD(P)H oxidase-induced oxidative stress. Copyright © 2016 Elsevier B.V. All rights reserved.

The role of angiotensin II in the renal responses to somatic nerve stimulation in the rat.

PubMed Central

Handa, R K; Johns, E J

1987-01-01

1. Electrical stimulation of the brachial nerves at 3 Hz (15 V, 0.2 ms), in sodium pentobarbitone-anaesthetized rats whose renal arterial pressure was held constant, elicited a 26% increase in systemic blood pressure, a 15% rise in heart rate, an 11% reduction in renal blood flow, did not alter glomerular filtration rate and significantly reduced absolute and fractional sodium excretions and urine flow by 44, 49 and 31%, respectively. 2. In a separate group of rats, brachial nerve stimulation at 3 Hz increased plasma renin activity approximately 2-fold, while in animals in which the brachial nerves were not stimulated plasma renin activity did not change. 3. Following inhibition of the renin-angiotensin system with captopril or sar-1-ile-8-angiotensin II, brachial nerve stimulation resulted in similar increases in systemic blood pressure and heart rate as in the animals with an intact renin-angiotensin system but, in captopril-infused rats, did not change renal haemodynamics or urine flow while absolute and fractional sodium excretions were reduced by 20 and 25%, respectively. In sar-1-ile-8-angiotensin II-infused animals, similar nerve stimulation decreased renal blood flow by 12%, glomerular filtration rate by 7% and absolute and fractional sodium excretions and urine flow by 25, 18 and 18%, respectively. These decreases in sodium and water output were significantly smaller than those observed in animals with an intact renin-angiotensin system. 4. Stimulation of the brachial nerves increased post-ganglionic efferent renal nerve activity by 20% and the magnitude of this response was unaffected following inhibition of the renin-angiotensin system. 5. The results show that low rates of brachial nerve stimulation in the rat can increase efferent renal nerve activity and result in an antinatriuresis and antidiuresis which is dependent on the presence of angiotensin II, and appears to be due to an action of angiotensin II at the level of the kidney. PMID:3328780

Body Mass Index Predicts 24-Hour Urinary Aldosterone Levels in Patients With Resistant Hypertension.

PubMed

Dudenbostel, Tanja; Ghazi, Lama; Liu, Mingchun; Li, Peng; Oparil, Suzanne; Calhoun, David A

2016-10-01

Prospective studies indicate that hyperaldosteronism is found in 20% of patients with resistant hypertension. A small number of observational studies in normotensive and hypertensive patients suggest a correlation between aldosterone levels and obesity while others could not confirm these findings. The correlation between aldosterone levels and body mass index (BMI) in patients with resistant hypertension has not been previously investigated. Our objective was to determine whether BMI is positively correlated with plasma aldosterone concentration, plasma renin activity, aldosterone:renin ratio, and 24-hour urinary aldosterone in black and white patients. We performed a cross-sectional analysis of a large diverse cohort (n=2170) with resistant hypertension. The relationship between plasma aldosterone concentration, plasma renin activity, aldosterone:renin ratio, 24-hour urinary aldosterone, and BMI was investigated for the entire cohort, by sex and race (65.3% white, 40.3% men). We demonstrate that plasma aldosterone concentration and aldosterone:renin ratio were significantly correlated to BMI (P<0.0001) across the first 3 quartiles, but not from the 3rd to 4th quartile of BMI. Plasma renin activity was not correlated with BMI. Twenty-four-hour urinary aldosterone was positively correlated across all quartiles of BMI for the cohort (P<0.0001) and when analyzed by sex (men P<0.0001; women P=0.0013) and race (P<0.05), and stronger for men compared with women (r=0.19, P<0.001 versus r=0.05, P=0.431, P=0.028) regardless of race. In both black and white patients, aldosterone levels were positively correlated to increasing BMI, with the correlation being more pronounced in black and white men. These findings suggest that obesity, particularly the abdominal obesity typical of men, contributes to excess aldosterone in patients with resistant hypertension. © 2016 American Heart Association, Inc.

Discordant orthostatic reflex renin-angiotensin and sympathoneural responses in premenopausal exercising-hypoestrogenic women.

PubMed

O'Donnell, Emma; Goodman, Jack M; Mak, Susanna; Murai, Hisayoshi; Morris, Beverley L; Floras, John S; Harvey, Paula J

2015-05-01

Our prior observations in normotensive postmenopausal women stimulated the hypotheses that compared with eumenorrheic women, active hypoestrogenic premenopausal women with functional hypothalamic amenorrhea would demonstrate attenuated reflex renin-angiotensin-aldosterone system responses to an orthostatic challenge, whereas to defend blood pressure reflex increases in muscle, sympathetic nerve activity would be augmented. To test these hypotheses, we assessed, in recreationally active women, 12 with amenorrhea (ExFHA; aged 25 ± 1 years; body mass index 20.7 ± 0.7 kg/m(2); mean ± SEM) and 17 with eumenorrhea (ExOv; 24 ± 1 years; 20.9 ± 0.5 kg/m(2)), blood pressure, heart rate, plasma renin, angiotensin II, aldosterone, and muscle sympathetic nerve activity at supine rest and during graded lower body negative pressure (-10, -20, and -40 mm Hg). At baseline, heart rate and systolic blood pressure were lower (P<0.05) in ExFHA (47 ± 2 beats/min and 94 ± 2 mm Hg) compared with ExOv (56 ± 2 beats/min and 105 ± 2 mm Hg), but muscle sympathetic nerve activity and renin-angiotensin-aldosterone system constituents were similar (P>0.05). In response to graded lower body negative pressure, heart rate increased (P<0.05) and systolic blood pressure decreased (P<0.05) in both groups, but these remained consistently lower in ExFHA (P<0.05). Lower body negative pressure elicited increases (P<0.05) in renin, angiotensin II, and aldosterone in ExOv, but not in ExFHA (P>0.05). Muscle sympathetic nerve activity burst incidence increased reflexively in both groups, but more so in ExFHA (P<0.05). Otherwise, healthy hypoestrogenic ExFHA women demonstrate low blood pressure and disruption of the normal circulatory response to an orthostatic challenge: plasma renin, angiotensin II, and aldosterone fail to increase and blood pressure is defended by an augmented sympathetic vasoconstrictor response. © 2015 American Heart Association, Inc.

The action of bombesin on the kidney of the anaesthetized dog.

PubMed

Erspamer, V; Melchiorri, P; Sopranzi, N

1973-07-01

1. In the anaesthetized dog bombesin had a potent antidiuretic effect, and sometimes arrested urine flow completely. Threshold doses, by i.v. infusion, were of the order of 0.5-1 (ng/kg)/minute. Antidiuresis was the result of a reduction in glomerular filtration rate provoked by a fall in intraglomerular hydrostatic pressure. This, in its turn, was due to afferent vasoconstriction.2. The spasmogenic effect of bombesin on the smooth muscle of the afferent arterioles was directly demonstrated by the radioactive microspheres technique and indirectly by the (85)Kr washout method and by [(3)H]-p-aminohippurate clearance. The vascular compartment most sensitive to bombesin was that of the outer cortical zone, especially in its external half.3. Filtration fraction decreased under the influence of bombesin, indicating that the effect of the polypeptide on postglomerular arterioles was, if present, only of minor importance.4. At high infusion rates (above 6 (ng/kg)/min), bombesin produced a decrease in [(3)H]-p-aminohippurate extraction. The effect of the polypeptide on fractional distal delivery of sodium varied with the dose: at moderate infusion rates it decreased, at high infusion rates it increased. The total glucose appearing in urine following a glucose load was sharply reduced by bombesin. However, the glomerular filtration rate/maximum tubular glucose transport ratio did not show any appreciable change.5. Afferent vasoconstriction produced by bombesin was accompanied by an intense activation of the renin-angiotensin system, as shown by a conspicuous increase in renin secretion, followed by increases in renin activity and angiotensin II concentration in arterial blood. When bombesin was infused into one renal artery only the infused kidney showed afferent vasoconstriction and increased renin secretion. The time-course of renin secretion produced by bombesin depended upon the rate of infusion of the polypeptide. At low rates an increased renin secretion was observed throughout the infusion period, at high rates two peaks of renin secretion could be seen, one at the beginning of the infusion, the other soon after the infusion had finished.6. The mechanism of action of bombesin is discussed and the interest of the polypeptide as a possible hormonal regulator of the circulation and function of the kidney is pointed out.

Design and Optimization of Renin Inhibitors: Orally Bioavailable Alkyl Amines

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

Tice, C.; Xu, Z; Yuan, J

2009-01-01

Structure-based drug design led to the identification of a novel class of potent, low MW alkylamine renin inhibitors. Oral administration of lead compound 21l, with MW of 508 and IC{sub 50} of 0.47 nM, caused a sustained reduction in mean arterial blood pressure in a double transgenic rat model of hypertension.

Renin and aldosterone measurements in the management of arterial hypertension.

PubMed

Viola, A; Monticone, S; Burrello, J; Buffolo, F; Lucchiari, M; Rabbia, F; Williams, T A; Veglio, F; Mengozzi, G; Mulatero, P

2015-06-01

Renin-angiotensin-aldosterone system (RAAS) is recognized as the main regulatory system of hemodynamics in man, and its derangements have a key role in the development and maintenance of arterial hypertension. Classification of the hypertensive states according to different patterns of renin and aldosterone levels ("RAAS profiling") allows the diagnosis of specific forms of secondary hypertension and may identify distinct hemodynamic subsets in essential hypertension. In this review, we summarize the application of RAAS profiling for the diagnostic assessment of hypertensive patients and discuss how the pathophysiological framework provided by RAAS profiling may guide therapeutic decision-making, especially in the context of uncontrolled hypertension not responding to multi-therapy. © Georg Thieme Verlag KG Stuttgart · New York.

High phosphate diet increases arterial blood pressure via a parathyroid hormone mediated increase of renin.

PubMed

Bozic, Milica; Panizo, Sara; Sevilla, Maria A; Riera, Marta; Soler, Maria J; Pascual, Julio; Lopez, Ignacio; Freixenet, Montserrat; Fernandez, Elvira; Valdivielso, Jose M

2014-09-01

There is growing evidence suggesting that phosphate intake is associated with blood pressure levels. However, data from epidemiological studies show inconsistent results. The present study was designed to evaluate the effect of high circulating phosphorus on arterial blood pressure of healthy rats and to elucidate the potential mechanism that stands behind this effect. Animals fed a high phosphate diet for 4 weeks showed an increase in blood pressure, which returned to normal values after the addition of a phosphate binder (lanthanum carbonate) to the diet. The expression of renin in the kidney was higher, alongside an increase in plasma renin activity, angiotensin II (Ang II) levels and left ventricular hypertrophy. The addition of the phosphate binder blunted the increase in renin and Ang II levels. The levels of parathyroid hormone (PTH) were also higher in animals fed a high phosphate diet, and decreased when the phosphate binder was present in the diet. However, blood P levels remained elevated. A second group of rats underwent parathyroidectomy and received a continuous infusion of physiological levels of PTH through an implanted mini-osmotic pump. Animals fed a high phosphate diet with continuous infusion of PTH did not show an increase in blood pressure, although blood P levels were elevated. Finally, unlike with verapamil, the addition of losartan to the drinking water reverted the increase in blood pressure in rats fed a high phosphate diet. The results of this study suggest that a high phosphate diet increases arterial blood pressure through an increase in renin mediated by PTH.

Deterioration of kidney function by the (pro)renin receptor blocker handle region peptide in aliskiren-treated diabetic transgenic (mRen2)27 rats.

PubMed

te Riet, Luuk; van den Heuvel, Mieke; Peutz-Kootstra, Carine J; van Esch, Joep H M; van Veghel, Richard; Garrelds, Ingrid M; Musterd-Bhaggoe, Usha; Bouhuizen, Angelique M; Leijten, Frank P J; Danser, A H Jan; Batenburg, Wendy W

2014-05-15

Dual renin-angiotensin system (RAS) blockade in diabetic nephropathy is no longer feasible because of the profit/side effect imbalance. (Pro)renin receptor [(P)RR] blockade with handle region peptide (HRP) has been reported to exert beneficial effects in various diabetic models in a RAS-independent manner. To what degree (P)RR blockade adds benefits on top of RAS blockade is still unknown. In the present study, we treated diabetic TGR(mREN2)27 rats, a well-established nephropathy model with high prorenin levels [allowing continuous (P)RR stimulation in vivo], with HRP on top of renin inhibition with aliskiren. Aliskiren alone lowered blood pressure and exerted renoprotective effects, as evidenced by reduced glomerulosclerosis, diuresis, proteinuria, albuminuria, and urinary aldosterone levels as well as diminished renal (P)RR and ANG II type 1 receptor expression. It also suppressed plasma and tissue RAS activity and suppressed cardiac atrial natriuretic peptide and brain natriuretic peptide expression. HRP, when given on top of aliskiren, did not alter the effects of renin inhibition on blood pressure, RAS activity, or aldosterone. However, it counteracted the beneficial effects of aliskiren in the kidney, induced hyperkalemia, and increased plasma plasminogen activator-inhibitor 1, renal cyclooxygenase-2, and cardiac collagen content. All these effects have been linked to (P)RR stimulation, suggesting that HRP might, in fact, act as a partial agonist. Therefore, the use of HRP on top of RAS blockade in diabetic nephropathy is not advisable. Copyright © 2014 the American Physiological Society.

Leptin regulates ACE activity in mice.

PubMed

Hilzendeger, Aline Mourao; Morais, Rafael Leite; Todiras, Mihail; Plehm, Ralph; da Costa Goncalves, Andrey; Qadri, Fatimunnisa; Araujo, Ronaldo Carvalho; Gross, Volkmar; Nakaie, Clovis Ryuichi; Casarini, Dulce Elena; Carmona, Adriana Karaoglanovic; Bader, Michael; Pesquero, João Bosco

2010-09-01

Leptin is a hormone related to metabolism. It also influences blood pressure, but the mechanisms triggered in this process are not yet elucidated. Angiotensin-I converting enzyme (ACE) regulates cardiovascular functions and recently has been associated with metabolism control and obesity. Here, we used ob/ob mice, a model lacking leptin, to answer the question whether ACE and leptin could interact to influence blood pressure, thereby linking the renin-angiotensin system and obesity. These mice are obese and diabetic but have normal 24 h mean arterial pressure. Our results show that plasma and lung ACE activities as well as ACE mRNA expression were significantly decreased in ob/ob mice. In agreement with these findings, the hypotensive effect produced by enalapril administration was attenuated in the obese mice. Plasma renin, angiotensinogen, angiotensin I, bradykinin, and angiotensin 1-7 were increased, whereas plasma angiotensin II concentration was unchanged in obese mice. Chronic infusion of leptin increased renin activity and angiotensin II concentration in both groups and increased ACE activity in ob/ob mice. Acute leptin infusion restored ACE activity in leptin-deficient mice. Moreover, the effect of an ACE inhibitor on blood pressure was not changed in ob/+ mice during leptin treatment but increased four times in obese mice. In summary, our findings show that the renin-angiotensin system is altered in ob/ob mice, with markedly reduced ACE activity, which suggests a possible connection between the renin-angiotensin system and leptin. These results point to an important interplay between the angiotensinergic and the leptinergic systems, which may play a role in the pathogenesis of obesity, hypertension, and metabolic syndrome.

Addressing the theoretical and clinical advantages of combination therapy with inhibitors of the renin-angiotensin-aldosterone system: antihypertensive effects and benefits beyond BP control.

PubMed

Ferrario, Carlos M

2010-02-27

This article reviews the importance of the renin-angiotensin-aldosterone system (RAAS) in the cardiometabolic continuum; presents the pros and cons of dual RAAS blockade with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs); and examines the theoretical and practical benefits supporting the use of direct renin inhibitors (DRIs) in combination with ACEIs or ARBs. The author reviewed the literature for key publications related to the biochemical physiology of the RAAS and the pharmacodynamic effects of ACEIs, ARBs, and DRIs, with a particular focus on dual RAAS blockade with these drug classes. Although ACEI/ARB combination therapy produces modest improvement in BP, it has not resulted in the major improvements predicted given the importance of the RAAS across the cardiorenal disease continuum. This may reflect the fact that RAAS blockade with ACEIs and/or ARBs leads to exacerbated renin release through loss of negative-feedback inhibition, as well as ACE/aldosterone escape through RAAS and non-RAAS-mediated mechanisms. Plasma renin activity (PRA) is an independent predictor of morbidity and mortality, even for patients receiving ACEIs and ARBs. When used alone or in combination with ACEIs and ARBs, the DRI aliskiren effectively reduces PRA. Reductions in BP are greater with these combinations, relative to the individual components alone. It is possible that aliskiren plus either an ACEI or ARB may provide greater RAAS blockade than monotherapy with ACEIs or ARBs, and lead to additive improvement in BP and clinically important outcomes. Copyright 2009 Elsevier Inc. All rights reserved.

Hypertension and depressed symptomatology: a cluster related to the activation of the renin-angiotensin-aldosterone system (RAAS). Findings from population based KORA F4 study.

PubMed

Häfner, S; Baumert, J; Emeny, R T; Lacruz, M E; Bidlingmaier, M; Reincke, M; Ladwig, K H

2013-10-01

Preliminary evidence points to aldosterone being not only prominently involved in the systemic regulation of the blood pressure but also to play a role in the pathophysiology of depression. We evaluated whether the combination of hypertension and depressed symptomatology is useful to screen for individuals suffering an activation of the renin-angiotensin-aldosterone system (RAAS). We conducted a cross-sectional analysis in participants from the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study conducted between 2006 and 2008 in Southern Germany. A total of 1805 participants of the F4 study were included in the study. The association between aldosterone and renin levels and the different combinations of hypertension and depressed symptomatology was examined in four different models of multiple linear regression adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and behavioural risk factors. Individuals suffering both, depressed symptomatology and hypertension exhibited highly significantly increased aldosterone levels (p<0.001) and slightly, not significantly increased renin levels (p=0.08) compared to individuals with no depressed symptomatology and no hypertension. No significant activation of the RAAS was seen in only depressed or only hypertensive individuals. The finding of highly significantly increased aldosterone levels and increased renin levels in individuals suffering both, depressed symptomatology and hypertension provides further evidence for the involvement of the RAAS in the pathogenesis of depressed symptomatology. These findings have important implications for future research concerning the pathophysiological pathways that link depression and cardiovascular disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

To live alone and to be depressed, an alarming combination for the renin-angiotensin-aldosterone-system (RAAS).

PubMed

Häfner, S; Baumert, J; Emeny, R T; Lacruz, M E; Bidlingmaier, M; Reincke, M; Kuenzel, H; Holle, R; Rupprecht, R; Ladwig, K H

2012-02-01

The renin-angiotensin-aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose "living alone" to be our paradigm of chronic stress. Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither "living alone" nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p<0.01) and renin level (p=0.03). Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group. Copyright © 2011 Elsevier Ltd. All rights reserved.

CHBPR: ANGIOTENSIN II, INDEPENDENT OF PLASMA RENIN ACTIVITY, CONTRIBUTES TO THE HYPERTENSION OF AUTONOMIC FAILURE

PubMed Central

Arnold, Amy C.; Okamoto, Luis E.; Gamboa, Alfredo; Shibao, Cyndya; Raj, Satish R.; Robertson, David; Biaggioni, Italo

2013-01-01

At least half of primary autonomic failure patients exhibit supine hypertension, despite profound impairments in sympathetic activity. While the mechanisms underlying this hypertension are unknown, plasma renin activity is often undetectable suggesting renin-angiotensin pathways are not involved. However, because aldosterone levels are preserved, we tested the hypothesis that angiotensin II is intact and contributes to the hypertension of autonomic failure. Indeed, circulating angiotensin II was paradoxically increased in hypertensive autonomic failure patients (52±5 pg/ml, n=11) compared to matched healthy controls (27±4 pg/ml, n=10; p=0.002), despite similarly low renin activity (0.19±0.06 versus 0.34±0.13 ng/ml/hr, respectively; p=0.449). To determine the contribution of angiotensin II to supine hypertension in these patients, we administered the AT1 receptor blocker losartan (50 mg) at bedtime in a randomized, double-blind, placebo-controlled study (n=11). Losartan maximally reduced systolic blood pressure by 32±11 mmHg at 6 hours after administration (p<0.05), decreased nocturnal urinary sodium excretion (p=0.0461), and did not worsen morning orthostatic tolerance. In contrast, there was no effect of the captopril on supine blood pressure in a subset of these patients. These findings suggest that angiotensin II formation in autonomic failure is independent of plasma renin activity, and perhaps angiotensin converting enzyme. Furthermore, these studies suggest that elevations in angiotensin II contribute to the hypertension of autonomic failure, and provide rationale for the use of AT1 receptor blockers for treatment of these patients. PMID:23266540

Changes in the renin-angiotensin-aldosterone system in response to dietary salt intake in normal and hypertensive pregnancy. A randomized trial.

PubMed

Nielsen, Lise H; Ovesen, Per; Hansen, Mie R; Brantlov, Steven; Jespersen, Bente; Bie, Peter; Jensen, Boye L

2016-11-01

It was hypothesized that primary renal sodium retention blunted the reactivity of the renin-angiotensin-aldosterone system to changes in salt intake in preeclampsia (PE). A randomized, cross-over, double-blinded, dietary intervention design was used to measure the effects of salt tablets or placebo during low-salt diet in PE patients (n = 7), healthy pregnant women (n = 15), and nonpregnant women (n = 13). High-salt intake decreased renin and angiotensin II concentrations significantly in healthy pregnant women (P < .03) and in nonpregnant women (P < .001), but not in PE (P = .58), while decreases in aldosterone and increases in brain natriuretic peptid (BNP) were similar in the groups. In PE patients, uterine and umbilical artery indices were not adversely changed during low-salt diet. Creatinine clearance was significantly lower in PE with no change by salt intake. PE patients displayed alterations of plasma renin and angiotensin II in response to changes in dietary salt intake compatible with a primary increase in renal sodium reabsorption in hypertensive pregnancies. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension

PubMed Central

Muñoz-Durango, Natalia; Fuentes, Cristóbal A.; Castillo, Andrés E.; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E.; Kalergis, Alexis M.

2016-01-01

Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage. PMID:27347925

Effect of dietary sodium intake on central angiotensinergic pathways.

PubMed

DiBona, Gerald F; Jones, Susan Y

2002-06-28

The role of central angiotensinergic pathways in the cardiovascular regulation has been examined using the microinjection of angiotensin peptides and angiotensin receptor antagonists. However, in such studies, neither the overall nor the local level of activity of the renin-angiotensin system is generally known. Herein, physiological changes in the endogenous level of activity of the renin-angiotensin system were produced by alterations in the dietary sodium intake. Microinjection of the angiotensin II AT1 receptor antagonists losartan or candesartan into the rostral ventrolateral medulla produced the bradycardic, depressor and renal sympathoinhibitory responses which were greater in low sodium diet rats with stimulated activity of the renin-angiotensin system than in high sodium diet rats with suppressed activity of the renin-angiotensin system activity. The renal sympathoexcitatory responses to activation of the paraventricular nucleus by microinjection of bicuculline, known to be dependent on the excitatory synaptic inputs to the rostral ventrolateral medulla mediated by AT1 receptors, were greater in low sodium diet rats than in high sodium rats. These observations support the view that physiologically regulated angiotensin peptides of the brain origin exert a local paracrine or autocrine action on sites that influence the renal sympathetic nerve activity.

Role of the Renin-Angiotensin-Aldosterone System beyond Blood Pressure Regulation: Molecular and Cellular Mechanisms Involved in End-Organ Damage during Arterial Hypertension.

PubMed

Muñoz-Durango, Natalia; Fuentes, Cristóbal A; Castillo, Andrés E; González-Gómez, Luis Martín; Vecchiola, Andrea; Fardella, Carlos E; Kalergis, Alexis M

2016-06-23

Arterial hypertension is a common condition worldwide and an important predictor of several complicated diseases. Arterial hypertension can be triggered by many factors, including physiological, genetic, and lifestyle causes. Specifically, molecules of the renin-angiotensin-aldosterone system not only play important roles in the control of blood pressure, but they are also associated with the genesis of arterial hypertension, thus constituting a need for pharmacological interventions. Chronic high pressure generates mechanical damage along the vascular system, heart, and kidneys, which are the principal organs affected in this condition. In addition to mechanical stress, hypertension-induced oxidative stress, chronic inflammation, and the activation of reparative mechanisms lead to end-organ damage, mainly due to fibrosis. Clinical trials have demonstrated that renin-angiotensin-aldosterone system intervention in hypertensive patients lowers morbidity/mortality and inflammatory marker levels as compared to placebo patients, evidencing that this system controls more than blood pressure. This review emphasizes the detrimental effects that a renin-angiotensin-aldosterone system (RAAS) imbalance has on health considerations above and beyond high blood pressure, such as fibrotic end-organ damage.

The Aldosterone Renin Ratio (ARR) APP as Tool to Enhance the Detection Rate of Primary Aldosteronism.

PubMed

Rossi, Gian Paolo; Bisogni, Valeria

2016-06-01

Primary aldosteronism is one of the most common forms of secondary hypertension, but it is often under diagnosed, which leads to the development of cardiovascular damage, and excess costs for long-term drug treatment and management of complications. The aldosterone to renin ratio (ARR) is a key step for early detection of primary aldosteronism, but unfortunately is not easily estimated. This is because plasma aldosterone and renin are measured with different assays, which provide results in different units of measure, with ensuing difficulty of obtaining the calculation of the ARR in the proper units and impossibility of interpreting results with reference to established cut off values. Therefore, doctors are often unable to draw unambiguous conclusions to be used for the clinical decision-making. To the aim of making the diagnostic work-up easier, we have developed an Application that provide a swift calculation of the ARR regardless of the units of measure used for plasma aldosterone and renin values. If the concomitant serum potassium level is available the App also provides the patient's probability of having an aldosterone-producing adenoma based on a validated logistic discriminant analysis.

Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies.

PubMed

Patel, Seema; Rauf, Abdur; Khan, Haroon; Abu-Izneid, Tareq

2017-10-01

Renin-angiotensin-aldosterone system (RAAS) is a vital system of human body, as it maintains plasma sodium concentration, arterial blood pressure and extracellular volume. Kidney-secreted renin enzyme acts on its substrate to form angiotensin II, a versatile effector peptide hormone. Every organ is affected by RAAS activation and the resultant hypertension, cell proliferation, inflammation, and fibrosis. The imbalance of renin and angiotensin II can result in an overwhelming number of chronic and acute diseases. RAAS is influenced by other enzymes, hormones, pumps and signaling pathways, hence, this review discusses important facets of this system, its crosstalk with other crucial factors like estrogen, thyroid, cortisol, kallikrein-kinin system, Wnt/β-catenin signaling, and sodium-potassium pump. The nexus of RAAS with the above-discussed systems was scantily explored before. So, this review furnishes a new perspective in comprehension of inflammation diseases. It is followed by the formulation of hypotheses, which can contribute to better management of an array of pathologies plaguing mankind. Manipulation of RAAS, by bending it towards ACE2 expression can regulate endocrine functions, which can be critical for a number of pathological management. Dietary intervention can restore RAAS to normalcy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cholecalciferol administration blunts the systemic renin-angiotensin system in essential hypertensives with hypovitaminosis D.

PubMed

Carrara, Davide; Bernini, Matteo; Bacca, Alessandra; Rugani, Ilaria; Duranti, Emiliano; Virdis, Agostino; Ghiadoni, Lorenzo; Taddei, Stefano; Bernini, Giampaolo

2014-03-01

Vitamin D plasma levels are negatively associated with blood pressure and cardiovascular mortality, and vitamin D supplementation reduces cardiovascular events. Renin-angiotensin system (RAS) suppression may be one of the mechanisms involved. However, there are no interventional prospective studies demonstrating a reduction in circulating RAS components after vitamin D treatment. Fifteen consecutive drug-free patients with essential hypertension and hypovitaminosis D underwent therapy with an oral dose of 25000 I.U. of cholecalciferol once a week for two months, while maintaining a constant-salt diet. In basal conditions and at the end of the study, RAS activity (plasma angiotensinogen, renin, PRA, angiotensin II, aldosterone and urinary angiotensinogen) was investigated, in addition to blood pressure and plasma vitamin D levels (25(OH)D). After cholecalciferol administration, all patients exhibited normalized plasma 25(OH)D values. At the end of the study, a reduction (p < 0.05) in plasma renin and aldosterone, and a decrement, although not significant, of PRA and angiotensin II, was observed. No difference was found in plasma and urinary angiotensinogen or blood pressure values. Our data indicate that in essential hypertensives with hypovitaminosis D, pharmacological correction of vitamin D levels can blunt systemic RAS activity.

Impact of passive permeability and gut efflux transport on the oral bioavailability of novel series of piperidine-based renin inhibitors in rodents.

PubMed

Lévesque, Jean-François; Bleasby, Kelly; Chefson, Amandine; Chen, Austin; Dubé, Daniel; Ducharme, Yves; Fournier, Pierre-André; Gagné, Sébastien; Gallant, Michel; Grimm, Erich; Hafey, Michael; Han, Yongxin; Houle, Robert; Lacombe, Patrick; Laliberté, Sébastien; MacDonald, Dwight; Mackay, Bruce; Papp, Robert; Tschirret-Guth, Richard

2011-09-15

An oral bioavailability issue encountered during the course of lead optimization in the renin program is described herein. The low F(po) of pyridone analogs was shown to be caused by a combination of poor passive permeability and gut efflux transport. Substitution of pyridone ring for a more lipophilic moiety (logD>1.7) had minimal effect on rMdr1a transport but led to increased passive permeability (P(app)>10 × 10(-6) cm/s), which contributed to overwhelm gut transporters and increase rat F(po). LogD and in vitro passive permeability determination were found to be key in guiding SAR and improve oral exposure of renin inhibitors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Present and Future in the Treatment of Diabetic Kidney Disease

PubMed Central

de Arriba, Gabriel

2015-01-01

Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade. PMID:25945357

Effect of renin-angiotensin system on sodium intake.

PubMed Central

Chiaraviglio, E

1976-01-01

1. Water and saline intake was measured in rats depleted of Na by I.P. dialysis. Na intake was prevented 180 min but not 60-90 min after bilateral nephrectomy. Unilateral nephrectomy as well as ureteral ligature had no effect on Na intake. 2. Renin (3u.) injected I.P. re-established the Na appetite abolished by nephrectomy. 3. Angiotensin I (5 ng) or II (5-40 ng) injected into the 3rd ventricle, also restored the Na intake and this effect was dose-dependent. 4. The angiotensin converting-enzyme inhibitor Sq 20,881 (1 mg/kg) inhibited the effect of AI but not that of AII in restoring Na intake. 5. It is concluded that the kidneys might play a role in the regulation of Na intake through the renin-angiotensin system. PMID:1255521

The contributions of renin and vasopressin to the adaptation of the Australian spinifex hopping mouse (Notomys alexis) to free water deprivation.

PubMed

Weaver, D; Walker, L; Alcorn, D; Skinner, S

1994-05-01

Xeric-adaptation was studied during 28 days of total water deprivation (TWD) in Notomys alexis. Beyond 7 days, the initial reductions in body weight and increases in haematocrit, plasma renin and juxtaglomerular (JG) cell morphological activity returned to normal. Mus musculus showed similar changes at 7 days but could not be maintained thereafter. TWD decreased the blood pressure of Notomys but endogenous angiotensin and vasopressin did not support pressure to a greater extent than controls, as revealed by selective antagonists. The normal morphology of the JG apparatus in Notomys was similar to other rodents. Fluid volume and blood pressure maintenance during TWD in Notomys do not depend upon enhanced activities of the renin-angiotensin and antidiuretic hormonal systems.

Effect of chronic diuretic treatment on the plasma renin-angiotensin-aldosterone system in essential hypertension.

PubMed Central

Lijnen, P; Fagard, R; Staessen, J; Amery, A

1981-01-01

1 Chronic treatment with a constant dose of hydrochlorothiazide or tienilic acid increases plasma renin activity (PRA) acutely to reach a maximum within the first week. 2 During chronic diuretic therapy from 1 month to 1 year, PRA remained elevated at a rather constant level, though this was somewhat lower than the maximum level reached after 1 week. 3 A significant (P less than 0.01) correlation (r = 0.74) between changes in plasma angiotensin II and renin activity provoked by chronic treatment for 3 months with hydrochlorothiazide and tienilic acid was found. 4 The increase in plasma aldosterone during chronic treatment with hydrochlorothiazide and tienilic acid (1000 mg) is related (r = 0.68; P less than 0.01) to the rise in plasma angiotensin II. PMID:7028060

Chronobiology of the renin-angiotensin-aldosterone system in dogs: relation to blood pressure and renal physiology.

PubMed

Mochel, Jonathan P; Fink, Martin; Peyrou, Mathieu; Desevaux, Cyril; Deurinck, Mark; Giraudel, Jérôme M; Danhof, Meindert

2013-11-01

The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in the regulation of blood pressure and volume homeostasis. Its contribution to the development of cardiovascular diseases has long been recognized. Extensive literature has shown that peptides of the RAAS oscillate with a circadian periodicity in humans, under strong influence of posture, sleep, and age. Although observations of time-variant changes in the renin cascade are available in dogs, no detailed chronobiological investigation has been conducted so far. The present studies were designed to explore the circadian variations of plasma renin activity (RA) and urinary aldosterone-to-creatinine ratio (UA:C) in relation to blood pressure (BP), sodium (UNa, UNa,fe), and potassium (UK, UK,fe) renal handling. Data derived from intensive blood and urine sampling, as well as continuous BP monitoring, were collected throughout a 24-h time period, and analyzed by means of nonlinear mixed-effects models. Differences between the geometric means of day and night observations were compared by parametric statistics. Our results show that variables of the renin cascade, BP, and urinary electrolytes oscillate with significant day-night differences in dogs. An approximately 2-fold (1.6-3.2-fold) change between the average day and night measurements was found for RA (p < 0.001), UA:C (p = 0.01), UK,fe (p = 0.01), and UNa (p = 0.007). Circadian variations in BP, albeit small (less than 10 mm Hg), were statistically significant (p < 0.01) and supported by the model-based analysis. For all variables but UNa and UNa,fe, the levels were higher at night than during the day. The data also indicate that blood pressure oscillates in parallel to the RAAS, such that, as opposed to healthy humans, BP does not drop at night in dogs. The postprandial decrease in RA is assumed to be related to body fluid volume expansion secondary to water and sodium intake, whereas the reduction of UA:C reflects aldosterone-stimulated secretion by the renin-angiotensin II pathway. UNa and UNa,fe peaked in the afternoon, about 7-8 h after food intake, which is consistent with the "impulse-response pattern" of sodium excretion described in previous publications. Finally, UK and UK,fe mirrored aldosterone-mediated potassium secretion in the kidney tubules. To describe the circadian variations of the various variables, two different mathematical representations were applied. A cosine model with a fixed 24-h period was found to fit the periodic variations of RA, UA:C, UK, UK,fe, and BP well, whereas changes in UNa and UNa,fe were best characterized by a surge model. The use of nonlinear mixed effects allowed estimation of population characteristics that can influence the periodicity of the RAAS. Specifically, sodium intake was found to interact with the tonic and the phasic secretion of renin, suggesting that varying feeding time could also impact the chronobiology of the renin cascade.

Chronobiology and Pharmacologic Modulation of the Renin-Angiotensin-Aldosterone System in Dogs: What Have We Learned?

PubMed

Mochel, Jonathan P; Danhof, Meindert

2015-01-01

Congestive heart failure (CHF) is a primary cause of morbidity and mortality with an increasing prevalence in human and canine populations. Recognition of the role of renin-angiotensin-aldosterone system (RAAS) overactivation in the pathophysiology of CHF has led to significant medical advances. By decreasing systemic vascular resistance and angiotensin II (AII) production, angiotensin-converting enzyme (ACE) inhibitors such as benazepril improve cardiac hemodynamics and reduce mortality in human and dog CHF patients. Although several experiments have pointed out that efficacy of ACE inhibitors depends on the time of administration, little attention is paid to the optimum time of dosing of these medications. A thorough characterization of the chronobiology of the renin cascade has the potential to streamline the therapeutic management of RAAS-related diseases and to help determining the optimal time of drug administration that maximizes efficacy of ACE inhibitors, while minimizing the occurrence of adverse effects. We have developed an integrated pharmacokinetic-pharmacodynamic model that adequately captures the disposition kinetics of the paradigm drug benazeprilat, as well as the time-varying changes of systemic renin-angiotensin-aldosterone biomarkers, without and with ACE inhibition therapy. Based on these chronobiological investigations, the optimal efficacy of ACE inhibitors is expected with bedtime dosing. The data further show that benazepril influences the dynamics of the renin-angiotensin-aldosterone cascade, resulting in a profound decrease in AII and aldosterone (ALD), while increasing renin activity for about 24 h. From the results of recent investigations in human, it is hypothesized that reduction of AII and ALD is one of the drivers of increased survival and improved quality of life in dogs receiving ACE inhibitors. To support and consolidate this hypothesis, additional efforts should be directed toward the collection of circulating RAAS peptides in spontaneous cases of canine CHF. If such a link could be established, profiling of these biomarkers could support determination of the severity of heart failure, complement clinical and echocardiographic findings, and be used for therapeutic drug monitoring purposes.

Combination Direct Renin Inhibition with Angiotensin Type 1 Receptor Blockade improves Aldosterone but does not improve Kidney Injury in the Transgenic Ren2 rat

PubMed Central

Whaley-Connell, Adam; Habibi, Javad; Nistala, Ravi; Hayden, Melvin R; Pulakat, Lakshmi; Sinak, Catherine; Locher, Bonnie; Ferrario, Carlos M; Sowers, James R

2012-01-01

Enhanced renin-angiotensin-aldosterone system (RAAS) activation contributes to proteinuria and chronic kidney disease by increasing glomerular and tubulointerstitial oxidative stress, promotion of fibrosis. Renin activation is the rate limiting step in angiotensin (Ang II) and aldosterone generation, and recent work suggests direct renin inhibition improves proteinuria comparable to that seen with Ang type 1 receptor (AT1R) blockade. This is important as, even with contemporary use of AT1R blockade, the burden of kidney disease remains high. Thereby, we sought to determine if combination direct renin inhibition with AT1R blockade in vivo, via greater attenuation of kidney oxidative stress, would attenuate glomerular and proximal tubule injury to a greater extent than either intervention alone. We utilized the transgenic Ren2 rat with increased tissue RAS activity and higher serum levels of aldosterone, which manifests hypertension and proteinuria. Ren2 rats were treated with renin inhibition (aliskiren), AT1R blockade (valsartan), the combination (aliskiren+valsartan), or vehicle for 21 days. Compared to Sprague-Dawley controls, Ren2 rats displayed increased systolic pressure (SBP), circulating aldosterone, proteinuria and greater urine levels of the proximal tubule protein excretory marker beta-N-acetylglucosaminidase (β-NAG). These functional and biochemical alterations were accompanied by increases in kidney tissue NADPH oxidase subunit Rac1 and 3-nitrotyrosine (3-NT) content as well as fibronectin and collagen type III. These findings occurred in conjunction with reductions in the podocyte-specific protein podocin as well as the proximal tubule-specific megalin. Further, in transgenic animals there was increased tubulointerstitial fibrosis on light microscopy as well as ultrastructural findings of glomerular podocyte foot-process effacement and reduced tubular apical endosomal/lysosomal activity. Combination therapy led to greater reductions in SBP and serum aldosterone, but did not result in greater improvement in markers of glomerular and tubular injury (ie. β-NAG) compared to either intervention alone. Further, combination therapy did not improve markers of oxidative stress and podocyte and proximal tubule integrity in this transgenic model of RAAS-mediated kidney damage despite greater reductions in serum aldosterone and BP levels. PMID:22465166

Novel approach of fragment-based lead discovery applied to renin inhibitors.

PubMed

Tawada, Michiko; Suzuki, Shinkichi; Imaeda, Yasuhiro; Oki, Hideyuki; Snell, Gyorgy; Behnke, Craig A; Kondo, Mitsuyo; Tarui, Naoki; Tanaka, Toshimasa; Kuroita, Takanobu; Tomimoto, Masaki

2016-11-15

A novel approach was conducted for fragment-based lead discovery and applied to renin inhibitors. The biochemical screening of a fragment library against renin provided the hit fragment which showed a characteristic interaction pattern with the target protein. The hit fragment bound only to the S1, S3, and S3 SP (S3 subpocket) sites without any interactions with the catalytic aspartate residues (Asp32 and Asp215 (pepsin numbering)). Prior to making chemical modifications to the hit fragment, we first identified its essential binding sites by utilizing the hit fragment's substructures. Second, we created a new and smaller scaffold, which better occupied the identified essential S3 and S3 SP sites, by utilizing library synthesis with high-throughput chemistry. We then revisited the S1 site and efficiently explored a good building block attaching to the scaffold with library synthesis. In the library syntheses, the binding modes of each pivotal compound were determined and confirmed by X-ray crystallography and the library was strategically designed by structure-based computational approach not only to obtain a more active compound but also to obtain informative Structure Activity Relationship (SAR). As a result, we obtained a lead compound offering synthetic accessibility as well as the improved in vitro ADMET profiles. The fragments and compounds possessing a characteristic interaction pattern provided new structural insights into renin's active site and the potential to create a new generation of renin inhibitors. In addition, we demonstrated our FBDD strategy integrating highly sensitive biochemical assay, X-ray crystallography, and high-throughput synthesis and in silico library design aimed at fragment morphing at the initial stage was effective to elucidate a pocket profile and a promising lead compound. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can Screening and Confirmatory Testing in the Management of Patients with Primary Aldosteronism be Improved?

PubMed

Stowasser, Michael; Ahmed, Ashraf; Guo, Zeng; Wolley, Martin; Ungerer, Jacobus; McWhinney, Brett; Poglitsch, Marko; Gordon, Richard

2017-12-01

Widespread application of the plasma aldosterone/renin ratio (ARR) as a screening test has led to the recognition that primary aldosteronism (PA) is the most common specifically treatable and potentially curable form of hypertension, accounting for 5-10% of patients. Maximal detection requires accurate diagnostic approaches and awareness and control of factors that confound results, including most antihypertensives, posture, time of day, dietary salt, and plasma potassium. Recent studies have revealed potential for false positives in patients on beta-adrenoceptor blockers, and, when direct renin concentration (but not plasma renin activity) is used to measure renin, in women during the luteal phase of the menstrual cycle or receiving estrogen-containing contraceptives or hormonal replacement therapy. In addition to verapamil slow release, hydralazine and prazosin, moxonidine has minimal effects on the ARR and can be used to control hypertension during work-up. Fludrocortisone suppression testing, while probably the most reliable means of definitively confirming or excluding PA, is time consuming and expensive, requiring a five day inpatient stay. A novel approach, upright (seated) saline infusion suppression testing (SST), has shown excellent reliability with much greater sensitivity than conventional recumbent SST in a recent pilot study, and requires only a day visit. Accurate measurement of aldosterone is essential for each step of PA workup: introduction of new, highly reliable high-throughput mass spectrometric methods into clinical practice has represented a major advance. In response to concerns raised about accuracy of renin assays, new mass spectrometric methods for measuring angiotensin II are currently being assessed in the clinical setting. © Georg Thieme Verlag KG Stuttgart · New York.

The effect of puberty on diurnal sodium regulation.

PubMed

Mahler, B; Kamperis, K; Ankarberg-Lindgren, C; Djurhuus, J C; Rittig, S

2015-11-15

The aim of this study was to investigate the impact of sex and puberty stage on circadian changes in sodium excretion, sodium-regulating hormones, and hemodynamics. Thirty-nine healthy volunteers (9 prepuberty boys, 10 prepuberty girls, 10 puberty boys, and 10 puberty girls) were included. They all underwent a 24-h circadian in-patient study under standardized conditions regarding activity, diet, and fluid intake. Blood samples were drawn every 4 h, and the urine was collected in fractions. Blood pressure and heart rate were noninvasively monitored. Atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin were measured in blood. Children in puberty had lower plasma levels of renin (P<0.05) and angiotensin II (P<0.05) and a 26% reduction in filtered sodium without changes in sodium excretion compared with prepuberty children. A circadian rhythm in sodium excretion, the renin-angiotensin system, ANP, and blood pressure was found with a midnight ANP peak (P<0.001), a nighttime decrease in hemodynamic parameters (P<0.001), an increase in plasma renin (P<0.001) and angiotensin II (P<0.001), and a decrease in sodium excretion (P<0.001) mainly on the basis of increased sodium reabsorption (P<0.001). The timing of the changes did not depend on sex or puberty group. There is a circadian rhythm of sodium excretion and sodium regulation in 7- to 15-yr-old children. This rhythm is similar in boys and girls. As an important new finding, puberty changes the plasma levels of renin and angiotensin II without changing the amount of sodium excreted or the day to night sodium excretion ratio. Copyright © 2015 the American Physiological Society.

Maternal Dexamethasone Treatment Alters Tissue and Circulating Components of the Renin-Angiotensin System in the Pregnant Ewe and Fetus

PubMed Central

Jellyman, Juanita K.; De Blasio, Miles J.; Johnson, Emma; Giussani, Dino A.; Broughton Pipkin, Fiona; Fowden, Abigail L.

2015-01-01

Antenatal synthetic glucocorticoids promote fetal maturation in pregnant women at risk of preterm delivery and their mechanism of action may involve other endocrine systems. This study investigated the effect of maternal dexamethasone treatment, at clinically relevant doses, on components of the renin-angiotensin system (RAS) in the pregnant ewe and fetus. From 125 days of gestation (term, 145 ± 2 d), 10 ewes carrying single fetuses of mixed sex (3 female, 7 male) were injected twice im, at 10–11 pm, with dexamethasone (2 × 12 mg, n = 5) or saline (n = 5) at 24-hour intervals. At 10 hours after the second injection, maternal dexamethasone treatment increased angiotensin-converting enzyme (ACE) mRNA levels in the fetal lungs, kidneys, and heart and ACE concentration in the circulation and lungs, but not kidneys, of the fetuses. Fetal cardiac mRNA abundance of angiotensin II (AII) type 2 receptor decreased after maternal dexamethasone treatment. Between the two groups of fetuses, there were no significant differences in plasma angiotensinogen or renin concentrations; in transcript levels of renal renin, or AII type 1 or 2 receptors in the lungs and kidneys; or in pulmonary, renal or cardiac protein content of the AII receptors. In the pregnant ewes, dexamethasone administration increased pulmonary ACE and plasma angiotensinogen, and decreased plasma renin, concentrations. Some of the effects of dexamethasone treatment on the maternal and fetal RAS were associated with altered insulin and thyroid hormone activity. Changes in the local and circulating RAS induced by dexamethasone exposure in utero may contribute to the maturational and tissue-specific actions of antenatal glucocorticoid treatment. PMID:26039155

Synergic effects of renin and aldosterone on right ventricular function in hypertension: a tissue Doppler study.

PubMed

Gregori, Mario; Giammarioli, Benedetta; Tocci, Giuliano; Befani, Alberto; Ciavarella, Giuseppino Massimo; Ferrucci, Andrea; Paneni, Francesco

2015-12-01

Right ventricular dysfunction (RVD) is associated with poor cardiovascular outcome. The renin-angiotensin-aldosterone system is involved in alterations of the left ventricular geometry and function. Detrimental effects of the renin-angiotensin-aldosterone system on the right ventricular function are being postulated, but data supporting this assumption are still lacking. The aim of the study was to assess the impact of hyperreninemia, hyperaldosteronism or their combination on right ventricular function in hypertensive individuals. Plasma renin activity (PRA) and plasma aldosterone concentrations (PACs) were measured in 116 hypertensive patients, divided as follows: normal PRA and PAC (n = 38); high PRA and normal PAC (hypereninemia) (n = 26); normal PRA and high PAC (hyperaldosternism) (n = 27); high PRA and PAC (HRA) (n = 25). Echocardiographic evaluation of the left and right ventricles (RV), including tissue Doppler imaging, was performed. RVD was identified by tissue Doppler Imaging-derived Myocardial Performance Index, calculated with a multisegmental approach. Indices of the right ventricular structure and function, as well as the prevalence of RVD, were higher in hyperreninemia and hyperaldosternism groups as compared with the normal group, and a further increase was observed in the HRA patients. Regression models showed a similar risk of RVD in the hyperreninemia and hyperaldosternism patients, regardless of systemic and pulmonary pressure, as well as left ventricular dysfunction. Notably, patients with both hyperreninemia and hyperaldosternism exhibited the strongest association with RVD as compared with patients with only hyperreninemia or hyperaldosternism. Isolated hyperreninemia or hyperaldosternism determines a similar impairment of the right ventricular function, whereas their combination is further detrimental. Renin and aldosterone may represent early biomarkers of right ventricular dysfunction in hypertension.

Role of the Renin-Angiotensin System, Renal Sympathetic Nerve System, and Oxidative Stress in Chronic Foot Shock-Induced Hypertension in Rats

PubMed Central

Dong, Tao; Chen, Jing-Wei; Tian, Li-Li; Wang, Lin-Hui; Jiang, Ren-Di; Zhang, Zhe; Xu, Jian-Bing; Zhao, Xiao-Dong; Zhu, Wei; Wang, Guo-Qing; Sun, Wan-Ping; Zhang, Guo-Xing

2015-01-01

Objective: The renin-angiotensin system (RAS) and renal sympathetic nerve system (RSNS) are involved in the development of hypertension. The present study is designed to explore the possible roles of the RAS and the RSNS in foot shock-induced hypertension. Methods: Male Sprague-Dawley rats were divided into six groups: control, foot shock, RSNS denervation, denervation plus foot shock, Captopril (angiotensin I converting enzyme inhibitor, ACE inhibitor) plus foot shock, and Tempol (superoxide dismutase mimetic) plus foot shock. Rats received foot shock for 14 days. We measured the quantity of thiobarbituric acid reactive substances (TBARS), corticosterone, renin, and angiotensin II (Ang II) in plasma, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and renal noradrenaline content. RAS component mRNA and protein levels were quantified in the cerebral cortex and hypothalamus. Results: The two week foot shock treatment significantly increased systolic blood pressure, which was accompanied by an increase in angiotensinogen, renin, ACE1, and AT1a mRNA and protein expression in the cerebral cortex and hypothalamus, an increase of the plasma concentrations of renin, Ang II, corticosterone, and TBARS, as well as a decrease in plasma SOD and GSH-Px activities. Systolic blood pressure increase was suppressed by denervation of the RSNS or treatment with Captopril or Tempol. Interestingly, denervation or Tempol treatment both decreased main RAS components not only in the circulatory system, but also in the central nervous system. In addition, decreased antioxidant levels and increased TBARS and corticosterone levels were also partially restored by denervation or treatment with Tempol or Captopril. Conclusions: RAS, RSNS and oxidative stress reciprocally potentiate to play important roles in the development of foot shock-induced hypertension. PMID:25999788

On the Mechanism of Serotonin-Induced Dipsogenesis in the Rat

NASA Technical Reports Server (NTRS)

Kikta, Dianne C.; Barney, Christopher C.; Threatte, Rose M.; Fregly, Melvin J.; Rowland, Neil E.; Greenleaf, John E.

1983-01-01

Subcutaneous administration of 1-5-hydroxytryptophan (5-HTP), the precursor of serotonin, to female rats induces copious drinking accompanied by activation of the renin-angiotensin system. Neither a reduction in blood pressure nor body temperature accompanied administration of 5-HTP. The objective of the present study was to determine whether serotonin-induced dipsogenesis, like that of 5-HTP, is mediated via the renin-angiotensin system. Serotonin (2 mg/kg, SC)-induced drinking was inhibited by the dopaminergic antagonist, haloperidol (150 /micro g/kg, IP), which also inhibits angiotensin II-induced drinking, Both captopril (35 mg/kg, IP), an angiotensin converting enzyme inhibitor, and propranolol (6 micro g/kg, IP), a beta-adrenergic antagonist, blocked serotonin-induced dipsogenesis. The alpha(sub a),-adrenergic agonist, clonidine (6.25 micro g/kg, SC), which suppresses renin release from the kidney, attenuated serotonin-induced water intake. The dipsogenic responses to submaximal concentrations of both serotonin (1 mg/kg, SC) and isoproterenol (8 micro g/kg, SC) were additive rather than interactive suggesting that similar pathways mediate both responses. The serotonergic receptor antagonist, methysergide (3 mg/kg, IP), inhibited serotonin-induced drinking but had no effect on isoproterenol (25micro g/kg, SC)-induced dipsogenesis. However, neither serotonin (2 mg/kg, SC) nor isoproterenol (25 micro g/kg, SC)-induced drinking was inhibited by cinansefin (25 micro g/kg, IP). These data indicate that serotonin induces drinking in rats via the renin-angiotensin system. However, the results of the studies using methysergide suggest that scrotonin appears to act at a point prior to activation of beta-adrenoceptors in the pathway leading to release of renin from the kidneys.

Maternal high-sodium intake alters the responsiveness of the renin-angiotensin system in adult offspring.

PubMed

Ramos, Débora R; Costa, Nauilo L; Jang, Karen L L; Oliveira, Ivone B; da Silva, Alexandre A; Heimann, Joel C; Furukawa, Luzia N S

2012-05-22

The goal of the current study was to evaluate the impact of maternal sodium intake during gestation on the systemic and renal renin-angiotensin-aldosterone-system (RAAS) of the adult offspring. Female Wistar rats were fed high- (HSD-8.0% NaCl) or normal-sodium diets (NSD-1.3% NaCl) from 8 weeks of age until the delivery of their first litter. After birth, the offspring received NSD. Tail-cuff blood pressure (TcBP) was measured in the offspring between 6 and 12 weeks of age. At 12 weeks of age, the offspring were subjected to either one week of HSD or low sodium diet (LSD-0.16% NaCl) feeding to evaluate RAAS responsiveness or to acute saline overload to examine sodium excretory function. Plasma (PRA) and renal renin content (RRC), serum aldosterone (ALDO) levels, and renal cortical and medullary renin mRNA expression levels were evaluated at the end of the study. TcBP was higher among dams fed HSD, but no TcBP differences were observed among the offspring. Male offspring, however, exhibited increased TcBP after one week of HSD feeding, and this effect was independent of maternal diet. Increased RAAS responsiveness to the HSD and LSD was also observed in male offspring. The baseline levels of PRA, ALDO, and cortical and medullary renin gene expression were lower but the RRC levels were higher among HSD-fed male offspring (HSDoff). Conversely, female HSDoff showed reduced sodium excretion 4 h after saline overload compared with female NSDoff. High maternal sodium intake is associated with gender-specific changes in RAAS responsiveness among adult offspring. Copyright © 2012 Elsevier Inc. All rights reserved.

Genetic variation in renin predicts the effects of thiazide diuretics.

PubMed

Huang, Chin-Chou; Chung, Chia-Min; Hung, Shuen-Iu; Leu, Hsin-Bang; Wu, Tao-Cheng; Huang, Po-Hsun; Lin, Shing-Jong; Pan, Wen-Harn; Chen, Jaw-Wen

2011-08-01

While genetic variants of renin-angiotensin-aldosterone system (RAAS) may modify the blood pressure (BP) response to thiazide diuretics, there was no evidence of genetic variations in renin (REN) playing a role. This study aimed to address the potential effects of genetic variations of RAAS on the response to initial treatment of hydrochlorothiazide (HCTZ). We enrolled nondiabetic hypertensive patients with a systolic blood pressure (SBP) ≥140 or a diastolic blood pressure (DBP) ≥90mmHg, who were either previously untreated or unsatisfactorily treated. After lifestyle modification and diet instruction for 2weeks, 90 patients with persistently elevated BP were given HCTZ 50 mg every morning for 2 weeks. Single nucleotide polymorphism markers were selected from genes involving in RAAS, including rs7079 and rs699 of angiotensinogen, rs4293 and rs4353 of angiotensin-converting enzyme and rs1464816 and rs11240688 of REN. The patients were divided into three groups according to the SBP response after HCTZ. The upper 1/3 responders had older age (P=0·035), higher SBP (P=0·039), higher pulse pressure (P=0·006) and lower plasma REN activity (PRA) (P=0·020) when compared with the lower 1/3 responders. Renin rs11240688 CC polymorphism (β=9·931, corrected P=0·012), Log PRA (β=7·451, P=0·004) and baseline SBP (β=0·299, P=0·006) were the independent predictors for the BP lowering response. In addition to PRA, renin rs11240688 CC polymorphism may also independently predict the effect of HCTZ. © 2011 The Authors. European Journal of Clinical Investigation © 2011 Stichting European Society for Clinical Investigation Journal Foundation.

Characterization of resistant hypertension: association between resistant hypertension, aldosterone, and persistent intravascular volume expansion.

PubMed

Gaddam, Krishna K; Nishizaka, Mari K; Pratt-Ubunama, Monique N; Pimenta, Eduardo; Aban, Inmaculada; Oparil, Suzanne; Calhoun, David A

2008-06-09

Resistant hypertension is a common clinical problem and greatly increases the risk of target organ damage. We evaluated the characteristics of 279 consecutive patients with resistant hypertension (uncontrolled despite the use of 3 antihypertensive agents) and 53 control subjects (with normotension or hypertension controlled by using

Role of the renin-angiotensin system, renal sympathetic nerve system, and oxidative stress in chronic foot shock-induced hypertension in rats.

PubMed

Dong, Tao; Chen, Jing-Wei; Tian, Li-Li; Wang, Lin-Hui; Jiang, Ren-Di; Zhang, Zhe; Xu, Jian-Bing; Zhao, Xiao-Dong; Zhu, Wei; Wang, Guo-Qing; Sun, Wan-Ping; Zhang, Guo-Xing

2015-01-01

The renin-angiotensin system (RAS) and renal sympathetic nerve system (RSNS) are involved in the development of hypertension. The present study is designed to explore the possible roles of the RAS and the RSNS in foot shock-induced hypertension. Male Sprague-Dawley rats were divided into six groups: control, foot shock, RSNS denervation, denervation plus foot shock, Captopril (angiotensin I converting enzyme inhibitor, ACE inhibitor) plus foot shock, and Tempol (superoxide dismutase mimetic) plus foot shock. Rats received foot shock for 14 days. We measured the quantity of thiobarbituric acid reactive substances (TBARS), corticosterone, renin, and angiotensin II (Ang II) in plasma, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and renal noradrenaline content. RAS component mRNA and protein levels were quantified in the cerebral cortex and hypothalamus. The two week foot shock treatment significantly increased systolic blood pressure, which was accompanied by an increase in angiotensinogen, renin, ACE1, and AT1a mRNA and protein expression in the cerebral cortex and hypothalamus, an increase of the plasma concentrations of renin, Ang II, corticosterone, and TBARS, as well as a decrease in plasma SOD and GSH-Px activities. Systolic blood pressure increase was suppressed by denervation of the RSNS or treatment with Captopril or Tempol. Interestingly, denervation or Tempol treatment both decreased main RAS components not only in the circulatory system, but also in the central nervous system. In addition, decreased antioxidant levels and increased TBARS and corticosterone levels were also partially restored by denervation or treatment with Tempol or Captopril. RAS, RSNS and oxidative stress reciprocally potentiate to play important roles in the development of foot shock-induced hypertension.

Vitamin D receptor deficit induces activation of renin angiotensin system via SIRT1 modulation in podocytes.

PubMed

Chandel, Nirupama; Ayasolla, Kamesh; Wen, Hongxiu; Lan, Xiqian; Haque, Shabirul; Saleem, Moin A; Malhotra, Ashwani; Singhal, Pravin C

2017-02-01

Vitamin D receptor (VDR) deficient status has been shown to be associated with the activation of renin angiotensin system (RAS). We hypothesized that lack of VDR would enhance p53 expression in podocytes through down regulation of SIRT1; the former would enhance the transcription of angiotensinogen (Agt) and angiotensinogen II type 1 receptor (AT1R) leading to the activation of RAS. Renal tissues of VDR mutant (M) mice displayed increased expression of p53, Agt, renin, and AT1R. In vitro studies, VDR knockout podocytes not only displayed up regulation p53 but also displayed enhanced expression of Agt, renin and AT1R. VDR deficient podocytes also displayed an increase in mRNA expression for p53, Agt, renin, and AT1R. Interestingly, renal tissues of VDR-M as well as VDR heterozygous (h) mice displayed attenuated expression of deacetylase SIRT1. Renal tissues of VDR-M mice showed acetylation of p53 at lysine (K) 382 residues inferring that enhanced p53 expression in renal tissues could be the result of ongoing acetylation, a consequence of SIRT1 deficient state. Notably, podocytes lacking SIRT1 not only showed acetylation of p53 at lysine (K) 382 residues but also displayed enhanced p53 expression. Either silencing of SIRT1/VDR or treatment with high glucose enhanced podocyte PPAR-y expression, whereas, immunoprecipitation (IP) of their lysates with anti-retinoid X receptor (RXR) antibody revealed presence of PPAR-y. It appears that either the deficit of SIRT1 has de-repressed expression of PPAR-y or enhanced podocyte expression of PPAR-y (in the absence of VDR) has contributed to the down regulation of SIRT1. Copyright © 2017 Elsevier Inc. All rights reserved.

Predominance of AT(1) blockade over mas-mediated angiotensin-(1-7) mechanisms in the regulation of blood pressure and renin-angiotensin system in mRen2.Lewis rats.

PubMed

Varagic, Jasmina; Ahmad, Sarfaraz; VonCannon, Jessica L; Moniwa, Norihito; Brosnihan, K Bridget; Wysocki, Jan; Batlle, Daniel; Ferrario, Carlos M

2013-05-01

We investigated whether the antihypertensive actions of the angiotensin II (Ang II) receptor (AT(1)-R) blocker, olmesartan medoxomil, may in part be mediated by increased Ang-(1-7) in the absence of significant changes in plasma Ang II. mRen2.Lewis congenic hypertensive rats were administered either a vehicle (n = 14) or olmesartan (0.5 mg/kg/day; n = 14) by osmotic minipumps. Two weeks later, rats from both groups were further randomized to receive either the mas receptor antagonist A-779 (0.5 mg/kg/day; n = 7 per group) or its vehicle (n = 7 per group) for the next 4 weeks. Blood pressure was monitored by telemetry, and circulating and tissue components of the renin-angiotensin system (RAS) were measured at the completion of the experiments. Antihypertensive effects of olmesartan were associated with an increase in plasma renin concentration, plasma Ang I, Ang II, and Ang-(1-7), whereas serum aldosterone levels and kidney Ang II content were reduced. Preserved Ang-(1-7) content in kidneys was associated with increases of ACE2 protein but not activity and no changes on serum and kidney ACE activity. There was no change in cardiac peptide levels after olmesartan treatment. The antihypertensive effects of olmesartan were not altered by concomitant administration of the Ang-(1-7) receptor antagonist except for a mild further increase in plasma renin concentration. Our study highlights the independent regulation of RAS among plasma, heart, and kidney tissue in response to AT(1)-R blockade. Ang-(1-7) through the mas receptor does not mediate long-term effects of olmesartan besides counterbalancing renin release in response to AT(1)-R blockade.

Functional and molecular evidence for expression of the renin angiotensin system and ADAM17-mediated ACE2 shedding in COS7 cells

PubMed Central

Grobe, Nadja; Di Fulvio, Mauricio; Kashkari, Nada; Chodavarapu, Harshita; Somineni, Hari K.; Singh, Richa

2015-01-01

The renin angiotensin system (RAS) plays a vital role in the regulation of the cardiovascular and renal functions. COS7 is a robust and easily transfectable cell line derived from the kidney of the African green monkey, Cercopithecus aethiops. The aims of this study were to 1) demonstrate the presence of an endogenous and functional RAS in COS7, and 2) investigate the role of a disintegrin and metalloproteinase-17 (ADAM17) in the ectodomain shedding of angiotensin converting enzyme-2 (ACE2). Reverse transcription coupled to gene-specific polymerase chain reaction demonstrated expression of ACE, ACE2, angiotensin II type 1 receptor (AT1R), and renin at the transcript levels in total RNA cell extracts. Western blot and immunohistochemistry identified ACE (60 kDa), ACE2 (75 kDa), AT1R (43 kDa), renin (41 kDa), and ADAM17 (130 kDa) in COS7. At the functional level, a sensitive and selective mass spectrometric approach detected endogenous renin, ACE, and ACE2 activities. ANG-(1–7) formation (m/z 899) from the natural substrate ANG II (m/z 1,046) was detected in lysates and media. COS7 cells stably expressing shRNA constructs directed against endogenous ADAM17 showed reduced ACE2 shedding into the media. This is the first study demonstrating endogenous expression of the RAS and ADAM17 in the widely used COS7 cell line and its utility to study ectodomain shedding of ACE2 mediated by ADAM17 in vitro. The transfectable nature of this cell line makes it an attractive cell model for studying the molecular, functional, and pharmacological properties of the renal RAS. PMID:25740155

Renin-angiotensin-aldosterone system in normal and hypertensive pregnancy. Response to postural stimuli.

PubMed

Fagundes, V G; Lamas, C C; Francischetti, E A

1992-02-01

Most studies that have attempted to distinguish pregnancy-induced hypertension from chronic hypertension in pregnancy include arbitrary clinical definitions and morphological reports based on renal biopsy. To evaluate whether these conditions have different responses to stimuli to the renin-angiotensin-aldosterone system, we studied four normal nonpregnant women, eight normal pregnant women, 10 women with pregnancy-induced hypertension, and 14 with chronic hypertension in pregnancy, in the third trimester of pregnancy, after they had sequentially adopted the supine, the left lateral recumbent, and the orthostatic positions for 90 minutes each. Postural maneuvers did not significantly change mean arterial pressure in pregnancy-induced hypertensive or in normal pregnant women, although in chronic hypertensive women, a significant reduction in this parameter was observed in left lateral recumbency. The renin-angiotensin-aldosterone system was significantly less activated with women in the supine position in pregnancy-induced hypertensive and chronic hypertensive women; however, as opposed to pregnancy-induced hypertensive women, those with chronic hypertension reassumed their humoral response to upright posture, which was accompanied by a significant reduction in sodium excretion. The parallelism between plasma renin activity and aldosterone levels, absent in normal pregnancy, returned in pregnancy-induced hypertensive and chronic hypertensive women in the erect posture (r = 0.73, p less than 0.01; r = 0.68, p less than 0.01, respectively). These data suggest that the adoption of the left lateral recumbent position in pregnancy reduces mean arterial pressure only in chronic hypertensive women. Moreover, in chronic hypertension, the upright position provoked a significant response of the renin-angiotensin-aldosterone system. This effect was not observed in women with pregnancy-induced hypertension.

Targeting renin-angiotensin system in malignant hypertension in atypical hemolytic uremic syndrome

PubMed Central

Raghunathan, V.; Sethi, S. K.; Dragon-Durey, M. A.; Dhaliwal, M.; Raina, R.; Jha, P.; Bansal, S. B.; Kher, V.

2017-01-01

Hypertension is common in hemolytic uremic syndrome (HUS) and often difficult to control. Local renin-angiotensin activation is believed to be an important part of thrombotic microangiopathy, leading to a vicious cycle of progressive renal injury and intractable hypertension. This has been demonstrated in vitro via enhanced tissue factor expression on glomerular endothelial cells which is enhanced by angiotensin II. We report two pediatric cases of atypical HUS with severe refractory malignant hypertension, in which we targeted the renin-angiotensin system by using intravenous (IV) enalaprilat, oral aliskiren, and oral enalapril with quick and dramatic response of blood pressure. Both drugs, aliskiren and IV enalaprilat, were effective in controlling hypertension refractory to multiple antihypertensive medications. These appear to be promising alternatives in the treatment of severe atypical HUS-induced hypertension and hypertensive emergency. PMID:28356668

Juxtaglomerular cell tumor of the kidney: report of two cases with a papillary pattern.

PubMed

Têtu, B; Vaillancourt, L; Camilleri, J P; Bruneval, P; Bernier, L; Tourigny, R

1993-11-01

We report the clinicopathologic, immunohistochemical, and electron microscopic study of two cases of juxtaglomerular cell tumor of the kidney with a hitherto unreported dominant papillary pattern. Both tumors were associated with high blood pressure that did not respond to medical therapy, but that returned to normal after removal of the kidney. They were well delineated, tan, and had no necrosis. The cores of the papillary structures consisted of polygonal cells found to express renin by immunohistochemistry and to contain renin protogranules by electron microscopy. The papillary fronds were covered by one layer of cuboidal epithelial cells that did not stain for renin and had ultrastructural features reminiscent of the collecting duct epithelium. These tumors must be differentiated from malignant papillary tumors of the kidney, such as papillary clear cell carcinoma, transitional cell carcinoma, and collecting duct carcinoma.

Erythrocyte 2,3-diphosphoglycerate and serum enzyme concentrations in trained and sedentary men.

PubMed

Lijnen, P; Hespel, P; Van Oppens, S; Fiocchi, R; Goossens, W; Vanden Eynde, E; Amery, A

1986-04-01

The acute effect of exercise on the intraerythrocyte 2,3-diphosphoglycerate concentration and on various serum enzymes and some related variables was investigated in 14 male athletes before and after a 50-min cross-country run and compared at rest to 15 sedentary subjects. Compared to the sedentary subjects, the athletes had higher resting levels of serum creatine phosphokinase, plasma myoglobin, and renin substrate but had a lower plasma renin activity. The red blood cell 2,3-diphosphoglycerate concentration increased after exercise in the runners and was not different at rest between the athletes and the sedentary subjects. Our data therefore suggest that the resting plasma renin activity is reduced in athletes when compared to sedentary subjects. Training seems however not to alter the resting level of 2,3-diphosphoglycerate in the red blood cells.

Iron Overload Accelerates the Progression of Diabetic Retinopathy in Association with Increased Retinal Renin Expression.

PubMed

Chaudhary, Kapil; Promsote, Wanwisa; Ananth, Sudha; Veeranan-Karmegam, Rajalakshmi; Tawfik, Amany; Arjunan, Pachiappan; Martin, Pamela; Smith, Sylvia B; Thangaraju, Muthusamy; Kisselev, Oleg; Ganapathy, Vadivel; Gnana-Prakasam, Jaya P

2018-02-14

Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Increased iron accumulation is associated with several degenerative diseases. However, there are no reports on the status of retinal iron or its implications in the pathogenesis of DR. In the present study, we found that retinas of type-1 and type-2 mouse models of diabetes have increased iron accumulation compared to non-diabetic retinas. We found similar iron accumulation in postmortem retinal samples from human diabetic patients. Further, we induced diabetes in HFE knockout (KO) mice model of genetic iron overload to understand the role of iron in the pathogenesis of DR. We found increased neuronal cell death, vascular alterations and loss of retinal barrier integrity in diabetic HFE KO mice compared to diabetic wildtype mice. Diabetic HFE KO mouse retinas also exhibited increased expression of inflammation and oxidative stress markers. Severity in the pathogenesis of DR in HFE KO mice was accompanied by increase in retinal renin expression mediated by G-protein-coupled succinate receptor GPR91. In light of previous reports implicating retinal renin-angiotensin system in DR pathogenesis, our results reveal a novel relationship between diabetes, iron and renin-angiotensin system, thereby unraveling new therapeutic targets for the treatment of DR.

Aliskiren Regulates Neonatal Fc Receptor and IgG Metabolism with Attenuation of Anti-GBM Glomerulonephritis in Mice.

PubMed

Kang, Ju Hyung; Baik, Haing Woon; Yoo, Seung-Min; Kim, Joo Heon; Cheong, Hae Il; Park, Chung-Gyu; Kang, Hee Gyung; Ha, Il-Soo

2016-01-01

Renin, in addition to its activation of the renin-angiotensin system, binds to the (pro)renin receptor (PRR) and triggers inflammatory and fibrogenic signaling in tissue. In addition, aliskiren, a direct renin inhibitor, has been shown to affect IgG metabolism by altering PRR and neonatal Fc receptors (FcRns). We investigated the effect of aliskiren on proteinuria, glomerular extracellular matrix, expressions of fibronectin, transforming growth factor β1 (TGF-β1), PRR, FcRn and renal metabolism of IgG in a mice model of anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). IgG deposition and expressions of FcRn and PRR were enhanced at glomeruli and urinary IgG levels increased in anti-GBM GN. Aliskiren attenuated anti-GBM GN with reduction of proteinuria and cortical expressions of fibronectin and TGF-β1. In addition, aliskiren suppressed the renal cortical expressions of FcRn and PRR. Aliskiren also reduced the glomerular IgG depositions and the urinary IgG levels albeit with increased circulating serum IgG levels. These results suggest that suppression of FcRn and PRR and regulation of IgG metabolism may be related to the attenuation of anti-GBM GN by aliskiren. © 2016 S. Karger AG, Basel.

[(Pro) renin receptor in the pathogenesis of proliferative diabetic retinopathy].

PubMed

Kanda, Atsuhiro

2014-11-01

The renin-angiotensin system (RAS), originally regarded as an important controller of systemic blood pressure (circulatory RAS), plays a pivotal role in pathological vascular conditions including inflammation and angiogenesis (tissue RAS). (Pro) renin receptor [(P) RR] is known to bind with prorenin causing the dual activation of tissue renin-angiotensin system (RAS) together with RAS-independent intracellular signaling pathways and contributes to the molecular pathogenesis of end-organ damage. In this review, we investigated localization and expression of (P)RR in fibrovascular tissues and vitreous fluids from patients with proliferative diabetic retinopathy and evaluated the molecular mechanisms in vitro in order to confirm the conclusions regarding (P) RR from animal studies. (P)RR immunoreactivity was detected in vascular endothelial cells, co-localized with prorenin, phosphorylated extracellular signal-regulated kinase and vascular endothelial growth factor (VEGF). Protein levels of soluble (P) RR in the vitreous fluids were higher in proliferative diabetic retinopathy (PDR) eyes than in non-diabetic control eyes, and were significantly correlated with vitreous VEGF levels and the vascular density of fibrovascular tissues. We herein report the first evidence that shows the close association of (P) RR with angiogenic activity in human PDR. The present data suggest the validity of (P) RR as a molecular target for the treatment of PDR.

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

Mechanisms of Hypertension: The Expanding Role of Aldosterone

PubMed Central

FREEL, E. MARIE; CONNELL, JOHN M.C.

2005-01-01

Hypertension is a common disorder that affects a large heterogeneous patient population. Subgroups can be identified on the basis of their responses to hormonal and biologic stimuli. These subgroups include low-renin hypertensives and nonmodulators. Aldosterone, the principal human mineralocorticoid, is increasingly recognized as playing a significant role in cardiovascular morbidity, and its role in hypertension has recently been reevaluated with studies that suggest that increased aldosterone biosynthesis (as defined by an elevated aldosterone to renin ratio) is a key phenotype in up to 15% of individuals with hypertension. It was reported previously that a polymorphism of the gene (C to T conversion at position −344) encoding aldosterone synthase is associated with hypertension, particularly in individuals with a high ratio. However, the most consistent association with this variant is a relative impairment of adrenal 11β-hydroxylation. This review explores the evidence for this and provides a hypothesis linking impaired 11β-hydroxylation and hypertension with a raised aldosterone to renin ratio. It is also speculated that there is substantial overlap between this group of patients and previously identified low-renin hypertensives and nonmodulators. Thus, these groups may form a neurohormonal spectrum reflecting different stages of hypertension or indeed form sequential steps in the natural history of hypertension in genetically susceptible individuals. PMID:15284285

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.

The effect of vagotomy on sodium reabsorption and renin release in anaesthetized dogs subjected to 60 degrees head-up tilt.

PubMed Central

DiBona, G F; Johns, E J; Osborn, J L

1981-01-01

1. Anaesthetized dogs were subjected to two 15 min periods of 60 degrees head-up tilt. Renal perfusion pressure was regulated to minimize changes during tilting. 2. In both intact and vagotomized animals there was a fall in systemic arterial pressure and a rise in heart rate. In both intact and vagotomized animals glomerular filtration rate fell slightly during the first tilt but remained unchanged in the second tilt period. Renal blood flow was unchanged throughout. 3. Both absolute and fractional excretions of sodium were reduced in intact animals subjected to the two consecutive periods of tilt. Following vagotomy these responses were as large as those observed in intact animals. 4. Tilting caused an increase in renin secretion from the kidney in both tilting periods to which the intact animals were subjected. In the vagotomized animals the increase in renin secretion was as large as that observed in intact animals. 5. The results of the present study show that, under the experimental conditions used, vagal afferent activity had no measurable effect on the decreases in sodium excretion or increases in renin secretion mediated by the renal nerves during short periods of 60 degrees head-up tilt. PMID:7033504

Blocking the RAAS at different levels: an update on the use of the direct renin inhibitors alone and in combination.

PubMed

Cagnoni, Francesca; Njwe, Christian Achiri Ngu; Zaninelli, Augusto; Ricci, Alessandra Rossi; Daffra, Diletta; D'Ospina, Antonio; Preti, Paola; Destro, Maurizio

2010-08-09

The renin-angiotensin-aldosterone system (RAAS), an important regulator of blood pressure and mediator of hypertension-related complications, is a prime target for cardiovascular drug therapy. Angiotensin-converting enzyme inhibitors (ACEIs) were the first drugs to be used to block the RAAS. Angiotensin II receptor blockers (ARBs) have also been shown to be equally effective for treatment. Although these drugs are highly effective and are widely used in the management of hypertension, current treatment regimens with ACEIs and ARBs are unable to completely suppress the RAAS. Combinations of ACEIs and ARBs have been shown to be superior than to either agent alone for some, but certainly not all, composite cardiovascular and kidney outcomes, but dual RAAS blockade with the combination of an ACEI and an ARB is sometimes associated with an increase in the risk for adverse events, primarily hyperkalemia and worsening renal function. The recent introduction of the direct renin inhibitor, aliskiren, has made available new combination strategies to obtain a more complete blockade of the RAAS with fewer adverse events. Renin system blockade with aliskiren and another RAAS agent has been, and still is, the subject of many large-scale clinical trials and furthermore, is already available in some countries as a fixed combination.

Effect of antigravity suit inflation on cardiovascular, PRA, and PVP responses in humans. [Plasma Renin Activity and Plasma VasoPressin

NASA Technical Reports Server (NTRS)

Kravik, S. E.; Keil, L. C.; Geelen, G.; Wade, C. E.; Barnes, P. R.

1986-01-01

The effects of lower body and abdominal pressure, produced by antigravity suit inflation, on blood pressure, pulse rate, fluid and electrolyte shift, plasma vasopressin and plasma renin activity in humans in upright postures were studied. Five men and two women stood upright for 3 hr with the suit being either inflated or uninflated. In the control tests, the suit was inflated only during the latter part of the trials. Monitoring was carried out with a sphygnomanometer, with sensors for pulse rates, and using a photometer and osmometer to measure blood serum characteristics. The tests confirmed earlier findings that the anti-g suit eliminates increases in plasma renin activity. Also, the headward redistribution of blood obtained in the tests commends the anti-g suit as an alternative to water immersion or bed rest for initial weightlessness studies.

Zero gravity and cardiovascular homeostasis. The relationship between endogenous hyperprolactinemia and plasma aldosterone

NASA Technical Reports Server (NTRS)

Haber, E.; Re, R. N.; Kourides, I. A.; Weihl, A. C.; Maloof, F.

1978-01-01

Prolactin, thyrotropin and aldosterone were measured by radioimmunoassay and plasma renin activity by the radioimmunoassay of angiotensin I in normal women before and after the intravenous injection of 200 micrograms of thyrotropin releasing hormone. Prolactin increased at 15 minutes following thyrotropin releasing hormone. Plasma renin activity was not different from control levels during the first hour following the administration of thyrotropin releasing hormone, nor did the plasma aldosterone concentration differ significantly from the control levels during this period. However, with upright posture, an increase in aldosterone and in plasma renin activity was noted, demonstrating a normal capacity to secrete aldosterone. Similarly, no change in aldosterone was seen in 9 patients with primary hypothyroidism given thyrotropin releasing hormone, despite the fact that the increase in prolactin was greater than normal. These data demonstrate that acutely or chronically elevated serum prolactin levels do not result in increased plasma aldosterone levels in humans.

Hemodynamics, renal function, plasma renin, and aldosterone in man after 5 to 14 days of bedrest

NASA Technical Reports Server (NTRS)

Melada, G. A.; Goldman, R. H.; Luetscher, J. A.; Zager, P. G.

1975-01-01

Continuous bedrest for 5 to 14 days had no significant effect on resting heart rate, blood pressure, or cardiac output in six normal men. Head-up tilt induced greater tachycardia in 5 of 6 patients after bed rest than in the control period. Propranolol diminished both tachycardia and the incidence of hypotension and faintness in upright posture. Plasma volume fell, extracellular fluid volume increased, and plasma renin activity was significantly elevated following bedrest. Unusually large increases in plasma renin followed head-up tilt or administration of isoproterenol during bedrest and after resuming normal activity. During bedrest, plasma aldosterone was often increased in the early morning. It is concluded that after bedrest, upright posture evokes strong beta-adrenergic activity as well as exaggerated metabolic and circulatory responses which can be reduced or abolished by the beta-adrenergic blocker, propranolol.

Effect of bedrest on circadian rhythms of plasma renin, aldosterone, and cortisol

NASA Technical Reports Server (NTRS)

Chavarri, M.; Ganguly, A.; Luetscher, J. A.; Zager, P. G.

1977-01-01

Previous studies of normal men after 5 d of bedrest showed that circulatory instability on head-up tilt or standing is preceded by increased plasma renin activity (PRA) at bedrest. In the present study, the circadian rhythms of PRA, aldosterone, and cortisol have been observed in five normal men on a constant diet. In ambulatory controls, PRA and aldosterone increased normally after standing. On the third morning of bedrest, PRA was higher than before, and at noon, PRA was higher than in standing controls. The nocturnal peaks of PRA resulting from episodic renin secretion during sleep were higher after bedrest. Plasma aldosterone was also increased by bedrest. The findings are compatible with the theory that intermittent beta-adrenergic nerve activity during sleep is increased after bedrest, but other factors, such as loss of body sodium and a lower plasma volume, may also be involved.

The Low-Renin Hypertension Phenotype: Genetics and the Role of the Mineralocorticoid Receptor.

PubMed

Baudrand, Rene; Vaidya, Anand

2018-02-11

A substantial proportion of patients with hypertension have a low or suppressed renin. This phenotype of low-renin hypertension (LRH) may be the manifestation of inherited genetic syndromes, acquired somatic mutations, or environmental exposures. Activation of the mineralocorticoid receptor is a common final mechanism for the development of LRH. Classically, the individual causes of LRH have been considered to be rare diseases; however, recent advances suggest that there are milder and "non-classical" variants of many LRH-inducing conditions. In this regard, our understanding of the underlying genetics and mechanisms accounting for LRH, and therefore, potentially the pathogenesis of a large subset of essential hypertension, is evolving. This review will discuss the potential causes of LRH, with a focus on implicated genetic mechanisms, the expanding recognition of non-classical variants of conditions that induce LRH, and the role of the mineralocorticoid receptor in determining this phenotype.

Combination of direct renin inhibition with angiotensin type 1 receptor blockade improves aldosterone but does not improve kidney injury in the transgenic Ren2 rat.

PubMed

Whaley-Connell, Adam; Habibi, Javad; Nistala, Ravi; Hayden, Melvin R; Pulakat, Lakshmi; Sinak, Catherine; Locher, Bonnie; Ferrario, Carlos M; Sowers, James R

2012-06-10

Enhanced renin-angiotensin-aldosterone system (RAAS) activation contributes to proteinuria and chronic kidney disease by increasing glomerular and tubulointerstitial oxidative stress, promotion of fibrosis. Renin activation is the rate limiting step in angiotensin (Ang II) and aldosterone generation, and recent work suggests direct renin inhibition improves proteinuria comparable to that seen with Ang type 1 receptor (AT(1)R) blockade. This is important as, even with contemporary use of AT(1)R blockade, the burden of kidney disease remains high. Thereby, we sought to determine if combination of direct renin inhibition with AT(1)R blockade in vivo, via greater attenuation of kidney oxidative stress, would attenuate glomerular and proximal tubule injury to a greater extent than either intervention alone. We utilized the transgenic Ren2 rat with increased tissue RAS activity and higher serum levels of aldosterone, which manifests hypertension and proteinuria. Ren2 rats were treated with renin inhibition (aliskiren), AT(1)R blockade (valsartan), the combination (aliskiren+valsartan), or vehicle for 21days. Compared to Sprague-Dawley controls, Ren2 rats displayed increased systolic pressure (SBP), circulating aldosterone, proteinuria and greater urine levels of the proximal tubule protein excretory marker beta-N-acetylglucosaminidase (β-NAG). These functional and biochemical alterations were accompanied by increases in kidney tissue NADPH oxidase subunit Rac1 and 3-nitrotyrosine (3-NT) content as well as fibronectin and collagen type III. These findings occurred in conjunction with reductions in the podocyte-specific protein podocin as well as the proximal tubule-specific megalin. Further, in transgenic animals there was increased tubulointerstitial fibrosis on light microscopy as well as ultrastructural findings of glomerular podocyte foot-process effacement and reduced tubular apical endosomal/lysosomal activity. Combination therapy led to greater reductions in SBP and serum aldosterone, but did not result in greater improvement in markers of glomerular and tubular injury (i.e. β-NAG) compared to either intervention alone. Further, combination therapy did not improve markers of oxidative stress and podocyte and proximal tubule integrity in this transgenic model of RAAS-mediated kidney damage despite greater reductions in serum aldosterone and BP levels. Published by Elsevier B.V.

Potentiation of Hormonal Responses to Hemorrhage and Fasting, but not Hypoglycemia in Conscious Adrenalectomized Rats

NASA Technical Reports Server (NTRS)

Darlington, Daniel N.; Keil, Lanny C.; Dallman, Mary F.

1989-01-01

Bilateral adrenalectomy (ADRX) in rats removes the source of two major stress-responsive hormones, corticosterone and epinephrine. To test how ADRX rats with-stand stress, we performed the following experiments in adult male rats provided with indwelling femoral arterial and venous cannulae and either ADRX or sham-adrenalectomized (Sham) 3 days later and given 0.5% NaCl to drink. Five to 6 days after adrenal surgery the rats were studied after either a 15 ml/kg.5 min hemorrhage or after an overnight fast followed by insulin-induced hypoglycemia. In fed unstressed ADRX rats, basal mean arterial blood pressure was slightly decreased; heart rate was increased; blood volume, vasopressin, and oxytocin concentrations were not different from sham values; and renin and norepinephrine were significantly elevated. The recovery of arterial pressure after hemorrhage in the ADRX rats was similar to that in the sham group over a 5-h period; however, the responses of vasopressin and oxytocin were significantly greater, and those of renin and norepinephrine were markedly potentiated in the ADRX group. Heart rate recovered faster in the ADRX group and was elevated, compared to the sham value, for most of the 5-h period. Restitution of blood volume was attenuated in the ADRX group, although the restitution of plasma protein was not different between the groups. A significant difference in the change in plasma osmolality between groups after hemorrhage may account for the attenuated restitution of blood volume. After an overnight fast, which reduced blood volume in both groups of rats, the plasma renin concentration rose still further in ADRX rats; the differences in other measured variables observed between fed ADRX and sham groups remained the same. The insulin-induced 50% decrease in glucose caused minor effects on arterial blood pressure and heart rate and occasioned responses in renin and norepinephrine of similar magnitudes in the two groups. We conclude that in the absence of the adrenals, rats restore arterial pressure after hemorrhage remarkably well through potentiation of the responses of other vasoactive neural and hormonal systems. In these studies the marked potentiation of the renin response suggests that the renin-angiotensin system may be important in the maintenance of arterial blood pressure after reductions in blood volume.

Nocturnal pituitary hormone and renin profiles during chronic heat exposure.

PubMed

Saini, J; Brandenberger, G; Libert, J P; Follenius, M

1993-07-01

To establish the principal endocrine systems involved in the initial adaptation to chronic passive heat exposure, responses of the hydromineral and pituitary systems were compared. Nocturnal plasma profiles of growth hormone, prolactin, thyrotropin, and plasma renin activity were determined during a period of prolonged heat exposure designed to simulate a hot climate. Two groups of six male subjects (G1 and G2) were kept for 11 days in a climatically controlled apartment. The G1 group was exposed to 20 degrees C throughout the study, and the G2 group was exposed to 20 degrees C for 5 days and to 35 degrees C for the following 6 days. Blood was collected continuously during the 1st and 10th nights from 2300 to 0700 h and was sampled in 10-min aliquots for hormone analysis. Heat exposure increased the nocturnal mean core temperature (P < 0.02) and stimulated plasma renin activity (P < 0.01) but had little effect on the pituitary hormones except for a small increase in prolactin (P < 0.05). For the G1 group there was no change in hormone profiles. These results demonstrate that the principal initial endocrine system involved in acclimatization to passive heat exposure is the renin-angiotensin system, reflecting counteractive measures against salt and water losses. In contrast, 5 days of continuous heat exposure does not provoke metabolic changes, indicated by the small effect on pituitary hormone profiles.

Alteration at transcriptional level of cardiac renin-angiotensin system by letrozole treatment.

PubMed

Shekarforoush, Shahnaz; Koohpeyma, Farhad; Safari, Fatemeh

2018-06-17

The use of aromatase inhibitors (AIs) for breast cancer led to a marked change in ventricular function. Since accumulating evidence indicates that overactivation of the cardiac renin-angiotensin system (RAS) plays an important role in the development of cardiovascular diseases such as hypertrophy and remodelling, we aimed to investigate whether letrozole alters the transcription level of RAS related genes in the cardiac tissue. Twenty four rats were randomly divided into four groups (n = 6 per group): two groups were letrozole treated (1 and 2 mg/kg/day orally), one group was vehicle treated (DMSO) and one group was the control group without any treatment. 12 weeks after beginning treatment with letrozole, we examined the rate of transcription of renin, angiotensinogen, AngII type 1a and 1b (AT1a and AT1b) and type 2 receptors (AT2) in the rat heart using real-time polymerase chain reaction. The cardiac mRNA levels of several components of the RAS in the rats treated with letrozole were significantly increased including AT1a receptor (80%), renin (51%), and angiotensinogen (33%). Though not significant, AT2 receptor levels were observed to decrease with increasing doses of letrozole. Letrozole can induce significant changes in some RAS related genes. These alterations are important to understand the pathways and consequences beyond cardiac events induced by breast cancer treatments.

High-salt diets during pregnancy affected fetal and offspring renal renin-angiotensin system.

PubMed

Mao, Caiping; Liu, Rong; Bo, Le; Chen, Ningjing; Li, Shigang; Xia, Shuixiu; Chen, Jie; Li, Dawei; Zhang, Lubo; Xu, Zhice

2013-07-01

Intrauterine environments are related to fetal renal development and postnatal health. Influence of salty diets during pregnancy on renal functions and renin-angiotensin system (RAS) was determined in the ovine fetuses and offspring. Pregnant ewes were fed high-salt diet (HSD) or normal-salt diet (NSD) for 2 months during middle-to-late gestation. Fetal renal functions, plasma hormones, and mRNA and protein expressions of the key elements of renal RAS were measured in the fetuses and offspring. Fetal renal excretion of sodium was increased while urine volume decreased in the HSD group. Fetal blood urea nitrogen was increased, while kidney weight:body weight ratio decreased in the HSD group. The altered ratio was also observed in the offspring aged 15 and 90 days. Maternal and fetal plasma antidiuretic hormone was elevated without changes in plasma renin activity and Ang I levels, while plasma Ang II was decreased. The key elements of local renal RAS, including angiotensinogen, angiotensin converting enzyme (ACE), ACE2, AT1, and AT2 receptor expression in both mRNA and protein, except renin, were altered following maternal high salt intake. The results suggest that high intake of salt during pregnancy affected fetal renal development associated with an altered expression of the renal key elements of RAS, some alterations of fetal origins remained after birth as possible risks in developing renal or cardiovascular diseases.

Role of (Pro)Renin Receptor in Albumin Overload-Induced Nephropathy in Rats.

PubMed

Fang, Hui; Deng, Mokan; Zhang, Linlin; Lu, Aihua; Su, Jiahui; Xu, Chuanming; Zhou, Li; Wang, Lei; Ou, Jing-Song; Wang, Weidong; Yang, Tianxin

2018-05-30

Proteinuria is not only a common feature of chronic kidney diseases (CKD) but also an independent risk factor promoting CKD progression to end-stage renal failure. However, the underlying molecular mechanisms for protein overload-induced renal injury remain elusive. The present study examined the role of (pro)renin receptor (PRR) in pathogenesis of albumin overload (AO)-induced nephropathy and activation of intrarenal renin-angiotensin system (RAS) in rats. Wistar rats underwent unilateral nephrectomy and were treated for 7 weeks with vehicle, bovine serum albumin (5 g/kg/d via a single i.p. injection) alone or in conjunction with a PRR decoy inhibitor PRO20 (500 μg/kg/d via 3 s.c. injections). The AO rat model exhibited severe proteinuria, tubular necrosis, and interstitial fibrosis, oxidative stress, inflammation, accompanied by elevated urinary N-acetyl-beta-D-glucosaminidase activity and urinary β2-microglobulin secretion, all of which were significantly attenuated by PRO20. Urinary and renal levels of renin, angiotensinogen (AGT), and Ang II were elevated by AO and suppressed by PRO20, contrasting to largely unaltered plasma levels of the RAS parameters. The AO model also showed increased renal expression of full-length PRR and soluble PRR (sPRR) and urinary excretion of sPRR. Taken together, we conclude that PRR antagonism with PRO20 alleviates AO-induced nephropathy via inhibition of intrarenal RAS.

Long-term effects of telmisartan on blood pressure, the renin-angiotensin-aldosterone system, and lipids in hypertensive patients.

PubMed

Aoki, Akiko; Ogawa, Tetsuya; Sumino, Hiroyuki; Kumakura, Hisao; Takayama, Yoshiaki; Ichikawa, Shuichi; Nitta, Kosaku

2010-05-01

We prospectively evaluated long-term (12 months) effects of telmisartan on blood pressure (BP), circulating renin-angiotensin-aldosterone levels, and lipids in hypertensive patients. There were 13 men and 11 women, 59 +/- 8.7 years of age (mean +/- SEM), with untreated essential hypertension. The 20-60 mg doses of telmisartan were administered once daily in the morning until BP130/85 was obtained. Blood pressure and plasma renin activity, plasma angiotensin (Ang) I and Ang II, serum angiotensin-converting enzyme (ACE) activity, plasma aldosterone concentration, plasma human atrial natriuretic peptide (hANP) concentration, and serum lipids were obtained 6 and 12 months after starting telmisartan administration. Systolic and diastolic BP were significantly (P < 0.001, P < 0.001) decreased from 162 +/- 3.3 and 97.7 +/- 2.1 mmHg to 128 +/- 3.8 and 79.6 +/- 2.0 mmHg after 12 months of treatment, respectively. Plasma Ang I and Ang II were unchanged at 12 months. Plasma renin activity and serum ACE activity were significantly (P < 0.001, P < 0.05) increased and plasma aldosterone concentration was unchanged during the study period. Total cholesterol levels were unchanged, but serum triglycerides levels were significantly decreased at 12 months (P < 0.01). Plasma hANP showed no significant alteration throughout the 12-month period. In hypertensive patients, telmisartan is a beneficial antihypertensive drug that also lowers serum triglycerides.

Therapeutic perspectives in hypertension: novel means for renin-angiotensin-aldosterone system modulation and emerging device-based approaches.

PubMed

Unger, Thomas; Paulis, Ludovit; Sica, Domenic A

2011-11-01

The conventional antihypertensive therapies including renin-angiotensin-aldosterone system antagonists (converting enzyme inhibitors, receptor blockers, renin inhibitors, and mineralocorticoid receptor blockers), diuretics, β-blockers, and calcium channel blockers are variably successful in achieving the challenging target blood pressure values in hypertensive patients. Difficult to treat hypertension is still a commonly observed problem world-wide. A number of drugs are considered to be used as novel therapies for hypertension. Renalase supplementation, vasopeptidase inhibitors, endothelin antagonists, and especially aldosterone antagonists (aldosterone synthase inhibitors and novel selective mineralocorticoid receptor blockers) are considered an option in resistant hypertension. In addition, the aldosterone antagonists as well as (pro)renin receptor blockers or AT(2) receptor agonists might attenuate end-organ damage. This array of medications has now been complemented by a number of new approaches of non-pharmacological strategies including vaccination, genomic interference, controlled breathing, baroreflex activation, and probably most successfully renal denervation techniques. However, the progress on innovative therapies seems to be slow and the problem of resistant hypertension and proper blood pressure control appears to be still persisting. Therefore the regimens of currently available drugs are being fine-tuned, resulting in the establishment of several novel fixed-dose combinations including triple combinations with the aim to facilitate proper blood pressure control. It remains an exciting question which approach will confer the best blood pressure control and risk reduction in this tricky disease.

Collecting Duct Nitric Oxide Synthase 1ß Activation Maintains Sodium Homeostasis During High Sodium Intake Through Suppression of Aldosterone and Renal Angiotensin II Pathways.

PubMed

Hyndman, Kelly A; Mironova, Elena V; Giani, Jorge F; Dugas, Courtney; Collins, Jessika; McDonough, Alicia A; Stockand, James D; Pollock, Jennifer S

2017-10-24

During high sodium intake, the renin-angiotensin-aldosterone system is downregulated and nitric oxide signaling is upregulated in order to remain in sodium balance. Recently, we showed that collecting duct nitric oxide synthase 1β is critical for fluid-electrolyte balance and subsequently blood pressure regulation during high sodium feeding. The current study tested the hypothesis that high sodium activation of the collecting duct nitric oxide synthase 1β pathway is critical for maintaining sodium homeostasis and for the downregulation of the renin-angiotensin-aldosterone system-epithelial sodium channel axis. Male control and collecting duct nitric oxide synthase 1β knockout (CDNOS1KO) mice were placed on low, normal, and high sodium diets for 1 week. In response to the high sodium diet, plasma sodium was significantly increased in control mice and to a significantly greater level in CDNOS1KO mice. CDNOS1KO mice did not suppress plasma aldosterone in response to the high sodium diet, which may be partially explained by increased adrenal AT1R expression. Plasma renin concentration was appropriately suppressed in both genotypes. Furthermore, CDNOS1KO mice had significantly higher intrarenal angiotensin II with high sodium diet, although intrarenal angiotensinogen levels and angiotensin-converting enzyme activity were similar between knockout mice and controls. In agreement with inappropriate renin-angiotensin-aldosterone system activation in the CDNOS1KO mice on a high sodium diet, epithelial sodium channel activity and sodium transporter abundance were significantly higher compared with controls. These data demonstrate that high sodium activation of collecting duct nitric oxide synthase 1β signaling induces suppression of systemic and intrarenal renin-angiotensin-aldosterone system, thereby modulating epithelial sodium channel and other sodium transporter abundance and activity to maintain sodium homeostasis. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Dual renin-angiotensin system blockade plus oral methylprednisone for the treatment of proteinuria in IgA nephropathy.

PubMed

Trimarchi, Hernán; Muryan, Alexis; Young, Pablo; Forrester, Mariano; Iotti, Alejandro; Pereyra, Horacio; Lombi, Fernando; Seminario, Omar; Alonso, Mirta; Iotti, Roberto

2007-01-01

Renin-angiotensin system inhibition is a widely accepted approach to initially deal with proteinuria in IgA nephropathy, while the role of immunosuppressants remains controversial in many instances. A prospective, uncontrolled, open-label trial was undertaken in patients with biopsy-proven IgA nephropathy with proteinuria > 0.5 g/day and normal renal function to assess the efficacy of a combination treatment of angiotensin converting enzyme inhibitors plus angiotensin receptor blockers enalapril valsartan coupled with methylprednisone to decrease proteinuria to levels below 0.5 g/day. Twenty patients were included: Age 37.45 +/- 13.26 years (50% male); 7 patients (35%) were hypertensive; proteinuria 2.2 +/- 1.86 g/day; serum creatinine 1.07 +/- 0.29 mg/dl; mean follow-up 60.10 +/- 31.47 months. IgA nephropathy was subclassified according to Haas criteria. Twelve patients (60%) were class II; seven (35%) were class III and one (5%) class V. All patients received dual renin-angiotensin system blockade as tolerated. Oral methylprednisone was started at 0.5 mg/kg/day for the initial 8 weeks and subsequently tapered bi-weekly until the maintenance dose of 4 mg was reached. Oral steroids were discontinued after 24 weeks (6 months) of therapy but renin-angiotensin inhibition remained unchanged. At 10 weeks of therapy proteinuria decreased to 0.15 +/- 0.07 g/day (P < 0.001) while serum creatinine did not vary: 1.07 +/- 0.28 mg/dl (P = ns). After a mean follow-up of 42.36 +/- 21.56 months urinary protein excretion (0.12 +/- 0.06 g/day) and renal function (serum creatinine 1.06 +/- 0.27 mg/dl) remained stable. No major side effects were reported during the study. Renin-angiotensin blockade plus oral steroids proved useful to significantly decrease proteinuria to < 0.5 g/day in patients with IgA nephropathy without changes in renal function.

Biomarkers of activation of renin-angiotensin-aldosterone system in heart failure: how useful, how feasible?

PubMed

Emdin, Michele; Fatini, Cinzia; Mirizzi, Gianluca; Poletti, Roberta; Borrelli, Chiara; Prontera, Concetta; Latini, Roberto; Passino, Claudio; Clerico, Aldo; Vergaro, Giuseppe

2015-03-30

Renin-angiotensin-aldosterone system (RAAS), participated by kidney, liver, vascular endothelium, and adrenal cortex, and counter-regulated by cardiac endocrine function, is a complex endocrine system regulating systemic functions, such as body salt and water homeostasis and vasomotion, in order to allow the accomplishment of physiological tasks, such as orthostasis, physical and emotional stimuli, and to react towards the hemorrhagic insult, in tight conjunction with other neurohormonal axes, namely the sympathetic nervous system, the endothelin and vasopressin systems. The systemic as well as the tissue RAAS are also dedicated to promote tissue remodeling, particularly relevant after damage, when chronic activation may configure as a maladaptive response, leading to fibrosis, hypertrophy and apoptosis, and organ dysfunction. RAAS activation is a fingerprint of systemic arterial hypertension, kidney dysfunction, vascular atherosclerotic disease, and is definitely an hallmark of heart failure, which rapidly shifts from organ disease to a disorder of neurohormonal regulatory systems. Chronic RAAS activation is an indirect or direct target of most effective pharmacological treatments in heart failure, such as beta-blockers, inhibitors of angiotensin converting enzyme, angiotensin receptor blockers, direct renin inhibitors, and mineralocorticoid receptor blockers. Biomarkers of RAAS activation are available, with different feasibility and accuracy, such as plasma renin activity, renin, angiotensin II, and aldosterone, which all accompany the increasing clinical severity of heart failure disease, and are well recognized prognostic factors, even in patients with optimal therapy. Polymorphisms influencing the expression and activity of RAAS pathways have been recognized as clinically relevant biomarkers, likely influencing either the individual clinical phenotype, or the response to drugs. This solid, growing evidence strongly suggests the rationale for the use of biomarkers of the RAAS activation, as a guide to tailor individual therapy in the current practice, and their implementation as a rule-in marker for future trials on novel drugs in the heart failure setting. Copyright © 2014 Elsevier B.V. All rights reserved.

Structural analysis of the intracellular domain of (pro)renin receptor fused to maltose-binding protein

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

Zhang, Yanfeng; Gao, Xiaoli; Michael Garavito, R., E-mail: garavito@msu.edu

2011-04-22

Highlights: {yields} Crystal structure of the intracellular domain of (pro)renin receptor (PRR-IC) as MBP fusion protein at 2.0 A (maltose-free) and 2.15 A (maltose-bound). {yields} MBP fusion protein is a dimer in crystals in the presence and absence of maltose. {yields} PRR-IC domain is responsible for the dimerization of the fusion protein. {yields} Residues in the PRR-IC domain, particularly two tyrosines, dominate the intermolecular interactions, suggesting a role for the PRR-IC domain in PRR dimerization. -- Abstract: The (pro)renin receptor (PRR) is an important component of the renin-angiotensin system (RAS), which regulates blood pressure and cardiovascular function. The integral membranemore » protein PRR contains a large extracellular domain ({approx}310 amino acids), a single transmembrane domain ({approx}20 amino acids) and an intracellular domain ({approx}19 amino acids). Although short, the intracellular (IC) domain of the PRR has functionally important roles in a number of signal transduction pathways activated by (pro)renin binding. Meanwhile, together with the transmembrane domain and a small portion of the extracellular domain ({approx}30 amino acids), the IC domain is also involved in assembly of V{sub 0} portion of the vacuolar proton-translocating ATPase (V-ATPase). To better understand structural and multifunctional roles of the PRR-IC, we report the crystal structure of the PRR-IC domain as maltose-binding protein (MBP) fusion proteins at 2.0 A (maltose-free) and 2.15 A (maltose-bound). In the two separate crystal forms having significantly different unit-cell dimensions and molecular packing, MBP-PRR-IC fusion protein was found to be a dimer, which is different with the natural monomer of native MBP. The PRR-IC domain appears as a relatively flexible loop and is responsible for the dimerization of MBP fusion protein. Residues in the PRR-IC domain, particularly two tyrosines, dominate the intermonomer interactions, suggesting a role for the PRR-IC domain in protein oligomerization.« less

Acetazolamide and ADH, Renin, Aldosterone, and Water Electrolytes at 4100 M in Man,

DTIC Science & Technology

1986-05-01

Prevention of acute mountain sickness by dexamethasone . N. Engl. J. Med. 310:683-686, 1984 22 Terhaard , Zu11o, and M. Tentiev. 14ochani, 1 , w ,- *j...7 D- AlES 14 RCET ZOL AIDE RIND RON RENIN LDOSTERONE N D MTER 1 1 .ELECTROLYTES AT 4101 N.. (U) RNY R SEARCH INST OF SENVIRONMIENTALMEDICINE NATICK...S * UNCLASSIFIED I SECURITY CLASSIFICATION OF THIS PAGE (Iflew Date Entered) REOT OUENAIN AEREAD INSTRUCTIONS 1 .e %k REPOT DCUMNTATON AGEBEFORE

[Up-regulation of intrarenal renin-angiotensin system contributes to renal damage in high-salt induced hypertension rats].

PubMed

Wu, Hai-yan; Liang, Yao-xian; Bai, Qiong; Zhuang, Zhen; A, La-ta; Zheng, Dan-xia; Wang, Yue

2015-02-18

To test the hypothesis that in a high-salt induced hypertension in normal rats, whether the changes of intrarenal renin-agiotensin system (RAS) play a critical role in renal damage and could be reflected by urinary angiotensinogen (AGT). In the study, 27 normotensive male Wistar-Kyoto rats were divided into control group [0.3% (mass faction) NaCl in chow, n=9, NS], high-salt diet group [8% (mass faction) NaCl in chow, n=9, HS] and high-salt diet with Losartan group [8% (mass faction) NaCl in chow and 20 mg/(kg×d) Losartan in gavages, n=9, HS+L)], and were fed for six weeks. The blood pressure was monitored and urine samples were collected every 2 weeks. AGTs in plasma, kidney and urine were measured by ELISA kits. The renal cortex expression of mRNA and protein of AGT were measured by Real-time PCR and immunohistochemistry (IHC). The renin activity and ANG II were measured by radioimmunoassay (RIA) kits. Compared with NS, the systolic blood pressure (SBP) [(156 ± 2) mmHg vs. (133 ± 3) mmHg, P<0.05] increased significantly at the end of the 2nd week, and the urinary protein [(14.07 ± 2.84) mg/24 h vs. (7.62 ± 3.02) mg/24 h, P<0.05] increased significantly at the end of the 6th week in HS. Compared with HS, there was no significant difference in SBP (P>0.05) but the proteinuria [(9.69 ± 2.73) mg/24 h vs. (14.07 ± 2.84) mg/24 h, P<0.01] decreased significantly in HS+L. Compared with NS, there was no significant difference in the plasma renin activity, angiotensinogen and ANG II level in HS (P>0.05), but the renal cortex renin content [(8.72 ± 1.98) ng/(mL × h) vs. (4.37 ± 1.26) ng/(mL × h), P<0.05], AGT formation [(4.02 ± 0.60) ng/mg vs. (2.59 ± 0.42) ng/mg, P<0.01], ANG II level [(313.8 ± 48.76) pmol/L vs. (188.9 ± 46.95) pmol/L, P<0.05] were increased significantly in HS, and the urinary AGT and ANG II excretion rates increased significantly (P<0.05). Compared with HS, the plasma renin activity, angiotensinogen and ANG II level were significantly increased (P<0.05), but the renal cortex renin content, AGT formation, ANG II level significantly decreased (P<0.05), and the urinary AGT and ANG II excretion rates decreased significantly in HS+L (P<0.05). The urinary AGT excretion rates were positively correlated with the AGT level in the renal cortex (P<0.05). Up-regulation of intarenal RAS may contribute to renal damage in high-salt induced hypertension rats. Urinary AGT may reflect the status of intrarenal RAS.

The critical role of the central nervous system (pro)renin receptor in regulating systemic blood pressure

PubMed Central

Xu, Quanbin; Jensen, Dane D.; Peng, Hua; Feng, Yumei

2016-01-01

The systemic renin–angiotensin system (RAS) has long been recognized as a critically important system in blood pressure (BP) regulation. However, extensive evidence has shown that a majority of RAS components are also present in many tissues and play indispensable roles in BP regulation. Here, we review evidence that RAS components, notably including the newly identified (pro)renin receptor (PRR), are present in the brain and are essential for the central regulation of BP. Binding of the PRR to its ligand, prorenin or renin, increases BP and promotes progression of cardiovascular diseases in an angiotensin II-dependent and -independent manner, establishing the PRR a promising antihypertensive drug target. We also review the existing PRR blockers, including handle region peptide and PRO20, and propose a rationale for blocking prorenin/PRR activation as a therapeutic approach that does not affect the actions of the PRR in vacuolar H+-ATPase and development. Finally, we summarize categories of currently available antihypertensive drugs and consider future perspectives. PMID:27113409

In Situ Hybridization Method Reveals (Pro)renin Receptor Expressing Cells in the Pituitary Gland of Rats: Correlation with Anterior Pituitary Hormones.

PubMed

Takahashi, Kazuhiro; Yatabe, Megumi; Fujiwara, Ken; Hirose, Takuo; Totsune, Kazuhito; Yashiro, Takashi

2013-02-28

Expression of (pro)renin receptor ((P)RR), a specific receptor for renin and prorenin, was studied in rat pituitary gland. In situ hybridization showed that cells expressing (P)RR mRNA were widely distributed in the anterior lobe and intermediate lobe of the pituitary gland. Double-staining using in situ hybridization for (P)RR mRNA and immunohistochemistry for the pituitary hormones showed that (P)RR mRNA was expressed in most of the GH cells and ACTH cells in the anterior lobe. (P)RR mRNA was also expressed in a few prolactin cells and TSH cells, but not in LH cells. The present study has shown for the first time the distribution of (P)RR mRNA expressing cells in the rat pituitary gland. These findings suggest that (P)RR plays physiological roles in the pituitary gland, such as the modulation of the pituitary hormone secretion.

Need for beta-blockade in hypertension reduced with long-term minoxidil.

PubMed Central

Brunner, H R; Jaeger, P; Ferguson, R K; Jequier, E; Turini, G; Gavras, H

1978-01-01

Sequential changes in plasma renin activity and urinary aldosterone and noradrenaline were assessed in eight patients with severe hypertension after minoxidil had been added to their treatment. Doses of 2.5--27.5 (mean 12.5) mg/day reduced the mean blood pressure from 166/113 +/-6/2 mm Hg to 124/88+/-4/2 mm Hg in one week. Plasma renin activity and urinary aldosterone and noradrenaline increased twofold to threefold initially but returned to baseline values within two to three weeks and remained unchanged during a mean follow-up of 5.1 months. Beta-blocking drugs were then withdrawn slowly in six patients without adverse effects, though blood pressure and heart rate increased in three patients, who required minimal doses of beta-blockers. Plasma renin activity and urinary aldosterone and noradrenaline did not change significantly after beta-blockade had been stopped. We conclude that the need for beta-blockade is greatly reduced with long-term minoxidil treatment and that it may be unnecessary in some patients. PMID:28811

Changes of blood levels of several hormones, catecholamines, prostaglandins, electrolytes and cAMP in man during emotional stress.

PubMed

Tigranian, R A; Orloff, L L; Kalita, N F; Davydova, N A; Pavlova, E A

1980-01-01

The levels of several hormones (ACTH, GH, TSH, FSH, LH, parathyroid hormone--PTH, insulin, thyroxine--T4, triiodothyronine--T3, cortisol, testosterone, aldosterone, renin), catecholamines (epinephrine, norepinephrine, dopamin), prostaglandins (F1 alpha, F2 alpha, A + E), electrolytes (Na, K, Ca, Mg), cAMP and glucose in blood were measured before and immediately after the examination in 15 male students aged 28 to 35 years. Simultaneously the blood pressure was measured and hemodynamic measures were registered with the aid of echocardiography. A remarkable increase of catecholamines, ACTH, renin, T3, PTH, cAMP, PG F1 alpha, PG F2 alpha and Ca was found before the examination together with the increase of blood pressure. After the examination the levels of catecholamines, renin, aldosterone, T3, PTH, GH, FSH, LH, testosterone, PG A + E, glucose and Ca were found to be increased, while these of insulin, Na, PG F1 alpha, PG F2 alpha were decreased. The decrease of blood pressure was also found.

Vaccination: a novel strategy for inhibiting the renin-angiotensin-aldosterone system.

PubMed

Gradman, Alan H; Pinto, Rehka

2008-12-01

Immunologic approaches to renin-angiotensin-aldosterone system (RAAS) inhibition have been studied for more than 50 years. In animal models, vaccination against renin was effective but resulted in fatal autoimmune renal disease; vaccines directed at small peptides including angiotensin I and II and a segment of the AT(1) receptor reduced blood pressure (BP) without causing autoimmune disease. In humans, angiotensin I vaccination did not reduce BP. More promising is the AngQb vaccine, which uses an immunization technology involving conjugation of angiotensin II to virus-like particles. In a phase 2 trial, hypertensive patients vaccinated with 300 microg showed a difference of 9.0/4.0 mm Hg from baseline in mean daytime ambulatory BP after 14 weeks (P = 0.015 for systolic BP, P = 0.064 for diastolic BP), and a marked reduction in early morning BP. No serious adverse events were attributed to vaccine administration. Although questions remain regarding efficacy and safety, RAAS immunization represents an innovative and promising approach to hypertension treatment.

Plasma renin activity, aldosterone and catecholamine levels when swimming and running.

PubMed

Guezennec, C Y; Defer, G; Cazorla, G; Sabathier, C; Lhoste, F

1986-01-01

The purpose of this study was to determine the response of plasma renin activity (PRA), plasma aldosterone concentration (PAC) and catecholamines to two graded exercises differing by posture. Seven male subjects (19-25 years) performed successively a running rest on a treadmill and a swimming test in a 50-m swimming pool. Each exercise was increased in severity in 5-min steps with intervals of 1 min. Oxygen consumption, heart rate and blood lactate, measured every 5 min, showed a similar progression in energy expenditure until exhaustion, but there was a shorter time to exhaustion in the last step of the running test. PRA, PAC and catecholamines were increased after both types of exercise. The PRA increase was higher after the running test (20.9 ng AngI X ml-1 X h-1) than after swimming (8.66 ng AngI X ml-1 X h-1). The PAC increase was slightly greater after running (123 pg X ml-1) than swimming (102 pg X ml-1), buth the difference was not significant. Plasma catecholamine was higher after the swimming test. These results suggest that the volume shift induced by the supine position and water pressure during swimming decreased the PRA response. The association after swimming compared to running of a decreased PRA and an enhanced catecholamine response rule out a strict dependence of renin release under the effect of plasma catecholamines and is evidence of the major role of neural pathways for renin secretion during physical exercise.

Drug discovery in renin-angiotensin system intervention: past and future.

PubMed

Williams, Bryan

2016-06-01

The renin-angiotensin system (RAS) plays a central role in the control of blood pressure in the body and the way this interacts with other systems is widely recognized. This has not always been the case and this review summarizes how our knowledge has evolved from the initial discovery of renin by Tigerstedt and Berman in 1898. This includes the identification of angiotensin in the 1950s to the proposed relationship between this system, hypertension and ultimately cardiovascular disease. While the RAS is far more complex than originally thought, much is now known about this system and the wide ranging effects of angiotensin in the body. This has enabled the development of therapies that target the various proteins in this pathway and hence are implicated in disease. The first of these treatments was the angiotensin converting enzyme inhibitors (ACE-Is), followed by the angiotensin receptor blockers (ARBs), and more recently the direct renin inhibitors (DRIs). Clinical outcome trials have shown these drugs to be effective, but as they act at contrasting points in the RAS, there are differences in their efficacy and safety profiles. RAS blockade is the foundation of modern combination therapy with a calcium channel blocker and/or a diuretic given to reduce blood pressure and limit the impact of RAS activation. Other options that complement these treatments may be available in the future and will offer more choice to clinicians. © The Author(s), 2016.

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

Reddy, M.K.; Baskaran, K.; Molteni, A.

The angiotensin-converting enzyme (ACE) inhibitor captopril inhibits mitosis in several cell types that contain ACE and renin activity. In the present study, we evaluated the effect of the ACE inhibitors captopril and CGS 13945 (10{sup {minus}8} to 10{sup {minus}2}M) on proliferation and gene expression in hamster pancreatic duct carcinoma cells in culture. These cells lack renin and ACE activity. Both ACE inhibitors produced a dose-dependent reduction in tumor cell proliferation within 24 hr. Captopril at a concentration of 0.36 mM and CGS 13945 at 150 {mu}M decreased cellular growth rate to approximately half that of the control. Neither drug influencedmore » the viability or the cell cycle distribution of the tumor cells. Slot blot analysis of mRNA for four genes, proliferation associated cell nuclear antigen (PCNA), K-ras, protein kinase C-{Beta} (PKC-{Beta}) and carbonic anhydrase II (CA II) was performed. Both ACE inhibitors increased K-ras expression by a factor of 2, and had no effect on CA II mRNA levels. Captopril also lowered PCNA by 40% and CGS 13945 lowered PKC-{Beta} gene expression to 30% of the control level. The data demonstrate that ACE inhibitors exhibit antimitotic activity and differential gene modulation in hamster pancreatic duct carcinoma cells. The absence of renin and ACE activity in these cells suggests that the antimitotic action of captopril and CGS 13945 is independent of renin-angiotensin regulation. The growth inhibition may occur through downregulation of growth-related gene expression. 27 refs., 5 figs.« less

New Frontiers in the Intrarenal Renin-Angiotensin System: A Critical Review of Classical and New Paradigms

PubMed Central

Zhuo, Jia L.; Ferrao, Fernanda M.; Zheng, Yun; Li, Xiao C.

2013-01-01

The renin-angiotensin system (RAS) is well-recognized as one of the oldest and most important regulators of arterial blood pressure, cardiovascular, and renal function. New frontiers have recently emerged in the RAS research well beyond its classic paradigm as a potent vasoconstrictor, an aldosterone release stimulator, or a sodium-retaining hormone. First, two new members of the RAS have been uncovered, which include the renin/(Pro)renin receptor (PRR) and angiotensin-converting enzyme 2 (ACE2). Recent studies suggest that prorenin may act on the PRR independent of the classical ACE/ANG II/AT1 receptor axis, whereas ACE2 may degrade ANG II to generate ANG (1–7), which activates the Mas receptor. Second, there is increasing evidence that ANG II may function as an intracellular peptide to activate intracellular and/or nuclear receptors. Third, currently there is a debate on the relative contribution of systemic versus intrarenal RAS to the physiological regulation of blood pressure and the development of hypertension. The objectives of this article are to review and discuss the new insights and perspectives derived from recent studies using novel transgenic mice that either overexpress or are deficient of one key enzyme, ANG peptide, or receptor of the RAS. This information may help us better understand how ANG II acts, both independently or through interactions with other members of the system, to regulate the kidney function and blood pressure in health and disease. PMID:24273531

Renin inhibition improves metabolic syndrome, and reduces angiotensin II levels and oxidative stress in visceral fat tissues in fructose-fed rats

PubMed Central

Chen, Jin-Shuen

2017-01-01

Renin–angiotensin system in visceral fat plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. However, the effects of renin inhibition on visceral adiposity in metabolic syndrome are not fully investigated. We investigated the effects of renin inhibition on visceral adiposity in fructose-fed rats. Male Wistar–Kyoto rats were divided into 4 groups for 8-week experiments: Group Con (standard chow diet), Group Fru (high-fructose diet; 60% fructose), Group FruA (high-fructose diet and concurrent aliskiren treatment; 100 mg/kg body weight [BW] per day), and Group FruB (high-fructose diet and subsequent, i.e. 4 weeks after initiating high-fructose feeding, aliskiren treatment; 100 mg/kg BW per day). The high-fructose diet induced metabolic syndrome, increased visceral fat weights and adipocyte sizes, and augmented angiotensin II (Ang II), NADPH oxidase (NOX) isoforms expressions, oxidative stress, and dysregulated production of adipocytokines from visceral adipose tissues. Concurrent and subsequent aliskiren administration ameliorated metabolic syndrome, dysregulated adipocytokines, and visceral adiposity in high fructose-fed hypertensive rats, and was associated with reducing Ang II levels, NOX isoforms expressions and oxidative stress in visceral fat tissues. Therefore, this study demonstrates renin inhibition could improve metabolic syndrome, and reduce Ang II levels and oxidative stress in visceral fat tissue in fructose-fed rats, and suggests that visceral adipose Ang II plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. PMID:28700686

The protective arm of the renin-angiotensin system may counteract the intense inflammatory process in fetuses with posterior urethral valves.

PubMed

Rocha, Natalia P; Bastos, Fernando M; Vieira, Érica L M; Prestes, Thiago R R; Silveira, Katia D da; Teixeira, Mauro M; Simões E Silva, Ana Cristina

2018-03-11

Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end-stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve. Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme-linked immunosorbent assay. Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang-(1-7) and angiotensin-converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls. Increased urinary levels of angiotensin-converting enzyme 2 and of Ang-(1-7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Inhibiting renin angiotensin system in rate limiting step by aliskiren as a new approach for preventing indomethacin induced gastric ulcers.

PubMed

Halici, Zekai; Polat, Beyzagul; Cadirci, Elif; Topcu, Atilla; Karakus, Emre; Kose, Duygu; Albayrak, Abdulmecit; Bayir, Yasin

2016-10-25

Previously blocking the renin angiotensin system (RAAS) has been effective in the prevention of gastric damage. Therefore, the aim of this study was to investigate the effects of aliskiren, and thus, direct renin blockage, in indomethacin-induced gastric damage model. Effects of aliskiren were evaluated in indomethacin-induced gastric damage model on Albino Wistar rats. Effects of famotidine has been investigated as standard antiulcer agent. Stereological analyses for ulcer area determination, biochemical analyses for oxidative status determination and molecular analyses for tissue cytokine and cyclooxygenase determination were performed on stomach tissues. In addition, to clarify antiulcer effect mechanism of aliskiren pylorus ligation-induced gastric acid secretion model was applied on rats. Aliskiren was able to inhibit indomethacin-induced ulcer formation. It also inhibited renin, and thus, decreased over-produced Angiotensin-II during ulcer formation. Aliskiren improved the oxidative status and cytokine profile of the stomach, which was most probably impaired by increased Angiotensin II concentration. Aliskiren also increased gastroprotective prostaglandin E2 concentration. Finally, aliskiren did not change the gastric acidity in pylorus ligation model. Aliskiren exerted its protective effects on stomach tissue by decreasing inflammatory cytokines and oxidative stress as a result of inhibiting the RAAS, at a rate-limiting step, as well as its end product, angiotensin II. Aliskiren also significantly increased protective factors such as PGE2, but not affect aggressive factors such as gastric acidity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of Aminoglutethimide on Blood Pressure and Steroid Secretion in Patients with Low Renin Essential Hypertension

PubMed Central

Taylor, Addison A.; Mitchell, Jerry R.; Bartter, Frederic C.; Snodgrass, Wayne R.; McMurtry, Randolph J.; Gill, John R.; Franklin, Ronald B.

1978-01-01

An inhibitor of adrenal steroid biosynthesis, aminoglutethimide, was administered to seven patients with low renin essential hypertension, and the antihypertensive action of the drug was compared with its effects on adrenal steroid production. In all patients aldosterone concentrations in plasma and urine were within normal limits before the study. Mean arterial pressure was reduced from a pretreatment value of 117±2 (mean±SE) mm Hg to 108±3 mm Hg after 4 days of aminoglutethimide therapy and further to 99±3 mm Hg when drug administration was stopped (usually 21 days). Body weight was also reduced from 81.6±7.2 kg in the control period to 80.6±7.0 kg after 4 days of drug treatment and to 80.1±6.7 kg at the termination of therapy. Plasma renin activity was not significantly increased after 4 days of treatment but had risen to the normal range by the termination of aminoglutethimide therapy. Mean plasma concentrations of deoxycorticosterone and cortisol were unchanged during aminoglutethimide treatment whereas those of 18-hydroxydeoxycorticosterone, progesterone, 17α-hydroxyprogesterone, and 11-deoxycortisol were increased as compared to pretreatment values. In contrast, aminoglutethimide treatment reduced mean plasma aldosterone concentrations to about 30% of control values. Excretion rates of 16β-hydroxydehydroepiandrosterone, 16-oxo-androstenediol, 17-hydroxycorticosteroids and 17-ketosteroids, and the secretion rate of 16β-hydroxydehydroepiandrosterone were not significantly altered by aminoglutethimide treatment whereas the excretion rate of aldosterone was reduced from 3.62±0.5 (mean±SE) in the control period to 0.9±0.2 μg/24 h after 4 days and to 1.1±0.3 μg/24 h at the termination of aminoglutethimide treatment. The gradual lowering of blood pressure and body weight during aminoglutethimide therapy is consistent with the view that the antihypertensive effect of the drug is mediated through a reduction in the patients' extracellular fluid volume, probably secondary to the persistent decrease in aldosterone production. The observation that chronic administration of aminoglutethimide lowered blood pressure in these patients and elevated their plasma renin activity to the normal range without decreasing production of the adrenal steroids, deoxycorticosterone, 18-hydroxydeoxycorticosterone, and 16β-hydroxydehydroepiandrosterone, makes it unlikely that these steroids are responsible either for the decreased renin or the elevated blood pressure in patients with low renin essential hypertension. PMID:149141

Autonomic, locomotor and cardiac abnormalities in a mouse model of muscular dystrophy: targeting the renin-angiotensin system.

PubMed

Sabharwal, Rasna; Chapleau, Mark W

2014-04-01

New Findings What is the topic of this review? This symposium report summarizes autonomic, cardiac and skeletal muscle abnormalities in sarcoglycan-δ-deficient mice (Sgcd-/-), a mouse model of limb girdle muscular dystrophy, with emphasis on the roles of autonomic dysregulation and activation of the renin-angiotensin system at a young age. What advances does it highlight? The contributions of the autonomic nervous system and the renin-angiotensin system to the pathogenesis of muscular dystrophy are highlighted. Results demonstrate that autonomic dysregulation precedes and predicts later development of cardiac dysfunction in Sgcd-/- mice and that treatment of young Sgcd-/- mice with the angiotensin type 1 receptor antagonist losartan or with angiotensin-(1-7) abrogates the autonomic dysregulation, attenuates skeletal muscle pathology and increases spontaneous locomotor activity. Muscular dystrophies are a heterogeneous group of genetic muscle diseases characterized by muscle weakness and atrophy. Mutations in sarcoglycans and other subunits of the dystrophin-glycoprotein complex cause muscular dystrophy and dilated cardiomyopathy in animals and humans. Aberrant autonomic signalling is recognized in a variety of neuromuscular disorders. We hypothesized that activation of the renin-angiotensin system contributes to skeletal muscle and autonomic dysfunction in mice deficient in the sarcoglycan-δ (Sgcd) gene at a young age and that this early autonomic dysfunction contributes to the later development of left ventricular (LV) dysfunction and increased mortality. We demonstrated that young Sgcd-/- mice exhibit histopathological features of skeletal muscle dystrophy, decreased locomotor activity and severe autonomic dysregulation, but normal LV function. Autonomic regulation continued to deteriorate in Sgcd-/- mice with age and was accompanied by LV dysfunction and dilated cardiomyopathy at older ages. Autonomic dysregulation at a young age predicted later development of LV dysfunction and higher mortality in Sgcd-/- mice. Treatment of Sgcd-/- mice with the angiotensin type 1 receptor blocker losartan for 8-9 weeks, beginning at 3 weeks of age, decreased fibrosis and oxidative stress in skeletal muscle, increased locomotor activity and prevented autonomic dysfunction. Chronic infusion of the counter-regulatory peptide angiotensin-(1-7) resulted in similar protection. We conclude that activation of the renin-angiotensin system, at a young age, contributes to skeletal muscle and autonomic dysfunction in muscular dystrophy. We speculate that the latter is mediated via abnormal sensory nerve and/or cytokine signalling from dystrophic skeletal muscle to the brain and contributes to age-related LV dysfunction, dilated cardiomyopathy, arrhythmias and premature death. Therefore, correcting the early autonomic dysregulation and renin-angiotensin system activation may provide a novel therapeutic approach in muscular dystrophy.

Resistant Hypertension On Treatment (ResHypOT): sequential nephron blockade compared to dual blockade of the renin-angiotensin-aldosterone system plus bisoprolol in the treatment of resistant arterial hypertension - study protocol for a randomized controlled trial.

PubMed

Cestário, Elizabeth do Espirito Santo; Fernandes, Letícia Aparecida Barufi; Giollo-Júnior, Luiz Tadeu; Uyemura, Jéssica Rodrigues Roma; Matarucco, Camila Suemi Sato; Landim, Manoel Idelfonso Paz; Cosenso-Martin, Luciana Neves; Tácito, Lúcia Helena Bonalume; Moreno, Heitor; Vilela-Martin, José Fernando; Yugar-Toledo, Juan Carlos

2018-02-12

Resistant hypertension is characterized when the blood pressure (BP) remains above the recommended goal after taking three antihypertensive drugs with synergistic actions at their maximum recommended tolerated doses, preferably including a diuretic. Identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether acting on the control of intravascular volume or sodium balance, or acting on the effects of the renin-angiotensin-aldosterone system (RAAS) on the kidney. This is a randomized, open-label, clinical trial is designed to compare sequential nephron blockade and its contribution to the intravascular volume component with dual blockade of the RAAS plus bisoprolol and the importance of serum renin in maintaining BP levels. The trial has two arms: sequential nephron blockade versus dual blockade of the RAAS (with an angiotensin converting enzyme (ACE) inhibitor plus a beta-blocker) both added-on to a thiazide diuretic, a calcium-channel blocker and an angiotensin receptor-1 blocker (ARB). Sequential nephron blockade consists in a progressive increase in sodium depletion using a thiazide diuretic, an aldosterone-receptor blocker, furosemide and, finally, amiloride. On the other hand, the dual blockade of the RAAS consists of the progressive addition of an ACE inhibitor until the maximum dose and then the administration of a beta-blocker until the maximum dose. The primary outcomes will be reductions in the systolic BP, diastolic BP, mean BP and pulse pressure (PP) after 20 weeks of treatment. The secondary outcomes will evaluate treatment safety and tolerability, biochemical changes, evaluation of renal function and recognition of hypotension (ambulatory BP monitoring (ABPM)). The sample size was calculated assuming an alpha error of 5% to reject the null hypothesis with a statistical power of 80% giving a total of 40 individuals per group. In recent years, the cost of resistant hypertension (RH) treatment has increased. Thus, identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether by acting on the control of intravascular volume or sodium balance, or by acting on the effects of the RAAS on the kidney. Sequential Nephron Blockade vs. Dual Blockade Renin-angiotensin System + Bisoprolol in Resistant Arterial Hypertension (ResHypOT). ClinicalTrials.gov, ID: NCT02832973 . Registered on 14 July 2016. First received: 12 June 2016. Last updated: 18 July 2016.

Effects of head-down tilt on fluid and electrolyte balance

NASA Technical Reports Server (NTRS)

Volicer, L.; Jean-Charles, R.; Chobanian, A. V.

1976-01-01

The metabolic effects of -5 deg tilt were studied in eight normal individuals. Exposure to tilt for 24 hr increased sodium excretion and decreased plasma volume. Plasma renin activity and plasma aldosterone levels were not significantly different from supine values during the first 6 hr of tilting, but were increased significantly at the end of the 24-hr tilt period. Creatinine clearance and potassium balance were not affected by the tilt. These findings indicate that head-down tilt induces a sodium diuresis and stimulation of the renin-angiotensin-aldosterone system.

Reducing Disease Activity in Animal Models of MS by Activation of the Protective Arm of the Renin-Angiotensin System

DTIC Science & Technology

2015-10-01

patients, there is little evidence for a role of ACE2/A( 1 -7)/Mas axis, only a solitary assessment showing decreased ACE2 levels in the CSF of MS...project? Major Goals (Year 1 ): 1 : Measure levels of RAS components in the spinal cord of mice with EAE (animal model of MS) prior to, and at multiple...AWARD NUMBER: W81XWH-14- 1 -0523 TITLE: Reducing Disease Activity in Animal Models of MS by Activation of the Protective Arm of the Renin

Aldosteronism and hypertension.

PubMed

Calhoun, David A

2006-09-01

A growing body of evidence suggests that hyperaldosteronism contributes significantly to the development and the severity of hypertension as well as to resistance to antihypertensive treatment. In cross-sectional analyses, plasma aldosterone levels have been shown to relate to BP levels, particularly in obese individuals. In these same individuals, BP was not related to plasma renin activity, suggesting an effect of aldosterone on BP independent of renin-angiotensin II. In a recent prospective analysis from the Framingham investigators, baseline serum aldosterone was strongly associated with development of hypertension during a 4-yr follow-up.

Increased Dietary Salt Changes Baroreceptor Sensitivity and Intrarenal Renin-Angiotensin System in Goldblatt Hypertension.

PubMed

Shimoura, Caroline G; Lincevicius, Gisele S; Nishi, Erika E; Girardi, Adriana C C; Simon, Karin A; Bergamaschi, Cassia T; Campos, Ruy R

2017-01-01

Renovascular hypertension (2-kidney 1-clip model (2K1C)) is characterized by renin-angiotensin system (RAS) activation. Increased Angiotensin II (AngII) leads to sympathoexcitation, oxidative stress, and alterations in sodium and water balance. The aim of this study was to evaluate whether a discrete increase in sodium chloride intake in 2K1C rats leads to changes in cardiovascular and autonomic function, oxidative stress, and renin angiotensin aldosterone system. After 4 weeks of induction of hypertension, rats were fed a normal sodium diet (0.4% NaCl) or a high-sodium diet (2% NaCl) for 2 consecutive weeks. Experiments were carried out for 6 weeks after clipping. Mean arterial pressure (MAP), renal sympathetic nerve activity (rSNA), arterial baroreflex control of rSNA, and heart rate (HR) were assessed. Thiobarbituric acid reactive substances and glutathione were measured as indicators of systemic oxidative stress. Angiostensin-converting enzyme (ACE), ACE2, and angiotensinogen were evaluated in clipped and unclipped kidneys as also urinary angiotensinogen and plasma renin activity. Angiotensinogen, plasma renin activity (PRA) and angiotensin-converting enzyme (ACE) and ACE2 in clipped and unclipped kidneys were evaluated. High-sodium diet did not change systemic oxidative stress, and basal values of MAP, HR, or rSNA; however, increased renal (-0.7±0.2 vs. -1.5±0.1 spikes/s/mm Hg) and cardiac (-0.9±0.14 vs. -1.5±0.14 bpm/mm Hg) baroreceptor reflex sensitivity in 2K1C rats. Although there was no alteration in PRA, a high-salt diet significantly decreased urinary angiotensinogen, ACE, and ACE2 expressions in the clipped and unclipped kidneys. Increased arterial baroreceptor control associated with a suppression of the intrarenal RAS in the 2K1C rats on high-salt diet provide a salt-resistant effect on hypertension and sympathoexcitation in renovascular hypertensive rats. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Human vascular renin-angiotensin system and its functional changes in relation to different sodium intakes.

PubMed

Boddi, M; Poggesi, L; Coppo, M; Zarone, N; Sacchi, S; Tania, C; Neri Serneri, G G

1998-03-01

A growing body of evidence supports the existence of a tissue-based renin-angiotensin system (RAS) in the vasculature, but the functional capacity of vascular RAS was not investigated in humans. In 28 normotensive healthy control subjects, the metabolism of angiotensins through vascular tissue was investigated in normal, low, and high sodium diets by the measurement of arterial-venous gradient of endogenous angiotensin (Ang) I and Ang II in two different vascular beds (forearm and leg), combined with the study of 125I-Ang I and 125I-Ang II kinetics. In normal sodium diet subjects, forearm vascular tissue extracted 36+/-6% of 125I-Ang I and 30+/-5% of 125I-Ang II and added 14.9+/-5.1 fmol x 100 mL(-1) x min(-1) of de novo formed Ang I and 6.2+/-2.8 fmol x 100 mL(-1) x min(-1) of Ang II to antecubital venous blood. Fractional conversion of 125I-Ang I through forearm vascular tissue was about 12%. Low sodium diet increased (P<.01) plasma renin activity, whereas de novo Ang I and Ang II formation by forearm vascular tissue became undetectable. Angiotensin degradation (33+/-7% for Ang I and 30+/-7% for Ang II) was unchanged, and vascular fractional conversion of 125I-Ang I decreased from 12% to 6% (P<.01). In high sodium diet subjects, plasma renin activity decreased, and de novo Ang I and Ang II formation by forearm vascular tissue increased to 22 and 14 fmol x 100 mL(-1) x min(-1), respectively (P<.01). Angiotensin degradation did not significantly change, whereas fractional conversion of 125I-Ang I increased from 12% to 20% (P<.01). Leg vascular tissue functional activities of RAS paralleled those of forearm vascular tissue both at baseline and during different sodium intake. These results provide consistent evidence for the existence of a functional tissue-based RAS in vascular tissue of humans. The opposite changes of plasma renin activity and vascular angiotensin formation indicate that vascular RAS is independent from but related to circulating RAS.

Epistatic Effects of Polymorphisms in Genes from the Renin-Angiotensin, Bradykinin, and Fibrinolytic Systems on Plasma t-PA and PAI-1 Levels

PubMed Central

Asselbergs, Folkert W.; Williams, Scott M.; Hebert, Patricia R.; Coffey, Christopher S.; Hillege, Hans L.; Navis, Gerjan; Vaughan, Douglas E.; van Gilst, Wiek H.; Moore, Jason H.

2007-01-01

Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) directly influence thrombus formation and degradation and thereby risk for arterial thrombosis. Activation of the renin-angiotensin system has been linked to the production of PAI-1 expression via the angiotensin II type 1 receptor (AT1R). In addition, bradykinin can induce the release of t-PA through a B2 receptor mechanism. In the present study, we aimed to investigate the epistatic effects of polymorphisms in genes from the renin-angiotensin, bradykinin and fibrinolytic systems on plasma t-PA and PAI-1 levels in a large population-based sample (n=2,527). We demonstrated a strong significant interaction within genetic variations of the bradykinin B2 gene (p=0.002) and between ACE and bradykinin B2 (p=0.003) polymorphisms on t-PA levels in females. In males, polymorphisms in the bradykinin B2 and AT1R gene showed the most strong effect on t-PA levels (p=0.006). In both females as well as males, the bradykinin B2 gene interacted with AT1R gene on plasma PAI-1 levels (p=0.026 and p=0.039, respectively). In addition, the current study found a borderline significant interaction between PAI 4G5G and ACE I/D on plasma t-PA and PAI-1 levels. These results support the idea that the interplay between the renin-angiotensin, bradykinin, and fibrinolytic systems might play an important role in t-PA and PAI-1 biology. PMID:17207964

Low LBNP Tolerance in Men is Associated With Attenuated Activation of The Renin-Angiotensin System

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Petersen, T. W.; Gabrielsen, A.; Pump, B.; Bie, P.; Christensen, N.-J.; Warberg, J.; Videbaeck, R.; Simonson, S. R.; Norsk, P.

1999-01-01

Vasoactive hormone concentrations [epinephrine (pE), norepinephrine (pNE), angiotensin II (pATII), vasopressin (pVP), endothelin 1 (pET1)] and plasma renin activity (pRA) were measured during lower body negative pressure (LBNP) to test the hypothesis that responsiveness of the renin-angiotensin system is related to LBNP tolerance. Healthy men (2,822 cal/day(exp -1), 2 mmol*kg(exp -1)*day(exp -1)) Na(+)) were exposed to 30 minutes of progressive LBNP to -50 mmHg. LBNP was uneventful for seven men (25 +/- 2 years, HiTol group), but eight men (26 +/- 3 years) reached pre-syncope after 11 +/- 1 minutes (P < 0.001, LoTol group). Mean arterial pressure was unchanged. Central venous pressure and left atrial diameter decreased in both groups (5-6 mmHg by approx. 30%, P < 0.05). Control [hormone] were similar but, pRA differed between groups (LoTol 0.6 +/- 0.1, HiTol 1.2 +/- 0.1 ng Ang1/(ml(exp -1)*h(exp -1)), P < 0.05). LBNP increased (P < 0.05) pRA and pATII more in HiTol (9.9 +/- 2.2 ng Ang1/(ml(exp -1)*h(exp -1)) and 58 +/- 12 pg/ml(exp -1)) than LoTol (4.3 +/- 0.9 ng Ang1/(ml*h) and 28 +/- 6 pg/ml(exp -1)). In contrast, pVP was higher (P < 0.05) in LoTol than in HiTol. The response of the renin-angiotensin system seems linked to the occurrence of pre-syncope, and measurement of resting pRA may be predictive.

Reliability of a Bayesian network to predict an elevated aldosterone-to-renin ratio.

PubMed

Ducher, Michel; Mounier-Véhier, Claire; Lantelme, Pierre; Vaisse, Bernard; Baguet, Jean-Philippe; Fauvel, Jean-Pierre

2015-05-01

Resistant hypertension is common, mainly idiopathic, but sometimes related to primary aldosteronism. Thus, most hypertension specialists recommend screening for primary aldosteronism. To optimize the selection of patients whose aldosterone-to-renin ratio (ARR) is elevated from simple clinical and biological characteristics. Data from consecutive patients referred between 1 June 2008 and 30 May 2009 were collected retrospectively from five French 'European excellence hypertension centres' institutional registers. Patients were included if they had at least one of: onset of hypertension before age 40 years, resistant hypertension, history of hypokalaemia, efficient treatment by spironolactone, and potassium supplementation. An ARR>32 ng/L and aldosterone>160 ng/L in patients treated without agents altering the renin-angiotensin system was considered as elevated. Bayesian network and stepwise logistic regression were used to predict an elevated ARR. Of 334 patients, 89 were excluded (31 for incomplete data, 32 for taking agents that alter the renin-angiotensin system and 26 for other reasons). Among 245 included patients, 110 had an elevated ARR. Sensitivity reached 100% or 63.3% using Bayesian network or logistic regression, respectively, and specificity reached 89.6% or 67.2%, respectively. The area under the receiver-operating-characteristic curve obtained with the Bayesian network was significantly higher than that obtained by stepwise regression (0.93±0.02 vs. 0.70±0.03; P<0.001). In hypertension centres, Bayesian network efficiently detected patients with an elevated ARR. An external validation study is required before use in primary clinical settings. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of vasopressin blockade on blood pressure during water deprivation in intact and baroreceptor-denervated conscious dogs.

PubMed

Gregory, L C; Quillen, E W; Keil, L C; Chang, D; Reid, I A

1988-04-01

Previous studies have provided evidence that vasopressin plays an important role in blood pressure regulation during water deprivation. However, these investigations have been complicated by reflex compensatory increases in cardiac output and renin secretion. The aim of the present study was to investigate the effect of blockade of the vasoconstrictor action of vasopressin in conscious water-deprived dogs in which the low- and/or high-pressure baroreceptors were denervated to minimize reflex responses. Vasopressin blockade in sham-operated dogs (n = 7) did not change arterial pressure. Heart rate rose from 78 +/- 9 to 119 +/- 13 beats/min (P less than 0.01), and plasma renin activity increased from 10.9 +/- 2.1 to 21.6 +/- 4.6 ng.ml-1.3 h-1 (P less than 0.01). In carotid sinus-denervated dogs (n = 6), vasopressin blockade again failed to decrease arterial pressure. Heart rate increased from 105 +/- 10 to 132 +/- 10 beats/min (P less than 0.01), and plasma renin activity rose from 6.8 +/- 1.7 to 15.5 +/- 2.4 ng.ml-1.3 h-1 (P less than 0.01). The antagonist also failed to change blood pressure in cardiac-denervated dogs (n = 5). Heart rate increased from 111 +/- 9 to 119 +/- 1 beats/min (P less than 0.01), but plasma renin activity did not increase significantly. In marked contrast, vasopressin blockade in sinoaortic/cardiac-denervated dogs (n = 7) promptly decreased arterial pressure from 115 +/- 8 to 94 +/- 7 mmHg (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

AT1-receptor blockade, but not renin inhibition, reduces aneurysm growth and cardiac failure in fibulin-4 mice.

PubMed

Te Riet, Luuk; van Deel, Elza D; van Thiel, Bibi S; Moltzer, Els; van Vliet, Nicole; Ridwan, Yanto; van Veghel, Richard; van Heijningen, Paula M; Robertus, Jan Lukas; Garrelds, Ingrid M; Vermeij, Marcel; van der Pluijm, Ingrid; Danser, A H Jan; Essers, Jeroen

2016-04-01

Increasing evidence supports a role for the angiotensin II-AT1-receptor axis in aneurysm development. Here, we studied whether counteracting this axis via stimulation of AT2 receptors is beneficial. Such stimulation occurs naturally during AT1-receptor blockade with losartan, but not during renin inhibition with aliskiren. Aneurysmal homozygous fibulin-4 mice, displaying a four-fold reduced fibulin-4 expression, were treated with placebo, losartan, aliskiren, or the β-blocker propranolol from day 35 to 100. Their phenotype includes cystic media degeneration, aortic regurgitation, left ventricular dilation, reduced ejection fraction, and fractional shortening. Although losartan and aliskiren reduced hemodynamic stress and increased renin similarly, only losartan increased survival. Propranolol had no effect. No drug rescued elastic fiber fragmentation in established aneurysms, although losartan did reduce aneurysm size. Losartan also increased ejection fraction, decreased LV diameter, and reduced cardiac pSmad2 signaling. None of these effects were seen with aliskiren or propranolol. Longitudinal micro-CT measurements, a novel method in which each mouse serves as its own control, revealed that losartan reduced LV growth more than aneurysm growth, presumably because the heart profits both from the local (cardiac) effects of losartan and its effects on aortic root remodeling. Losartan, but not aliskiren or propranolol, improved survival in fibulin-4 mice. This most likely relates to its capacity to improve structure and function of both aorta and heart. The absence of this effect during aliskiren treatment, despite a similar degree of blood pressure reduction and renin-angiotensin system blockade, suggests that it might be because of AT2-receptor stimulation.

Cushing's disease and hypertension: in vivo and in vitro study of the role of the renin-angiotensin-aldosterone system and effects of medical therapy.

PubMed

van der Pas, R; van Esch, J H M; de Bruin, C; Danser, A H J; Pereira, A M; Zelissen, P M; Netea-Maier, R; Sprij-Mooij, D M; van den Berg-Garrelds, I M; van Schaik, R H N; Lamberts, S W J; van den Meiracker, A H; Hofland, L J; Feelders, R A

2014-02-01

Cushing's disease (CD) is often accompanied by hypertension. CD can be treated surgically and, given the expression of somatostatin subtype 5 and dopamine 2 receptors by corticotroph pituitary adenomas, pharmacologically. Indeed, we recently observed that stepwise medical combination therapy with the somatostatin-analog pasireotide, the dopamine-agonist cabergoline, and ketoconazole (which directly suppresses steroidogenesis) biochemically controlled CD patients and lowered their blood pressure after 80 days. Glucocorticoids (GC) modulate the renin-angiotensin-aldosterone system (RAAS) among others by increasing hepatic angiotensinogen expression and stimulating mineralocorticoid receptors (MR). This study therefore evaluated plasma RAAS components in CD patients before and after drug therapy. In addition, we studied whether cabergoline/pasireotide have direct relaxant effects in angiotensin II (Ang II)-constricted iliac arteries of spontaneously hypertensive rats, with and without concomitant GR/MR stimulation with dexamethasone or hydrocortisone. Baseline concentrations of angiotensinogen were elevated, while renin and aldosterone were low and suppressed, respectively, even in patients treated with RAAS-blockers. This pattern did not change after 80 days of treatment, despite blood pressure normalization, nor after 4 years of remission. In the presence of dexamethasone, pasireotide inhibited Ang II-mediated vasoconstriction. The low plasma renin concentrations, even under RAAS blockade, in CD may be the consequence of increased GC-mediated MR stimulation and/or the elevated angiotensinogen levels in such patients. The lack of change in RAAS-parameters despite blood pressure and cortisol normalization suggests persisting consequences of long-term exposure to cortisol excess. Finally, pasireotide may have a direct vasodilating effect contributing to blood pressure lowering.

Reno-Cerebral Reflex Activates the Renin-Angiotensin System, Promoting Oxidative Stress and Renal Damage After Ischemia-Reperfusion Injury.

PubMed

Cao, Wei; Li, Aiqing; Li, Jiawen; Wu, Chunyi; Cui, Shuang; Zhou, Zhanmei; Liu, Youhua; Wilcox, Christopher S; Hou, Fan Fan

2017-09-01

A kidney-brain interaction has been described in acute kidney injury, but the mechanisms are uncertain. Since we recently described a reno-cerebral reflex, we tested the hypothesis that renal ischemia-reperfusion injury (IRI) activates a sympathetic reflex that interlinks the renal and cerebral renin-angiotensin axis to promote oxidative stress and progression of the injury. Bilateral ischemia-reperfusion activated the intrarenal and cerebral, but not the circulating, renin-angiotensin system (RAS), increased sympathetic activity in the kidney and the cerebral sympathetic regulatory regions, and induced brain inflammation and kidney injury. Selective renal afferent denervation with capsaicin or renal denervation significantly attenuated IRI-induced activation of central RAS and brain inflammation. Central blockade of RAS or oxidative stress by intracerebroventricular (ICV) losartan or tempol reduced the renal ischemic injury score by 65% or 58%, respectively, and selective renal afferent denervation or reduction of sympathetic tone by ICV clonidine decreased the score by 42% or 52%, respectively (all p < 0.05). Ischemia-reperfusion-induced renal damage and dysfunction persisted after controlling blood pressure with hydralazine. This study uncovered a novel reflex pathway between ischemic kidney and the brain that sustains renal oxidative stress and local RAS activation to promote ongoing renal damage. These data suggest that the renal and cerebral renin-angiotensin axes are interlinked by a reno-cerebral sympathetic reflex that is activated by ischemia-reperfusion, which contributes to ischemia-reperfusion-induced brain inflammation and worsening of the acute renal injury. Antioxid. Redox Signal. 27, 415-432.

Involvement of skeletal renin-angiotensin system and kallikrein-kinin system in bone deteriorations of type 1 diabetic mice with estrogen deficiency.

PubMed

Zhang, Yan; Wang, Liang; Liu, Jin-Xin; Wang, Xin-Luan; Shi, Qi; Wang, Yong-Jun

This study was aimed to investigate the involvement of skeletal renin-angiotensin system (RAS) and kallikrein-kinin system (KKS) in bone deteriorations of mice in response to the combination treatment of estrogen deficiency and hyperglycemia. The female C57BL/6J mice were sham-operated or ovariectomized with vehicle or streptozotocin (STZ) treatment. Two weeks later, the biochemistries in serum and urine were determined by standard colorimetric methods or ELISA. The H&E and TRAP staining were performed at the tibial proximal metaphysis. The polymerase chain reaction and immunoblotting were applied for molecular analysis on mRNA and protein expression. The mice after treating with ovariectomy and STZ showed the decreased level of serum Ca and the increased level of serum PTH and urine Ca. The H&E staining showed trabecular bone abnormalities as demonstrated by the loss, disconnection and separation of trabecular bone network as well as the loss of chondrocytes and appearance of chondrocyte cluster at growth plate of tibia. The significant increase of matured osteoclast number was shown in group with double treatments. The combination treatment significantly up-regulated mRNA expression of AGT, ACE, renin receptor, MMP-9 and CAII, and protein expression of renin, and decreased the ratio of OPG/RANKL and the expression of bradykinin receptors in bone tissue. Ovariectomy combined with STZ induction produced more detrimental actions on bone through the activation of local bone RAS and the down-regulation of bradykinin receptors, as compared to the respective single treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Association Between Pituitary-Adrenal Axis Dominance Over the Renin-Angiotensin-Aldosterone System and Hypertension.

PubMed

Daimon, Makoto; Kamba, Aya; Murakami, Hiroshi; Takahashi, Kazuhisa; Otaka, Hideyuki; Makita, Koushi; Yanagimachi, Miyuki; Terui, Ken; Kageyama, Kazunori; Nigawara, Takeshi; Sawada, Kaori; Takahashi, Ippei; Nakaji, Shigeyuki

2016-03-01

The hypothalamus-pituitary-adrenal (HPA) axis and the renin-angiotensin aldosterone system (RAAS) are well known to be associated with hypertension. However, the extent of the effects is not yet well elucidated in general conditions. To separately determine the effect of the HPA axis and the RAAS on hypertension in a general population. A population-based study of 859 Japanese individuals enrolled in the 2014 Iwaki study and without hypertension or steroid treatment (age, 50.2 ± 14.7 years). Hypertension prevalence, plasma concentration of aldosterone, ACTH, cortisol, and plasma renin activity. Principal component (PC) analysis using these four hormones identified two PCs (PC1 and PC2), which represent levels of these hormones as a whole, and dominance between the HPA axis (ACTH and cortisol) and the RAAS (plasma renin activity and plasma concentration of aldosterone), respectively. Association between these PCs and hypertension was significant (PC1, high vs low, odds ratio [OR], 1.48; 95% confidence interval [CI], 1.09-2.02; and PC2, HPA axis vs RAAS dominancy, OR, 2.08; and 95% CI, 1.51-2.85). However, association between the hormone levels as a whole and hypertension became insignificant after adjustment for multiple factors including these PCs together. However, association between the HPA axis dominance and hypertension remained significant even after the adjustment (the HPA axis vs the RAAS, OR, 1.73; 95% CI, 1.20-2.48). The HPA axis dominance over the RAAS is significantly associated with hypertension in a Japanese population.

Effect of aldosterone breakthrough on albuminuria during treatment with a direct renin inhibitor and combined effect with a mineralocorticoid receptor antagonist.

PubMed

Sato, Atsuhisa; Fukuda, Seiichi

2013-10-01

We have reported observing aldosterone breakthrough in the course of relatively long-term treatment with renin-angiotensin (RA) system inhibitors, where the plasma aldosterone concentration (PAC) increased following an initial decrease. Aldosterone breakthrough has the potential to eliminate the organ-protective effects of RA system inhibitors. We therefore conducted a study in essential hypertensive patients to determine whether aldosterone breakthrough occurred during treatment with the direct renin inhibitor (DRI) aliskiren and to ascertain its clinical significance. The study included 40 essential hypertensive patients (18 men and 22 women) who had been treated for 12 months with aliskiren. Aliskiren significantly decreased blood pressure and plasma renin activity (PRA). The PAC was also decreased significantly at 3 and 6 months; however, the significant difference disappeared after 12 months. Aldosterone breakthrough was observed in 22 of the subjects (55%). Urinary albumin excretion differed depending on whether breakthrough occurred. For the subjects in whom aldosterone breakthrough was observed, eplerenone was added. A significant decrease in urinary albumin excretion was observed after 1 month, independent of changes in blood pressure. In conclusion, this study demonstrated that aldosterone breakthrough occurs in some patients undergoing DRI therapy. Aldosterone breakthrough affects the drug's ability to improve urinary albumin excretion, and combining a mineralocorticoid receptor antagonist with the DRI may be useful for decreasing urinary albumin excretion. When the objective is organ protection in hypertensive patients, a two-pronged approach using combination therapy to inhibit both the RA system and aldosterone may be highly effective.

Aldosterone, cognitive function, and cerebral hemodynamics in hypertension and antihypertensive therapy.

PubMed

Hajjar, Ihab; Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A

2015-03-01

Animal studies suggest that the renin-angiotensin-aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90 mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = -0.02; P = 0.03), lower CO2 vasoreactivity (β = -0.11; P = 0.007), and decreased autoregulation abilities (β = -0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90 mm Hg). Plasma renin activity was not associated with any of the measures. Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Urinary angiotensinogen as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease patients.

PubMed

Xu, Z; Xu, B; Xu, C

2015-06-01

Urinary angiotensinogen (AGT) mainly derives from the AGT produced in proximal tubular cells. Evidence exists that supports the correlation between urinary AGT and circulating AGT. To investigate the role of urinary AGT as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease (CKD) patients. ELISA-based method used to quantify urinary AGT. Analyzed the relationship between urinary AGT and intrarenal angiotensin II (Ang II) activity in 128 CKD patients. ELISA was applied to measure the urinary and plasma renin activity, AGT, Ang II and aldosterone. Furthermore expression levels of intrarenal renin, AGT, Ang II and Ang II receptor were examined by immunohistochemistry staining (IHCS) in 72 CKD patients undergoing renal biopsy. The logarithmic transformation Log(urinary AGT/UCre) levels showed a normal distribution. Therefore, Log(urinary AGT/UCre) levels were used for the analyses. Average urinary AGT was 2.02 ± 0.55 ng/(mg Cr). Hypertension, urinary protein, urinary Ang II and urinary type IV collagen (Col IV) positively correlated with urinary AGT. Estimated glomerular filtration rate (eGFR), urinary sodium and serum AGT negatively correlated with urinary AGT. Multiple regression analysis indicated that low serum AGT, high urinary protein, urinary Ang II and urinary Col IV correlated significantly with high urinary AGT. We observed positive correlation between urinary AGT and positive IHCS area of AGT, Ang II and Ang II type 1 receptor in renal tissue. These data suggest that urinary AGT might be a potential biomarker of intrarenal Ang II activity in CKD patients.

Renin-Angiotensin-Aldosterone System Inhibition Increases Podocyte Derivation from Cells of Renin Lineage

PubMed Central

Lichtnekert, Julia; Kaverina, Natalya V.; Eng, Diana G.; Gross, Kenneth W.; Kutz, J. Nathan; Pippin, Jeffrey W.

2016-01-01

Because adult podocytes cannot proliferate and are therefore unable to self-renew, replacement of these cells depends on stem/progenitor cells. Although podocyte number is higher after renin-angiotensin-aldosterone system (RAAS) inhibition in glomerular diseases, the events explaining this increase are unclear. Cells of renin lineage (CoRL) have marked plasticity, including the ability to acquire a podocyte phenotype. To test the hypothesis that RAAS inhibition partially replenishes adult podocytes by increasing CoRL number, migration, and/or transdifferentiation, we administered tamoxifen to Ren1cCreERxRs-tdTomato-R CoRL reporter mice to induce permanent labeling of CoRL with red fluorescent protein variant tdTomato. We then induced experimental FSGS, typified by abrupt podocyte depletion, with a cytopathic antipodocyte antibody. RAAS inhibition by enalapril (angiotensin-converting enzyme inhibitor) or losartan (angiotensin-receptor blocker) in FSGS mice stimulated the proliferation of CoRL, increasing the reservoir of these cells in the juxtaglomerular compartment (JGC). Compared with water or hydralazine, RAAS inhibition significantly increased the migration of CoRL from the JGC to the intraglomerular compartment (IGC), with more glomeruli containing RFP+CoRL and, within these glomeruli, more RFP+CoRL. Moreover, RAAS inhibition in FSGS mice increased RFP+CoRL transdifferentiation in the IGC to phenotypes, consistent with those of podocytes (coexpression of synaptopodin and Wilms tumor protein), parietal epithelial cells (PAX 8), and mesangial cells (α8 integrin). These results show that in the context of podocyte depletion in FSGS, RAAS inhibition augments CoRL proliferation and plasticity toward three different glomerular cell lineages. PMID:27080979

The Adipose Renin-Angiotensin System Modulates Systemic Markers of Insulin Sensitivity and Activates the Intrarenal Renin-Angiotensin System

DOE PAGES

Kim, Suyeon; Soltani-Bejnood, Morvarid; Quignard-Boulange, Annie; ...

2006-01-01

Background . The adipose tissue renin-angiotensin system (RAS) contributes to regulation of fat mass and may also impact systemic functions such as blood pressure and metabolism. Methods and results . A panel of mouse models including mice lacking angiotensinogen, Agt ( Agt -KO), mice expressing Agt solely in adipose tissue (aP2- Agt/Agt -KO), and mice overexpressing Agt in adipose tissue (aP2- Agt ) was studied. Total body weight, epididymal fat pad weight, and circulating levels of leptin, insulin, and resistin were significantly decreased in Agt -KO mice, while plasma adiponectin levels were increased. aP2- Agt mice exhibited increased adiposity andmore » plasma leptin and insulin levels compared to wild type (WT) controls. Angiotensinogen and type I Ang II receptor protein levels were also elevated in kidney of aP2- Agt mice. Conclusion . These findings demonstrate that alterations in adipose RAS activity significantly impact both local and systemic physiology in a way that may contribute to the detrimental health effects of obesity.« less

Cyclical secretion of prorenin during the menstrual cycle: synchronization with luteinizing hormone and progesterone.

PubMed Central

Sealey, J E; Atlas, S A; Glorioso, N; Manapat, H; Laragh, J H

1985-01-01

Plasma prorenin, a high molecular weight precursor form of renin, (renin, EC 3.4.23.15; old number, EC 3.4.99.19), was measured three times weekly in normal young women during the menstrual cycle and was related to changes in luteinizing hormone, estradiol, and progesterone. In all subjects a stable baseline level of prorenin occurred during the follicular phase. Then, simultaneously or soon after the luteinizing hormone peak, plasma prorenin consistently increased about 2-fold. Baseline prorenin ranged from 18 to 40 ng per ml per hr, and peak prorenin ranged from 35 to 65 ng per ml per hr. The maximum increase in prorenin averaged 80%. Prorenin remained elevated during the mid-luteal phase of the menstrual cycle and returned to baseline during the late-luteal phase in coordination with the decrease in progesterone. The changes in prorenin were not synchronized with changes in active renin which was significantly increased only during the mid-luteal phase. These findings suggest that prorenin may be involved in reproductive physiology. PMID:3909151

Big angiotensin-25: a novel glycosylated angiotensin-related peptide isolated from human urine.

PubMed

Nagata, Sayaka; Hatakeyama, Kinta; Asami, Maki; Tokashiki, Mariko; Hibino, Hajime; Nishiuchi, Yuji; Kuwasako, Kenji; Kato, Johji; Asada, Yujiro; Kitamura, Kazuo

2013-11-29

The renin-angiotensin system (RAS), including angiotensin II (Ang II), plays an important role in the regulation of blood pressure and body fluid balance. Consequently, the RAS has emerged as a key target for treatment of kidney and cardiovascular disease. In a search for bioactive peptides using an antibody against the N-terminal portion of Ang II, we identified and characterized a novel angiotensin-related peptide from human urine as a major molecular form. We named the peptide Big angiotensin-25 (Bang-25) because it consists of 25 amino acids with a glycosyl chain and added cysteine. Bang-25 is rapidly cleaved by chymase to Ang II, but is resistant to cleavage by renin. The peptide is abundant in human urine and is present in a wide range of organs and tissues. In particular, immunostaining of Bang-25 in the kidney is specifically localized to podocytes. Although the physiological function of Bang-25 remains uncertain, our findings suggest it is processed from angiotensinogen and may represent an alternative, renin-independent path for Ang II synthesis in tissue. Copyright © 2013. Published by Elsevier Inc.

Effects of bombesin on erythropoietin production in the anaesthetized dog.

PubMed

Melchiorri, P; Sopranzi, N; Roseghini, M

1976-08-01

Bombesin, a tetradecapeptide isolated from the skin of some European discoglossid frogs, has been reported previously to reduce renal blood flow and glomerular filtration rate and to increase plasma renin activity in anaesthetized dogs. In the present study bombesin was infused intravenously in anaesthetized dogs at dose levels of 3, 6 and 12 ng/kg/min for 6 h and renal blood flow, glomerular filtration rate, oxygen consumption, oxygen extraction by the kidney tissue, as well as plasma erythropoietin levels (ESF) and plasma renin activity were measured. Plasma levels of ESF increased during bombesin infusion only when renal blood flow was reduced to a level of 1 ml/g/min or less. In this situation glomerular filtration was blocked, renal oxygen consumption was decreased to 10% of normal and oxygen extraction by the kidney was increased by 2 times. No correlation was found between plasma renin activity and ESF concentrations during bombesin infusion. It is concluded that the stimulant action of bombesin on ESF production is a consequence of the renal hypoxia induced by the reduction in renal blood flow.

The Radioimmunoassay of Fluid and Electrolyte Hormones

NASA Technical Reports Server (NTRS)

Keil, Lanny C.

1985-01-01

The subject of the paper will be the assay of fluid/electrolyte hormones. ADH (antidiuretic hormone also referred to as vasopressin) reduces fluid loss by increasing water reabsorption by the kidney. The stimuli for its release from the pituitary are loss of blood, dehydration, or increased salt intake. Angiotensin II is the next hormone of interest. It is "generated" from a blood protein by the release of renin from the kidney. One of its functions is to stimulate the secretion of aldosterone from the adrenal gland. Release of renin is also stimulated by volume and sodium loss.

Kallikrein and Renin in the Membrane Fractions of the Rat Kidney.

DTIC Science & Technology

1980-05-23

Zingg, E.A. and Hedlin, A.H.: Kallikrein and plasmin as activators of inactive renin. Lancet 11:1375, 1978 32. Inagami, T ., Yokosawa , N., Takahashi, N...FRACTIONS Technical Report to 8/15/60 OF THE RAT KIDNEY, t 8/15/- 0 6 PEOPORMINS~1.RPOTNME 7/. 1 AuTN’OR/f’) B CoNfrt*C; OW ; R^R NT NJ4S._R...E’ T PSJ’ , TASK . :) A DA RE AR 5W S. UNIT 10 ELE E 4 POI~f-r University of Texas Health Science Center AREA ORKUNIT sMBES 5323 Harry Hines Blvd

Neural regulation of renal tubular sodium reabsorption and renin secretion: integrative aspects.

PubMed

DiBona, G F

1987-01-01

Efferent renal sympathetic nerve activity plays an important role in the regulation of renal function. Via its direct influence on renal tubular sodium reabsorption throughout the entire mammalian nephron, alterations in efferent renal sympathetic nerve activity represent an important physiological contribution to the overall role of the kidney in the regulation of external sodium balance and the defense against sodium deficit and surfeit. Abnormalities of this mechanism can lead to inappropriate renal sodium retention and augmentation of renin secretion, two factors which are capable of contributing to the development and maintenance of hypertension.

[Renin-angiotensin-aldosterone system (RAAS) and its pharmacologic modulation].

PubMed

Giestas, Anabela; Palma, Isabel; Ramos, Maria Helena

2010-01-01

The renin-angiotensin-aldosterone system (RAAS) is a neuroendocrine complex system that regulates the modulation of salt and water homeostasis, and regulation of blood pressure. Through its multiple interactions it protects the endothelium, heart, brain and kidney. In addition, the RAAS regulates the vascular response to injury and inflammation. Chronic activation/dysregulation of the RAAS leads to hypertension and perpetuates a cascade of proinflammatory, prothrombotic and atherogenic effects associated with endorgan damage (heart, brain, kidney, endothelium). Consequently, the RAAS is an important therapeutic target in these situations. This article presents an overview of physiology, pathophysiology and pharmacologic modulation of the RAAS.

Screening for primary aldosteronism in an argentinian population: a multicenter prospective study.

PubMed

Leal Reyna, Mariela; Gómez, Reynaldo M; Lupi, Susana N; Belli, Susana H; Fenili, Cecilia A; Martínez, Marcela S; Ruibal, Gabriela F; Rossi, María A; Chervin, Raúl A; Cornaló, Dora; Contreras, Liliana N; Costa, Liliana; Nofal, María T; Damilano, Sergio A; Pardes, Ester M

2015-10-01

Primary aldosteronism (PA) is characterized by the autonomous overproduction of aldosterone. Its prevalence has increased since the use of the aldosterone (ALD)/plasma renin activity (PRA) ratio (ARR). The objective of this study is to determine ARR and ARC (ALD/plasma renin concentration ratio) cut-off values (COV) and their diagnostic concordance (DC%) in the screening for PA in an Argentinian population.Design multicenter prospective study. We studied 353 subjects (104 controls and 249 hypertensive patients). Serum aldosterone, PRA and ARR were determined. In 220 randomly selected subjects, 160 hypertensive patients and 60 controls, plasma renin concentration (PRC) was simultaneously measured and ARC was determined. According to the 95th percentile of controls, we determined a COV of 36 for ARR and 2.39 for ARC, with ALD ≥ 15 ng/dL. In 31/249 hypertensive patients, ARR was ≥ 36. PA diagnosis was established in 8/31 patients (23/31 patients did not complete confirmatory tests). DC% between ARR and ARC was calculated. A significant correlation between ARR and ARC (r = 0.742; p < 0.0001) was found only with PRA > 0.3 ng/mL/h and PRC > 5 pg/mL. DC% for ARR and ARC above or below 36 and 2.39 was 79.1%, respectively. This first Argentinian multicenter study determined a COV of 36 for ARR and 2.39 for ARC. Applying an ARR ≥ 36 in the hypertensive group, we confirmed PA in a higher percentage of patients than the previously reported one in our population. As for ARC, further studies are needed for its clinical application, since DC% is acceptable only for medium range renin values.

Hypertension: renin-angiotensin-aldosterone system alterations.

PubMed

Te Riet, Luuk; van Esch, Joep H M; Roks, Anton J M; van den Meiracker, Anton H; Danser, A H Jan

2015-03-13

Blockers of the renin-angiotensin-aldosterone system (RAAS), that is, renin inhibitors, angiotensin (Ang)-converting enzyme (ACE) inhibitors, Ang II type 1 receptor antagonists, and mineralocorticoid receptor antagonists, are a cornerstone in the treatment of hypertension. How exactly they exert their effect, in particular in patients with low circulating RAAS activity, also taking into consideration the so-called Ang II/aldosterone escape that often occurs after initial blockade, is still incompletely understood. Multiple studies have tried to find parameters that predict the response to RAAS blockade, allowing a personalized treatment approach. Consequently, the question should now be answered on what basis (eg, sex, ethnicity, age, salt intake, baseline renin, ACE or aldosterone, and genetic variance) a RAAS blocker can be chosen to treat an individual patient. Are all blockers equal? Does optimal blockade imply maximum RAAS blockade, for example, by combining ≥2 RAAS blockers or by simply increasing the dose of 1 blocker? Exciting recent investigations reveal a range of unanticipated extrarenal effects of aldosterone, as well as a detailed insight in the genetic causes of primary aldosteronism, and mineralocorticoid receptor blockers have now become an important treatment option for resistant hypertension. Finally, apart from the deleterious ACE-Ang II-Ang II type 1 receptor arm, animal studies support the existence of protective aminopeptidase A-Ang III-Ang II type 2 receptor and ACE2-Ang-(1 to 7)-Mas receptor arms, paving the way for multiple new treatment options. This review provides an update about all these aspects, critically discussing the many controversies and allowing the reader to obtain a full understanding of what we currently know about RAAS alterations in hypertension. © 2015 American Heart Association, Inc.

Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion.

PubMed

Qi, Ying; Wang, Xiaojing; Rose, Kristie L; MacDonald, W Hayes; Zhang, Bing; Schey, Kevin L; Luther, James M

2016-02-01

Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry-based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112-122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112-122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. Copyright © 2016 by the American Society of Nephrology.

Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion

PubMed Central

Qi, Ying; Wang, Xiaojing; Rose, Kristie L.; MacDonald, W. Hayes; Zhang, Bing; Schey, Kevin L.

2016-01-01

Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry–based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112–122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112–122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. PMID:26113616

The ovine fetal endocrine reflex responses to haemorrhage are not mediated by cardiac nerves

PubMed Central

Wood, Charles E

2002-01-01

This study was designed to test the hypothesis that cardiac receptors tonically inhibit the secretion of renin, arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) in late-gestation fetal sheep. Eight chronically catheterised fetal sheep between 122 and 134 days gestation were subjected to injection or infusion of saline or 4 % procaine into the pericardial space. Fetal blood pressure and heart rate were monitored and fetal blood samples were drawn to measure the response to these injections. Injection of procaine into the pericardial space effectively blocked cardiac nerves, as evidenced by a reduction in the variability of fetal heart rate and by the blockade of reflex reductions in fetal heart rate after intravenous injection of phenylephrine (an α-adrenergic agonist which raises blood pressure). Injection of saline had no discernable effects on any of the measured variables. A single injection of procaine, followed by a slow infusion, produced a transient blockade of cardiac nerves. Multiple injections of procaine produced a sustained blockade of cardiac nerves and a sustained rise in fetal plasma renin activity and ACTH. In none of the experiments did procaine significantly alter fetal plasma AVP concentrations. In 11 fetuses between 121 and 134 days gestation, we combined the cardiac nerve blockade with slow haemorrhage to test the cardiac nerves as mediators of the endocrine response to haemorrhage in utero. Cardiac nerve blockade exaggerated the fetal blood gas response to haemorrhage somewhat but did not significantly alter the magnitude of the ACTH, AVP, or plasma renin activity response to haemorrhage. We conclude that cardiac nerves in the late-gestation fetal sheep have minor influences on plasma renin activity and ACTH in normovolaemic fetuses, but that changes in cardiac nerve activity do not mediate the endocrine responsiveness to haemorrhage. PMID:12042365

Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension.

PubMed

Rossi, Gian Paolo; Ceolotto, Giulio; Rossitto, Giacomo; Seccia, Teresa Maria; Maiolino, Giuseppe; Berton, Chiara; Basso, Daniela; Plebani, Mario

2016-09-01

The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients. We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA. At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02]. This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

Effects of sex and the common ADRB1 389 genetic polymorphism on the hemodynamic response to dobutamine.

PubMed

Yogev, Dotan; Basheer, Maamoun; Blotnick, Simcha; Caraco, Yoseph; Muszkat, Mordechai

2015-11-01

The ADRB1 389 polymorphism affects responses to the β-1 adrenergic receptor (β1AR) agonist in vitro. Previous studies on its effect on the response to dobutamine stress echocardiography were conflicting. In addition, sex differences in the response to dobutamine have been suggested. The aim of this study was to determine whether the ADRB1 389 polymorphism affects the hemodynamic response to dobutamine in healthy individuals including men and women. Healthy individuals were recruited according to their ADRB1 49 and 389 genotypes [15 Arg389Arg, 10 Gly389Arg, and 10 Gly389Gly individuals, (all Ser49Ser), 21 men and 14 women]. Dobutamine was infused at 2, 4, and 6 mcg/kg/min. Standardized exercise was performed during the last minute of each infusion. Resting heart rate (HR) response to 6 mcg/kg/min dobutamine (ΔHR) was 4.7-fold larger in Arg389Arg than in Gly389Gly [(mean ± SD) 12.95 ± 6.99, 2.75 ± 1.65 bpm, respectively, PANOVA=0.012]. Renin response to dobutamine (ΔRenin) was 3.9-fold greater in Arg389Arg than in Gly389Gly (PANOVA=0.032). Among Arg389Gly heterozygotes, ΔHR and ΔRenin were not significantly different from either homozygote group. In multivariate analysis for ΔHR variance, significant contributions were observed for genotype (P=0.011), baseline HR (P=0.011), and borderline effect for sex (P=0.049). In healthy individuals, HR and renin responses to dobutamine were more than three-fold greater among ADRB1 Arg389 compared with Gly389 homozygotes. Future studies on the effect of the ADRB1 389 polymorphism on dobutamine stress echocardiography should compare Arg389 and Gly389 homozygotes.

Shifts in renin-angiotensin system components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa region of streptozotocin-induced diabetic mice.

PubMed

Qian, Xiaobing; Lin, Leilei; Zong, Yao; Yuan, Yongguang; Dong, Yanmin; Fu, Yue; Shao, Wanwen; Li, Yujie; Gao, Qianying

2018-03-01

This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabetic mice. Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. Compared with control mice, diabetic mice had significantly higher blood glucose concentrations (p < 0.001) and significantly lower body weights (p < 0.001). Colour photography and FFA did not reveal any vessel abnormalities in the diabetic mice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2 + pericytes were observed in diabetic mice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabetic mice. Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabetic mice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.

Vasopressin and angiotensin II in reflex regulation of ACTH, glucocorticoids, and renin: effect of water deprivation

NASA Technical Reports Server (NTRS)

Brooks, V. L.; Keil, L. C.

1992-01-01

Angiotensin II (ANG II) and vasopressin participate in baroreflex regulation of adrenocorticotropic hormone (ACTH), glucocorticoid, and renin secretion. The purpose of this study was to determine whether this participation is enhanced in water-deprived dogs, with chronically elevated plasma ANG II and vasopressin levels, compared with water-replete dogs. The baroreflex was assessed by infusing increasing doses of nitroprusside (0.3, 0.6, 1.5, and 3.0 micrograms.kg-1.min-1) in both groups of animals. To quantitate the participation of ANG II and vasopressin, the dogs were untreated or pretreated with the competitive ANG II antagonist saralasin, a V1-vasopressin antagonist, or combined V1/V2-vasopressin antagonist, either alone or in combination. The findings were as follows. 1) Larger reflex increases in ANG II, vasopressin, and glucocorticoids, but not ACTH, were produced in water-deprived dogs compared with water-replete dogs. 2) ANG II blockade blunted the glucocorticoid and ACTH responses to hypotension in water-deprived dogs, but not water-replete dogs. In contrast, vasopressin blockade reduced the ACTH response only in water-replete dogs. 3) Vasopressin or combined vasopressin and ANG II blockade reduced the plasma level of glucocorticoids related either to the fall in arterial pressure or to the increase in plasma ACTH concentration in water-replete dogs, and this effect was enhanced in water-deprived dogs. 4) In both water-deprived and water-replete animals, saralasin and/or a V1-antagonist increased the renin response to hypotension, but a combined V1/V2-antagonist did not. These results reemphasize the importance of endogenous ANG II and vasopressin in the regulation of ACTH, glucocorticoid, and renin secretion.(ABSTRACT TRUNCATED AT 250 WORDS).

Long-term systemic angiotensin II type 1 receptor blockade regulates mRNA expression of dorsomedial medulla renin-angiotensin system components.

PubMed

Gilliam-Davis, Shea; Gallagher, Patricia E; Payne, Valerie S; Kasper, Sherry O; Tommasi, Ellen N; Westwood, Brian M; Robbins, Michael E; Chappell, Mark C; Diz, Debra I

2011-07-14

In Fischer 344 (F344) rats, renin-angiotensin system (RAS) blockade for 1 yr with the angiotensin II type 1 (AT(1)) receptor blocker L-158,809 prevents age-related impairments in metabolic function, similar to transgenic rats with low glial angiotensinogen (Aogen). Brain RAS regulation may contribute to the benefits of long-term systemic AT(1) antagonism. We assessed the mRNA of RAS components in the dorsomedial medulla of F344 rats at 3 (young; n = 8) or 15 mo of age (old; n = 7) and in rats treated from 3 to 15 mo of age with 20 mg/l of the AT(1) receptor antagonist L-158,809 (Old+L; n = 6). Aogen and renin mRNA were lower in the young compared with old group. Angiotensin-converting enzyme (ACE) mRNA was lower in the old and Old+L compared with the young group. ACE2 and neprilysin expression were significantly higher in Old+L compared with young or old rats. AT(1b), AT(2), and Mas receptor mRNA were higher with treatment. Leptin receptor mRNA was lower in the old rats and this was prevented by L-158,809 treatment. Dual-specificity phosphatase 1 (DUSP1) mRNA was highest in the Old+L group. Aggregate correlate summation revealed a positive relationship for Mas receptor mRNA with food intake. The findings provide evidence for regulation of dorsomedial medullary renin and Aogen mRNA during aging. Long-term AT(1) receptor blockade increases the mRNA of the enzymes ACE2 and neprilysin and the MAS receptor, which could potentially shift the balance from ANG II to ANG-(1-7) and prevent age-related declines in the leptin receptor and its signaling pathway.

Novel inhibitors of the cellular renin-angiotensin system components, poricoic acids, target Smad3 phosphorylation and Wnt/β-catenin pathway against renal fibrosis.

PubMed

Wang, Ming; Chen, Dan-Qian; Chen, Lin; Cao, Gang; Zhao, Hui; Liu, Dan; Vaziri, Nosratola D; Guo, Yan; Zhao, Ying-Yong

2018-07-01

Tubulo-interstitial fibrosis is the final pathway in the progression of chronic kidney disease (CKD) to kidney failure. The renin-angiotensin system (RAS) plays a major role in CKD progression. Hence, we determined the efficacy of novel RAS inhibitors isolated from Poria cocos against renal fibrosis. Effects of three novel tetracyclic triterpenoid compounds, poricoic acid ZC (PZC), poricoic acid ZD (PZD) and poricoic acid ZE (PZE), were investigated on TGFβ1- and angiotensin II (AngII)-treated HK-2 cells and unilateral ureteral obstruction (UUO) in mice. Immunofluorescence staining, quantitative real-time PCR, siRNA, co-immunoprecipitation and Western blot analyses were used to evaluate expression of key molecules in RAS, Wnt/β-catenin and TGFβ/Smad pathways. Addition of the above compounds to culture media and their administration to UUO mice: (i) significantly attenuated epithelial-to-mesenchymal transition and extracellular matrix production in TGFβ1- and AngII-treated HK-2 cells and UUO mice by inhibiting Wnt/β-catenin pathway activation and Smad3 phosphorylation; (ii) selectively inhibited Smad3 phosphorylation by blocking the interaction of TGFBR1 with Smad3; and (iii) specifically inhibited Smad3 activation. PZC and PZD showed a strong inhibitory effect on all RAS components, and PZE showed a strong inhibitory effect on renin. Furthermore, the secolanostane tetracyclic triterpenoids, PZC and PZD, showed a stronger inhibitory effect than the lanostane tetracyclic triterpenoid PZE. Therefore, compounds with secolanostance skeleton showed stronger bioactivity than those with lanostance skeleton. The secolanostane tetracyclic triterpenoids effectively blocked RAS by simultaneously targeting multiple RAS components and lanostane tetracyclic triterpenoids inhibited renin and protected against tubulo-interstitial fibrosis. © 2018 The British Pharmacological Society.

Recombinant erythropoietin acutely decreases renal perfusion and decouples the renin-angiotensin-aldosterone system.

PubMed

Aachmann-Andersen, Niels J; Christensen, Soren J; Lisbjerg, Kristian; Oturai, Peter; Johansson, Pär I; Holstein-Rathlou, Niels-Henrik; Olsen, Niels V

2018-03-01

The effect of recombinant erythropoietin (rhEPO) on renal and systemic hemodynamics was evaluated in a randomized double-blinded, cross-over study. Sixteen healthy subjects were tested with placebo, or low-dose rhEPO for 2 weeks, or high-dose rhEPO for 3 days. Subjects refrained from excessive salt intake, according to instructions from a dietitian. Renal clearance studies were done for measurements of renal plasma flow, glomerular filtration rate (GFR) and the segmentel tubular handling of sodium and water (lithium clearance). rhEPO increased arterial blood pressure, total peripheral resistance, and renal vascular resistance, and decreased renal plasma flow in the high-dose rhEPO intervention and tended to decrease GFR. In spite of the decrease in renal perfusion, rhEPO tended to decrease reabsorption of sodium and water in the proximal tubule and induced a prompt decrease in circulating levels of renin and aldosterone, independent of changes in red blood cell mass, blood volumes, and blood pressure. We also found changes in biomarkers showing evidence that rhEPO induced a prothrombotic state. Our results suggest that rhEPO causes a direct downregulation in proximal tubular reabsorption that seems to decouple the activity of the renin-angiotensin-aldosterone system from changes in renal hemodynamics. This may serve as a negative feed-back mechanism on endogenous synthesis of EPO when circulating levels of EPO are high. These results demonstrates for the first time in humans a direct effect of rhEPO on renal hemodynamics and a decoupling of the renin-angiotensin-aldosterone system. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

High-fat diet amplifies renal renin angiotensin system expression, blood pressure elevation, and renal dysfunction caused by Ceacam1 null deletion.

PubMed

Li, Caixia; Culver, Silas A; Quadri, Syed; Ledford, Kelly L; Al-Share, Qusai Y; Ghadieh, Hilda E; Najjar, Sonia M; Siragy, Helmy M

2015-11-01

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAMl), a substrate of the insulin receptor tyrosine kinase, regulates insulin action by promoting insulin clearance. Global null mutation of Ceacam1 gene (Cc1(-/-)) results in features of the metabolic syndrome, including insulin resistance, hyperinsulinemia, visceral adiposity, elevated blood pressure, and albuminuria. It also causes activation of the renal renin-angiotensin system (RAS). In the current study, we tested the hypothesis that high-fat diet enhances the expression of RAS components. Three-month-old wild-type (Cc1(+/+)) and Cc1(-/-) mice were fed either a regular or a high-fat diet for 8 wk. At baseline under regular feeding conditions, Cc1(-/-) mice exhibited higher blood pressure, urine albumin-to-creatinine ratio (UACR), and renal expression of angiotensinogen, renin/prorenin, angiotensin-converting enzyme, (pro)renin receptor, angiotensin subtype AT1 receptor, angiotensin II, and elevated PI3K phosphorylation, as detected by p85α (Tyr(508)) immunostaining, inflammatory response, and the expression of collagen I and collagen III. In Cc1(+/+) mice, high-fat diet increased blood pressure, UACR, the expression of angiotensin-converting enzyme and angiotensin II, PI3K phosphorylation, inflammatory response, and the expression of collagen I and collagen III. In Cc1(-/-) mice, high-fat intake further amplified these parameters. Immunohistochemical staining showed increased p-PI3K p85α (Tyr(508)) expression in renal glomeruli, proximal, distal, and collecting tubules of Cc1(-/-) mice fed a high-fat diet. Together, this demonstrates that high-fat diet amplifies the permissive effect of Ceacam1 deletion on renal expression of all RAS components, PI3K phosphorylation, inflammation, and fibrosis. Copyright © 2015 the American Physiological Society.

Maternal corticosterone exposure in the mouse programs sex-specific renal adaptations in the renin-angiotensin-aldosterone system in 6-month offspring.

PubMed

Cuffe, James S M; Burgess, Danielle J; O'Sullivan, Lee; Singh, Reetu R; Moritz, Karen M

2016-04-01

Short-term maternal corticosterone (Cort) administration at mid-gestation in the mouse reduces nephron number in both sexes while programming renal and cardiovascular dysfunction in 12-month male but not female offspring. The renal renin-angiotensin-aldosterone system (RAAS), functions in a sexually dimorphic manner to regulate both renal and cardiovascular physiology. This study aimed to identify if there are sex-specific differences in basal levels of the intrarenal RAAS and to determine the impact of maternal Cort exposure on the RAAS in male and female offspring at 6 months of age. While intrarenal renin concentrations were higher in untreated females compared to untreated males, renal angiotensin II concentrations were higher in males than females. Furthermore, basal plasma aldosterone concentrations were greater in females than males. Cort exposed male but not female offspring had reduced water intake and urine excretion. Cort exposure increased renal renin concentrations and elevated mRNA expression of Ren1, Ace2, and Mas1 in male but not female offspring. In addition, male Cort exposed offspring had increased expression of the aldosterone receptor, Nr3c2 and renal sodium transporters. In contrast, Cort exposure increased Agtr1a mRNA levels in female offspring only. This study demonstrates that maternal Cort exposure alters key regulators of renal function in a sex-specific manner at 6 months of life. These finding likely contribute to the disease outcomes in male but not female offspring in later life and highlights the importance of renal factors other than nephron number in the programming of renal and cardiovascular disease. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

The role of the renin-angiotensin system in the development of insulin resistance in skeletal muscle.

PubMed

Henriksen, Erik J; Prasannarong, Mujalin

2013-09-25

The canonical renin-angiotensin system (RAS) involves the initial action of renin to cleave angiotensinogen to angiotensin I (ANG I), which is then converted to ANG II by the angiotensin converting enzyme (ACE). ANG II plays a critical role in numerous physiological functions, and RAS overactivity underlies many conditions of cardiovascular dysregulation. In addition, ANG II, by acting on both endothelial and myocellular AT1 receptors, can induce insulin resistance by increasing cellular oxidative stress, leading to impaired insulin signaling and insulin-stimulated glucose transport activity. This insulin resistance associated with RAS overactivity, when coupled with progressive ß-cell dysfunction, eventually leads to the development of type 2 diabetes. Interventions that target RAS overactivity, including ACE inhibitors, ANG II receptor blockers, and, most recently, renin inhibitors, are effective both in reducing hypertension and in improving whole-body and skeletal muscle insulin action, due at least in part to enhanced Akt-dependent insulin signaling and insulin-dependent glucose transport activity. ANG-(1-7), which is produced from ANG II by the action of ACE2 and acts via Mas receptors, can counterbalance the deleterious actions of the ACE/ANG II/AT1 receptor axis on the insulin-dependent glucose transport system in skeletal muscle. This beneficial effect of the ACE2/ANG-(1-7)/Mas receptor axis appears to depend on the activation of Akt. Collectively, these findings underscore the importance of RAS overactivity in the multifactorial etiology of insulin resistance in skeletal muscle, and provide support for interventions that target the RAS to ameliorate both cardiovascular dysfunctions and insulin resistance in skeletal muscle tissue. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Plasma renin activity to plasma aldosterone concentration ratio correlates with night-time and pulse pressures in essential hypertensive patients treated with angiotensin-converting enzyme inhibitors/AT1 blockers.

PubMed

Spannella, Francesco; Giulietti, Federico; Balietti, Paolo; Borioni, Elisabetta; Lombardi, Francesca E; Ricci, Maddalena; Cocci, Guido; Landi, Laura; Sarzani, Riccardo

2017-11-01

Angiotensin-converting enzyme inhibitors (ACE-I) and AT1 blockers (ARB) are commonly used antihypertensive drugs, but several factors may affect their effectiveness. We evaluated the associations between ambulatory blood pressure (BP) monitoring (ABPM) parameters and plasma renin activity (PRA)-to-plasma aldosterone concentration (PAC) ratio (RAR) to test renin-angiotensin-aldosterone system inhibition in essential hypertensive patients treated with ACE-I or ARB for at least 12 months. We evaluated 194 consecutive patients referred to our Hypertension Centre. ABPM, PRA and PAC tests were performed without any changes in drug therapy. RAR, PRA and PAC tertiles were considered for the analyses. Mean age: 57.4 ± 12.0 years; male prevalence: 63.9%. No differences between RAR tertiles regarding the use of ACE-I or ARB (P = 0.385), as well as the other antihypertensive drug classes, were found. A reduction of all ABPM values considered (24-h BP, daytime BP and night-time BP and 24-h pulse pressure (PP), daytime PP and night-time PP) and a better BP control were observed at increasing RAR tertiles, with an odds ratio = 0.12 to be not controlled during night-time period for patients in the third tertile compared with patients in the first tertile (P < 0.001). This association remained significant even after adjusting for 24-h BP control. All the associations were also confirmed for PRA tertiles, but not for PAC tertiles. Higher RAR values indicate effective renin-angiotensin-aldosterone system inhibition and lower night-time and pulse pressures in real-life clinical practice. It could be a useful biomarker in the management of essential hypertensive patients treated with ACE-I or ARB.

Race, obesity, and the renin-angiotensin-aldosterone system: treatment response in children with primary hypertension.

PubMed

South, Andrew M; Arguelles, Lester; Finer, Gal; Langman, Craig B

2017-09-01

Pediatric primary hypertension (HTN) is increasingly recognized, but the effect of patient characteristics such as obesity and race on treatment outcomes is not well described. The renin-angiotensin-aldosterone system (RAAS) may also contribute to HTN. We hypothesized patient parameters of these factors, including baseline RAAS, influence blood pressure (BP) response to pharmacological treatment in HTN. This was a retrospective cohort of 102 consecutive patients with HTN. Primary outcomes were changes per year in systolic and diastolic BP (SBP, DBP). Secondary outcome was change per year in left ventricular mass index (LVMI). We evaluated whether baseline plasma renin activity (PRA), aldosterone, renin-to-aldosterone ratio, overweight/obesity, race, initial drug choice, and multidrug therapy were associated with the outcomes using general linear regression models adjusted for confounding variables. Racially diverse (43% Hispanic, 28% black, 25% white) and predominantly overweight/obese (75%) patients were studied. Median length of follow-up was 14.5 months. Higher baseline aldosterone was associated with decreased SBP (-1.03 mmHg/year), DBP (-0.95 mmHg/year), and DBP z score (-0.07/year) during the study period. Higher baseline PRA was associated with decreased SBP z score (-0.04/year) and LVMI (-2.89 g/m 2.7 /year). Stratified analyses revealed the relationships between baseline aldosterone and PRA, and annual reductions in outcomes were strengthened in nonobese and white patients. Pretreatment aldosterone and PRA predicted short-term follow-up BP and LVMI, especially in nonobese and white patients. The RAAS profile could guide treatment of HTN and suggests consideration of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers as first-line treatment options.

Familial Analysis of Epistatic and Sex-Dependent Association of Genes of the Renin-Angiotensin-Aldosterone System and Blood Pressure.

PubMed

Scurrah, Katrina J; Lamantia, Angela; Ellis, Justine A; Harrap, Stephen B

2017-06-01

Renin-angiotensin-aldosterone system genes have been inconsistently associated with blood pressure, possibly because of unrecognized influences of sex-dependent genetic effects or gene-gene interactions (epistasis). We tested association of systolic blood pressure with single-nucleotide polymorphisms (SNPs) at renin ( REN ), angiotensinogen ( AGT ), angiotensin-converting enzyme ( ACE ), angiotensin II type 1 receptor ( AGTR1 ), and aldosterone synthase ( CYP11B2 ), including sex-SNP or SNP-SNP interactions. Eighty-eight tagSNPs were tested in 2872 white individuals in 809 pedigrees from the Victorian Family Heart Study using variance components models. Three SNPs (rs8075924 and rs4277404 at ACE and rs12721297 at AGTR1 ) were individually associated with lower systolic blood pressure with significant ( P <0.00076) effect sizes ≈1.7 to 2.5 mm Hg. Sex-specific associations were seen for 3 SNPs in men (rs2468523 and rs2478544 at AGT and rs11658531 at ACE ) and 1 SNP in women (rs12451328 at ACE ). SNP-SNP interaction was suggested ( P <0.005) for 14 SNP pairs, none of which had shown individual association with systolic blood pressure. Four SNP pairs were at the same gene (2 for REN , 1 for AGT , and 1 for AGTR1 ). The SNP rs3097 at CYP11B2 was represented in 5 separate pairs. SNPs at key renin-angiotensin-aldosterone system genes associate with systolic blood pressure individually in both sexes, individually in one sex only and only when combined with another SNP. Analyses that incorporate sex-dependent and epistatic effects could reconcile past inconsistencies and account for some of the missing heritability of blood pressure and are generally relevant to SNP association studies for any phenotype. © 2017 American Heart Association, Inc.

The Role of RAAS Inhibition by Aliskiren on Paracetamol-Induced Hepatotoxicity Model in Rats.

PubMed

Karcioglu, Saliha Sena; Palabiyik, Saziye Sezin; Bayir, Yasin; Karakus, Emre; Mercantepe, Tolga; Halici, Zekai; Albayrak, Abdulmecit

2016-03-01

Paracetamol is one of the most popular and widely used analgesic and antipyretic agents, but an overdose can cause hepatotoxicity and lead to acute liver failure. Aliskiren directly inhibits renin which downregulates the renin-angiotensin-aldosterone system (RAAS). Recent findings suggest that RAAS system takes part in the pathogenesis of liver fibrosis. We aimed to reveal the relationship between hepatotoxicity and the RAAS by examining paracetamol induced hepatotoxicity. Rats were separated into five groups as follows: control, 100 mg/kg aliskiren (p.o.), 2 g/kg paracetamol (per os (p.o.)), 2 g/kg paracetamol + 50mg/kg aliskiren (p.o.), and 2 g/kg paracetamol + 100 mg/kg aliskiren(p.o.). Samples were analyzed at the biochemical, molecular, and histopathological levels. Paracetamol toxicity increased alanine aminotransferases (ALT), aspartate aminotransferases (AST), renin, and angiotensin II levels in the serum samples. In addition, the SOD activity and glutathione (GSH) levels decreased while Lipid Peroxidation (MDA) levels increased in the livers of the rats treated with paracetamol. Paracetamol toxicity caused a significant increase in TNF-α and TGF-β. Both aliskiren doses showed an improvement in ALT, AST, oxidative parameters, angiotensin II, and inflammatory cytokines. Only renin levels increased in aliskiren treatment groups due to its pharmacological effect. A histopathological examination of the liver showed that aliskiren administration ameliorated the paracetamol-induced liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the paracetamol group but not in other treatment groups when compared to the control group. In light of these observations, we suggest that the therapeutic administration of aliskiren prevented oxidative stress and cytokine changes and also protected liver tissues during paracetamol toxicity by inhibiting the RAAS. © 2015 Wiley Periodicals, Inc.

Increased methylglyoxal formation with upregulation of renin angiotensin system in fructose fed Sprague Dawley rats.

PubMed

Dhar, Indu; Dhar, Arti; Wu, Lingyun; Desai, Kaushik M

2013-01-01

The current epidemic of obesity and type 2 diabetes is attributed to a high carbohydrate diet, containing mainly high fructose corn syrup and sucrose. More than two thirds of diabetic patients have hypertension. Methylglyoxal is a highly reactive dicarbonyl generated during glucose and fructose metabolism, and a major precursor of advanced glycation end products (AGEs). Plasma methylglyoxal levels are increased in hypertensive rats and diabetic patients. Our aim was to examine the levels of methylglyoxal, mediators of the renin angiotensin system and blood pressure in male Sprague-Dawley rats treated with a high fructose diet (60% of total calories) for 4 months. The thoracic aorta and kidney were used for molecular studies, along with cultured vascular smooth muscle cells (VSMCs). HPLC, Western blotting and Q-PCR were used to measure methylglyoxal and reduced glutathione (GSH), proteins and mRNA, respectively. Fructose treated rats developed a significant increase in blood pressure. Methylglyoxal level and protein and mRNA for angiotensin II, AT1 receptor, adrenergic α1D receptor and renin were significantly increased, whereas GSH levels were decreased, in the aorta and/or kidney of fructose fed rats. The protein expression of the receptor for AGEs (RAGE) and NF-κB were also significantly increased in the aorta of fructose fed rats. MG treated VSMCs showed increased protein for angiotensin II, AT1 receptor, and α1D receptor. The effects of methylglyoxal were attenuated by metformin, a methylglyoxal scavenger and AGEs inhibitor. In conclusion, we report a strong association between elevated levels of methylglyoxal, RAGE, NF-κB, mediators of the renin angiotensin system and blood pressure in high fructose diet fed rats.

Angiotensin II and its different receptor subtypes in placenta and fetal membranes.

PubMed

Kalenga, M K; de Gasparo, M; Thomas, K; de Hertogh, R

1996-01-01

The recent discovery of a local renin-angiotensin system in trophoblastic tissues has raised many questions regarding its role in the physiology of normal gestation and its implications in the pathophysiology of hypertension during pregnancy. In this article, the authors first review the most interesting aspects of the chorioplacental renin-angiotensin system, dwelling on the tissue distribution of angiotensin II and its receptor subtypes in the placenta and fetal membranes of different species. The relationship between angiotensin II and other locally synthesized chorioplacental substances is also analysed and the therapeutic implications of phenomena observed in pregnancy-associated hypertension are discussed.

Renin-Angiotensin System in Diabetes.

PubMed

Rein, Johannes; Bader, Michael

2017-11-17

The renin-angiotensin system (RAS) has two different axes, the classical one with the effector peptide angiotensin II and the new one with the effector peptide angiotensin (1-7). Both peptides have been shown to be involved in the pathogenesis of diabetes mellitus and its consequences, nephropathy, retinopathy and cardiomyopathy in animal models and patients. In diabetes, angiotensin II acts mostly deleterious and angiotensin (1-7) protective. In this review we summarize the knowledge about the role of the different RAS axes in diabetes mellitus and the use of drugs interfering with the RAS in the therapy of the disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Hormonal status and fluid electrolyte metabolism in motion sickness

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

Grigoriev, A.I.; Nichiporuk, I.A.; Yasnetsov, V.V.

1988-04-01

In the first experimental series, 10 healthy male test subjects with a high susceptibility to motion sickness showed a significant increase of ACTH, cortisol, STH, prolactin, ADH, aldosterone concentrations, and plasma renin activity after vestibular tests. The 10 subjects with a moderate susceptibility exhibited a still higher increase of the hormones, except plasma renin. The 8 test subjects with a low susceptibility displayed a considerable increase in ACTH, cortisol, and STH after vestibular stimulation. In the second experimental series, the increase of STH, cortisol, ADH, aldosterone and renin occurred immediately after rotation in the moderate susceptibility subjects and an hourmore » after exposure in the high susceptibility subjects. This may be indicative of specific immediate adaptation mechanisms or excitation transfer in the CNS in high susceptibility persons. In the third experimental animal series, the permeability of the blood-brain barrier for /sup 125/I and IgG increased after rotation. Greater concentrations of potassium, chloride, and urea in CSF are suggestive of an inhibition process activation in the CNS and, probably, of an active urea transport by the vascular plexus epithelium which maintains constant osmotic pressure of cerebral extracellular fluid and prevents hyper-hydration of CNS neurons.« less

Upregulation of Cyclooxygenase-2 Expression in Porcine Macula Densa With Chronic Nitric Oxide Synthase Inhibition

PubMed Central

Kommareddy, M.; McAllister, R. M.; Ganjam, V. K.; Turk, J. R.; Laughlin, M. Harold

2012-01-01

The objective of this study was to investigate the effects of chronic inhibition of nitric oxide synthase (NOS) on cyclooxygenase-2 (COX-2) expression in the macula densa (MD) of swine, as well as the effects on expression of related proteins. Adult female Yucatan swine were given either tap water (control, n = 6) or water with NG-nitro-l-arginine methyl ester (L-NAME, 100 mg/liter, n = 5) for a minimum of 30 days. Duplicate samples of kidney were fixed or snap frozen. There was a significant (P = .0082) upregulation of COX-2 mRNA expression in the MD of L-NAME, as well as an apparent increase in COX-2 protein. Plasma renin activity also increased with L-NAME treatment (control, 0.34 ± 0.08 ng/ml; L-NAME, 1.26 ± 0.03 ng/ml; P = .00000003). There were no differences between groups in expression of either inducible NOS or renin protein or in serum electrolyte concentrations. In conclusion, with chronic inhibition of NOS, COX-2 in MD is upregulated, perhaps to compensate for loss of nitric oxide. Increases in COX-2 products may counteract renal arteriolar constriction and sustain renin release. PMID:21160023

Upregulation of cyclooxygenase-2 expression in porcine macula densa with chronic nitric oxide synthase inhibition.

PubMed

Kommareddy, M; McAllister, R M; Ganjam, V K; Turk, J R; Laughlin, M Harold

2011-11-01

The objective of this study was to investigate the effects of chronic inhibition of nitric oxide synthase (NOS) on cyclooxygenase-2 (COX-2) expression in the macula densa (MD) of swine, as well as the effects on expression of related proteins. Adult female Yucatan swine were given either tap water (control, n = 6) or water with N (G)-nitro-L-arginine methyl ester (L-NAME, 100 mg/liter, n = 5) for a minimum of 30 days. Duplicate samples of kidney were fixed or snap frozen. There was a significant (P = .0082) upregulation of COX-2 mRNA expression in the MD of L-NAME, as well as an apparent increase in COX-2 protein. Plasma renin activity also increased with L-NAME treatment (control, 0.34 ± 0.08 ng/ml; L-NAME, 1.26 ± 0.03 ng/ml; P = .00000003). There were no differences between groups in expression of either inducible NOS or renin protein or in serum electrolyte concentrations. In conclusion, with chronic inhibition of NOS, COX-2 in MD is upregulated, perhaps to compensate for loss of nitric oxide. Increases in COX-2 products may counteract renal arteriolar constriction and sustain renin release.

Emerging drugs which target the renin-angiotensin-aldosterone system.

PubMed

Steckelings, Ulrike Muscha; Paulis, Ludovit; Unger, Thomas; Bader, Michael

2011-12-01

The renin-angiotensin-aldosterone system (RAAS) is already the most important target for drugs in the cardiovascular system. However, still new developments are underway to interfere with the system on different levels. The novel strategies to interfere with RAAS aim to reduce the synthesis of the two major RAAS effector hormones, angiotensin (Ang) II and aldosterone, or interfere with their receptors, AT1 and mineralocorticoid receptor, respectively. Moreover, novel targets have been identified in RAAS, such as the (pro)renin receptor, and molecules, which counteract the classical actions of Ang II and are therefore beneficial in cardiovascular diseases. These include the AT2 receptor and the ACE2/Ang-(1-7)/Mas axis. The search for drugs activating these tissue-protective arms of RAAS is therefore the most innovative field in RAAS pharmacology. Most of the novel pharmacological strategies to inhibit the classical RAAS need to prove their superiority above the existing treatment in clinical trials and then have to compete against these now quite cheap drugs in a competitive market. The newly discovered targets have functions beyond the cardiovascular system opening up novel therapeutic areas for drugs interfering with RAAS components.

A Novel Single-Strand RNAi Therapeutic Agent Targeting the (Pro)renin Receptor Suppresses Ocular Inflammation.

PubMed

Kanda, Atsuhiro; Ishizuka, Erdal Tan; Shibata, Atsushi; Matsumoto, Takahiro; Toyofuku, Hidekazu; Noda, Kousuke; Namba, Kenichi; Ishida, Susumu

2017-06-16

The receptor-associated prorenin system (RAPS) refers to the pathogenic mechanism whereby prorenin binding to the (pro)renin receptor [(P)RR] dually activates the tissue renin-angiotensin system (RAS) and RAS-independent intracellular signaling. Here we revealed significant upregulation of prorenin and soluble (P)RR levels in the vitreous fluid of patients with uveitis compared to non-inflammatory controls, together with a positive correlation between these RAPS components and monocyte chemotactic protein-1 among several upregulated cytokines. Moreover, we developed a novel single-strand RNAi agent, proline-modified short hairpin RNA directed against human and mouse (P)RR [(P)RR-PshRNA], and we determined its safety and efficacy in vitro and in vivo. Application of (P)RR-PshRNA in mice caused significant amelioration of acute (uveitic) and chronic (diabetic) models of ocular inflammation with no apparent adverse effects. Our findings demonstrate the significant implication of RAPS in the pathogenesis of human uveitis and the potential usefulness of (P)RR-PshRNA as a therapeutic agent to reduce ocular inflammation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Thermoase-Derived Flaxseed Protein Hydrolysates and Membrane Ultrafiltration Peptide Fractions Have Systolic Blood Pressure-Lowering Effects in Spontaneously Hypertensive Rats

PubMed Central

Nwachukwu, Ifeanyi D.; Girgih, Abraham T.; Malomo, Sunday A.; Onuh, John O.; Aluko, Rotimi E.

2014-01-01

Thermoase-digested flaxseed protein hydrolysate (FPH) samples and ultrafiltration membrane-separated peptide fractions were initially evaluated for in vitro inhibition of angiotensin I-converting enzyme (ACE) and renin activities. The two most active FPH samples and their corresponding peptide fractions were subsequently tested for in vivo antihypertensive activity in spontaneously hypertensive rats (SHR). The FPH produced with 3% thermoase digestion showed the highest ACE- and renin-inhibitory activities. Whereas membrane ultrafiltration resulted in significant (p < 0.05) increases in ACE inhibition by the <1 and 1–3 kDa peptides, only a marginal improvement in renin-inhibitory activity was observed for virtually all the samples after membrane ultrafiltration. The FPH samples and membrane fractions were also effective in lowering systolic blood pressure (SBP) in SHR with the largest effect occurring after oral administration (200 mg/kg body weight) of the 1–3 kDa peptide fraction of the 2.5% FPH and the 3–5 kDa fraction of the 3% FPH. Such potent SBP-lowering capacity indicates the potential of flaxseed protein-derived bioactive peptides as ingredients for the formulation of antihypertensive functional foods and nutraceuticals. PMID:25302619

Aliskiren: review of efficacy and safety data with focus on past and recent clinical trials.

PubMed

Sen, Selçuk; Sabırlı, Soner; Ozyiğit, Tolga; Uresin, Yağız

2013-09-01

Aliskiren is the newest antihypertensive drug and the first orally active direct renin inhibitor to become available for clinical use. Clinical data have substantiated that the antihypertensive effectiveness of aliskiren is similar to that of the other major antihypertensive agents. Furthermore, aliskiren has a similar safety profile to placebo. Combination treatment with aliskiren showed significant blood pressure and proteinuria reductions compared with monotherapy. Aliskiren decreases plasma renin activity in contrast to other renin-angiotensin-aldosterone related drugs. The efficacy of aliskiren in treating major cardiovascular events and the prevention of end-organ damage are being investigated in the ASPIRE HIGHER program. Although the first studies of the ASPIRE HIGHER program such as ALOFT, AVOID, AGELESS showed favorable findings, ASPIRE and AVANT-GARDE studies provided contradictory results. Subsequently, the ALTITUDE study was terminated early because of safety issues and lack of beneficial effects. Most recently, the ASTRONAUT trial showed no reduction in cardiovascular death or heart failure rehospitalization with the addition of aliskiren to standard therapy in patients who were hospitalized for heart failure and with reduced left-ventricular ejection fraction. The results of ongoing studies in other patient groups such as the ATMOSPHERE trial are awaited.

Aliskiren: a novel renoprotective agent or simply an alternative to ACE inhibitors?

PubMed

Wiggins, Kathryn J; Kelly, Darren J

2009-07-01

Chronic kidney disease (CKD) is a common condition that is increasing in prevalence in developed nations. The economic and psychosocial costs of CKD are considerable, and are associated with high levels of morbidity and mortality. Specific treatments do not exist for many causes of CKD. Therefore, treatment is reliant on the introduction of therapies that retard progression of structural renal damage and renal impairment. At present, aside from judicious use of antihypertensive agents to lower blood pressure, and possibly low-protein diets and statin therapy, blockade of the renin-angiotensin-aldosterone system (RAAS) with angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) are the only widely available treatments. Although these measures attenuate the inexorable progression to renal failure, they do not halt it. One limiting factor may be feedback effects of ACEis and ARBs, such as increased plasma renin activity. Aliskiren is a newer agent that inhibits renin, the rate-limiting step in the RAAS. There are several theoretical reasons to suggest that aliskiren may have renoprotective actions superior to those of ACEis and ARBs. In this paper the available evidence regarding renoprotective effects of aliskiren is reviewed, with an emphasis on comparison with ACEis and ARBs.

Vitamin D increases plasma renin activity independently of plasma Ca2+ via hypovolemia and β-adrenergic activity

PubMed Central

Atchison, Douglas K.; Harding, Pamela

2013-01-01

1, 25-Dihydroxycholechalciferol (calcitriol) and 19-nor-1, 25-dihydroxyvitamin D2 (paricalcitol) are vitamin D receptor (VDR) agonists. Previous data suggest VDR agonists may actually increase renin-angiotensin activity, and this has always been assumed to be mediated by hypercalcemia. We hypothesized that calcitriol and paricalcitol would increase plasma renin activity (PRA) independently of plasma Ca2+ via hypercalciuria-mediated polyuria, hypovolemia, and subsequent increased β-adrenergic sympathetic activity. We found that both calcitriol and paricalcitol increased PRA threefold (P < 0.01). Calcitriol caused hypercalcemia, but paricalcitol did not. Both calcitriol and paricalcitol caused hypercalciuria (9- and 7-fold vs. control, P < 0.01) and polyuria (increasing 2.6- and 2.2-fold vs. control, P < 0.01). Paricalcitol increased renal calcium-sensing receptor (CaSR) expression, suggesting a potential cause of paricalcitol-mediated hypercalciuria and polyuria. Volume replacement completely normalized calcitriol-stimulated PRA and lowered plasma epinephrine by 43% (P < 0.05). β-Adrenergic blockade also normalized calcitriol-stimulated PRA. Cyclooxygenase-2 inhibition had no effect on calcitriol-stimulated PRA. Our data demonstrate that vitamin D increases PRA independently of plasma Ca2+ via hypercalciuria, polyuria, hypovolemia, and increased β-adrenergic activity. PMID:23926179

Sodium sensitive hypertension: renal and adrenal non-modulation in its pathogenesis

NASA Technical Reports Server (NTRS)

Hollenberg, N. K.; Williams, G. H.

1988-01-01

The thrust of this essay will be to organize a growing body of evidence which indicates that an abnormality of the kidney, and the adrenal, involving disordered regulation through the renin-angiotensin system, is responsible for the pathogenesis in about 45% of patients--a discrete subgroup that may be most common cause of hypertension. That fundamental abnormality leads to disordered renal sodium handling and sodium-sensitive hypertension, abnormalities in the renal vascular response to changes in sodium intake and to angiotensin II, blunted decrements of renin release in response to saline or angiotensin II, and an accentuated renal vasodilator response to angiotensin converting enzyme (ACE) inhibition. ACE inhibition not only increases renal blood flow substantially more in these patients than it does in normal subjects, ACE inhibition also restores to normal the renal vascular and adrenal response to angiotensin II, renin release in response to angiotensin II, renal sodium handling--and ultimately blood pressure. Finally, and perhaps most intriguing, similar abnormalities have been found in 50% of the normotensive offspring of patients with essential hypertension and evidence is accruing to indicate that the abnormality is inherited as a Mendelian dominant.

Effects of olmesartan on the renin-angiotensin-aldosterone system for patients with essential hypertension after cardiac surgery--investigation using a candesartan change-over study.

PubMed

Sezai, Akira; Soma, Masayoshi; Hata, Mitsumasa; Yoshitake, Isamu; Unosawa, Satoshi; Wakui, Shinji; Shiono, Motomi

2011-01-01

Various angiotensin II receptor blockers are widely used for the treatment of hypertension in recent years. The results of large-scale clinical studies have shown that they have various efficacies: not only hypotensive effects but also organ protective effects. In this study, the effects of a change-over from candesartan to olmesartan on renin-angiotensin-aldsterone system, cardiomegaly and peripheral circulation were studied. Participants enrolled in this trial were outpatients with essential hypertension after cardiac surgery who had received candesartan for more than one year. Fifty-six patients switched from candesartan to olmesartan. The primary endpoints were 1) renin activity, angiotensin II, aldosterone, and 2) left ventricular mass index (LVMI). It was clear that angiotensin II and aldosterone are decreased by the potent hypotensive effects of olmesartan in a change-over from candesartan to olmesartan. Since LVMI and BNP were decreased, inhibitory effects on myocardial hypertrophy were also confirmed. In the present study, left ventricular hypertrophy and on arterial compliance were inhibited by a decrease in angiotensin II and aldosterone due to the change-over to olmesartan. In the future, protective effects on organs will be clarified by long-term observations.

Atrial fibrillation and arterial hypertension: A common duet with dangerous consequences where the renin angiotensin-aldosterone system plays an important role.

PubMed

Seccia, Teresa Maria; Caroccia, Brasilina; Muiesan, Maria Lorenza; Rossi, Gian Paolo

2016-03-01

Atrial fibrillation (AF) represents the most common sustained cardiac arrhythmia, as it affects 1%-2% of the general population and up to 15% of people over 80 years. High blood pressure, due to its high prevalence in the general population, is by far the most common condition associated with AF, although a variety of diseases, including valvular, coronary heart and metabolic diseases, are held to create the substrate favouring AF. Due to the concomitance of these conditions, it is quite challenging to dissect the precise role of high blood pressure in triggering/causing AF. Hence, even though the intimate association between high blood pressure and AF has been known for decades, the underlying mechanisms remain partially unknown. Accumulating evidences point to a major role of the renin-angiotensin-aldosterone system in inducing cardiac inflammation and fibrosis, and therefore electric and structural atrial and ventricular remodelling, with changes in ions and cell junctions leading to AF development. These evidences are herein reviewed with a particular emphasis to the role of the renin-angiotensin-system aldosterone system. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Current status of renin-aldosterone angiotensin system-targeting anti-hypertensive drugs as therapeutic options for Alzheimer's disease.

PubMed

Ashby, Emma Louise; Kehoe, Patrick G

2013-10-01

Hypertension is a modifiable risk factor for Alzheimer's disease (AD) and other dementias. Yet, despite this well-documented association, few of the current strategies to treat AD are directed at this possible target. The renin-aldosterone angiotensin system (RAAS) is a centrally active modifiable pathway that is involved in cerebral blood flow regulation. Currently, three classes of RAAS-targeting drugs are licensed for treatment of peripheral hypertension--angiotensin-converting enzyme inhibitors (ACE-Is), angiotensin II receptor blockers (ARBs) and direct renin inhibitors (DRIs). All of these are generally well tolerated and have been shown to offer varying degrees of protection on aspects of cognition and dementia, thus making them an attractive therapeutic option for AD. This review summarises existing evidence regarding the plausibility of using RAAS-targeting drugs as a strategy to treat AD and highlights unresolved aspects to such approaches, namely the potential impact of altering angiotensin II-mediated processes in the central nervous system. Continued biochemical research of the RAAS pathway in combination with formal investigation of current RAAS-modifying drugs in randomised clinical trials is now necessary to determine their therapeutic value in AD.

Renin Angiotensin Aldosterone System (RAAS): its biology and drug targets for treating diabetic nephropathy.

PubMed

Zain, Maryam; Awan, Fazli Rabbi

2014-09-01

Diabetes mellitus is a multifactorial disorder of hyperglycemia caused by a combination of biochemical, molecular and genetic factors, which leads to the dysfunction of various organs including kidneys. Diabetic nephropathy (DN) is one of the microvascular complications of diabetes that results due to poor glycemic control. Several molecular and biochemical pathways have been implicated in the pathogenesis of DN. Of these, the Renin Angiotensin Aldosterone System (RAAS) is considered as a key pathway. RAAS involves various subsystems which contribute to the development of DN. Mutations in several genes of the RAAS pathway have been associated with the development of DN. These genes or their products present them as therapeutic targets for potent drugs to control or prevent DN, and development of new drugs for targeting the RAAS. Drugs in use for DN are mainly the Angiotensin Converting Enzyme (ACE) inhibitors, Angiotensin Receptors Blockers (ARB) and renin inhibitors which play important roles in reducing DN. Hence, the present review is focused on the pathophysiology and genetic factors for DN by exploring the RAAS pathway and emphasizing the benefits of blocking this pathway to control and prevent DN.

Plasma vasopressin and renin activity in women exposed to bed rest and +G/z/ acceleration

NASA Technical Reports Server (NTRS)

Keil, L. C.; Ellis, S.

1976-01-01

To study the effect of prolonged recumbency on plasma vasopressin and renin activity, eight women were subjected to 17 days of absolute bed rest. The tolerance to +3G vertical acceleration of the subjects was tested before and after 14 days of bed rest. From day 2 and through day 17 of bed rest, plasma arginine vasopressin (AVP) levels were reduced 33%. Plasma renin activity (PRA) increased 91% above ambulatory control values from days 10 through 15 of bed rest. When compared to precentrifuge values, exposure to vertical acceleration prior to bed rest provoked a 20-fold rise in mean plasma AVP but resulted in only a slight increase in PRA. After bed rest, acceleration increased plasma AVP 7-fold; however, the magnitude of this increase was less than the post +3G acceleration value obtained prior to bed rest. After bed rest, no significant rise was noted in PRA following +3G acceleration. This study demonstrates that prolonged bed rest leads to a significant rise in the PRA of female subjects, while exposure to positive vertical acceleration provokes a marked rise in plasma AVP.

The risks and benefits of patients temporarily discontinuing medications in the event of an intercurrent illness: a systematic review protocol.

PubMed

Morden, Andrew; Horwood, Jeremy; Whiting, Penny; Savovic, Jelena; Tomlinson, Laurie; Blakeman, Thomas; Tomson, Charles; Richards, Alison; Stone, Tracey; Caskey, Fergus

2015-10-24

Acute kidney injury (AKI) is common and often leads to significant morbidity and/or death. The development of AKI, or complications associated with it, may be due to use of certain medications in at-risk patients experiencing an intercurrent illness. Implicated drugs include diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), metformin and sulfonylureas. Expert consensus opinion (and clinical guidelines) recommend considering discontinuation of diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin and sulfonylureas in the event of an intercurrent illness to prevent AKI onset or reduce severity or complications. However, the evidence base for these recommendations is very limited. This systematic review aims to address the available evidence for the temporary discontinuation of diuretics, ACE inhibitors, angiotensin receptor blockers, direct renin inhibitors, non-steroidal anti-inflammatories and metformin and sulfonylureas for those at risk of AKI or with newly diagnosed AKI. Randomised controlled trials; non-randomised trials; cohort studies; case-control studies; interrupted time series studies; and before-and-after studies featuring adults aged 18 and over in any setting currently taking diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs and metformin; experiencing an intercurrent illness; or undergoing a radiological/surgical procedure (planned or unplanned) will be searched for. Relevant trial registers and systematic review databases will be searched. Systematic reviews will be assessed for methodological quality using the ROBIS tool, trials will be assessed using the Cochrane risk of bias tool, and observational studies will be assessed using the ACROBAT-NRS tool. If sufficient studies assessing similar populations, study type, settings and outcomes are found, then a formal meta-analysis will be performed to estimate summary measures of effect. If not, a narrative synthesis will be adopted. This review will synthesise evidence for the efficacy of discontinuing diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin or sulfonylureas to prevent or delay onset of AKI or associated complications. Results will provide guidance on efficacy and safety of this strategy and potentially help to develop an intervention to test the best mechanism of guiding medication discontinuation in at-risk populations. PROSPERO CRD42015023210.

Effect of additive renin inhibition with aliskiren on renal blood flow in patients with Chronic Heart Failure and Renal Dysfunction (Additive Renin Inhibition with Aliskiren on renal blood flow and Neurohormonal Activation in patients with Chronic Heart Failure and Renal Dysfunction).

PubMed

Schroten, Nicolas F; Damman, Kevin; Hemmelder, Marc H; Voors, Adriaan A; Navis, Gerjan; Gaillard, Carlo A J M; van Veldhuisen, Dirk J; Van Gilst, Wiek H; Hillege, Hans L

2015-05-01

We examined the effect of the renin inhibitor, aliskiren, on renal blood flow (RBF) in patients with heart failure with reduced ejection fraction (HFREF) and decreased glomerular filtration rate (GFR). Renal blood flow is the main determinant of GFR in HFREF patients. Both reduced GFR and RBF are associated with increased mortality. Aliskiren can provide additional renin-angiotensin-aldosterone system inhibition and increases RBF in healthy individuals. Patients with left ventricular ejection fraction ≤45% and estimated GFR 30 to 75 mL/min per 1.73 m(2) on optimal medical therapy were randomized 2:1 to receive aliskiren 300 mg once daily or placebo. Renal blood flow and GFR were measured using radioactive-labeled (125)I-iothalamate and (131)I-hippuran at baseline and 26 weeks. After 41 patients were included, the trial was halted based on an interim safety analysis showing futility. Mean age was 68 ± 9 years, 82% male, GFR (49 ± 16 mL/min per 1.73 m(2)), RBF (294 ± 77 mL/min per 1.73 m(2)), and NT-proBNP 999 (435-2040) pg/mL. There was a nonsignificant change in RBF after 26 weeks in the aliskiren group compared with placebo (-7.1 ± 30 vs +14 ± 54 mL/min per 1.73 m(2); P = .16). However, GFR decreased significantly in the aliskiren group compared with placebo (-2.8 ± 6.0 vs +4.4 ± 9.6 mL/min per 1.73 m(2); P = .01) as did filtration fraction (-2.2 ± 3.3 vs +1.1 ± 3.1%; P = .01). There were no significant differences in plasma aldosterone, NT-proBNP, urinary tubular markers, or adverse events. Plasma renin activity was markedly reduced in the aliskiren group versus placebo throughout the treatment phase (P = .007). Adding aliskiren on top of optimal HFREF medical therapy did not improve RBF and was associated with a reduction of GFR and filtration fraction. Copyright © 2015 Mosby, Inc. All rights reserved.

[Adrenal hormones in the formation of atherosclerotic precursors in adolescents with primary arterial hypertension].

PubMed

Bogmat, L F

1993-01-01

The components of blood lipid spectrum (total cholesterol, triglycerides and high density lipoprotein cholesterol) were studied in 131 adolescents (12-18 years old) with primary arterial hypertension at various levels of adrenal hormones (hydrocortisone and aldosterone) and blood plasma renin activity. The optimal ratio of lipid components in blood was detected if concentrations of adrenal hormones and blood plasma renin activity were low. Hyperfunction of the adrenal cortex in teen-agers contributed both to the development of hypertension and to atherosclerotic changes in vessels. This suggests that definite forms of hypertension occurred in adults, with specific impairments in the metabolism of blood serum lipids, were developed during the juvenile age.

The Renin Angiotensin Aldosterone System in Obesity and Hypertension: Roles in the Cardiorenal Metabolic Syndrome.

PubMed

Cabandugama, Peminda K; Gardner, Michael J; Sowers, James R

2017-01-01

In the United States, more than 50 million people have blood pressure at or above 120/80 mm Hg. All components of cardiorenal metabolic syndrome (CRS) are linked to metabolic abnormalities and obesity. A major driver for CRS is obesity. Current estimates show that many of those with hypertension and CRS show some degree of systemic and cardiovascular insulin resistance. Several pathophysiologic factors participate in the link between hypertension and CRS. This article updates recent literature with a focus on the function of insulin resistance, obesity, and renin angiotensin aldosterone system-mediated oxidative stress on endothelial dysfunction and the pathogenesis of hypertension. Copyright © 2016 Elsevier Inc. All rights reserved.

[Pathophysiological role of tissue renin-angiotensin-aldosterone system (RAAS) in human atherosclerosis].

PubMed

Fukui, Kensuke; Yamada, Hiroyuki; Matsubara, Hiroaki

2012-09-01

Renin-angiotensin-aldosterone system (RAAS) has been demonstrated to play an important role in the pathogenesis of atherosclerosis development both in animal experiments and in clinical studies. Numerous clinical studies have shown that blockade of RAAS exerts beneficial effects to restore the impaired endothelial function and to reduce the mortality and morbidity of cardiovascular diseases beyond their blood pressure lowering effect. However, the underlying mechanisms of stabilizing vulnerable plaque and inhibiting plaque rupture associated with acute coronary syndrome have not yet been fully elucidated. Here, we summarized the characteristics of tissue RAAS expressions in human atherosclerotic lesions and assessed their therapeutic relevance in the prevention of atherosclerotic cardiovascular diseases.

[Osmolality and secretion of vasopressins during pregnancy in Meriones crassus].

PubMed

Baddouri, K; Quyou, A

1991-01-01

Endocrine and renal parameters were measured in a desert rodent, Meriones crassus. In virgin females, the urine and plasma osmolality was 2018 +/- 136 and 325 +/- 3 mosm/kg (m +/- SEM), the level of circulating vasopressin, 162 +/- 22 pg/ml and the plasma renin activity 14.3 +/- 0.9 ng/ml per h. During pregnancy, the renin-angiotensin system was activated, and the plasma vasopressin values remained similar to those of virgin animals in spite of a lower blood plasma osmotic pressure. During this period, the regulation of the hydromineral balance was modified. These data suggest a lowering of the osmotic thresholds for vasopressin and possibly also for thirst during pregnancy in this desert rodent.

Nephroprotective action of renin-angiotensin-aldosterone system blockade in chronic kidney disease patients: the landscape after ALTITUDE and VA NEPHRON-D trails.

PubMed

Rutkowski, Boleslaw; Tylicki, Leszek

2015-03-01

The intervention in the renin-angiotensin-aldosterone system (RAAS) is currently the most effective strategy that combines blood pressure lowering and renoprotection. Several large, randomized, controlled trials evidenced the renoprotective potential of the angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in nephropathies of almost any etiology. Mineralocorticoid receptor antagonists and direct renin inhibitor, aliskiren, as add-on treatments to standard therapy including the optimal dose of ACEIs or ARBs reduce albuminuria or proteinuria and slow development of renal dysfunction more than placebo. No clinical evidence is available however about whether these strategies may influence on long-term kidney outcome. Three recent trials suggested that aggressive RAAS blockade, that is, combination of 2 RAAS-blocking agents, does not decrease cardiovascular and renal morbidity and may carry an increased risk of serious complications. This article reviews an evidence-based approach on the use of RAAS-inhibiting agents in chronic kidney disease and considers the implementation of dual RAAS blockade with reference to the results of ALTITUDE and VA NEPHRON-D trails aiming to aid clinicians in their treatment decisions for patients with chronic kidney disease. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Control plasma renin activity and changes in sympathetic tone as determinants of minoxidil-induced increase in plasma renin activity.

PubMed Central

O'Malley, K; Velasco, M; Wells, J; McNay, J L

1975-01-01

A study was made of the possible mechanism(s) underlying minoxidil-induced increase in plasma renin activity (PRA). 10 patients with essential hypertension were treated with minoxidil and subsequently with a combination of minoxidil plus propranolol. Minoxidil lowered mean arterial pressure 31.6 plus or minus 3.3 mm Hg, mean plus or minus SEM. There was an associated increase in both PRA, 6.26 plus or minus 2.43 NG/ML/H, and heart rate, 21.4 plus or minus 2.7 beats/min. The changes in PRA and heart rate were positively correlated, r, 0.79. Addition of propranolol reduced mean arterial pressure by a further 10.1 plus or minus 1.5 mm Hg and returned heart rate to control levels. Propranolol reduced PRA significantly but not to control levels. Control PRA positively correlated with PRA on minoxidil, r, 0.97, and with PRA on minoxidil plus propranolol, r, 0.98. We conclude that control PRA is a major determinant of change in PRA with minoxidil. Minoxidil increased PRA by at least two mechanisms: (a) an adrenergic mechanism closely related to change in heart rate and blocked by propranolol, and (b) a mechanism(s) not sensitive to propranolol and possibly related to decrease in renal perfusion pressure. PMID:1127099

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis.

PubMed

Haznedaroglu, Ibrahim C; Beyazit, Yavuz

2013-03-01

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Prolonged fasting increases the response of the renin-angiotensin-aldosterone system, but not vasopressin levels, in postweaned northern elephant seal pups

NASA Technical Reports Server (NTRS)

Ortiz, R. M.; Wade, C. E.; Ortiz, C. L.

2000-01-01

The 8- to 12-week postweaning fast exhibited by northern elephant seal pups (Mirounga angustirostris) occurs without any apparent deleterious effects on fluid and electrolyte homeostasis. However, during the fast the role of vasopressin (AVP) has been shown to be inconclusive and the involvement of the renin-angiotensin-aldosterone system (RAAS) has yet to be examined. To examine the effects of prolonged fasting on these osmoregulatory hormones, 15 postweaned pups were serially blood-sampled during the first 49 days of their fast. Fasting did not induce significant changes in ionic or osmotic concentrations, suggesting electrolyte homeostasis. Total proteins were reduced by day 21 of fasting and remained depressed, suggesting a lack of dehydration. Aldosterone and plasma renin activity exhibited a correlated, linear increase over the first 49 days of the fast, suggesting an active RAAS. Aldosterone exhibited a parabolic trend over the fast with a peak at day 35, suggesting a shift in the sensitivity of the kidney to aldosterone later in the fast. AVP was elevated at day 49 only, but concentrations were relatively low. RAAS was modified during the postweaning fast in pups and appears to play a significant role in the regulation of electrolyte and, most likely, water homeostasis during this period. Copyright 2000 Academic Press.

Natriuretic Peptide Receptor Guanylyl Cyclase-A Protects Podocytes from Aldosterone-Induced Glomerular Injury

PubMed Central

Ogawa, Yoshihisa; Yokoi, Hideki; Kasahara, Masato; Mori, Kiyoshi; Kato, Yukiko; Kuwabara, Takashige; Imamaki, Hirotaka; Kawanishi, Tomoko; Koga, Kenichi; Ishii, Akira; Tokudome, Takeshi; Kishimoto, Ichiro; Sugawara, Akira; Nakao, Kazuwa

2012-01-01

Natriuretic peptides produced by the heart in response to cardiac overload exert cardioprotective and renoprotective effects by eliciting natriuresis, reducing BP, and inhibiting cell proliferation and fibrosis. These peptides also antagonize the renin-angiotensin-aldosterone system, but whether this mechanism contributes to their renoprotective effect is unknown. Here, we examined the kidneys of mice lacking the guanylyl cyclase-A (GC-A) receptor for natriuretic peptides under conditions of high aldosterone and high dietary salt. After 4 weeks of administering aldosterone and a high-salt diet, GC-A knockout mice, but not wild-type mice, exhibited accelerated hypertension with massive proteinuria. Aldosterone-infused GC-A knockout mice had marked mesangial expansion, segmental sclerosis, severe podocyte injury, and increased oxidative stress. Reducing the BP with hydralazine failed to lessen such changes; in contrast, blockade of the renin-angiotensin-aldosterone system markedly reduced albuminuria, ameliorated podocyte injury, and reduced oxidative stress. Furthermore, treatment with the antioxidant tempol significantly reduced albuminuria and abrogated the histologic changes. In cultured podocytes, natriuretic peptides inhibited aldosterone-induced mitogen-activated protein kinase phosphorylation. Taken together, these results suggest that renoprotective properties of the endogenous natriuretic peptide/GC-A system may result from the local inhibition of the renin-angiotensin-aldosterone system and oxidative stress in podocytes. PMID:22652704

Effect of hydration on plasma vasopressin, renin, and aldosterone responses to head-up tilt

NASA Technical Reports Server (NTRS)

Harrison, M. H.; Geelen, G.; Keil, L. C.; Wade, C. A.; Hill, L. C.

1986-01-01

If plasma vasopressin (PVP), plasma renin (PRA), and plasma aldosterone (PA) responses to change in posture are mediated only by alterations in intrathoracic baroreceptor activity hydration status should have minimal influence on these responses. To test this hypothesis, six male subjects underwent 45 min of 70 deg head-up tilt (HUT) following 26 h dehydration, and again, 105 min later, following rehydration. Compared with preceding supine hydrated control values, PVP, PRA, and PA increased (p less than 0.001) during dehydrated HUT, but only PVP and PRA increased during rehydrated HUT (p less than 0.001). The dissociation during rehydrated HUT of PRA and PA may have been related more to the reduction (p less than 0.001) in plasma potassium concentration than to the accompanying decrease (p less than 0.001) in plasma osmolality and sodium concentration. Although increases in PVP and PRA during HUT were attenuated (p less than 0.01) following rehydration, this attenuation was associated with the absence of symptoms of overt hypotension following rehydration. However, since rehydration did not abolish the increases in PVP and PRA induced by HUT, it is concluded that the present observations support the concept of intrathoracic baroreceptor involvement in the regulation of vasopressin secretion and renin release.

The relationship between vitamin D and the renin-angiotensin system in the pathophysiology of hypertension, kidney disease, and diabetes.

PubMed

Vaidya, Anand; Williams, Jonathan S

2012-04-01

Vitamin D has been implicated in the pathophysiology of extraskeletal conditions such as hypertension, kidney disease, and diabetes via its ability to negatively regulate the renin-angiotensin system (RAS). This article reviews the evidence supporting a link between vitamin D and the RAS in these conditions, with specific emphasis on translational observations and their limitations. A literature review of animal and human studies evaluating the role of vitamin D in hypertension, kidney disease, and diabetes was performed. Excess activity of the RAS has been implicated in the pathogenesis of hypertension, chronic kidney disease, decreased insulin secretion, and insulin resistance. Animal studies provide strong support for 1,25-dihydroxyvitamin D(3)-mediated downregulation of renin expression and RAS activity via its interaction with the vitamin D receptor. Furthermore, the activity of vitamin D metabolites in animals is associated with reductions in blood pressure, proteinuria and renal injury, and with improved β-cell function. Many observational, and a few interventional, studies in humans have supported these findings; however, there is a lack of well-designed prospective human interventional studies to definitively assess clinical outcomes. There is a need for more well-designed prospective interventional studies to validate this hypothesis in human clinical outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.

Hormonal control of angiotensinogen production.

PubMed

Dzau, V J; Herrmann, H C

The renin-angiotensin-aldosterone system appears to be under neural and hormonal control. Plasma angiotensinogen concentration is elevated in Cushing's disease, during pregnancy and in women taking oral contraceptives. An in vitro liver slice system was used to study the hormonal control of angiotensinogen synthesis and release in the rat. Dexamethasone administration in vivo resulted in increase in the in vitro rate of release of angiotensinogen by liver slices into the incubation media. This increase was inhibited by actinomycin D, an inhibitor of protein synthesis and vincristine which blocks secretion. Similarly, ethinyl estradiol treatment resulted in a 50% increase in angiotensinogen production. Hyperthyroid state was achieved by injecting rats with L-thyroxine daily for seven days. Hepatic production rate of angiotensinogen rose 21/2-fold above control and was accompanied by increases in plasma angiotensinogen concentration and plasma renin activity. In contrast, plasma angiotensinogen concentration and plasma renin activity were reduced in thyroidectomized rats. The rate of angiotensinogen production by liver slices of these rats decreased by five-fold below that of intact animals. These changes were largely corrected when thyroidectomized rats were treated with replacement doses of L-thyroxine. We conclude that hepatic angiotensinogen biosynthesis is under hormonal control. Glucocorticoid, estrogen and thyroid hormones all stimulate angiotensinogen production. These results may in part explain the pathogenesis of hypertension associated with certain disease states.

Positive relationship of sleep apnea to hyperaldosteronism in an ethnically diverse population.

PubMed

Sim, John J; Yan, Eric H; Liu, In Lu A; Rasgon, Scott A; Kalantar-Zadeh, Kamyar; Calhoun, David A; Derose, Stephen F

2011-08-01

Approximately, 50-60% of patients with sleep apnea have hypertension. To explore a mechanism of this relationship, we compared its prevalence in a hypertensive population with and without hyperaldosteronism. Using the Kaiser Permanente Southern California database, hypertensive individuals who had plasma aldosterone and plasma renin activity measured between 1 January 2006 and 31 December 2007 were evaluated. Hyperaldosteronism was defined as an aldosterone : renin ratio more than 30 and plasma aldosterone more than 20 ng/dl or an aldosterone : renin ratio more than 50 (ng/dl : ng/ml per h). Hypertension was identified by International Classification of Disease, Ninth Revision (ICD-9) coding and sleep apnea was defined by ICD-9 coding or procedural coding for dispensation of positive airway devices. Of 3428 hypertensive patients, 575 (17%) had hyperaldosteronism. Sleep apnea was present in 18% (105) with hyperaldosteronism vs. 9% (251) without hyperaldosteronism (P < 0.001). Odds ratio for sleep apnea in patients with hyperaldosteronism was 1.8 (95% confidence interval 1.3-2.6) after controlling for other sleep apnea risk factors. No ethnic group was at greater risk for sleep apnea. The prevalence of sleep apnea in a diverse hypertensive population is increased in patients with hyperaldosteronism, even when controlling for other sleep apnea risk factors.

Effect of dietary sodium intake on the responses to bicuculline in the paraventricular nucleus of rats.

PubMed

DiBona, G F; Jones, S Y

2001-08-01

The tachycardic, pressor, and renal sympathoexcitatory responses produced by administration of the gamma-aminobutyric acid antagonist bicuculline into the paraventricular nucleus of the rat are attenuated by the administration of losartan, an angiotensin II type 1 receptor antagonist, into the ipsilateral rostroventrolateral medulla. Therefore, excitatory synaptic inputs to pressor neurons in the rostroventrolateral medulla that arise from activation of the paraventricular nucleus are mediated predominantly by the action of angiotensin II on angiotensin II type 1 receptors. To examine whether such responses are influenced by physiological changes in the activity of the renin-angiotensin system, we measured heart rate, arterial pressure, and renal sympathetic nerve activity responses to the administration of bicuculline in the paraventricular nucleus in normal rats that were fed low-, normal-, and high-sodium diets and in rats with congestive heart failure. The rank order of both plasma renin activity and renal sympathoexcitatory responses was congestive heart failure>low-sodium diet>normal-sodium diet>high-sodium diet. The rank order of pressor and tachycardic responses exhibited a similar trend, but the differences between the groups were smaller and not statistically significant. The results indicate that the renal sympathoexcitatory responses to activation of the paraventricular nucleus are modulated by physiological alterations in the activity of the renin-angiotensin system.

Changeover Trial of Azilsartan and Olmesartan Comparing Effects on the Renin-Angiotensin-Aldosterone System in Patients with Essential Hypertension after Cardiac Surgery (CHAOS Study)

PubMed Central

Osaka, Shunji; Yaoita, Hiroko; Arimoto, Munehito; Hata, Hiroaki; Shiono, Motomi; Sakino, Hisakuni

2016-01-01

Background: Angiotensin II receptor blockers (ARBs) have been widely used to treat hypertension and large-scale clinical studies have shown various benefits. In this study, we compared olmesartan with azilsartan, the newest ARB. Methods: The subjects were outpatients who were clinically stable after cardiac surgery. Sixty patients were randomized to receive either azilsartan or olmesartan for 1 year and were switched to the other drug for the following 1 year. The primary endpoints were the levels of plasma renin activity, angiotensin II, and aldosterone. Results: Home blood pressure exceeded 140/90 mmHg and additional antihypertensive medication was administered to 12 patients (20 episodes) in the azilsartan group versus 4 patients (4 episodes) in the olmesartan group, with the number being significantly higher in the azilsartan group. After 1 year of treatment, both angiotensin II and aldosterone levels were significantly lower in the olmesartan group than the azilsartan group. Left ventricular mass index was also significantly lower in the olmesartan group than the azilsartan group. Conclusion: This study showed that olmesartan reduces angiotensin II and aldosterone levels more effectively than azilsartan. Accordingly, it may be effective in patients with increased renin-angiotensin-aldosterone system activity after cardiac surgery or patients with severe cardiac hypertrophy. PMID:27086671

Changeover Trial of Azilsartan and Olmesartan Comparing Effects on the Renin-Angiotensin-Aldosterone System in Patients with Essential Hypertension after Cardiac Surgery (CHAOS Study).

PubMed

Sezai, Akira; Osaka, Shunji; Yaoita, Hiroko; Arimoto, Munehito; Hata, Hiroaki; Shiono, Motomi; Sakino, Hisakuni

2016-06-20

Angiotensin II receptor blockers (ARBs) have been widely used to treat hypertension and large-scale clinical studies have shown various benefits. In this study, we compared olmesartan with azilsartan, the newest ARB. The subjects were outpatients who were clinically stable after cardiac surgery. Sixty patients were randomized to receive either azilsartan or olmesartan for 1 year and were switched to the other drug for the following 1 year. The primary endpoints were the levels of plasma renin activity, angiotensin II, and aldosterone. Home blood pressure exceeded 140/90 mmHg and additional antihypertensive medication was administered to 12 patients (20 episodes) in the azilsartan group versus 4 patients (4 episodes) in the olmesartan group, with the number being significantly higher in the azilsartan group. After 1 year of treatment, both angiotensin II and aldosterone levels were significantly lower in the olmesartan group than the azilsartan group. Left ventricular mass index was also significantly lower in the olmesartan group than the azilsartan group. This study showed that olmesartan reduces angiotensin II and aldosterone levels more effectively than azilsartan. Accordingly, it may be effective in patients with increased renin-angiotensin-aldosterone system activity after cardiac surgery or patients with severe cardiac hypertrophy.

Gain-of-function mutant of angiotensin II receptor, type 1A, causes hypertension and cardiovascular fibrosis in mice

PubMed Central

Billet, Sandrine; Bardin, Sabine; Verp, Sonia; Baudrie, Véronique; Michaud, Annie; Conchon, Sophie; Muffat-Joly, Martine; Escoubet, Brigitte; Souil, Evelyne; Hamard, Ghislaine; Bernstein, Kenneth E.; Gasc, Jean Marie; Elghozi, Jean-Luc; Corvol, Pierre; Clauser, Eric

2007-01-01

The role of the renin-angiotensin system has been investigated by overexpression or inactivation of its different genes in animals. However, there is no data concerning the effect of the constitutive activation of any component of the system. A knockin mouse model has been constructed with a gain-of-function mutant of the Ang II receptor, type 1A (AT1A), associating a constitutively activating mutation (N111S) with a C-terminal deletion, which impairs receptor internalization and desensitization. In vivo consequences of this mutant receptor expression in homozygous mice recapitulate its in vitro characteristics: the pressor response is more sensitive to Ang II and longer lasting. These mice present with a moderate (~20 mmHg) and stable increase in BP. They also develop early and progressive renal fibrosis and cardiac fibrosis and diastolic dysfunction. However, there was no overt cardiac hypertrophy. The hormonal parameters (low-renin and inappropriately normal aldosterone productions) mimic those of low-renin human hypertension. This new model reveals that a constitutive activation of AT1A leads to cardiac and renal fibrosis in spite of a modest effect on BP and will be useful for investigating the role of Ang II in target organs in a model similar to some forms of human hypertension. PMID:17607364

RAAS and stress markers in acute ischemic stroke: preliminary findings.

PubMed

Back, C; Thiesen, K L; Skovgaard, K; Edvinsson, L; Jensen, L T; Larsen, V A; Iversen, H K

2015-02-01

Angiotensin II type 1 receptor blockade has neuroprotective effects in animal stroke models, but no effects in clinical stroke trials. We evaluated cerebral and peripheral changes in the renin angiotensin aldosterone system (RAAS) and stress responses in acute ischemic stroke patients. Blood from a jugular and cubital vein was collected within 48 h of stroke onset, after 24 and 48 h, and renin, angiotensin I, angiotensin II, aldosterone, norepinephrine, epinephrine, and cortisol were measured. Post-stroke cubital vein samples were collected after 8 (4.7-10) months. The acute systolic blood pressure was significantly increased, 148 (141-168) vs 140 (130-147) mmHg post-stroke. Angiotensin I, renin and aldosterone levels were significantly lower, angiotensin II was unchanged, and ACE activity was higher in the acute phase compared to post-stroke. No differences in RAAS were detected between jugular and cubital plasma levels. Jugular venous plasma levels of epinephrine and cortisol were elevated in the acute phase compared to cubital levels (P < 0.05). Increased epinephrine and cortisol levels in the jugular vein blood may reflect a higher peripheral turnover. The observed changes in RAAS in the acute stroke phase are consistent with responses to increased blood pressure. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Capturing the dynamics of systemic Renin-Angiotensin-Aldosterone System (RAAS) peptides heightens the understanding of the effect of benazepril in dogs.

PubMed

Mochel, J P; Peyrou, M; Fink, M; Strehlau, G; Mohamed, R; Giraudel, J M; Ploeger, B; Danhof, M

2013-04-01

In dogs, activation of the Renin-Angiotensin-Aldosterone System (RAAS) is an important feature of congestive heart failure (CHF). Long-term increases in angiotensin II (AII) and aldosterone (ALD) lead to the progression of heart failure to its end stage. Angiotensin-converting enzyme inhibitors (ACEIs) are the foremost therapeutic option in the management of CHF. Recent literature has challenged the efficacy of ACEIs, based on modest reduction in urinary aldosterone (UALD) excretion despite marked inhibition of ACE activity. This study was designed to heighten the understanding of the effect of benazepril, a potent ACEI, on the RAAS, using a low-sodium diet as an experimental model of RAAS activation. Time course profiles of RAAS peptides and related areas under the curve (AUC) were used for comparison between benazepril and placebo groups. Results indicated substantial changes in the dynamics of these biomarkers. At presumed benazeprilat steady state, significant differences in AUC of plasma renin activity (+90%), angiotensin I (+43%), and AII (-53%) were found between benazepril and placebo-treated dogs. ALD decreased by 73% in plasma but only by 5% in urine. In conclusion, despite modest reduction in UALD excretion, benazepril markedly influences RAAS dynamics in dogs. © 2012 Blackwell Publishing Ltd.

The RenTg mice: a powerful tool to study renin-dependent chronic kidney disease.

PubMed

Huby, Anne-Cecile; Kavvadas, Panagiotis; Alfieri, Carlo; Abed, Ahmed; Toubas, Julie; Rastaldi, Maria-Pia; Dussaule, Jean-Claude; Chatziantoniou, Christos; Chadjichristos, Christos E

2012-01-01

Several studies have shown that activation of the renin-angiotensin system may lead to hypertension, a major risk factor for the development of chronic kidney disease (CKD). The existing hypertension-induced CDK mouse models are quite fast and consequently away from the human pathology. Thus, there is an urgent need for a mouse model that can be used to delineate the pathogenic process leading to progressive renal disease. The objective of this study was dual: to investigate whether mice overexpressing renin could mimic the kinetics and the physiopathological characteristics of hypertension-induced renal disease and to identify cellular and/or molecular events characterizing the different steps of the progression of CKD. We used a novel transgenic strain, the RenTg mice harboring a genetically clamped renin transgene. At 3 months, heterozygous mice are hypertensive and slightly albuminuric. The expression of adhesion markers such as vascular cell adhesion molecule-1 and platelet endothelial cell adhesion molecule-1 are increased in the renal vasculature indicating initiation of endothelial dysfunction. At 5 months, perivascular and periglomerular infiltrations of macrophages are observed. These early renal vascular events are followed at 8 months by leukocyte invasion, decreased expression of nephrin, increased expression of KIM-1, a typical protein of tubular cell stress, and of several pro-fibrotic agents of the TGFβ family. At 12 months, mice display characteristic structural alterations of hypertensive renal disease such as glomerular ischemia, glomerulo- and nephroangio-sclerosis, mesangial expansion and tubular dilation. The RenTg strain develops CKD progressively. In this model, endothelial dysfunction is an early event preceding the structural and fibrotic alterations which ultimately lead to the development of CKD. This model can provide new insights into the mechanisms of chronic renal failure and help to identify new targets for arresting and/or reversing the development of the disease.

(Pro)renin receptor: Involvement in diabetic retinopathy and development of molecular targeted therapy.

PubMed

Kanda, Atsuhiro; Ishida, Susumu

2018-03-25

The renin-angiotensin system (RAS), a crucial regulator of systemic blood pressure (circulatory RAS), plays distinct roles in pathological angiogenesis and inflammation in various organs (tissue RAS), such as diabetic microvascular complications. Using ocular clinical samples and animal disease models, we elucidated molecular mechanisms in which tissue RAS excites the expression of vascular endothelial growth factor (VEGF)-A responsible for retinal inflammation and angiogenesis, the two major pathological events in diabetic retinopathy (DR). Furthermore, we showed the involvement of (pro)renin receptor [(P)RR] in retinal RAS activation and its concurrent intracellular signal transduction (e.g., extracellular signal-regulated kinase); namely, the (P)RR-induced dual pathogenic bioactivity referred to as the receptor-associated prorenin system. Indeed, neovascular endothelial cells in the fibrovascular tissue collected from eyes with proliferative DR were immunoreactive for the receptor-associated prorenin system components including prorenin, (P)RR, phosphorylated extracellular signal-regulated kinase and VEGF-A. Protein levels of soluble (P)RR increased with its positive correlations with prorenin, renin enzymatic activity and VEGF in the vitreous of proliferative DR eyes, suggesting a close link between (P)RR and VEGF-A-driven angiogenic activity. Furthermore, we revealed an unsuspected, PAPS-independent role of (P)RR in glucose-induced oxidative stress. Recently, we developed an innovative single-strand ribonucleic acid interference molecule selectively targeting human and mouse (P)RR, and confirmed its efficacy in suppressing diabetes-induced retinal inflammation in mice. Our data using clinical samples and animal models suggested the significant implication of (P)RR in the pathogenesis of DR, and the potential usefulness of the ribonucleic acid interference molecule as a therapeutic agent to attenuate ocular inflammation and angiogenesis. © 2018 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

[The changes in renin-angiotensin-aldosterone-system in different subtypes of Cushing's syndrome].

PubMed

Cui, Jia; Dou, Jingtao; Yang, Guoqing; Zang, Li; Jin, Nan; Chen, Kang; Du, Jin; Gu, Weijun; Wang, Xianling; Yang, Lijuan; Lyu, Zhaohui; Ba, Jianming; Mu, Yiming; Lu, Juming; Li, Jiangyuan; Pan, Changyu

2015-07-01

Cushing's syndrome is a clinical condition resulting from chronic exposure to excess glucocorticoid. As a consequence, long-term hypercortisolism contributes significantly to the development of systemic disorders by direct and/or indirect effects. The present study was to analyze the changes of renin-angiotensin-aldosterone-system in different subtypes of Cushing's syndrome on the standard posture test. We retrospectively reviewed 150 patients with histologically confirmed Cushing's syndrome treated at the PLA General Hospital between 2002 and 2014. Among them, 128 patients were diagnosed as adreno-cortico-tropic-hormone (ACTH)-independent Cushing's syndrome, and 22 were ACTH-dependent Cushing's syndrome. All patients were undertaken the posture test. Plasma renin activity (PRA), angiotensin II, plasma aldosterone concertration (PAC) levels were measured before and after the test. Basal plasma PRA [0.5 (0.2,1.3)µg·L(-1)·h(-1), angiotensin II [(48.9±20.1) ng/L] and PAC [(285.0±128.1) pmol/L] levels were within the normal range in supine position. Compared with the subjects with ACTH-independent Cushing's syndrome, the basal PAC levels were higher in subjects with ACTH-dependent Cushing's syndrome [(348.0±130.4) pmol/L vs (274.2±125.0) pmol/L, P<0.05]. However, the PAC response in subjects with ACTH-dependent Cushing's syndrome [(49.7±26.4)%] was significantly lower than that in those with ACTH-independent Cushing's syndrome [(81.2±69.3)%] upon upright posture stimulation (P<0.05). There were no statistical significances in PRA and angiotensin II levels between the two groups. The basal PAC and PRA levels were positively correlated with ACTH, whereas PAC response was negatively correlated with ACTH. The renin-angiotensin-aldosterone-system activity in subjects with Cushing's syndrome was similar to that in normal control. The basal PAC level and its response to upright posture are differently associated with ACTH level in Cushing's syndrome.

High-intensity interval training has beneficial effects on cardiac remodeling through local renin-angiotensin system modulation in mice fed high-fat or high-fructose diets.

PubMed

de Oliveira Sá, Guilherme; Dos Santos Neves, Vívian; de Oliveira Fraga, Shyrlei R; Souza-Mello, Vanessa; Barbosa-da-Silva, Sandra

2017-11-15

HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS (renin-angiotensin system) in mice fed high-fat or high-fructose diets still need to be fully addressed. Sixty male C57BL/6 mice (12weeks old) were randomly divided into three groups, control (C), High-fat (HF), or High-fructose diet (HRU) and were monitored for eight weeks before being submitted to the HIIT. Each group was randomly assigned to 2 subgroups, one subgroup was started on a 12-week HIIT protocol (T=trained group), while the other subgroup remained non-exercised (NT=not-trained group). HIIT reduced BM and systolic blood pressure in high-fat groups, while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy in HF-T and HFRU-T. Notably, HIIT modulated key factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE (Angiotensin-converting enzyme), and (Angiotensin type 2 receptor) AT2R in HF-T and HFRU-T groups but reduced (Angiotensin type 1 receptor) AT1R protein expression only in the high-fat trained group. HIIT modulated ACE2/Ang (1-7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HF-T and HFRU-T groups, complying with elevated Mas (Mas proto-oncogene, G protein-coupled receptor) receptor mRNA gene expression after HIIT. This study shows the effectiveness of HIIT sessions in producing improvements in insulin sensitivity and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to HIIT protocol. Local RAS system in the heart mediates these findings and receptor MAS seems to play a pivotal role when it comes to the amelioration of cardiac structural and functional remodeling due to HIIT. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term systemic angiotensin II type 1 receptor blockade regulates mRNA expression of dorsomedial medulla renin-angiotensin system components

PubMed Central

Gilliam-Davis, Shea; Gallagher, Patricia E.; Payne, Valerie S.; Kasper, Sherry O.; Tommasi, Ellen N.; Westwood, Brian M.; Robbins, Michael E.; Chappell, Mark C.

2011-01-01

In Fischer 344 (F344) rats, renin-angiotensin system (RAS) blockade for 1 yr with the angiotensin II type 1 (AT1) receptor blocker L-158,809 prevents age-related impairments in metabolic function, similar to transgenic rats with low glial angiotensinogen (Aogen). Brain RAS regulation may contribute to the benefits of long-term systemic AT1 antagonism. We assessed the mRNA of RAS components in the dorsomedial medulla of F344 rats at 3 (young; n = 8) or 15 mo of age (old; n = 7) and in rats treated from 3 to 15 mo of age with 20 mg/l of the AT1 receptor antagonist L-158,809 (Old+L; n = 6). Aogen and renin mRNA were lower in the young compared with old group. Angiotensin-converting enzyme (ACE) mRNA was lower in the old and Old+L compared with the young group. ACE2 and neprilysin expression were significantly higher in Old+L compared with young or old rats. AT1b, AT2, and Mas receptor mRNA were higher with treatment. Leptin receptor mRNA was lower in the old rats and this was prevented by L-158,809 treatment. Dual-specificity phosphatase 1 (DUSP1) mRNA was highest in the Old+L group. Aggregate correlate summation revealed a positive relationship for Mas receptor mRNA with food intake. The findings provide evidence for regulation of dorsomedial medullary renin and Aogen mRNA during aging. Long-term AT1 receptor blockade increases the mRNA of the enzymes ACE2 and neprilysin and the MAS receptor, which could potentially shift the balance from ANG II to ANG-(1–7) and prevent age-related declines in the leptin receptor and its signaling pathway. PMID:21540301

Changes of poststimulatory plasma renin activity in women with hyperthyroidism or hypothyroidism in relation to therapy.

PubMed

Marcisz, Czeslaw; Kucharz, Eugene J; Marcisz-Orzel, Magdalena; Poręba, Ryszard; Orzel, Arkadiusz; Sioma-Markowska, Urszula

2011-01-01

The influence of thyroid hormones upon renin-angiotensin-aldosterone system is poorly understood. Under basal conditions, individuals belong to normal, low or high plasma renin activity (PRA) subjects. The study was designed to evaluate basal and poststimulatory PRA and serum aldosterone (Aldo) level in patients with hyperthyroidism or hypothyroidism during therapy. We examined 73 women with hyperthyroidism, 27 women with hypothyroidism and 36 healthy controls. The patients were investigated before initiation of therapy and after attainment of euthyroid state. All subjects were investigated under basal conditions (normal-sodium diet) and after application of a low-sodium diet for three days and upright position for 3 hr. PRA, serum Aldo level, blood pressure, serum sodium, potassium and thyroid hormone levels were determined in all subjects. The subjects were classified as low PRA (<1.0 ng/ml/h), normal PRA (1.0-4.0 ng/ml/h) and high PRA (>4.0 ng/ml/h) individuals according to results obtained under basal conditions. Relatively higher poststimulatory enhancement in PRA was found in patients with hyperthyroidism, especially those with low basal PRA, than in those with hypothyroidism. In women with thyroid dysfunctions poststimulatory increase in Aldo were relative lower than poststimulatory enhancement of PRA. After therapy these difference disappeared. The poststimulatory changes in PRA depended on the basal PRA. Poststimulatory PRA is higher in hyperthyroid women, especially those with low basal PRA. In women with hypothyroidism, basal and poststimulatory PRA is low. Blood pressure and severity of thyroid dysfunction was found to be similar in the patients with low, normal or high basic PRA. In women with thyroid dysfunctions, serum Aldo level and its relative poststimulatory increments are inadequate to changes of PRA; it is suggested that the dissociation in the renin-angiotensin-aldosterone system occurs in hyperthyroid and hypothyroid women.

Does Extremely Low Birth Weight Predispose to Low-Renin Hypertension?

PubMed

Raaijmakers, Anke; Zhang, Zhen-Yu; Claessens, Jolien; Cauwenberghs, Nicholas; van Tienoven, Theun Pieter; Wei, Fang-Fei; Jacobs, Lotte; Levtchenko, Elena; Pauwels, Steven; Kuznetsova, Tatiana; Allegaert, Karel; Staessen, Jan A

2017-03-01

Low birth weight and prematurity are risk factors for hypertension in adulthood. Few studies in preterm or full-term born children reported on plasma renin activity (PRA). We tested the hypothesis that renin might modulate the incidence of hypertension associated with prematurity. We enrolled 93 prematurely born children with birth weight <1000 g and 87 healthy controls born at term, who were all examined at ≈11 years. Renal length and glomerular filtration rate derived from serum cystatin C were 0.28 cm (95% confidence interval, 0.09-0.47) and 11.5 mL/min per 1.73 m 2 (6.4-16.6) lower in cases, whereas their systolic/diastolic blood pressure (BP) was 7.5 mm Hg (4.8-10.3)/4.0 mm Hg (2.1-5.8) higher ( P <0.001 for all). The odds of having systolic prehypertension or systolic hypertension associated with extreme low birth weight were 6.43 (2.52-16.4; P <0.001) and 10.9 (2.46-48.4; P =0.002). Twenty-four hours of urinary sodium excretion was similar in cases and controls (102.1 versus 106.8 mmol; P =0.47). Sodium load per nephron was estimated as sodium excretion divided by kidney length (mmol/cm). PRA was 0.54 ng/mL per hour (0.23-0.85; P =0.001) lower in cases. PRA, systolic BP, and sodium load were available in 43 cases and 56 controls. PRA decreased with systolic BP (slope -0.022 ng/mL per hour/ - mm Hg ; P =0.048), but was unrelated to sodium load (slope +0.13 mmol/cm - mm Hg ; P =0.54). The slope of PRA on systolic BP was similar ( P =0.17) in cases and controls. In conclusion, extremely low birth weight predisposes young adolescents to low-renin hypertension, but does not affect the inverse association between PRA and BP. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02147457. © 2017 American Heart Association, Inc.

Low plasma renin activity and high aldosterone/renin ratio are associated with untreated isolated systolic hypertension.

PubMed

Durukan, Mine; Guray, Umit; Aksu, Tolga; Guray, Yesim; Demirkan, Burcu; Korkmaz, Sule

2012-10-01

Isolated systolic hypertension (ISH) is generally encountered in elderly patients and there are scarce data regarding the renin-angiotensin-aldosterone system (RAAS) activity in patients with ISH. We aimed to determine the plasma renin activity (PRA), plasma aldosterone levels (PAL) and aldosterone/PRA ratio (PAL/PRA) in patients (age >50 years) with ISH and to compare these values with patients with essential hypertension (EH) as well as subjects with normal blood pressure values (control) who have similar age and cardiovascular risk profile. Consecutively, 42 untreated ISH patients, 30 patients with EH and 29 normal subjects were included in the study. Parameters were presented as median (interquartile range). There were no significant differences regarding age, gender and other cardiovascular risk factors among groups. As expected, systolic, diastolic blood pressure and pulse pressure values were significantly different among groups. Besides, PRA values were found to be significantly lower in patients with ISH (0.4 [0.2-1.1] ng/ml/h) compared with the EH (0.95 [0.5-2.6] ng/ml/h, p =0.024) and control (1.3 [0.7-2.1] ng/ml/h, p =0.001) groups. Although, PAL were similar among groups, PAL/PRA ratio was significantly higher in ISH group (134.1 [73-224]) compared with those with EH (42.2 [35-84], p <0.001) and the control group (53.3 [30-106], p =0.001). No significant difference was present with respect to PAL/PRA ratio between EH and control groups. Our findings suggested that in patients with ISH, despite lower PRA levels, PAL/PRA ratio is significantly higher compared with the patients with EH and subjects with normal blood pressure. Since higher PAL/PRA levels is an indicator of relative aldosterone excess, medications blocking RAAS activity including aldosterone antagonists may have useful cardiovascular consequences in addition to their antihypertensive effects in ISH.

[Clinical case of the month. Renovascular arterial hypertension complicated by diabetes insipidus: report of a case and review of the literature].

PubMed

Feloni, S; Radermacher, L; Remy, C; Jousten, J; Corman, V

2013-01-01

Mrs. A, a 62 year old patient with a history of hypertension, polyuria and polydipsia is hospitalized after a malaise. A severe hypokalemia, which is the cause of the polyuria and polydipsia, is discovered. The presence of hypertension and hypokalemia arises suspicion of a primary hyperaldosteronism and the plasma levels of renin and aldosterone are measured. Elevated aldosterone levels are combined with high plasma renin concentrations which permits to rule out primary hyperaldosteronism. Further explorations reveal a subocclusive ostial stenosis of the right renal artery. A treatment by sartan is instaured, which allows arterial pressure control and kalemia normalization. Chronic hypokalemia can be the cause of tubular nephropathy manifested by nephrogenic diabetes insipidus.

Metabolic Rate Regulation by the Renin-Angiotensin System: Brain vs. Body

PubMed Central

Grobe, Justin L.; Rahmouni, Kamal; Liu, Xuebo; Sigmund, Curt D.

2013-01-01

Substantial evidence supports a role for the renin-angiotensin system (RAS) in the regulation of metabolic function, but an apparent paradox exists where genetic or pharmacological inhibition of the RAS occasionally have similar physiological effects as chronic angiotensin infusion. Similarly, while RAS targeting in animal models has robust metabolic consequences, effects in humans are more subtle. Here we review the data supporting a role for the RAS in metabolic rate regulation and propose a model where the local brain RAS works in opposition to the peripheral RAS, thus helping to explain the paradoxically similar effects of RAS supplementation and inhibition. Selectively modulating the peripheral RAS or brain RAS may thus provide a more effective treatment paradigm for obesity and obesity-related disorders. PMID:22491893

The blockade of renin-angiotensin-aldosterone system in hemodialysis patients to control hypertension and prevent cardiovascular disease: optimal pharmacotherapy.

PubMed

Morishita, Yoshiyuki; Kusano, Eiji

2011-10-01

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in hemodialysis (HD) patients. Hypertension (HT) is a major risk factor for CVD. The renin-angiotensin-aldosterone system (RAAS) plays pivotal roles in the pathogenesis of HT in HD patients. Previous studies suggested that the blockade of RAAS may be effective to control blood pressure (BP) and to prevent CVD in HD patients. A certain level of preventive effects against CVD by RAAS blockade in HD patients has been reported independently from a BP lowering effect. This review focuses on the effect of blocking RAAS in HD patients for the control of HT and the prevention of CVD.

Prevalence of primary hyperaldosteronism in a systemic arterial hypertension league.

PubMed

Ribeiro, Maria Jacqueline Silva; Figueiredo Neto, José Albuquerque de; Memória, Edson Viriato; Lopes, Maíra de Castro; Faria, Manuel dos Santos; Salgado Filho, Natalino; Oliveira, Thiara Castro de

2009-01-01

Until recently, primary hyperaldosteronism was considered a rare cause of secondary hypertension. However, in recent years, many studies have suggested that this disease can affect up to 20% of hypertensive individuals. To determine the prevalence of primary hyperaldosteronism in hypertensive patients treated at the hypertension league of a university hospital. Serum aldosterone and plasma renin activity levels were measured in 105 patients while they were undergoing standard antihypertensive treatment, with the exception of those using betablockers and spironolactone, in fasting condition and after rest in the supine position for 20 minutes. Those with an aldosterone/plasma renin activity ratio > 25 were submitted to the saline suppression test and, after the confirmation of the autonomy of aldosterone secretion, a computed tomography of the adrenals was performed. The results are presented as percentages and means and standard deviations. Of the 105 patients, 6.54% presented refractory hypertension. Nine presented an aldosterone/plasma renin activity ratio > 25 (8.5% of the total). Of these, 08 were submitted to the saline suppression test and 01 (with refractory hypertension) had the diagnosis of primary hyperaldosteronism confirmed (0.96% of the total). A computed tomography of the adrenals was performed, which showed normal results. The prevalence of primary hyperaldosteronism in the studied sample was 0.96% of the total. However, when only the patients with refractory hypertension were evaluated, the prevalence was 14.3%.

Angiotensin II mediated signal transduction. Important role of tyrosine kinases.

PubMed

Haendeler, J; Berk, B C

2000-11-24

It has been 100 years since the discovery of renin by Bergman and Tigerstedt. Since then, numerous studies have advanced our understanding of the renin-angiotensin system. A remarkable aspect was the discovery that angiotensin II (AngII) is the central product of the renin-angiotensin system and that this octapeptide induces multiple physiological responses in different cell types. In addition to its well known vasoconstrictive effects, growing evidence supports the notion that AngII may play a central role not only in hypertension, but also in cardiovascular and renal diseases. Binding of AngII to the seven-transmembrane angiotensin II type 1 receptor is responsible for nearly all of the physiological actions of AngII. Recent studies underscore the new concept that activation of intracellular second messengers by AngII requires tyrosine phosphorylation. An increasing number of tyrosine kinases have been shown to be activated by AngII, including the Src kinase family, the focal adhesion kinase family, the Janus kinases and receptor tyrosine kinases. These actions of AngII contribute to the pathophysiology of cardiac hypertrophy and remodeling, vascular thickening, heart failure and atherosclerosis. In this review, we discuss the important role of tyrosine kinases in AngII-mediated signal transduction. Understanding the importance of tyrosine phosphorylation in AngII-stimulated signaling events may contribute to new therapies for cardiovascular and renal diseases.

Gender differences in anxiety and depressive symptoms in patients with primary hyperaldosteronism: a cross-sectional study.

PubMed

Apostolopoulou, Konstantina; Künzel, Heike E; Gerum, Sabine; Merkle, Katrin; Schulz, Sebastian; Fischer, Evelyn; Pallauf, Anna; Brand, Volker; Bidlingmaier, Martin; Endres, Stephan; Beuschlein, Felix; Reincke, Martin

2014-01-01

The renin-angiotensin-aldosterone-system (RAAS) has gained increasing attention in the investigation of the pathogenesis of depression. Primary hyperaldosteronism (PA) is associated with a marked aldosterone excess. Prior studies on PA describe an increased prevalence of anxiety and sub-threshold depressive symptoms in these patients. In a cross-sectional exploratory study we investigated 132 patients with PA. Twenty-seven patients were studied before initiation of specific treatment (U = untreated), 56 were studied 5.4 years after initiation of mineralocorticoid antagonist treatment (MRA) and 49 patients were studied 4.3 years after unilateral adrenalectomy (ADX). GAD-7 and PHQD self-rating questionnaires were used to assess symptoms for anxiety and depression. No significant difference was found between the three investigated groups. A higher prevalence for depression and anxiety compared to the normal population was found. Women of all groups had higher mean values compared to men, for depression in untreated patients this difference was found to be significant. Correlations between the psychopathology and hormones were only found for renin. Plasma renin concentration correlated significantly with anxious symptoms of untreated females. This study supports the RAAS to be involved in the pathogenesis of depression as patients with PA seem to be more depressive and anxious compared to the normal population. Gender differences in the regulation of the RAAS seem to be apparent, as females were more affected by the dysregulation than males.

Discovery of new sites for drug binding to the hypertension-related renin-angiotensinogen complex.

PubMed

Brás, Natércia F; Fernandes, Pedro A; Ramos, Maria J

2014-04-01

Renin (REN) is a key drug target to stop the hypertension cascade, but thus far only one direct inhibitor has been made commercially available. In this study, we assess an innovative REN inhibition strategy, by targeting the interface of the renin:angiotensinogen (REN:ANG) complex. We characterized the energetic role of interfacial residues of REN:ANG and identified the ones responsible for protein:protein binding, which can serve as drug targets for disruption of the REN:ANG association. For this purpose, we applied a computational alanine scanning mutagenesis protocol, which measures the contribution of each side chain for the protein:protein binding free energy with an accuracy of ≈ 1 kcal/mol. As a result, in REN and ANG, six and eight residues were found to be critical for binding, respectively. The leading force behind REN:ANG complexation was found to be the hydrophobic effect. The binding free energy per residue was found to be proportional to the buried area. Residues responsible for binding were occluded from water at the complex, which promotes an efficient pairing between the two proteins. Two druggable pockets involving critical residues for binding were found on the surface of REN, where small druglike molecules can bind and disrupt the ANG:REN association that may provide an efficient way to achieve REN inhibition and control hypertension.

Racial differences in sensitivity of blood pressure to aldosterone.

PubMed

Tu, Wanzhu; Eckert, George J; Hannon, Tamara S; Liu, Hai; Pratt, Linda M; Wagner, Mary Anne; Dimeglio, Linda A; Jung, Jeesun; Pratt, J Howard

2014-06-01

Blacks in comparison with whites are at risk for a more serious form of hypertension with high rates of complications. Greater sodium retention is thought to underlie the blood pressure (BP)-determining physiology of blacks, but specific mechanisms have not been identified. In a prospective observational study of BP, 226 black children and 314 white children (mean age, 10.6 years) were enrolled initially. Assessments were repeated in 85 blacks and 136 whites after reaching adulthood (mean age, 31 years). The relationship of BP to plasma aldosterone concentration in the context of the prevailing level of plasma renin activity was studied in blacks and whites. In a secondary interventional study, 9-α fludrocortisone was administered for 2 weeks to healthy adult blacks and whites to simulate hyperaldosteronism. BP responses in the 2 race groups were then compared. Although black children had lower levels of plasma renin activity and plasma aldosterone, their BP was positively associated with the plasma aldosterone concentration, an effect that increased as plasma renin activity decreased (P=0.004). Data from black adults yielded similar results. No similar relationship was observed in whites. In the interventional study, 9-α fludrocortisone increased BP in blacks but not in whites. In conclusion, aldosterone sensitivity is a significant determinant of BP in young blacks. Although its role in establishing the risk of hypertension is not known, it could be as relevant as the actual level of aldosterone.

Expression of classical components of the renin-angiotensin system in the human eye.

PubMed

White, Andrew J R; Cheruvu, Sarat C; Sarris, Maria; Liyanage, Surabhi S; Lumbers, Eugenie; Chui, Jeanie; Wakefield, Denis; McCluskey, Peter J

2015-03-01

The purpose of this study was to determine the relative expression of clinically-relevant components of the renin-angiotensin system (RAS) in the adult human eye. We obtained 14 post-mortem enucleated human eyes from patients whom had no history of inflammatory ocular disease nor pre-mortem ocular infection. We determined the gene expression for prorenin, renin, prorenin receptor, angiotensin-converting enzyme, angiotensinogen and angiotensin II Type 1 receptor, on tissue sections and in cultured human primary retinal pigment epithelial and iris pigment epithelial (RPE/IPE) cell lines, using both qualitative and quantitative reverse transcription polymerase chain reaction (RT-PCR). Protein expression was studied using indirect immunofluorescence (IF). Almost all components of the classical RAS were found at high levels, at both the transcript and protein level, in the eyes' uvea and retina; and at lower levels in the cornea, conjunctiva and sclera. There was a much lower level of expression in the reference cultured RPE/IPE cells lines. This study describes the distribution of RAS in the normal adult human eye and demonstrates the existence of an independent ocular RAS, with uveal and retinal tissues showing the highest expression of RAS components. These preliminary findings provide scope for examination of additional components of this system in the human eye, as well as possible differential expression under pathological conditions. © The Author(s) 2014.

Potential of a renin inhibitory peptide from the red seaweed Palmaria palmata as a functional food ingredient following confirmation and characterization of a hypotensive effect in spontaneously hypertensive rats.

PubMed

Fitzgerald, Ciaran; Aluko, Rotimi E; Hossain, Mohammad; Rai, Dilip K; Hayes, Maria

2014-08-20

This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.

Bartter syndrome

MedlinePlus

... may show: High levels of potassium , calcium, and chloride in the urine High levels of the hormones renin and aldosterone in the blood Low blood chloride Metabolic alkalosis These same signs and symptoms can ...

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

Relationship of biomarkers of extracellular matrix with myocardial function in Type 2 diabetes mellitus.

PubMed

Liu, Ju-Hua; Chen, Yan; Zhen, Zhe; Ho, Lai-Ming; Tsang, Anita; Yuen, Michele; Lam, Karen; Tse, Hung-Fat; Yiu, Kai-Hang

2017-07-01

The study evaluated the relationship of extracellular matrix and renin angiotensin system with myocardial dysfunction in Type 2 diabetes mellitus. All patients underwent resting and exercise echocardiography, including conventional parameters, E/E' ratio, global longitudinal strain and diastolic function reserve index. Plasma matrix metalloproteinase-1, TIMP-1, amino-terminal propeptide of type I and type III procollagen and renin angiotensin system activity were measured. As patients with diastolic dysfunction had a higher plasma level of TIMP-1 and propeptide of type III procollagen than those with no diastolic dysfunction. After multivariate adjustment, TIMP-1 associated with E/E' (both at rest and stress) and diastolic function reserve index. TIMP-1 is independently associated with myocardial diastolic dysfunction in patients with Type 2 diabetes mellitus.

Dual renin-angiotensin-aldosterone system blockade for diabetic kidney disease.

PubMed

Pichler, Raimund H; de Boer, Ian H

2010-08-01

Blockade of the renin-angiotensin-aldosterone system (RAAS) prevents the development and progression of diabetic kidney disease (DKD). It is controversial whether the simultaneous use of two RAAS inhibitors (ie, dual RAAS blockade) further improves renal outcomes. This review examines the scientific rationale and current clinical evidence addressing the use of dual RAAS blockade to prevent and treat DKD. It is concluded that dual RAAS blockade should not be routinely applied to patients with low or moderate risk of progressive kidney disease (normoalbuminuria or microalbuminuria with preserved glomerular filtration rate). For patients with high risk of progressive kidney disease (substantial albuminuria or impaired glomerular filtration rate), clinicians should carefully weigh the potential risks and benefits of dual RAAS blockade on an individual basis until ongoing clinical trials provide further insight.

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.

Advances in understanding the renin-angiotensin-aldosterone system (RAAS) in blood pressure control and recent pivotal trials of RAAS blockade in heart failure and diabetic nephropathy

PubMed Central

Ghazi, Lama; Drawz, Paul

2017-01-01

The renin-angiotensin-aldosterone system (RAAS) plays a fundamental role in the physiology of blood pressure control and the pathophysiology of hypertension (HTN) with effects on vascular tone, sodium retention, oxidative stress, fibrosis, sympathetic tone, and inflammation. Fortunately, RAAS blocking agents have been available to treat HTN since the 1970s and newer medications are being developed. In this review, we will (1) examine new anti-hypertensive medications affecting the RAAS, (2) evaluate recent studies that help provide a better understanding of which patients may be more likely to benefit from RAAS blockade, and (3) review three recent pivotal randomized trials that involve newer RAAS blocking agents and inform clinical practice. PMID:28413612

Advances in understanding the renin-angiotensin-aldosterone system (RAAS) in blood pressure control and recent pivotal trials of RAAS blockade in heart failure and diabetic nephropathy.

PubMed

Ghazi, Lama; Drawz, Paul

2017-01-01

The renin-angiotensin-aldosterone system (RAAS) plays a fundamental role in the physiology of blood pressure control and the pathophysiology of hypertension (HTN) with effects on vascular tone, sodium retention, oxidative stress, fibrosis, sympathetic tone, and inflammation. Fortunately, RAAS blocking agents have been available to treat HTN since the 1970s and newer medications are being developed. In this review, we will (1) examine new anti-hypertensive medications affecting the RAAS, (2) evaluate recent studies that help provide a better understanding of which patients may be more likely to benefit from RAAS blockade, and (3) review three recent pivotal randomized trials that involve newer RAAS blocking agents and inform clinical practice.

Influence of feeding schedules on the chronobiology of renin activity, urinary electrolytes and blood pressure in dogs.

PubMed

Mochel, Jonathan P; Fink, Martin; Bon, Charlotte; Peyrou, Mathieu; Bieth, Bruno; Desevaux, Cyril; Deurinck, Mark; Giraudel, Jérôme M; Danhof, Meindert

2014-06-01

The contribution of the renin-angiotensin-aldosterone system (RAAS) to the development of congestive heart failure (CHF) and hypertension (HT) has long been recognized. Medications that are commonly used in the course of CHF and HT are most often given with morning food for the sake of convenience and therapeutic compliance. However, biological rhythms and their responsiveness to environmental clues such as food intake may noticeably impact the effectiveness of drugs used in the management of cardiovascular disorders. Only sparse information about the effect of feeding schedules on the biology of the RAAS and blood pressure (BP) is presently available. Two studies were designed to explore the chronobiology of renin activity (RA), BP, renal sodium (UNa,fe) and potassium (UK,fe) handling in relation to meal timing in dogs. In a first experiment (Study a), blood and urinary samples for measurement of RA, UNa,fe and UK,fe were drawn from 18 healthy beagle dogs fed a normal-sodium diet at either 07:00, 13:00 or 19:00 h. In a second experiment (Study b), BP was recorded continuously from six healthy, telemetered beagle dogs fed a similar diet at 07:00, or 19:00 h. Data were collected throughout 24-h time periods, and analyzed by means of nonlinear mixed-effects models. Differences between the geometric means of early versus late time after feeding observations were further compared using parametric statistics. In agreement with our previous investigations, the results indicate that RA, UNa,fe, UK,fe, systolic, and diastolic BP oscillate with a circadian periodicity in dogs fed a regular diet at 07:00 h. A cosine model with a fixed 24-h period was found to fit the variations of RA, UK,fe and BP well, whereas cyclic changes in UNa,fe were best characterized by means of a combined cosine and surge model, reflecting a postprandial sodium excretion followed by a monotonous decay. Our data show that feeding time has a marked influence on the chronobiology of the renin cascade, urinary electrolytes, and BP. Introducing a 6- or 12-h delay in the dogs' feeding schedule caused a shift of similar magnitude (05:06 and 12:32 h for Studies a and b, respectively) in the rhythm of these biomarkers. In all study groups, RA and BP exhibited a marked fall just after food intake. The drop in RA is consistent with sodium and water-induced body fluid expansion, while the reduction of BP could be related to the decreased activity of renin and the secretion of vasodilatory gut peptides. An approximately 1.5-fold (1.2-1.6-fold) change between the average early and late time after feeding observations was found for RA (p < 0.0001), UNa,fe (p < 0.01) and UK,fe (p < 0.05). Postprandial variations in BP, albeit small (ca. 10 mmHg), were statistically significant (p < 0.01) and supported by the model-based analysis. In conclusion, the timing of food intake appears to be pivotal to the circadian organization of the renin cascade and BP. This synchronizing effect could be mediated by feeding-related signals, such as dietary sodium, capable of entraining circadian oscillators downstream of the master, light-dark-adjusted pacemaker in the suprachiasmatic nucleus.

Angiotensin II Receptor Blockers

MedlinePlus

... 2010. Mann JFE, et al. Renin-angiotensin system inhibition in the treatment of hypertension. http://www.uptodate. ... profit organization and proceeds from Web advertising help support our mission. Mayo Clinic does not endorse any ...

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

The Arrestin-selective Angiotensin AT1 Receptor Agonist [Sar1,Ile4,Ile8]-AngII Negatively Regulates Bradykinin B2 Receptor Signaling via AT1-B2 Receptor Heterodimers*

PubMed Central

Wilson, Parker C.; Lee, Mi-Hye; Appleton, Kathryn M.; El-Shewy, Hesham M.; Morinelli, Thomas A.; Peterson, Yuri K.; Luttrell, Louis M.; Jaffa, Ayad A.

2013-01-01

The renin-angiotensin and kallikrein-kinin systems are key regulators of vascular tone and inflammation. Angiotensin II, the principal effector of the renin-angiotensin system, promotes vasoconstriction by activating angiotensin AT1 receptors. The opposing effects of the kallikrein-kinin system are mediated by bradykinin acting on B1 and B2 bradykinin receptors. The renin-angiotensin and kallikrein-kinin systems engage in cross-talk at multiple levels, including the formation of AT1-B2 receptor heterodimers. In primary vascular smooth muscle cells, we find that the arrestin pathway-selective AT1 agonist, [Sar1,Ile4,Ile8]-AngII, but not the neutral AT1 antagonist, losartan, inhibits endogenous B2 receptor signaling. In a transfected HEK293 cell model that recapitulates this effect, we find that the actions of [Sar1,Ile4, Ile8]-AngII require the AT1 receptor and result from arrestin-dependent co-internalization of AT1-B2 heterodimers. BRET50 measurements indicate that AT1 and B2 receptors efficiently heterodimerize. In cells expressing both receptors, pretreatment with [Sar1,Ile4,Ile8]-AngII blunts B2 receptor activation of Gq/11-dependent intracellular calcium influx and Gi/o-dependent inhibition of adenylyl cyclase. In contrast, [Sar1,Ile4,Ile8]-AngII has no effect on B2 receptor ligand affinity or bradykinin-induced arrestin3 recruitment. Both radioligand binding assays and quantitative microscopy-based analysis demonstrate that [Sar1,Ile4,Ile8]-AngII promotes internalization of AT1-B2 heterodimers. Thus, [Sar1,Ile4,Ile8]-AngII exerts lateral allosteric modulation of B2 receptor signaling by binding to the orthosteric ligand binding site of the AT1 receptor and promoting co-sequestration of AT1-B2 heterodimers. Given the opposing roles of the renin-angiotensin and kallikrein-kinin systems in vivo, the distinct properties of arrestin pathway-selective and neutral AT1 receptor ligands may translate into different pharmacologic actions. PMID:23661707

The arrestin-selective angiotensin AT1 receptor agonist [Sar1,Ile4,Ile8]-AngII negatively regulates bradykinin B2 receptor signaling via AT1-B2 receptor heterodimers.

PubMed

Wilson, Parker C; Lee, Mi-Hye; Appleton, Kathryn M; El-Shewy, Hesham M; Morinelli, Thomas A; Peterson, Yuri K; Luttrell, Louis M; Jaffa, Ayad A

2013-06-28

The renin-angiotensin and kallikrein-kinin systems are key regulators of vascular tone and inflammation. Angiotensin II, the principal effector of the renin-angiotensin system, promotes vasoconstriction by activating angiotensin AT1 receptors. The opposing effects of the kallikrein-kinin system are mediated by bradykinin acting on B1 and B2 bradykinin receptors. The renin-angiotensin and kallikrein-kinin systems engage in cross-talk at multiple levels, including the formation of AT1-B2 receptor heterodimers. In primary vascular smooth muscle cells, we find that the arrestin pathway-selective AT1 agonist, [Sar(1),Ile(4),Ile(8)]-AngII, but not the neutral AT1 antagonist, losartan, inhibits endogenous B2 receptor signaling. In a transfected HEK293 cell model that recapitulates this effect, we find that the actions of [Sar(1),Ile(4), Ile(8)]-AngII require the AT1 receptor and result from arrestin-dependent co-internalization of AT1-B2 heterodimers. BRET50 measurements indicate that AT1 and B2 receptors efficiently heterodimerize. In cells expressing both receptors, pretreatment with [Sar(1),Ile(4),Ile(8)]-AngII blunts B2 receptor activation of Gq/11-dependent intracellular calcium influx and Gi/o-dependent inhibition of adenylyl cyclase. In contrast, [Sar(1),Ile(4),Ile(8)]-AngII has no effect on B2 receptor ligand affinity or bradykinin-induced arrestin3 recruitment. Both radioligand binding assays and quantitative microscopy-based analysis demonstrate that [Sar(1),Ile(4),Ile(8)]-AngII promotes internalization of AT1-B2 heterodimers. Thus, [Sar(1),Ile(4),Ile(8)]-AngII exerts lateral allosteric modulation of B2 receptor signaling by binding to the orthosteric ligand binding site of the AT1 receptor and promoting co-sequestration of AT1-B2 heterodimers. Given the opposing roles of the renin-angiotensin and kallikrein-kinin systems in vivo, the distinct properties of arrestin pathway-selective and neutral AT1 receptor ligands may translate into different pharmacologic actions.

Aldosterone and Renin Test

MedlinePlus

... Blood Ketones Blood Smear Blood Typing Blood Urea Nitrogen (BUN) BNP and NT-proBNP Body Fluid Analysis ... must be careful to maintain fluid and electrolyte balance. Kidney failure is a possible complication of Bartter ...

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease.

PubMed

Brudey, Chevelle; Park, Jeanie; Wiaderkiewicz, Jan; Kobayashi, Ihori; Mellman, Thomas A; Marvar, Paul J

2015-08-15

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed. Copyright © 2015 the American Physiological Society.

Fenoterol stimulates human erythropoietin production via activation of the renin angiotensin system

PubMed Central

Freudenthaler, S M; Schenck, T; Lucht, I; Gleiter, C H

1999-01-01

Aims The present study assessed the hypothesis that the β2 sympathomimetic fenoterol influences the production of erythropoietin (EPO) by activation of the renin angiotensin system (RAS), i.e. angiotensin II. Methods In an open, parallel, randomized study healthy volunteers received i.v. either placebo (electrolyte solution), fenoterol or fenoterol in combination with an oral dose of the AT1-receptor antagonist losartan. Results Compared with placebo treatment AUCEPO(0,24 h) was significantly increased after fenoterol application by 48% whereas no increase in the group receiving fenoterol and losartan could be detected. The rise of PRA was statistically significant under fenoterol and fenoterol plus lorsartan. Conclusions Stimulation of EPO production during fenoterol infusion appears to be angiotensin II-mediated. Thus, angiotensin II may be considered as one important physiological modulator of EPO production in humans. PMID:10583037

Fenoterol stimulates human erythropoietin production via activation of the renin angiotensin system.

PubMed

Freudenthaler, S M; Schenck, T; Lucht, I; Gleiter, C H

1999-10-01

The present study assessed the hypothesis that the beta2 sympathomimetic fenoterol influences the production of erythropoietin (EPO) by activation of the renin angiotensin system (RAS), i.e. angiotensin II. In an open, parallel, randomized study healthy volunteers received i.v. either placebo (electrolyte solution), fenoterol or fenoterol in combination with an oral dose of the AT1-receptor antagonist losartan. Compared with placebo treatment AUCEPO(0,24 h) was significantly increased after fenoterol application by 48% whereas no increase in the group receiving fenoterol and losartan could be detected. The rise of PRA was statistically significant under fenoterol and fenoterol plus lorsartan. Stimulation of EPO production during fenoterol infusion appears to be angiotensin II-mediated. Thus, angiotensin II may be considered as one important physiological modulator of EPO production in humans.

The intricacies of the renin angiotensin system in metabolic regulation

PubMed Central

Bruce, Erin; de Kloet, Annette D.

2017-01-01

Over recent years, the renin-angiotensin-system (RAS), which is best-known as an endocrine system with established roles in hydromineral balance and blood pressure control, has emerged as a fundamental regulator of many additional physiological and pathophysiological processes. In this manuscript, we celebrate and honor Randall Sakai’s commitment to his trainees, as well as his contribution to science. Scientifically, Randall made many notable contributions to the recognition of the RAS’s roles in brain and behavior. His interests, in this regard, ranged from its traditionally-accepted roles in hydromineral balance, to its less-appreciated functions in stress responses and energy metabolism. Here we review the current understanding of the role of the RAS in the regulation of metabolism. In particular, the opposing actions of the RAS within adipose tissue vs. its actions within the brain are discussed. PMID:27887998

A role for AT1 receptor-associated proteins in blood pressure regulation.

PubMed

Castrop, Hayo

2015-04-01

The renin angiotensin-system is one of the most important humoral regulators of blood pressure. The recently discovered angiotensin receptor-associated proteins serve as local modulators of the renin angiotensin-system. These proteins interact with the AT1 receptor in a tissue-specific manner and regulate the sensitivity of the target cell for angiotensin II. The predominant effect of the AT1 receptor-associated proteins on angiotensin II-induced signaling is the modulation of the surface expression of the AT1 receptor. This review provides an overview of our current knowledge with respect to the relevance of AT1 receptor-associated proteins for blood pressure regulation. Two aspects of blood pressure regulation will be discussed in detail: angiotensin II-dependent volume homoeostasis and vascular resistance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of hypovolemia, infusion, and oral rehydration on plasma electrolytes, ADH, renin activity, and +G/z/ tolerance

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Brock, P. J.; Haines, R. F.; Rositano, S. A.; Montgomery, L. D.; Keil, L. C.

1977-01-01

Effects on plasma volume, electrolyte shifts, and +G(z) tolerance induced by: (1) blood withdrawal; (2) blood infusion; and (3) oral fluid intake, were determined at 0.5 G/min in centrifugation tests of six ambulatory male patients, aged 21 to 27 yrs. Hypovolemia induced by withdrawal of 400 ml blood, blood infusion followed by repeated centrifugation, effects of consuming an isotonic drink (0.9% NaCl) to achieve oral rehydration, and donning of red adaptation goggles were studied for effects on acceleration tolerance, pre-acceleration and post-acceleration plasma renin activity (PRA) and plasma vasopressin levels. No significant changes in post-acceleration PRA compared to pre-acceleration PRA were found, and administration of oral rehydration is found as effective as blood replacement in counteracting hypovolemic effects.

[Angiotensin converting enzyme 2 and its emerging role in the regulation of the renin angiotensin system].

PubMed

Soler, María José; Lloveras, Josep; Batlle, Daniel

2008-07-12

The renin-angiotensin system (RAS) plays a key role in the regulation of cardiovascular and renal function. Thus, RAS blockade with an angiotensin-converting enzyme (ACE) and/or angiotensin receptor blocker decreases blood pressure, cardiovascular events, and delays the progression of kidney disease. The discovery of ACE2, a homologue of ACE, capable of degrading angiotensin II to angiotensin 1-7, may offer new insights into the RAS. In this review we discuss the possible protective role of ACE2 in different organs, namely heart, lungs and kidneys. The role of this enzyme is inferred from recent studies performed using genetically manipulated mice that lack the ACE2 gene and also mice treated with pharmacological ACE2 inhibitors. These results suggest that ACE2 might be a new therapeutic target within the RAS.

Endocrine and Hypertensive Disorders of Potassium Regulation: Primary Aldosteronism

PubMed Central

Weiner, I. David

2013-01-01

The identification that primary aldosteronism is a common cause of resistant hypertension is a significant advance in our ability to care for patients with hypertension. Primary aldosteronism is common, and when unrecognized is associated with increased incidence of adverse cardiovascular outcomes. Identification of primary aldosteronism is based upon use of the plasma aldosterone level, plasma renin activity and the aldosterone:renin ratio (ARR). Differentiation between unilateral and bilateral autonomous adrenal aldosterone production then guides further therapy, with use of mineralocorticoid receptor blockers for those with bilateral autonomous adrenal aldosterone production and laparoscopic adrenalectomy for those with unilateral autonomous aldosterone production. In this review, we discuss in detail the pathogenesis of primary aldosteronism-induced hypertension and potassium disorders, the evaluation of the patient with suspected primary aldosteronism and the management of primary aldosteronism, both through medications and through surgery. PMID:23953804

Renin-angiotensin-aldosterone system (RAAS) pharmacogenomics: implications in heart failure management.

PubMed

Beitelshees, Amber L; Zineh, Issam

2010-05-01

Blockade of the renin-angiotensin-aldosterone system (RAAS) with ACE inhibitors has been a cornerstone of heart failure therapy for over 15 years. More recently, further blockade of RAAS with aldosterone antagonists and angiotensin receptor blockers (ARBs) has been studied. While these therapies have certainly improved outcomes in the treatment of heart failure, morbidity and mortality remain extremely high. Furthermore, polypharmacy and complex regimens of seven medications on average is the norm for management of heart failure. This results in increased costs, patient burden, and uncertainty as to the best course of therapy. The ability to personalize patients' therapeutic regimens using pharmacogenomics has the potential of providing more effective and efficient use of RAAS-modulating medications. This review highlights the implications of major RAAS pharmacogenetic studies, while outlining future directions for translation to practice.

Management of hypertension and heart failure in patients with Addison's disease.

PubMed

Inder, Warrick J; Meyer, Caroline; Hunt, Penny J

2015-06-01

Addison's disease may be complicated by hypertension and less commonly by heart failure. We review the pathophysiology of the renin-angiotensin-aldosterone axis in Addison's disease and how this is altered in the setting of hypertension and heart failure. An essential first step in management in both conditions is optimizing glucocorticoid replacement and considering dose reduction if excessive. Following this, if a patient with Addison's disease remains hypertensive, the fludrocortisone dose should be reviewed and reduced if there are clinical and/or biochemical signs of mineralocorticoid excess. In the absence of such signs, where the renin is towards the upper end of the normal range or elevated, an angiotensin II (AII) receptor antagonist or angiotensin converting enzyme (ACE) inhibitor is the treatment of choice, and the fludrocortisone dose should remain unchanged. Dihydropyridine calcium channel blockers are clinically useful as second line agents, but diuretics should be avoided. In the setting of heart failure, there is an increase in total body sodium and water; therefore, it is appropriate to reduce and rarely consider ceasing the fludrocortisone. Loop diuretics may be used, but not aldosterone antagonists such as spironolactone or eplerenone. Standard treatment with ACE inhibitors, or as an alternative, AII receptor antagonists, are appropriate. Measurements of renin are no longer helpful in heart failure to determine the volume status but plasma levels of brain natriuretic peptide (BNP/proBNP) may help guide therapy. © 2014 John Wiley & Sons Ltd.

Intermittent hypoxia increases arterial blood pressure in humans through a Renin-Angiotensin system-dependent mechanism.

PubMed

Foster, Glen E; Hanly, Patrick J; Ahmed, Sofia B; Beaudin, Andrew E; Pialoux, Vincent; Poulin, Marc J

2010-09-01

Intermittent hypoxia (IH) is believed to contribute to the pathogenesis of hypertension in obstructive sleep apnea through mechanisms that include activation of the renin-angiotensin system. The objective of this study was to assess the role of the type I angiotensin II receptor in mediating an increase in arterial pressure associated with a single 6-hour IH exposure. Using a double-blind, placebo-controlled, randomized, crossover study design, we exposed 9 healthy male subjects to sham IH, IH with placebo medication, and IH with the type I angiotensin II receptor antagonist losartan. We measured blood pressure, cerebral blood flow, and ventilation at baseline and after exposure to 6 hours of IH. An acute isocapnic hypoxia experimental protocol was conducted immediately before and after exposure to IH. IH with placebo increased resting mean arterial pressure by 7.9+/-1.6 mm Hg, but mean arterial pressure did not increase with sham IH (1.9+/-1.5 mm Hg) or with losartan IH (-0.2+/-2.4 mm Hg; P<0.05). Exposure to IH prevented the diurnal decrease in the cerebral blood flow response to hypoxia, independently of the renin-angiotensin system. Finally, in contrast to other models of IH, the acute hypoxic ventilatory response did not change throughout the protocol. IH increases arterial blood pressure through activation of the type I angiotensin II receptor, without a demonstrable impact on the cerebrovascular or ventilatory response to acute hypoxia.

Administration of exogenous 1,25(OH)2D3 normalizes overactivation of the central renin-angiotensin system in 1α(OH)ase knockout mice.

PubMed

Zhang, Wei; Chen, Lulu; Zhang, Luqing; Xiao, Ming; Ding, Jiong; Goltzman, David; Miao, Dengshun

2015-02-19

Previously, we reported that active vitamin D deficiency in mice causes secondary hypertension and cardiac dysfunction, but the underlying mechanism remains largely unknown. To clarify whether exogenous active vitamin D rescues hypertension by normalizing the altered central renin-angiotensin system (RAS) via an antioxidative stress mechanism, 1-alpha-hydroxylase [1α(OH)ase] knockout mice [1α(OH)ase(-/-)] and their wild-type littermates were fed a normal diet alone or with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], or a high-calcium, high-phosphorus "rescue" diet with or without antioxidant N-acetyl-l-cysteine (NAC) supplementation for 4 weeks. Compared with their wild-type littermates, 1α(OH)ase(-/-)mice had high mean arterial pressure, increased levels of renin, angiotensin II (Ang II), and Ang II type 1 receptor, and increased malondialdehyde levels, but decreased anti-peroxiredoxin I and IV proteins and the antioxidative genes glutathione reductase (Gsr) and glutathione peroxidase 4 (Gpx4) in the brain samples. Except Ang II type 1 receptor, these pathophysiological changes were rescued by exogenous 1,25(OH)2D3 or NAC plus rescue diet, but not by rescue diet alone. We conclude that 1,25(OH)2D3 normalizes the altered central RAS in 1α(OH)ase(-/-)mice, at least partially, through a central antioxidative mechanism. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sodium-to-Potassium Ratio and Blood Pressure, Hypertension, and Related Factors12

PubMed Central

Perez, Vanessa; Chang, Ellen T.

2014-01-01

The potential cost-effectiveness and feasibility of dietary interventions aimed at reducing hypertension risk are of considerable interest and significance in public health. In particular, the effectiveness of restricted sodium or increased potassium intake on mitigating hypertension risk has been demonstrated in clinical and observational research. The role that modified sodium or potassium intake plays in influencing the renin-angiotensin system, arterial stiffness, and endothelial dysfunction remains of interest in current research. Up to the present date, no known systematic review has examined whether the sodium-to-potassium ratio or either sodium or potassium alone is more strongly associated with blood pressure and related factors, including the renin-angiotensin system, arterial stiffness, the augmentation index, and endothelial dysfunction, in humans. This article presents a systematic review and synthesis of the randomized controlled trials and observational research related to this issue. The main findings show that, among the randomized controlled trials reviewed, the sodium-to-potassium ratio appears to be more strongly associated with blood pressure outcomes than either sodium or potassium alone in hypertensive adult populations. Recent data from the observational studies reviewed provide additional support for the sodium-to-potassium ratio as a superior metric to either sodium or potassium alone in the evaluation of blood pressure outcomes and incident hypertension. It remains unclear whether this is true in normotensive populations and in children and for related outcomes including the renin-angiotensin system, arterial stiffness, the augmentation index, and endothelial dysfunction. Future study in these populations is warranted. PMID:25398734

Skeletal muscle myoblasts possess a stretch-responsive local angiotensin signalling system.

PubMed

Johnston, Adam P W; Baker, Jeff; De Lisio, Michael; Parise, Gianni

2011-06-01

A paucity of information exists regarding the presence of local renin-angiotensin systems (RASs) in skeletal muscle and associated muscle stem cells. Skeletal muscle and muscle stem cells were isolated from C57BL/6 mice and examined for the presence of a local RAS using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), Western blotting and liquid chromatography-mass spectrometry (LC-MS). Furthermore, the effect of mechanical stimulation on RAS member gene expression was analysed. Whole skeletal muscle, primary myoblasts and C2C12 derived myoblasts and myotubes differentially expressed members of the RAS including angiotensinogen, angiotensin-converting enzyme (ACE), angiotensin II (Ang II) type 1 (AT(1)) and type 2 (AT(2)). Renin transcripts were never detected, however, mRNA for the 'renin-like' enzyme cathepsin D was observed and Ang I and Ang II were identified in cell culture supernatants from proliferating myoblasts. AT(1) appeared to co-localise with polymerised actin filaments in proliferating myoblasts and was primarily found in the nucleus of terminally differentiated myotubes. Furthermore, mechanical stretch of proliferating and differentiating C2C12 cells differentially induced mRNA expression of angiotensinogen, AT(1) and AT(2). Proliferating and differentiated muscle stem cells possess a local stress-responsive RAS in vitro. The precise function of a local RAS in myoblasts remains unknown. However, evidence presented here suggests that Ang II may be a regulator of skeletal muscle myoblasts.

Prenatal exposure to angiotensin II increases blood pressure and decreases salt sensitivity in rats.

PubMed

Svitok, Pavel; Senko, Tomas; Panakova, Zuzana; Olexova, Lucia; Krskova, Lucia; Okuliarova, Monika; Zeman, Michal

2017-01-01

Renin angiotensin aldosterone system (RAAS) plays an essential role in the homeostatic control of arterial blood pressure, perfusion of tissues, and control of extracellular fluid. Its components are highly expressed in the developing kidney, general vasculature, brain, and heart. A modified intrauterine environment alters mechanisms controlling blood pressure (BP) and can lead to hypertension in the adult offspring and developmentally programmed RAAS can be involved in this process. There are very little data about the effects of increased angiotensin II (Ang II) concentrations during pregnancy on in utero development of the fetus. In our study, we administered Ang II to pregnant female rats via osmotic mini-pumps and evaluated the postnatal development and BP control in the offspring. To estimate possible developmental changes in sensitivity to salt, we exposed the offspring to a diet with increased salt content and measured plasma aldosterone levels and plasma renin activity. Increased Ang II during pregnancy raised BP in the offspring; however, salt sensitivity was decreased in comparison to controls. Relative weight of the left ventricle was decreased in the offspring prenatally exposed to Ang II, while relative kidney weight was reduced only in female offspring. Prenatal treatment led to increased aldosterone levels and decreased plasma renin activity, suggesting a complex physiological response. Our results suggest that conditions leading to upregulation of RAAS during pregnancy can influence the cardiovascular system of the fetus and have a long-term impact on the offspring's health.

Vitamin D in the Pathophysiology of Hypertension, Kidney Disease, and Diabetes: Examining the Relationship Between Vitamin D and the Renin-Angiotensin System in Human Diseases

PubMed Central

Vaidya, Anand; Williams, Jonathan S.

2011-01-01

Objective Vitamin D has been implicated in the pathophysiology of extra-skeletal conditions such as hypertension, kidney disease, and diabetes, via its ability to negatively regulate the renin-angiotensin system (RAS). This article reviews the evidence supporting a link between vitamin D and the RAS in these conditions, with specific emphasis on translational observations and their limitations. Methods Literature review of animal and human studies evaluating the role of vitamin D in hypertension, kidney disease, and diabetes. Results Excess activity of the RAS has been implicated in the pathogenesis of hypertension, chronic kidney disease, decreased insulin secretion, and insulin resistance. Animal studies provide strong support for 1,25(OH)2D mediated down-regulation of renin expression and RAS activity via its interaction with the vitamin D receptor. Furthermore, the activity of vitamin D metabolites in animals is associated with reductions in blood pressure, proteinuria and renal injury, and with improved β–cell function. Many observational, and a few interventional, studies in humans have supported these findings; however, there is a lack of well designed prospective human interventional studies to definitively assess clinical outcomes. Conclusion Animal studies implicate vitamin D receptor agonist therapy to lower RAS activity as a potential method to reduce the risk of hypertension, kidney disease, and diabetes. There is a need for more well designed prospective interventional studies to validate this hypothesis in human clinical outcomes. PMID:22075270

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.

The Renin-Aldosterone axis in kidney transplant recipients and its association with allograft function and structure

PubMed Central

Issa, Naim; Ortiz, Fernando; Reule, Scott; Kukla, Aleksandra; Kasiske, Bertram; Mauer, Michael; Jackson, Scott; Matas, Arthur J.; Ibrahim, Hassan N.

2013-01-01

The level of the renin-angiotensin-aldosterone system (RAAS) activity in kidney transplant recipients has not been extensively studied or serially profiled. To describe this axis and to determine its association with GFR change, interstitial expansion and end-stage renal disease (ESRD) we measured plasma renin activity (PRA) and plasma aldosterone levels annually for 5 years in 153 kidney transplant recipients randomly assigned to losartan or placebo. PRA and plasma aldosterone levels were in the normal range at all times and did not vary by immunosuppression regimen. Those on losartan exhibited higher PRA but similar plasma aldosterone levels. Neither baseline nor serial PRA or plasma aldosterone levels were associated with GFR decline, proteinuria or interstitial expansion. Losartan use, [HR 0.48 (95% CI 0.21–1.0), insignificant], and Caucasian donor, [HR 0.18 (95% CI 0.07–0.4), significant] were associated with less doubling of serum creatinine, death or ESRD. Hypertension, less than 3 HLA-matches, the combination of tacrolimus-rapamycin and acute rejection were associated with more events. Neither PRA nor plasma aldosterone levels were independently associated with this outcome. Higher serial plasma aldosterone levels were associated, however, with a significantly higher risk of ESRD, [HR 1.01 (95% CI 1.00–1.02)]. Thus, systemic RAAS is not overly activated in kidney transplant recipients but this may not reflect the intrarenal system. Importantly, plasma aldosterone levels may be associated with more ESRD. PMID:23965522

The neurohormonal network in the RAAS can bend before breaking.

PubMed

Wagman, Gabriel; Fudim, Marat; Kosmas, Constantine E; Panni, Robert E; Vittorio, Timothy J

2012-06-01

The renin-angiotensin-aldosterone system (RAAS) has evolved in humans as one of the main physiological networks by which blood pressure and blood flow to vital organs is maintained. The RAAS has evolved to circumvent life-threatening events such as hemorrhage and starvation. Although short-term activation of this system had been well suited to counteract such catastrophes of early man, excessive chronic activation of the RAAS plays a fundamental role in the development and progression of cardiovascular disease in modern man. The RAAS is an intricate network comprising a number of major organ systems (heart, kidney, and vasculature) and signaling pathways. The main protagonists are renin, angiotensinogen (Ang), angiotensin I (Ang I), angiotensin II (Ang II), and aldosterone (Aldo). The study and delineation of each of these substances has allowed modern medicine to create targets by which cardiovascular disease can be treated. The main modulators that have been synthesized in this respect are angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), mineralocorticoid receptor blockers (MRBs), and direct renin inhibitors (DRIs). Over the past few decades, each of these substances has proven efficacious to varying degrees amongst a number of clinical settings. Additionally, there exists data for and against the use of these agents in combination. The use of these agents in combination poses a larger question conceptually: can excessive pharmacological inhibition of the RAAS lead to patient harm? This perspective will examine the concept of a neurohormonal inhibition ceiling in pertinent experimental and clinical trials.

Losartan alleviates hyperuricemia-induced atherosclerosis in a rabbit model.

PubMed

Zheng, Hongchao; Li, Ning; Ding, Yueyou; Miao, Peizhi

2015-01-01

To investigate the mechanisms underlying the therapeutic effects of losartan on hyperuricemia-induced aortic atherosclerosis, in an experimental rabbit model. Male rabbits (n = 48) were divided into control, hyperuricemia (HU), hypercholesterolemia + hyperuricemia (HC + HU) and high-purine with 30-mg/kg/d losartan (HU + losartan) groups. Serum uric acid (UA) and plasma renin and angiotensin II activities were determined. Aortic tissue specimens were analyzed for histological changes and proliferating cell nuclear antigen (PCNA). Liver tissues were sampled for quantitative analyses of liver low-density lipoprotein receptor (LDLR) mRNA and protein via reverse transcription polymerase chain reaction and western blotting. After 12 weeks, serum UA and plasma renin and plasma angiotensin II activities were enhanced in the HU and HU + HC groups (P < 0.001) compared to the control, whereas in the HU + losartan group plasma renin activity was not different and serum UA concentrations as well as plasma angiotensin II activity were moderately enhanced (P < 0.05). Smooth muscle cell (SMC) PCNA expression increased strongly in the HU and HU + HC groups (P < 0.001), but was less pronounced in the HU + losartan group. In contrast, transcription and expression of LDLR mRNA and protein were significantly higher in the control and HU + losartan groups compared to the HU and HU + HC groups. Both the HU and HU + HC groups had elevated intima thickness and intima areas compared to the control and HU + losartan groups. Losartan can alleviate experimental atherosclerosis induced by hyperuricemia.

Losartan alleviates hyperuricemia-induced atherosclerosis in a rabbit model

PubMed Central

Zheng, Hongchao; Li, Ning; Ding, Yueyou; Miao, Peizhi

2015-01-01

Objective: To investigate the mechanisms underlying the therapeutic effects of losartan on hyperuricemia-induced aortic atherosclerosis, in an experimental rabbit model. Methods: Male rabbits (n = 48) were divided into control, hyperuricemia (HU), hypercholesterolemia + hyperuricemia (HC + HU) and high-purine with 30-mg/kg/d losartan (HU + losartan) groups. Serum uric acid (UA) and plasma renin and angiotensin II activities were determined. Aortic tissue specimens were analyzed for histological changes and proliferating cell nuclear antigen (PCNA). Liver tissues were sampled for quantitative analyses of liver low-density lipoprotein receptor (LDLR) mRNA and protein via reverse transcription polymerase chain reaction and western blotting. Results: After 12 weeks, serum UA and plasma renin and plasma angiotensin II activities were enhanced in the HU and HU + HC groups (P < 0.001) compared to the control, whereas in the HU + losartan group plasma renin activity was not different and serum UA concentrations as well as plasma angiotensin II activity were moderately enhanced (P < 0.05). Smooth muscle cell (SMC) PCNA expression increased strongly in the HU and HU + HC groups (P < 0.001), but was less pronounced in the HU + losartan group. In contrast, transcription and expression of LDLR mRNA and protein were significantly higher in the control and HU + losartan groups compared to the HU and HU + HC groups. Both the HU and HU + HC groups had elevated intima thickness and intima areas compared to the control and HU + losartan groups. Conclusions: Losartan can alleviate experimental atherosclerosis induced by hyperuricemia. PMID:26617751

Effects of a combined oral contraceptive containing 20 mcg of ethinylestradiol and 3 mg of drospirenone on the blood pressure, renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women.

PubMed

Giribela, Cassiana Rosa Galvão; Consolim-Colombo, Fernanda Marciano; Nisenbaum, Marcelo Gil; Moraes, Tercio Lemos de; Giribela, Aricia Helena Galvão; Baracat, Edmund Chada; Melo, Nilson Roberto de

2015-01-01

Combined oral contraceptives (COCs) may increase the risk for cardiovascular disease depending on the ethynyl estradiol (EE) dose and the androgenicity of the progestogens. Our objective was to evaluate the impact of a COC containing 20 mcg EE + 3 mg drospirenone on blood pressure (BP), renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women. Eighty-one healthy young women aged 30 ± 1 years (case group, n = 49, received COC; control group, n = 32, used no COC) were assessed twice, before and after the 6-month study. Statistical analysis employed the paired t-tests and expressed the data in mean and standard deviation. Results were as follows: no changes in BP or in BMI; a significant increase in aldosterone, plasma renin activity, triglycerides, and total cholesterol levels, but a non-significant increase in HDL and no significant changes in LDL levels (these parameters remained within normal ranges); a significant increase in the HOMA-IR index and a significant decrease in dehydroepiandrosterone sulfate (SDHEA), androstenedione, total testosterone, and free testosterone levels; no significant variations in the control group parameters. An oral contraceptive combination of a low EE dose and an anti-androgenic progestogen does not negatively influence the risk factors for a cardiovascular disease.

Thirst, Drinking Behavior, And Dehydration

NASA Technical Reports Server (NTRS)

Greenleaf, John

1996-01-01

Report describes review of physiological mechanisms of involuntary dehydration. Researchers considered cellular dehydration and effects of sodium on thirst, as well as extracellular dehydration and restoration of vascular volume, effects of renin on thirst, and effects of heat.

Choosing Blood Pressure Medications

MedlinePlus

... 14, 2016. Fisher NDL, et al. Renin inhibitors. Journal of Clinical Hypertension. 2011;13:662. Wong GWK, et al. Blood ... blockers (mineralocorticoid receptor antagonism) and potassium-sparing diuretics. Journal of Clinical Hypertension. 2011;13:644. Mann JFE. Choice of therapy ...

Pyrogenic renal hyperemia: the role of prostaglandins.

PubMed

Gagnon, J A; Ramwell, P W; Flamenbaum, W

1978-01-01

The intravenous administration of triple typhoid vaccine to anesthetized dogs resulted in a significant increase in renal blood flow accompanied by a modest decline in systemic blood pressure. This renal hyperemia was associated with elevated renal secretory rates of renin and prostaglandin E and F. Measurements of the intracortical distribution of radiolabeled microspheres revealed a progressive decrease in outer cortical blood flow rates and a progressive increase in inner cortical flow rates. When meclofenamate, an inhibitor of prostaglandin synthetase, was administered concomitantly with triple typhoid vaccine renal hyperemia did not develop. The renal renin secretory rate increased modestly and intracortical renal blood flow was not redistributed. The increased renal blood flow after triple typhoid vaccine administration to unanesthetized dogs was also reversed by meclofenamate. The marked increase in prostaglandin secretion by the kidney during renal hyperemia following triple typhoid vaccine administration (pyrogen), and the effect of meclofenamate, is consonant with a role for increased renal synthesis and release of prostaglandins.

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.

A Brief Introduction into the Renin-Angiotensin-Aldosterone System: New and Old Techniques.

PubMed

Thatcher, Sean E

2017-01-01

The renin-angiotensin-aldosterone system (RAAS) is a complex system of enzymes, receptors, and peptides that help to control blood pressure and fluid homeostasis. Techniques in studying the RAAS can be difficult due to such factors as peptide/enzyme stability and receptor localization. This paper gives a brief account of the different components of the RAAS and current methods in measuring each component. There is also a discussion of different methods in measuring stem and immune cells by flow cytometry, hypertension, atherosclerosis, oxidative stress, energy balance, and other RAAS-activated phenotypes. While studies on the RAAS have been performed for over 100 years, new techniques have allowed scientists to come up with new insights into this system. These techniques are detailed in this Methods in Molecular Biology Series and give students new to studying the RAAS the proper controls and technical details needed to perform each procedure.

Dual renin-angiotensin-aldosterone blockade: promises and pitfalls.

PubMed

Chrysant, Steven G; Chrysant, George S

2015-01-01

Single renin-angiotensin-aldosterone system (RAAS) blockade has been shown to be effective and safe for the treatment of hypertension, coronary heart disease (CHD), heart failure (HF), diabetes, and chronic kidney disease (CKD) with proteinuria. Due to the action of RAAS blockers at various levels of the RAAS cascade, it was hypothesized that dual RAAS blockade would result in more complete inhibition of angiotensin II (Ang II) production and be more effective in blocking its detrimental cardiovascular remodeling effects. Unfortunately, several clinical trials in patients with hypertension, CHD, HF, and CKD with proteinuria have demonstrated no superiority of dual versus single RAAS blockade, but a higher incidence of adverse events. Based on these findings, dual RAAS blockade is no longer recommended for the routine treatment of various cardiovascular diseases, except diabetic nephropathy with proteinuria and HF with reduced ejection fraction. All the new information gathered from studies within the last 3 years will be presented in this review.

The Renin-Angiotensin-Aldosterone System (RAAS) and Cardiac Arrhythmias

PubMed Central

Iravanian, Shahriar; Dudley, Samuel C.

2008-01-01

The role of the renin-angiotensin-aldosterone system (RAAS) in many cardiovascular disorders, including hypertension, cardiac hypertrophy, and atherosclerosis is well established, whereas its relationship with cardiac arrhythmias is a new area of investigation. Atrial fibrillation and malignant ventricular tachyarrhythmias, especially in the setting of cardiac hypertrophy or failure, appear to be examples of RAAS-related arrhythmias, since treatment with RAAS modulators, including angiotensin converting enzyme inhibitors, angiotensin receptor blockers and mineralocorticoid receptor blockers, reduces the incidence of these arrhythmias. RAAS has a multitude of electrophysiological effects and can potentially cause arrhythmia through a variety of mechanisms. We review new experimental results that suggest RAAS has pro-arrhythmic effects on membrane and sarcoplasmic reticulum ion channels and that increased oxidative stress is likely contributing to the increased arrhythmic incidence. A summary of ongoing clinical trials that will address the clinical usefulness of RAAS modulators for prevention or treatment of arrhythmias is presented. PMID:18456194

The renin-angiotensin-aldosterone system (RAAS) and cardiac arrhythmias.

PubMed

Iravanian, Shahriar; Dudley, Samuel C

2008-06-01

The role of the renin-angiotensin-aldosterone system (RAAS) in many cardiovascular disorders, including hypertension, cardiac hypertrophy, and atherosclerosis, is well established, whereas its relationship with cardiac arrhythmias is a new area of investigation. Atrial fibrillation and malignant ventricular tachyarrhythmias, especially in the setting of cardiac hypertrophy or failure, seem to be examples of RAAS-related arrhythmias because treatment with RAAS modulators, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor blockers, reduces the incidence of these arrhythmias. RAAS has a multitude of electrophysiological effects and can potentially cause arrhythmia through a variety of mechanisms. We review new experimental results that suggest that RAAS has proarrhythmic effects on membrane and sarcoplasmic reticulum ion channels and that increased oxidative stress is likely contributing to the increased arrhythmic incidence. A summary of ongoing clinical trials that will address the clinical usefulness of RAAS modulators for prevention or treatment of arrhythmias is presented.

The therapeutic potential of renin angiotensin aldosterone system (RAAS) in chronic pain: from preclinical studies to clinical trials.

PubMed

Bessaguet, Flavien; Magy, Laurent; Desmoulière, Alexis; Demiot, Claire

2016-01-01

The prevalence rate of chronic pain is 15% to 25% in adults while the therapeutic arsenal is still insufficient, especially in relieving neuropathic pain. Peripheral pain transmission is conducted by the small Aδ and C sensory nerve fibres. They express elements from the renin-angiotensin-aldosterone system (RAAS), a well-known blood pressure regulator. Recently, studies have demonstrated the role of angiotensin II, its derivatives and aldosterone in the modulation of pain perception, by interacting with receptors expressed by sensory nerve fibres or through the central nervous system. Here, we assess the effects of RAAS modulators in the conduction of pain with molecular, preclinical and clinical approaches, in normal or pathological conditions. Currently, some clinical studies have been carried out on the pain-relieving effect of RAAS modulators and suggest their potential in the management of chronic, inflammatory or neuropathic pain.

The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome

PubMed Central

Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique

2012-01-01

The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment. PMID:22227126

Apparent mineralocorticoid excess syndrome: report of one family with three affected children.

PubMed

Al-Harbi, Taiba; Al-Shaikh, Adnan

2012-01-01

The syndrome of apparent mineralocorticoid excess (AME) is an autosomal recessive disorder characterized by hypertension, hypokalemia, low renin, and hypoaldosteronism. It is caused by deficiency of 11β-hydroxysteroid dehydrogenase, which results in a defect of the peripheral metabolism of cortisol to cortisone. As a consequence, the serum cortisol half-life (T½) is prolonged, ACTH is suppressed, and serum cortisol concentration is normal. The hormonal diagnosis of the disorder is made by the increased ratio of urine-free cortisol to cortisone. In patients with AME, this ratio is 5-18, while in normal individuals it is <0.5. These studies suggest that an abnormality in cortisol action or metabolism results in cortisol behaving as a potent mineralocorticoid and causing the syndrome of AME. We report three siblings - two female and one male - with the syndrome of apparent mineralocorticoid excess who presented with hypertension, hypokalemia, low renin, and low aldosterone levels. The finding of abnormally high ratios of 24-h urine-free cortisol to cortisone in our three patients (case 1, 8.4; case 2, 25; and case 3, 7.5) confirmed the diagnosis of apparent mineralocorticoid excess syndrome in these children. They were treated with oral potassium supplements. The addition of spironolactone resulted in a decrease in blood pressure, rise in serum potassium and a gradual increase in plasma renin activity in all three. In this study, the genetic testing of those three siblings with the typical clinical features of AME has detected missense mutation c.662C>T (p.Arg208Cys) in exon 3 of the HSD11B2 gene in the homozygous state.

(Pro)renin Receptor Is an Amplifier of Wnt/β-Catenin Signaling in Kidney Injury and Fibrosis.

PubMed

Li, Zhen; Zhou, Lili; Wang, Yongping; Miao, Jinhua; Hong, Xue; Hou, Fan Fan; Liu, Youhua

2017-08-01

The (pro)renin receptor (PRR) is a transmembrane protein with multiple functions. However, its regulation and role in the pathogenesis of CKD remain poorly defined. Here, we report that PRR is a downstream target and an essential component of Wnt/ β -catenin signaling. In mouse models, induction of CKD by ischemia-reperfusion injury (IRI), adriamycin, or angiotensin II infusion upregulated PRR expression in kidney tubular epithelium. Immunohistochemical staining of kidney biopsy specimens also revealed induction of renal PRR in human CKD. Overexpression of either Wnt1 or β -catenin induced PRR mRNA and protein expression in vitro Notably, forced expression of PRR potentiated Wnt1-mediated β -catenin activation and augmented the expression of downstream targets such as fibronectin, plasminogen activator inhibitor 1, and α -smooth muscle actin ( α -SMA). Conversely, knockdown of PRR by siRNA abolished β -catenin activation. PRR potentiation of Wnt/ β -catenin signaling did not require renin, but required vacuolar H + ATPase activity. In the mouse model of IRI, transfection with PRR or Wnt1 expression vectors promoted β -catenin activation, aggravated kidney dysfunction, and worsened renal inflammation and fibrotic lesions. Coexpression of PRR and Wnt1 had a synergistic effect. In contrast, knockdown of PRR expression ameliorated kidney injury and fibrosis after IRI. These results indicate that PRR is both a downstream target and a crucial element in Wnt signal transmission. We conclude that PRR can promote kidney injury and fibrosis by amplifying Wnt/ β -catenin signaling. Copyright © 2017 by the American Society of Nephrology.

[Atp6ap2/ (Pro) renin Receptor is Required for Laminar Formation during Retinal Development in Mice].

PubMed

Kanda, Atsuhiro

2015-11-01

(Pro) renin receptor [(P) RR], a key molecule for tissue renin-angiotensin system, was originally identified as Atp6ap2, an accessory subunit for vacuolar H(+)-ATPase that is a multi-subunit proton pump involved in fundamental cellular physiology. In this study, to elucidate the physiological functions of Atp6ap2/ (P) RR during retinal development in mammals, we used Cre-LoxP system to generate photoreceptor-specific conditional knock-out (CKO) mice, and revealed a critical role of Atp6ap2/(P) RR in photoreceptor development. Deletion of photoreceptor Atp6ap2/ (P) RR did not affect retinal cell differentiation, but led to laminar disorganization in the photoreceptor layer with dysfunction of photoreceptors. Cell adhesion and polarity molecules, all of which were co-localized with Atp6ap2 at the apical edge of the developing retina, were dispersed together with mislocalization of retinal progenitors apart from the apical surface in Atp6ap2 conditional knockout mice. Among these molecules, co-immunoprecipitation using retinal homogenates and Atp6ap2/(P) RR-transfected cells showed that Atp6ap2/(P) RR interacted with partitioning defective 3 homolog (Par3) protein, known to play a pivotal role in planar cell polarity in the Par-atypical protein kinase C system. Atp6ap2 interacted with Par3 protein that plays a pivotal role in planar cell polarity. Our data provide a novel function of Atp6ap2 required as a cell polarity determinant for retinal laminar formation.

Angiotensin converting enzyme DD genotype is associated with hypertensive crisis.

PubMed

Sunder-Plassmann, Gere; Kittler, Harald; Eberle, Corinna; Hirschl, Michael M; Woisetschläger, Christian; Derhaschnig, Ulla; Laggner, Anton N; Hörl, Walter H; Födinger, Manuela

2002-10-01

The genetic background of hypertensive crisis is unknown. We examined the association of polymorphisms in genes involved in the renin-angiotensin-aldosterone-system with hypertensive crisis. Population-based case-control study. Emergency department at a tertiary care university hospital. A total of 182 patients with essential hypertension who were admitted to an emergency department for treatment of hypertensive crisis and 182 age- and sex-matched healthy individuals. None. Analysis of polymorphisms in genes coding for angiotensinogen (AJT 704T-->C), angiotensin II receptor 1 (AGTR1 1166A-->C), renin (REN 2646G-->A), renin-binding protein (RENBP 61T-->C), alpha-adducin (ADD1 1378G-->T), beta-2-adrenergic receptor (ADRB2 46A-->G, 79C-->G), and angiotensin I converting enzyme (ACE I/D) was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. MAIN RESULTS Among patients, the ACE I/D polymorphism showed a deviation from Hardy-Weinberg equilibrium (p =.01). In controls, all polymorphisms were in the Hardy-Weinberg equilibrium. The frequency of the DD genotype was increased in patients (n = 70, 38.5%) vs. controls (n = 51; 28.0%;p =.03; odds ratio, 1.61; 95% confidence interval, 1.03-2.50), which was due to the DD genotype in 40 male patients (44%) vs. 23 in male controls (25.3%;p =.004; odds ratio, 3.48; 95% confidence interval, 1.47-8.30). There were no differences in genotype distributions among other polymorphisms. We demonstrate a possible association of the DD genotype with hypertensive crisis in men.

Angiotensin II-AT1-receptor signaling is necessary for cyclooxygenase-2-dependent postnatal nephron generation.

PubMed

Frölich, Stefanie; Slattery, Patrick; Thomas, Dominique; Goren, Itamar; Ferreiros, Nerea; Jensen, Boye L; Nüsing, Rolf M

2017-04-01

Deletion of cyclooxygenase-2 (COX-2) causes impairment of postnatal kidney development. Here we tested whether the renin angiotensin system contributes to COX-2-dependent nephrogenesis in mice after birth and whether a rescue of impaired renal development and function in COX-2 -/- mice was achievable. Plasma renin concentration in mouse pups showed a birth peak and a second peak around day P8 during the first 10 days post birth. Administration of the angiotensin II receptor AT1 antagonist telmisartan from day P1 to P3 did not result in cortical damage. However, telmisartan treatment from day P3 to P8, the critical time frame of renal COX-2 expression, led to hypoplastic glomeruli, a thinned subcapsular cortex and maturational arrest of superficial glomeruli quite similar to that observed in COX-2 -/- mice. In contrast, AT2 receptor antagonist PD123319 was without any effect on renal development. Inhibition of the renin angiotensin system by aliskiren and enalapril caused similar glomerular defects as telmisartan. Administration of the AT1 receptor agonist L162313 to COX-2 -/- pups improved kidney growth, ameliorated renal defects, but had no beneficial effect on reduced cortical mass. L162313 rescued impaired renal function by reducing serum urea and creatinine and mitigated pathologic albumin excretion. Moreover, glomerulosclerosis in the kidneys of COX-2 -/- mice was reduced. Thus, angiotensin II-AT1-receptor signaling is necessary for COX-2-dependent normal postnatal nephrogenesis and maturation. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

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.

Abnormal regulation of renin angiotensin aldosterone system is associated with right ventricular dysfunction in hypertension.

PubMed

Gregori, Mario; Tocci, Giuliano; Giammarioli, Benedetta; Befani, Alberto; Ciavarella, Giuseppino Massimo; Ferrucci, Andrea; Paneni, Francesco

2014-02-01

Right ventricular dysfunction (RVD) is a major predictor of cardiovascular mortality. Inadequate suppression of the renin-angiotensin-aldosterone system (RAAS) after postural manoeuvres favours alterations of left ventricular (LV) function. The effects of RAAS dysregulation on RV performance remain elusive. The present study investigated RV function in hypertensive patients with or without altered RAAS activation. Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 104 newly diagnosed hypertensive patients after both supine and upright positioning to assess dynamic changes of RAAS induced by antigravitational stress. Twenty-four-hour ambulatory blood pressure monitoring and echocardiographic evaluation of the right ventricle including tissue Doppler imaging (TDI) were performed. Patients were divided as follows: (1) normal PRA and PAC (N group [n = 58]), (2) suppressible RAAS after supine positioning (SR group [n = 24]), and (3), nonsuppressible RAAS (NSR group [n = 22]). RVD was identified by the TDI-derived myocardial performance index (MPI) calculated with a multisegmental approach. Patients in the NSR group had reduced indices of RV function compared with patients in the N and SR groups. MPI of the right ventricle as well as prevalence of RVD were also significantly higher in the NSR group. Regression models showed that inadequate RAAS suppression was independently associated with RVD, regardless of blood pressure values and LV dysfunction (LVD). Patients without supine normalization of RAAS display a significant impairment of RV function. Our findings suggest that a dynamic RAAS evaluation may help to identify hypertensive patients at higher risk of RVD. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Cardiac-specific suppression of NF-κB signaling prevents diabetic cardiomyopathy via inhibition of the renin-angiotensin system.

PubMed

Thomas, Candice M; Yong, Qian Chen; Rosa, Rodolfo M; Seqqat, Rachid; Gopal, Shanthi; Casarini, Dulce E; Jones, W Keith; Gupta, Sudhiranjan; Baker, Kenneth M; Kumar, Rajesh

2014-10-01

Activation of NF-κB signaling in the heart may be protective or deleterious depending on the pathological context. In diabetes, the role of NF-κB in cardiac dysfunction has been investigated using pharmacological approaches that have a limitation of being nonspecific. Furthermore, the specific cellular pathways by which NF-κB modulates heart function in diabetes have not been identified. To address these questions, we used a transgenic mouse line expressing mutated IκB-α in the heart (3M mice), which prevented activation of canonical NF-κB signaling. Diabetes was developed by streptozotocin injections in wild-type (WT) and 3M mice. Diabetic WT mice developed systolic and diastolic cardiac dysfunction by the 12th week, as measured by echocardiography. In contrast, cardiac function was preserved in 3M mice up to 24 wk of diabetes. Diabetes induced an elevation in cardiac oxidative stress in diabetic WT mice but not 3M mice compared with nondiabetic control mice. In diabetic WT mice, an increase in the phospholamban/sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 ratio and decrease in ryanodine receptor expression were observed, whereas diabetic 3M mice showed an opposite effect on these parameters of Ca(2+) handling. Significantly, renin-angiotensin system activity was suppressed in diabetic 3M mice compared with an increase in WT animals. In conclusion, these results demonstrate that inhibition of NF-κB signaling in the heart prevents diabetes-induced cardiac dysfunction through preserved Ca(2+) handling and inhibition of the cardiac renin-angiotensin system.

Cardiac-specific suppression of NF-κB signaling prevents diabetic cardiomyopathy via inhibition of the renin-angiotensin system

PubMed Central

Thomas, Candice M.; Yong, Qian Chen; Rosa, Rodolfo M.; Seqqat, Rachid; Gopal, Shanthi; Casarini, Dulce E.; Jones, W. Keith; Gupta, Sudhiranjan; Baker, Kenneth M.

2014-01-01

Activation of NF-κB signaling in the heart may be protective or deleterious depending on the pathological context. In diabetes, the role of NF-κB in cardiac dysfunction has been investigated using pharmacological approaches that have a limitation of being nonspecific. Furthermore, the specific cellular pathways by which NF-κB modulates heart function in diabetes have not been identified. To address these questions, we used a transgenic mouse line expressing mutated IκB-α in the heart (3M mice), which prevented activation of canonical NF-κB signaling. Diabetes was developed by streptozotocin injections in wild-type (WT) and 3M mice. Diabetic WT mice developed systolic and diastolic cardiac dysfunction by the 12th week, as measured by echocardiography. In contrast, cardiac function was preserved in 3M mice up to 24 wk of diabetes. Diabetes induced an elevation in cardiac oxidative stress in diabetic WT mice but not 3M mice compared with nondiabetic control mice. In diabetic WT mice, an increase in the phospholamban/sarco(endo)plasmic reticulum Ca2+-ATPase 2 ratio and decrease in ryanodine receptor expression were observed, whereas diabetic 3M mice showed an opposite effect on these parameters of Ca2+ handling. Significantly, renin-angiotensin system activity was suppressed in diabetic 3M mice compared with an increase in WT animals. In conclusion, these results demonstrate that inhibition of NF-κB signaling in the heart prevents diabetes-induced cardiac dysfunction through preserved Ca2+ handling and inhibition of the cardiac renin-angiotensin system. PMID:25085967

Dietary Sodium Restriction Decreases Insulin Secretion Without Affecting Insulin Sensitivity in Humans

PubMed Central

Byrne, Loretta M.; Yu, Chang; Wang, Thomas J.; Brown, Nancy J.

2014-01-01

Context: Interruption of the renin-angiotensin-aldosterone system prevents incident diabetes in high-risk individuals, although the mechanism remains unclear. Objective: To test the hypothesis that activation of the endogenous renin-angiotensin-aldosterone system or exogenous aldosterone impairs insulin secretion in humans. Design: We conducted a randomized, blinded crossover study of aldosterone vs vehicle and compared the effects of a low-sodium versus a high-sodium diet. Setting: Academic clinical research center. Participants: Healthy, nondiabetic, normotensive volunteers. Interventions: Infusion of exogenous aldosterone (0.7 μg/kg/h for 12.5 h) or vehicle during low or high sodium intake. Low sodium (20 mmol/d; n = 12) vs high sodium (160 mmol/d; n = 17) intake for 5–7 days. Main Outcome Measures: Change in acute insulin secretory response assessed during hyperglycemic clamps while in sodium balance during a low-sodium vs high-sodium diet during aldosterone vs vehicle. Results: A low-sodium diet increased endogenous aldosterone and plasma renin activity, and acute glucose-stimulated insulin (−16.0 ± 5.6%; P = .007) and C-peptide responses (−21.8 ± 8.4%; P = .014) were decreased, whereas the insulin sensitivity index was unchanged (−1.0 ± 10.7%; P = .98). Aldosterone infusion did not affect the acute insulin response (+1.8 ± 4.8%; P = .72) or insulin sensitivity index (+2.0 ± 8.8%; P = .78). Systolic blood pressure and serum potassium were similar during low and high sodium intake and during aldosterone infusion. Conclusions: Low dietary sodium intake reduces insulin secretion in humans, independent of insulin sensitivity. PMID:25029426

New drug therapies interfering with the renin-angiotensin-aldosterone system for resistant hypertension.

PubMed

Monge, Matthieu; Lorthioir, Aurélien; Bobrie, Guillaume; Azizi, Michel

2013-12-01

There is a persistent need for the development of new antihypertensive drugs, because the control of blood pressure is still not achievable in a significant proportion of hypertensive patients. Since the approval in 2007 of aliskiren, no other new antihypertensive based on new mechanism(s) of action have been approved. In fact, the development of promising novel drugs has been stopped for safety, efficacy or marketing reasons. Despite these difficulties, the pipeline is not dry and different new antihypertensive strategies targeting the renin-angiotensin-aldosterone pathway, are in clinical development stage. The dual angiotensin II receptor-neprilysin inhibitor LCZ696, a single molecule synthetized by cocrystallisation of valsartan and the neprilysin inhibitor prodrug AHU377 is in development for resistant hypertension and for heart failure. Daglutril is a dual neprylisin-endothelin converting enzyme inhibitor which was shown to decrease BP in patients with type 2 diabetic nephropathy. Aldosterone synthase inhibitors and the third and fourth generation non-steroidal dihydropyridine based mineralocorticoid receptors blockers are new ways to target the multiple noxious effects of aldosterone in the kidney, vessels and heart. Centrally acting aminopeptidase A inhibitors block brain angiotensin III formation, one of the main effector peptides of the brain renin angiotensin system. However, a long time will be still necessary to evaluate extensively the efficacy and safety of these new approaches. In the mean time, using appropriate and personalized daily doses of available drugs, decreasing physician inertia, improving treatment adherence, improving access to healthcare and reducing treatment costs remain major objectives to reduce the incidence of resistant hypertension.

The adipose renin-angiotensin system modulates sysemic markers of insulin sensitivity activates the intrarenal renin-angiotensin system

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

Kim, Suyeon; Soltani-Bejnood, Morvarid; Quignard-Boulange, Annie

2006-07-01

BACKGROUND: A growing body of data provides increasing evidence that the adipose tissue renin-angiotensin system (RAS) contributes to regulation of fat mass. Beyond its paracrine actions within adipose tissue, adipocyte-derived angiotensin II (Ang II) may also impact systemic functions such as blood pressure and metabolism. METHODS AND RESULTS: We used a genetic approach to manipulate adipose RAS activity in mice and then study the consequences on metabolic parameters and on feedback regulation of the RAS. The models included deletion of the angiotensinogen (Agt) gene (Agt-KO), its expression solely in adipose tissue under the control of an adipocyte-specific promoter (aP2-Agt/ Agt-KO),more » and overexpression in adipose tissue of wild type mice (aP2-Agt). Total body weight, epididymal fat pad weight, and circulating levels of leptin, insulin and resistin were significantly decreased in Agt-KO mice, while plasma adiponectin levels were increased. Overexpression of Agt in adipose tissue resulted in increased adiposity and plasma leptin and insulin levels compared to wild type (WT) controls. Angiotensinogen and type I Ang II receptor protein levels were also markedly elevated in kidney of aP2-Agt mice, suggesting that hypertension in these animals may be in part due to stimulation of the intrarenal RAS. CONCLUSIONS: Taken together, the results from this study demonstrate that alterations in adipose RAS activity significantly alter both local and systemic physiology in a way that may contribute to the detrimental health effects of obesity.« less

Is there benefit in dual renin-angiotensin-aldosterone system blockade? No, yes and maybe: a guide for the perplexed.

PubMed

Wong, Jencia

2013-05-01

Since the initial discovery of Angiotensin converting enzyme inhibitors (ACEI) in the 1960s and the launch of Captopril as the first available for clinical use in the 1970s, there now exist three other classes of drugs that block the renin angiotensin aldosterone system (RAAS): the angiotensin II receptor blockers (ARB), aldosterone antagonists (AA) and direct renin inhibitors (DRI). With the proven efficacy of RAAS blockers as monotherapy in many arenas there has been considerable interest in the use of dual therapy combinations of these medications that target different points in the pathway. By potentially offering a more complete RAAS blockade with a commensurate enhanced clinical effect, the strong biological rationale for dual therapy has led to it being embraced by clinicians as a treatment option, for hypertension and nephroprotection in particular. However, the initial enthusiasm for this treatment has been tempered by the recent results from several large trials such as ONTARGET and ALTITUDE, which do not support a specific dual therapy approach. In contrast, there is supportive evidence for dual blockade of specific combinations in selected patient groups and data are lacking for others. In the wake of this complex contemporary evidence, the conundrum now faced by clinicians committed to individualised care is, for which patients dual therapy could still be of benefit. This review examines for the practising clinician the current 'state of play' for dual blockade of various combinations and a perspective on its use in cardio-renal disease and diabetic complications.

Are "functionally related polymorphisms" of renin-angiotensin-aldosterone system gene polymorphisms associated with hypertension?

PubMed

Hahntow, Ines N; Mairuhu, Gideon; van Valkengoed, Irene Gm; Koopmans, Richard P; Michel, Martin C

2010-06-02

Genotype-phenotype association studies are typically based upon polymorphisms or haplotypes comprised of multiple polymorphisms within a single gene. It has been proposed that combinations of polymorphisms in distinct genes, which functionally impact the same phenotype, may have stronger phenotype associations than those within a single gene. We have tested this hypothesis using genes encoding components of the renin-angiotensin-aldosterone system and the high blood pressure phenotype. Our analysis is based on 1379 participants of the cross-sectional SUNSET study randomly selected from the population register of Amsterdam. Each subject was genotyped for the angiotensinogen M235T, the angiotensin-converting enzyme insertion/deletion and the angiotensin II type 1 receptor A1166C polymorphism. The phenotype high blood pressure was defined either as a categorical variable comparing hypertension versus normotension as in most previous studies or as a continuous variable using systolic, diastolic and mean blood pressure in a multiple regression analysis with gender, ethnicity, age, body-mass-index and antihypertensive medication as covariates. Genotype-phenotype relationships were explored for each polymorphism in isolation and for double and triple polymorphism combinations. At the single polymorphism level, only the A allele of the angiotensin II type 1 receptor was associated with a high blood pressure phenotype. Using combinations of polymorphisms of two or all three genes did not yield stronger/more consistent associations. We conclude that combinations of physiologically related polymorphisms of multiple genes, at least with regard to the renin-angiotensin-aldosterone system and the hypertensive phenotype, do not necessarily offer additional benefit in analyzing genotype/phenotype associations.

Aldosterone, Cognitive Function, and Cerebral Hemodynamics in Hypertension and Antihypertensive Therapy

PubMed Central

Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A.

2015-01-01

BACKGROUND Animal studies suggest that the renin–angiotensin–aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. METHODS Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. RESULTS At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = −0.02; P = 0.03), lower CO2 vasoreactivity (β = −0.11; P = 0.007), and decreased autoregulation abilities (β = −0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90mm Hg). Plasma renin activity was not associated with any of the measures. CONCLUSIONS Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. PMID:25213687

Angiotensin II-producing enzyme III from acidified serum of nephrectomized dogs.

PubMed

Haas, E; Lewis, L; Koshy, T J; Varde, A U; Renerts, L; Bagai, R C

1989-09-01

A highly active angiotensin-producing enzyme (enzyme III) was obtained from the serum of bilaterally nephrectomized dogs by acid treatment and ammonium sulfate fractionation. An inactive precursor (proenzyme III) was converted to enzyme III during prolonged storage (or by treatment with acid or with cathepsin G or by incubation at 38 degrees C as described in the following paper). Enzyme III reacted maximally at pH 7.7 and it produced up to 400 ng of angiotensin II/mL serum/h (i.e., amounts 4000 times higher than that generated by the endogenous renin present in serum after bilateral nephrectomy). Enzyme III produced angiotensin II at identical rates when either dog angiotensinogen or angiotensin I was used as substrate, but the rate was 710 times higher with synthetic tetradecapeptide renin substrate. Enzyme III is not identical to renin, cathepsin G, tonin, enzyme I, enzyme II, the calcium-dependent angiotensin I-converting enzyme, or the calcium-independent carboxy peptidase, which acts by sequential cleavage of angiotensin I. Enzyme III was inhibited by alpha-1-antitrypsin, diisopropyl fluorophosphate, and lima bean trypsin inhibitor (hence it is a serine proteinase). It was not inhibited by Captopril, Teprotide, or Enalapril. It had been reported previously that cathepsin G released from neutrophil granulocytes, by producing high local concentrations of angiotensin II, may provide a mobile means for modulating blood flow in tissue microvasculature during the inflammatory response. The present study offers a new, additional pathway, by enzyme III, for a similar rapid formation of angiotensin II from serum protein substrate or angiotensin I.

Living high training low induces physiological cardiac hypertrophy accompanied by down-regulation and redistribution of the renin-angiotensin system

PubMed Central

Shi, Wei; Meszaros, J Gary; Zeng, Shao-ju; Sun, Ying-yu; Zuo, Ming-xue

2013-01-01

Aim: Living high training low” (LHTL) is an exercise-training protocol that refers living in hypoxia stress and training at normal level of O2. In this study, we investigated whether LHTL caused physiological heart hypertrophy accompanied by changes of biomarkers in renin-angiotensin system in rats. Methods: Adult male SD rats were randomly assigned into 4 groups, and trained on living low-sedentary (LLS, control), living low-training low (LLTL), living high-sedentary (LHS) and living high-training low (LHTL) protocols, respectively, for 4 weeks. Hematological parameters, hemodynamic measurement, heart hypertrophy and plasma angiotensin II (Ang II) level of the rats were measured. The gene and protein expression of angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II receptor I (AT1) in heart tissue was assessed using RT-PCR and immunohistochemistry, respectively. Results: LLTL, LHS and LHTL significantly improved cardiac function, increased hemoglobin concentration and RBC. At the molecular level, LLTL, LHS and LHTL significantly decreased the expression of ACE, AGT and AT1 genes, but increased the expression of ACE and AT1 proteins in heart tissue. Moreover, ACE and AT1 protein expression was significantly increased in the endocardium, but unchanged in the epicardium. Conclusion: LHTL training protocol suppresses ACE, AGT and AT1 gene expression in heart tissue, but increases ACE and AT1 protein expression specifically in the endocardium, suggesting that the physiological heart hypertrophy induced by LHTL is regulated by region-specific expression of renin-angiotensin system components. PMID:23377552

Diabetes Mellitus, Microalbuminuria, and Subclinical Cardiac Disease: Identification and Monitoring of Individuals at Risk of Heart Failure.

PubMed

Swoboda, Peter P; McDiarmid, Adam K; Erhayiem, Bara; Ripley, David P; Dobson, Laura E; Garg, Pankaj; Musa, Tarique A; Witte, Klaus K; Kearney, Mark T; Barth, Julian H; Ajjan, Ramzi; Greenwood, John P; Plein, Sven

2017-07-17

Patients with type 2 diabetes mellitus and elevated urinary albumin:creatinine ratio (ACR) have increased risk of heart failure. We hypothesized this was because of cardiac tissue changes rather than silent coronary artery disease. In a case-controlled observational study 130 subjects including 50 ACR+ve diabetes mellitus patients with persistent microalbuminuria (ACR >2.5 mg/mol in males and >3.5 mg/mol in females, ≥2 measurements, no previous renin-angiotensin-aldosterone therapy, 50 ACR-ve diabetes mellitus patients and 30 controls underwent cardiovascular magnetic resonance for investigation of myocardial fibrosis, ischemia and infarction, and echocardiography. Thirty ACR+ve patients underwent further testing after 1-year treatment with renin-angiotensin-aldosterone blockade. Cardiac extracellular volume fraction, a measure of diffuse fibrosis, was higher in diabetes mellitus patients than controls (26.1±3.4% and 23.3±3.0% P =0.0002) and in ACR+ve than ACR-ve diabetes mellitus patients (27.2±4.1% versus 25.1±2.9%, P =0.004). ACR+ve patients also had lower E' measured by echocardiography (8.2±1.9 cm/s versus 8.9±1.9 cm/s, P =0.04) and elevated high-sensitivity cardiac troponin T 18% versus 4% ≥14 ng/L ( P =0.05). Rate of silent myocardial ischemia or infarction were not influenced by ACR status. Renin-angiotensin-aldosterone blockade was associated with increased left ventricular ejection fraction (59.3±7.8 to 61.5±8.7%, P =0.03) and decreased extracellular volume fraction (26.5±3.6 to 25.2±3.1, P =0.01) but no changes in diastolic function or high-sensitivity cardiac troponin T levels. Asymptomatic diabetes mellitus patients with persistent microalbuminuria have markers of diffuse cardiac fibrosis including elevated extracellular volume fraction, high-sensitivity cardiac troponin T, and diastolic dysfunction, which may in part be reversible by renin-angiotensin-aldosterone blockade. Increased risk in these patients may be mediated by subclinical changes in tissue structure and function. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01970319. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Reninoma presenting as cardiac syncope

PubMed Central

Tak, Shahid I; Wani, Mohd Lateef; Khan, Khursheed A; Alai, Mohd Sultan; Shera, Altaf Hussain; Ahangar, Abdul G; Khan, Yasir Bashir; Nayeem-ul-Hassan; Irshad, Ifat

2011-01-01

Reninoma, a renin-secreting tumor of the juxta-glomerular cells of the kidney, is a rare but surgically treatable cause of secondary hypertension in children. We report a case of reninoma presenting as cardiac syncope with long QTc on electrocardiogram due to hypokalemia. PMID:21677812

ENALAPRIL: PHARMACOKINETIC/DYNAMIC INFERENCES FOR COMPARATIVE DEVELOPMENTAL TOXICITY

EPA Science Inventory

Enalapril is an antihypertensive drug of the class of angiotensin-converting enzyme inhibitors (ACEI) used in pregnancy for treatment of pre-existing or pregnancy-induced hypertension. The use of ACE inhibitors (drugs that act directly on the renin-angiotensin system) during the ...

Effects of Hydrocortisone on the Regulation of Blood Pressure: Results From a Randomized Controlled Trial.

PubMed

Werumeus Buning, Jorien; van Faassen, Martijn; Brummelman, Pauline; Dullaart, Robin P F; van den Berg, Gerrit; van der Klauw, Melanie M; Kerstens, Michiel N; Stegeman, Coen A; Muller Kobold, Anneke C; Kema, Ido P; Wolffenbuttel, Bruce H R; van Beek, André P

2016-10-01

Cardiovascular risk is increased in patients with secondary adrenal insufficiency, which may be ascribed to an unfavorable metabolic profile consequent to a relatively high hydrocortisone replacement dose. We determined the effects of a higher versus a lower glucocorticoid replacement dose on blood pressure (BP), the renin-angiotensin-aldosterone system, 11β-hydroxysteroid dehydrogenase enzyme activity and circulating (nor)metanephrines. Forty-seven patients with secondary adrenal insufficiency from the University Medical Center Groningen participated in this randomized double-blind crossover study. Patients randomly received 0.2-0.3 mg hydrocortisone/kg body weight followed by 0.4-0.6 mg hydrocortisone/kg body weight, or vice versa, each during 10 weeks. BP and regulating hormones were measured. The higher hydrocortisone dose resulted in an increase in systolic BP of 5 (12) mm Hg (P = .011), diastolic BP of 2 (9) mm Hg (P = .050), and a median [interquartile range] drop in plasma potassium of -0.1 [-0.3; 0.1] nmol/liter (P = .048). The higher hydrocortisone dose led to decreases in serum aldosterone of -28 [-101; 9] pmol/liter (P = .020) and plasma renin of -1.3 [-4.5; 1.2 ] pg/mL (P = .051), and increased the ratio of plasma and urinary cortisol to cortisone (including their metabolites) (P < .001 for all). Furthermore, on the higher dose, plasma and urinary normetanephrine decreased by -0.101 [-0.242; 0.029] nmol/liter (P < .001) and -1.48 [-4.06; 0.29] μmol/mol creatinine (P < .001) respectively. A higher dose of hydrocortisone increased systolic and diastolic BP and was accompanied by changes in the renin-angiotensin-aldosterone system, 11β-hydroxysteroid dehydrogenase enzyme activity, and circulating normetanephrine. This demonstrates that hydrocortisone dose even within the physiological range affects several pathways involved in BP regulation.

The obesity-related polymorphism PCSK1 rs6235 is associated with essential hypertension in the Han Chinese population.

PubMed

Li, Xiao-Mu; Ling, Yan; Lu, Da-Ru; Lu, Zhi-Qiang; Liu, Ying; Chen, Hong-Yan; Gao, Xin

2012-10-01

Proprotein convertase subtilisin/kexin-type 1 (PCSK1) is a prohormone convertase that has an important role in prohormone maturation including the process of prorenin to renin. We studied the association of the PCSK1 single-nucleotide polymorphism (SNP) rs6235 (encoding an S690T substitution) with essential hypertension (EH), obesity and related traits in the Han Chinese population. The rs6235 SNP in the PCSK1 gene was investigated using a case-control study design, with 1034 hypertension cases and 1112 normotensive controls. In this study, the rs6235 SNP was significantly associated with hypertension (OR=1.26, 95% CI (1.10-1.46), P=0.001); the odds ratios of GC vs GG and CC vs GG were 1.30 (95% CI (1.06-1.58), P=0.010) and 1.55 (95% CI (1.12-2.13), P=0.007), respectively. In the controls, the C-allele was associated with increased systolic (P=0.010) and diastolic (P=0.010) blood pressure levels. In all of the EH patients and EH patients without a history of renin-angiotensin-aldosterone (RAA) system-related antagonists, the C-allele was associated with increased plasma renin activity (P=0.00004 and 0.002, respectively) and aldosterone levels (P=0.018 and 0.005, respectively). The C-allele was also associated with increased body mass index (BMI) (P=0.010) in the normotensive controls. In conclusion, the PCSK1 SNP rs6235 was associated with EH and blood pressure in the Han Chinese population, and this association may be mediated by the SNP's effect on RAA levels. rs6235 was also associated with BMI in this population.

Why do hypertensive patients of African ancestry respond better to calcium blockers and diuretics than to ACE inhibitors and β-adrenergic blockers? A systematic review

PubMed Central

2013-01-01

Background Clinicians are encouraged to take an individualized approach when treating hypertension in patients of African ancestry, but little is known about why the individual patient may respond well to calcium blockers and diuretics, but generally has an attenuated response to drugs inhibiting the renin-angiotensin system and to β-adrenergic blockers. Therefore, we systematically reviewed the factors associated with the differential drug response of patients of African ancestry to antihypertensive drug therapy. Methods Using the methodology of the systematic reviews narrative synthesis approach, we sought for published or unpublished studies that could explain the differential clinical efficacy of antihypertensive drugs in patients of African ancestry. PUBMED, EMBASE, LILACS, African Index Medicus and the Food and Drug Administration and European Medicines Agency databases were searched without language restriction from their inception through June 2012. Results We retrieved 3,763 papers, and included 72 reports that mainly considered the 4 major classes of antihypertensive drugs, calcium blockers, diuretics, drugs that interfere with the renin-angiotensin system and β-adrenergic blockers. Pharmacokinetics, plasma renin and genetic polymorphisms did not well predict the response of patients of African ancestry to antihypertensive drugs. An emerging view that low nitric oxide and high creatine kinase may explain individual responses to antihypertensive drugs unites previous observations, but currently clinical data are very limited. Conclusion Available data are inconclusive regarding why patients of African ancestry display the typical response to antihypertensive drugs. In lieu of biochemical or pharmacogenomic parameters, self-defined African ancestry seems the best available predictor of individual responses to antihypertensive drugs. PMID:23721258

Aliskiren Attenuates Steatohepatitis and Increases Turnover of Hepatic Fat in Mice Fed with a Methionine and Choline Deficient Diet

PubMed Central

Lee, Kuei-Chuan; Chan, Che-Chang; Yang, Ying-Ying; Hsieh, Yun-Cheng; Huang, Yi-Hsiang; Lin, Han-Chieh

2013-01-01

Background & Aims Activation of the renin-angiotensin-system is known to play a role in nonalcoholic steatohepatitis. Renin knockout mice manifest decreased hepatic steatosis. Aliskiren is the first direct renin inhibitor to be approved for clinical use. Our study aims to evaluate the possible therapeutic effects and mechanism of the chronic administration of aliskiren in a dietary steatohepatitis murine model. Methods Male C57BL/6 mice were fed with a methionine and choline-deficient (MCD) diet to induce steatohepatitis. After 8 weeks of feeding, the injured mice were randomly assigned to receive aliskiren (50 mg·kg-1 per day) or vehicle administration for 4 weeks. Normal controls were also administered aliskiren (50 mg·kg-1 per day) or a vehicle for 4 weeks. Results In the MCD mice, aliskiren attenuated hepatic steatosis, inflammation and fibrosis. Aliskiren did not change expression of lipogenic genes but increase turnover of hepatic fat by up-regulating peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a, cytochrome P450-4A14 and phosphorylated AMP-activated protein kinase. Furthermore, aliskiren decreased the hepatic expression of angiotensin II and nuclear factor κB. The levels of oxidative stress, hepatocyte apoptosis, activation of Kupffer cells and hepatic stellate cells, and pro-fibrotic markers were also reduced in the livers of the MCD mice receiving aliskiren. Conclusions Aliskiren attenuates steatohepatitis and fibrosis in mice fed with a MCD diet. Thus, the noted therapeutic effects might come from not only the reduction of angiotensin II but also the up-regulation of fatty acid oxidation-related genes. PMID:24204981

Low-protein diet supplemented with ketoacids ameliorates proteinuria in 3/4 nephrectomised rats by directly inhibiting the intrarenal renin-angiotensin system.

PubMed

Zhang, Jia-Ying; Yin, Ying; Ni, Li; Long, Quan; You, Li; Zhang, Qian; Lin, Shan-Yan; Chen, Jing

2016-11-01

Low-protein diet plus ketoacids (LPD+KA) has been reported to decrease proteinuria in patients with chronic kidney diseases (CKD). However, the mechanisms have not been clarified. As over-activation of intrarenal renin-angiotensin system (RAS) has been shown to play a key role in the progression of CKD, the current study was performed to investigate the direct effects of LPD+KA on intrarenal RAS, independently of renal haemodynamics. In this study, 3/4 subtotal renal ablated rats were fed 18 % normal-protein diet (Nx-NPD), 6 % low-protein diet (Nx-LPD) or 5 % low-protein diet plus 1 % ketoacids (Nx-LPD+KA) for 12 weeks. Sham-operated rats fed NPD served as controls. The level of proteinuria and expression of renin, angiotensin II (AngII) and its type 1 receptors (AT1R) in the renal cortex were markedly higher in Nx-NPD group than in the sham group. LPD+KA significantly decreased the proteinuria and inhibited intrarenal RAS activation. To exclude renal haemodynamic impact on intrarenal RAS, the serum samples derived from the different groups were added to the culture medium of mesangial cells. It showed that the serum from Nx-NPD directly induced higher expression of AngII, AT1R, fibronectin and transforming growth factor-β1 in the mesangial cells than in the control group. Nx-LPD+KA serum significantly inhibited these abnormalities. Then, proteomics and biochemical detection suggested that the mechanisms underlying these beneficial effects of LPD+KA might be amelioration of the nutritional metabolic disorders and oxidative stress. In conclusion, LPD+KA could directly inhibit the intrarenal RAS activation, independently of renal haemodynamics, thus attenuating the proteinuria in CKD rats.

Low LBNP Tolerance in Men is Associated With Attenuated Activation of Renin-Angiotensin System

NASA Technical Reports Server (NTRS)

Greenleaf, John E.; Petersen, T. W.; Gabrielsen, A.; Pump, B.; Bie, P.; Christensen, N.-J.; Warberg, J.; Videbaeck, R.; Simonson, S. R.; Norsk, P.;

Losartan, an Angiotensin type I receptor, restores erectile function by downregulation of cavernous renin-angiotensin system in streptozocin-induced diabetic rats.

PubMed

Yang, Rong; Yang, Bin; Wen, Yanting; Fang, Feng; Cui, Souxi; Lin, Guiting; Sun, Zeyu; Wang, Run; Dai, Yutian

2009-03-01

The high incidence of erectile dysfunction (ED) in diabetes highlights the need for good treatment strategies. Recent evidence indicates that blockade of the angiotensin type I receptor (AT1) may reverse ED from various diseases. To explore the role of cavernous renin-angiotensin system (RAS) in the pathogenesis of diabetic ED and the role of losartan in the treatment of diabetic ED. The AT1 blocker (ARB) losartan (30 mg/kg/d) was administered to rats with streptozocin (65 mg/kg)-induced diabetes. Erectile function, cavernous structure, and tissue gene and protein expression of RAS in the corpora cavernosa were studied. We sought to determine the changes of cavernous RAS in the condition of diabetes and after treatment with losartan. RAS components (angiotensinogen, [pro]renin receptor, angiotensin-converting enzyme [ACE], and AT1) were expressed in cavernosal tissue. In diabetic rats, RAS components were upregulated, resulting in the increased concentration of angiotensin II (Ang II) in the corpora. A positive feedback loop for Ang II formation in cavernosum was also identified, which could contribute to overactivity of cavernous RAS in diabetic rats. Administration of losartan blocked the effect of Ang II, downregulated the expression of AT1 and Ang II generated locally, and partially restored erectile function (losartan-treated group revealed an improved intracavernous pressure/mean systemic arterial pressure ratio as compared with the diabetic group (0.480 +/- 0.031 vs. 0.329 +/- 0.020, P < 0.01). However, losartan could not elevate the reduced smooth muscle/collagen ratio in diabetic rats. The cavernous RAS plays a role in modulating erectile function in corpora cavernosa and is involved in the pathogenesis of diabetic ED. ARB can restore diabetic ED through downregulating cavernous RAS.

Pharmacogenomic Strain Differences in Cardiovascular Sensitivity to Propofol

PubMed Central

Stekiel, Thomas A.; Contney, Stephen J.; Roman, Richard J.; Weber, Craig A.; Stadnicka, Anna; Bosnjak, Zeljko J.; Greene, Andrew S; Moreno, Carol

2011-01-01

Introduction A pharmacogenomic approach was used to further localize the genetic region responsible for previously observed enhanced cardiovascular sensitivity to propofol in Dahl Salt Sensitive (SS) vs. control Brown Norway (BN) rats. Methods Propofol infusion levels that decreased blood pressure by 50% were measured in BN.13SS rats (substitution of SS chromosome 13 into BN) and in 5 congenic (partial substitution) strains of SS.13BN. The effect of superfused 2,6 diisopropylphenol on small mesenteric arterial vascular smooth muscle transmembrane potential was measured in congenic strains before and during superfusion with Rp-cAMPS and Rp-8-pCPT-cGMPS, inhibitors of protein kinase A and G respectively. The genetic locus and potential role of the renin gene in mediating VSM sensitivity to propofol were determined in three selected sub-congenic SS.BN13 strains. Results A 30 – 32% smaller propofol infusion rate reduced blood pressure by 50% in BN.13SS compared to BN and the SS.13BN congenic containing a 80 BN gene substitution. Compared to the latter, SS exhibited greater protein kinase A dependent vascular smooth muscle hyperpolarization in response to propofol. Using sub-congenics, the increased propofol-induced cardiovascular sensitivity and hyperpolarization was further localized to an 8-gene region (containing the BN renin gene). Blockade of angiotensin (AT1) receptors with losartan in this sub-congenic, elevated propofol-induced hyperpolarization by 3 fold, to that observed in SS. Conclusions Enhanced cardiovascular sensitivity to propofol in SS (compared to BN) is caused by an altered renin gene. Through modified second messenger function, this differentially regulates VSM contractile state and reduces vascular tone exacerbating cardiovascular depression by propofol. PMID:22020141

Elevated Plasma Levels of Soluble (Pro)Renin Receptor in Patients with Obstructive Sleep Apnea Syndrome in Parallel with the Disease Severity.

PubMed

Nishijima, Tsuguo; Tajima, Kazuki; Yamashiro, Yoshihiro; Hosokawa, Keisuke; Suwabe, Akira; Takahashi, Kazuhiro; Sakurai, Shigeru

2016-04-01

(Pro)renin receptor ((P)RR), a receptor for renin and prorenin, is implicated in the pathophysiology of diabetes mellitus, hypertension and their complications. Soluble (P)RR (s(P)RR) is composed of extracellular domain of (P)RR and thus exists in blood. We have reported that plasma concentrations of s(P)RR were elevated in male patients with obstructive sleep apnea syndrome (OSAS). The aim of the present study was to clarify the difference in plasma s(P)RR concentrations between male and female OSAS patients. Plasma s(P)RR concentrations were studied in 289 subjects (206 males and 83 females) consisting of 259 OSAS patients and 30 non-OSAS control subjects. The 259 OSAS patients were classified into mild (5 ≤ apnea hypopnea index (AHI) < 15 events/h), moderate (15 ≤ AHI < 30), and severe OSAS (AHI ≥ 30). Plasma s(P)RR levels were significantly elevated in all three OSAS groups compared to non-OSAS control subjects (AHI < 5) in the entire cohort and male subjects, whereas in female subjects, the significant elevation was found only in severe OSAS. Plasma s(P)RR levels were significantly correlated with AHI in both sexes, with a higher r value found in male subjects (male r = 0.413, p < 0.0001; female r = 0.263, p < 0.05). Importantly, when OSAS patients (26 males and 15 females) with AHI ≥ 20 underwent continuous positive airway pressure treatment, plasma s(P)RR levels were significantly decreased. In conclusion, plasma s(P)RR levels are elevated in both male and female OSAS patients in parallel with the disease severity.

High levels of circulating TNFR1 increase the risk of all-cause mortality and progression of renal disease in type 2 diabetic nephropathy.

PubMed

Fernández-Juárez, Gema; Villacorta Perez, Javier; Luño Fernández, José Luis; Martinez-Martinez, Ernesto; Cachofeiro, Victoria; Barrio Lucia, Vicente; Tato Ribera, Ana M; Mendez Abreu, Angel; Cordon, Alfredo; Oliva Dominguez, Jesus Angel; Praga Terente, Manuel

2017-05-01

Several studies have demonstrated that levels of circulating inflammatory markers such as tumour necrosis factorα (TNFα), are associated with early progression of diabetic nephropathy (DN). The aim of this study was to investigate whether there is an association between circulating TNFα receptor and disease progression in patients with advanced type 2 DN and severe proteinuria. Between 2006 and 2011, we measured levels of circulating soluble TNFα receptor 1 (TNFR1) and soluble TNFα receptor 2 (TNFR2) at baseline and 4 and 12 months in 101 patients included in a multicenter randomized controlled trial to compare the effect of optimal doses of renin-angiotensin system blockers in monotherapy or in combination (dual blockade) to slow progression of established type 2 DN. The primary composite endpoint was a >50% increase in baseline serum creatinine, end-stage renal disease, or death. The median follow-up was 32 months (IQR, 18-48), during which time 28 patients (22.7%) achieved the primary endpoint. The TNFR1 level, but not the TNFR2 level, was correlated with other inflammatory markers. Cox regression analysis showed that the highest TNFR1 levels (HR, 2.60; 95%CI, 1.11-86.34) and baseline proteinuria (HR 1.32; 95%CI 1.15-1.52) were associated with the primary endpoint. The mixed model analysis revealed that TNFR1 and the TNFR2 levels did not change after starting treatment with renin-angiotensin system blockers. Our results show that the highest levels of TNFR1 are independently associated with progression of renal disease and death in type 2 DN. The renin angiotensin blockers have no effect on these inflammatory markers. © 2016 Asian Pacific Society of Nephrology.

Hydronephrosis is associated with elevated plasmin in urine in pediatric patients and rats and changes in NCC and γ-ENaC abundance in rat kidney.

PubMed

Zachar, Rikke; Al-Mashhadi, Ammar; Dimke, Henrik; Svenningsen, Per; Jensen, Boye L; Carlström, Mattias

2018-05-16

Obstruction of urine flow at the level of the pelvo-ureteric junction (UPJO) and subsequent development of hydronephrosis is one of the most common congenital renal malformations. UPJO is associated with development of salt-sensitive hypertension, which is set by the obstructed kidney, and with a stimulated renin-angiotensin-aldosterone system (RAAS) in rodent models. This study aimed at investigating the hypothesis that i) in pediatric patients with UPJO the RAAS is activated prior to surgical relief of the obstruction; ii) in rats with UPJO the RAAS activation is reflected by increased abundance of renal aldosterone-stimulated Na+ transporters; and iii) the injured UPJO kidney allows aberrant filtration of plasminogen leading to proteolytic activation of the epithelial sodium channel gamma subunit (γ-ENaC). Hydronephrosis due to UPJO in pediatric patients and rats was associated with increased urinary plasminogen/creatinine ratio. In pediatric patients, plasma renin, angiotensin II, urine and plasma aldosterone and urine soluble pro-renin receptor did not differ significantly before and after surgery, or compared with controls. Increased plasmin/plasminogen ratio was seen in UPJO rats. Intact γ-ENaC abundance was not changed in UPJO kidney while low-molecular cleavage product abundance increased. The Na-Cl cotransporter (NCC) displayed significantly lower abundance in the UPJO kidney compared to the non-obstructed contralateral kidney. The Na-K-ATPase alpha-subunit was unaltered. Treatment with an angiotensin-converting enzyme inhibitor (8 days, captopril) significantly lowered blood pressure in UPJO rats. It is concluded that the RAAS contributes to hypertension following partial obstruction of urine flow at the pelvo-ureteric junction with potential contribution from proteolytic activation of ENaC.

Gender hormones and the progression of experimental polycystic kidney disease.

PubMed

Stringer, Kenneth D; Komers, Radko; Osman, Shukri A; Oyama, Terry T; Lindsley, Jessie N; Anderson, Sharon

2005-10-01

Male gender is a risk factor for progression of autosomal-dominant polycystic kidney disease (ADPKD), clinically and in the Han:SPRD rat model. Orchiectomy limits progression, but mechanisms of the detrimental effect of androgen, and/or beneficial effects of estrogen, are not known. This protocol tested the hypothesis that male gender (intact androgen status) promotes progression, while female gender (intact estrogen status) is protective; and that these disease-modifying effects are due to changes in expression of known fibrotic mediators. Studies were performed in male and female noncystic control (+/+) and cystic (+/-) rats subjected to orchiectomy, ovariectomy, or sham operation. At 12 weeks of age, renal function was measured. Blood and kidneys were taken for measurement of plasma and renal renin, endothelin (ET-1), endothelial nitric oxide synthase (eNOS), and vascular endothelial growth factor (VEGF), using biochemical, protein expression, and immunohistochemical methods. Cystic male rats exhibited significantly reduced glomerular filtration (GFR) and effective renal plasma flow (ERPF) rates, with suppression of plasma and renal renin, up-regulation of renal ET-1 and eNOS, and down-regulation of renal VEGF expression. Orchiectomy attenuated the fall in GFR and ERPF, while numerically limiting changes in eNOS and VEGF. Female rats exhibited less cystic growth, with normal renin status, lesser elevation of renal ET-1, and proportionately lesser changes in VEGF and eNOS. Ovariectomy led to higher blood pressure and reduced GFR and ERPF, with a trend toward upregulation of ET-1, and significant down-regulation of VEGF and eNOS. Female gender is protective, but ovariectomy attenuates the protective effect of female gender, in association with changes in renal expression of ET-1, VEGF, and eNOS. The accelerated disease in male rats can be attenuated by orchiectomy and consequent changes in expression of disease mediators.

Reversibility of the Effects of Aliskiren in the Renal Versus Systemic Circulation

PubMed Central

Schneider, Markus P.; Janka, Rolf; Ziegler, Thomas; Raff, Ulrike; Ritt, Martin; Ott, Christian; Veelken, Roland; Uder, Michael; Schmieder, Roland E.

2012-01-01

Summary Background and objectives Renal hemodynamic effects of inhibitors of the renin-angiotensin system can increase the risk of acute kidney injury under certain conditions. The BP-lowering effects of the renin inhibitor aliskiren are sustained 3–4 weeks after withdrawal. In this study, the reversibility of the renal hemodynamic effects of aliskiren was tested. Design, setting, participants, & measurements In this open-label study, renal perfusion was measured by 1.5-T magnetic resonance imaging–arterial spin labeling in 34 subjects with arterial hypertension before aliskiren (pre-aliskiren), after 4 weeks of aliskiren treatment (300 mg), and 4–5 days (∼2.5–3.0× plasma half-life) after withdrawal (post-aliskiren). Results Aliskiren reduced systolic BP from 152 ± 14 to 139 ± 16 mmHg (P<0.0001), which was sustained post-aliskiren (136 ± 13 mmHg, P=1.00 versus aliskiren). Aliskiren significantly altered renal perfusion (P=0.005), increasing from 272 ± 25 pre-aliskiren to 287 ± 29 ml/min per 100 g during aliskiren (P=0.03). This increase in renal perfusion was completely reversed post-aliskiren (272 ± 26 ml/min per 100 g, P=0.03 versus aliskiren, P=0.63 versus pre-aliskiren). No changes were noted in urinary angiotensinogen levels. Plasma renin activity was reduced by aliskiren, which was sustained post-aliskiren. Angiotensin II and aldosterone were reduced by aliskiren but recovered post-aliskiren to pre-aliskiren levels. Conclusions After withdrawal of aliskiren, the effects on BP were sustained, whereas increase in renal perfusion was reversed, which was associated with recovery of angiotensin II and aldosterone to pretreatment levels. Renal hemodynamic effects are more readily reversible than systemic effects of aliskiren. PMID:22173856

Effects of peripherally and centrally applied ghrelin on the oxidative stress induced by renin angiotensin system in a rat model of renovascular hypertension.

PubMed

Boshra, Vivian; Abbas, Amr M

2017-07-26

Renovascular hypertension (RVH) is a result of renal artery stenosis, which is commonly due to astherosclerosis. In this study, we aimed to clarify the central and peripheral effects of ghrelin on the renin-angiotensin system (RAS) in a rat model of RVH. RVH was induced in rats by partial subdiaphragmatic aortic constriction. Experiment A was designed to assess the central effect of ghrelin via the intracerebroventricular (ICV) injection of ghrelin (5 μg/kg) or losartan (0.01 mg/kg) in RVH rats. Experiment B was designed to assess the peripheral effect of ghrelin via the subcutaneous (SC) injection of ghrelin (150 μg/kg) or losartan (10 mg/kg) for 7 consecutive days. Mean arterial blood pressure (MAP), heart rate, plasma renin activity (PRA), and oxidative stress markers were measured in all rats. In addition, angiotensin II receptor type 1 (AT1R) concentration was measured in the hypothalamus of rats in Experiment B. RVH significantly increased brain AT1R, PRA, as well as the brain and plasma oxidative stress. Either SC or ICV ghrelin or losartan caused a significant decrease in MAP with no change in the heart rate. Central ghrelin or losartan caused a significant decrease in brain AT1R with significant alleviation of the brain oxidative stress. Central ghrelin caused a significant decrease in PRA, whereas central losartan caused a significant increase in PRA. SC ghrelin significantly decreased PRA and plasma oxidative stress, whereas SC losartan significantly increased PRA and decreased plasma oxidative stress. The hypotensive effect of ghrelin is mediated through the amelioration of oxidative stress, which is induced by RAS centrally and peripherally.

Dysregulated renin-angiotensin-aldosterone system contributes to pulmonary arterial hypertension

PubMed Central

De Man, Frances; Tu, Ly; Handoko, Louis; Rain, Silvia; Ruiter, Gerrina; François, Charlène; Schalij, Ingrid; Dorfmüller, Peter; Simonneau, Gérald; Fadel, Elie; Perros, Frederic; Boonstra, Anco; Postmus, Piet; Van Der Velden, Jolanda; Vonk-Noordegraaf, Anton; Humbert, Marc; Eddahibi, Saadia; Guignabert, Christophe

2012-01-01

Rationale Patients with idiopathic pulmonary arterial hypertension (iPAH) often have a low cardiac output. To compensate, neurohormonal systems like renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system are upregulated but this may have long-term negative effects on the progression of iPAH. Objectives Assess systemic and pulmonary RAAS-activity in iPAH-patients and determine the efficacy of chronic RAAS-inhibition in experimental PAH. Measurements and Main Results We collected 79 blood samples from 58 iPAH-patients in the VU University Medical Center Amsterdam (between 2004–2010), to determine systemic RAAS-activity. We observed increased levels of renin, angiotensin (Ang) I and AngII, which was associated with disease progression (p<0.05) and mortality (p<0.05). To determine pulmonary RAAS-activity, lung specimens were obtained from iPAH-patients (during lung transplantation, n=13) and controls (during lobectomy or pneumonectomy for cancer, n=14). Local RAAS-activity in pulmonary arteries of iPAH-patients was increased, demonstrated by elevated ACE-activity in pulmonary endothelial cells and increased AngII type 1 (AT1) receptor expression and signaling. In addition, local RAAS- upregulation was associated with increased pulmonary artery smooth muscle cell proliferation via enhanced AT1-receptor signaling in iPAH-patients compared to controls. Finally, to determine the therapeutic potential of RAAS-activity, we assessed the chronic effects of an AT1-receptor antagonist (losartan) in the monocrotaline PAH-rat model (60 mg/kg). Losartan delayed disease progression, decreased RV afterload and pulmonary vascular remodeling and restored right ventricular-arterial coupling in PAH-rats. Conclusions Systemic and pulmonary RAAS-activities are increased in iPAH-patients and associated with increased pulmonary vascular remodeling. Chronic inhibition of RAAS by losartan is beneficial in experimental PAH. PMID:22859525

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism.

PubMed

Babaya, Naru; Makutani, Yukako; Noso, Shinsuke; Hiromine, Yoshihisa; Ito, Hiroyuki; Taketomo, Yasunori; Ueda, Kazuki; Ushijima, Hokuto; Komoike, Yoshifumi; Yamazaki, Yuto; Sasano, Hironobu; Kawabata, Yumiko; Ikegami, Hiroshi

2017-12-06

We report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed. A 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8 × 5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection. A clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.

Dietary docosahexaenoic acid ameliorates, but rapeseed oil and safflower oil accelerate renal injury in stroke-prone spontaneously hypertensive rats as compared with soybean oil, which is associated with expression for renal transforming growth factor-beta, fibronectin and renin.

PubMed

Miyazaki, M; Takemura, N; Watanabe, S; Hata, N; Misawa, Y; Okuyama, H

2000-01-03

We have noted that n-3 fatty acid-rich oils, such as fish oil, perilla oil and flaxseed oil as well as ethyl docosahexaenoate (DHA) prolonged the survival time of stroke-prone spontaneously hypertensive rats (SHRSP) rats by approximately 10% as compared with linoleate (n-6)-rich safflower oil. Rapeseed oil with a relatively low n-6/n-3 ratio unusually shortened the survival time by approximately 40%, suggesting the presence of minor components unfavorable to SHRSP rats. This study examined the effects of dietary oils and DHA on renal injury and gene expression related to renal injury in SHRSP rats. Rats fed rapeseed oil- and safflower oil-supplemented diets developed more severe proteinuria than those fed soybean oil-supplemented diet used as a control, but there were no significant differences in blood pressure. In contrast, the DHA-supplemented diet inhibited the development of proteinuria and suppressed hypertension. The mRNA levels for renal TGF-beta, fibronectin and renin were higher in the rapeseed oil and safflower oil groups after 9 weeks of feeding of the experimental diet than in the soybean oil and DHA groups. The fatty acid composition of kidney phospholipids was markedly affected by these diets. These results indicate that the renal injury observed in the groups fed safflower oil with a high n-6/n-3 ratio and rapeseed oil with presumed minor components is accompanied by increased expression of the TGF-beta, renin and fibronectin genes, and that dietary DHA suppresses renal injury and gene expression as compared with soybean oil.

Hypertension management: rationale for triple therapy based on mechanisms of action.

PubMed

Neutel, Joel M; Smith, David H G

2013-10-01

An estimated 25% of patients will require 3 antihypertensive agents to achieve blood pressure (BP) control; combination therapy is thus an important strategy in hypertension treatment. This review discusses the triple-therapy combination of an angiotensin receptor blocker (ARB) or direct renin antagonist (DRI) with a calcium channel blocker (CCB) and a diuretic, with a focus on mechanisms of action. Multiple physiologic pathways contribute to hypertension. Combining antihypertensive agents not only better targets the underlying pathways, but also helps blunt compensatory responses that may be triggered by single-agent therapy. DRIs and ARBs target the renin-angiotensin-aldosterone system (RAAS) at the initial and final steps, respectively, and both classes lower BP by reducing the effects of angiotensin-2; however, ARBs may trigger a compensatory increase in renin activity. Dihydropyridine CCBs target L-type calcium channels and lower BP through potent vasodilation, but can trigger compensatory activation of the sympathetic nervous system (SNS) and RAAS. Thiazide diuretics lower BP initially through sodium depletion and plasma volume reduction, followed by total peripheral resistance reduction, but can also trigger compensatory activation of the SNS and RAAS. The combination of an agent targeting the RAAS with a CCB and diuretic is rational, and triple combinations of valsartan/amlodipine/hydrochlorothiazide, olmesartan/amlodipine/hydrochlorothiazide, and aliskiren/amlodipine/hydrochlorothiazide have demonstrated greater effectiveness compared with their respective dual-component combinations. In addition, single-pill, fixed-dose combinations can address barriers to BP control including clinical inertia and poor adherence. Fixed-dose antihypertensive combination products capitalize on complementary mechanisms of action and have been shown to result in improved BP control. © 2012 John Wiley & Sons Ltd.

The influence of a tilt training programme on the renin-angiotensin-aldosterone system activity in patients with vasovagal syncope.

PubMed

Gajek, Jacek; Zyśko, Dorota; Krzemińska, Sylwia; Mazurek, Walentyna

2009-08-01

We assessed the influence of short-term and long-term tilt training on the activity of the renin-angiotensin-aldosterone system (RAAS) in vasovagal patients. Thirty-nine patients (28 F, 11 M) aged 39.7 +/- 11.2 years with a history of vasovagal syncope and a positive head-up tilt test (HUT) were studied. Blood samples for plasma renin activity (PRA) and aldosterone (ALDO) concentration were drawn at the baseline, immediately after HUT and 10 min after HUT, during the diagnostic, the negative short-term (2-5 days) follow-up HUT and long-term (1-3 months) follow-up HUT. Tilt training was started after diagnostic HUT. In diagnostic HUT, PRA increased significantly immediately after HUT comparing to the baseline, during recovery the values did not change. ALDO concentration increased after HUT comparing to baseline and further increased during recovery. After short-term tilt training, PRA and ALDO concentrations did not significantly change compared to their corresponding values in diagnostic HUT. After long-term tilt training, PRA did not significantly change compared to the values in the diagnostic and short-term follow-up HUT. ALDO concentration also did not change significantly at the baseline and immediately after HUT, and 10 min after HUT ALDO concentration was significantly lower than after diagnostic HUT. Tilt training changes the response of RAAS to the prolonged orthostasis in vasovagal patients. The coupling between PRA and ALDO after diagnostic HUT has been found to be altered and the physiological relationship was restored after long-term tilt training. The beneficial effect of tilt training depends partially on changed RAAS activation.

Pitting type of pretibial edema in a patient with silent thyroiditis successfully treated by angiotensin ii receptor blockade.

PubMed

Kazama, Itsuro; Mori, Yoko; Baba, Asuka; Nakajima, Toshiyuki

2014-01-01

Female, 56 FINAL DIAGNOSIS: Thyroiditis - silent Symptoms: Palpitations • pretibial pitting edema • short of breath • sweating - Clinical Procedure: - Specialty: Endocrinology and Metabolic. Unknown etiology. Hyper- or hypothyroidism sometimes causes pretibial myxedema characterized by non-pitting infiltration of a proteinaceous ground substance. However, in those patients, the "pitting" type of pretibial edema as a result of increased sodium and fluid retention or vascular hyper-permeability rarely occurs, except in cases complicated by heart failures due to severe cardiomyopathy or pulmonary hypertension. A 56-year-old woman developed bilateral pretibial pitting edema, followed by occasional sweating, palpitations, and shortness of breath, which persisted for more than 2 months. The diagnosis of hyperthyroidism due to silent thyroiditis was supported by elevated levels of free thyroxine (T4) and triiodothyronine (T3), with a marked decrease in thyroid-stimulating hormone (TSH), and the negative results for TSH receptor antibodies with typical findings of destructive thyrotoxicosis. Despite her "pitting" type of pretibial edema, a chest radio-graph demonstrated the absence of cardiomyopathy or congestive heart failure. Oral administration of angiotensin II receptor blocker (ARB) was initiated for her systolic hypertension, with a relatively higher elevation of plasma renin activity compared to that of the aldosterone level. Although the symptoms characteristic to hyperthyroidism, such as increased sweating, palpitations and shortness of breath, slowly improved with a spontaneous resolution of the disease, ARB quickly resolved the pretibial pitting edema shortly after the administration.. In this case, increased activity of the renin-angiotensin-aldosterone system stimulated by thyroid hormone was likely responsible for the patient's pitting type of edema. The pharmacological blockade of the renin-angiotensin-aldosterone system was thought to be effective for the quick resolution of the symptom.

Heart-specific overexpression of (pro)renin receptor induces atrial fibrillation in mice.

PubMed

Lian, Hong; Wang, Xiaojian; Wang, Juan; Liu, Ning; Zhang, Li; Lu, Yingdong; Yang, Yanmin; Zhang, Lianfeng

2015-04-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia, causing substantial cardiovascular morbidity and mortality. The renin-angiotensin system (RAS) has been shown to be involved in the pathophysiology of AF. The (pro)renin receptor [(p)RR] is the last identified member of RAS. However, the role of (p)RR in AF is still unknown. Circulating levels of (p)RR were determined using an immunosorbent assay in 22 patients with AF (paroxysmal or persistent) and 22 healthy individuals. The plasma levels of (p)RR increased 3.6-fold in AF patients (P<0.001), indicating a relationship between (p)RR and AF. To investigate the role of (p)RR in the regulation of cardiac arrhythmia, we generated a transgenic mouse with overexpression of human (p)RR gene specifically in the heart. Electrocardiograms from (p)RR transgenic mice showed typical atrial flutter since 2 months, then spontaneously converted to atrial fibrillation by 10 months. The atria of the transgenic mice demonstrated significant dilation and fibrosis, and exhibited a high incidence of sudden death. Additionally, the genes of SERCA and HCN4, which are involved in the electrophysiology of AF, were significantly down-regulated and up-regulated respectively in transgenic mice atria. The phosphorylation of Erk1/2 significantly increased in the atria of the transgenic mice, and the activated Erk1/2 was found predominantly in cardiac fibroblasts, suggesting that the transgenic (p)RR gene may induce atrial fibrillation by activation of Erk1/2 in the cardiac fibroblasts of the atria. (p)RR promotes atrial structural and electrical remodeling in vivo, which indicates that (p)RR plays an important role in the pathological development of AF. Copyright © 2015. Published by Elsevier Ireland Ltd.

A high sodium intake reduces antiproteinuric response to renin-angiotensin-aldosterone system blockade in kidney transplant recipients.

PubMed

Monfá, Elena; Rodrigo, Emilio; Belmar, Lara; Sango, Cristina; Moussa, Fozi; Ruiz San Millán, Juan Carlos; Piñera, Celestino; Fernández-Fresnedo, Gema; Arias, Manuel

Post-transplant proteinuria is associated with lower graft and patient survival. Renin-angiotensin-aldosterone system blockers are used to reduce proteinuria and improve renal outcome. Although it is known that a high salt intake blunts the antiproteinuric effect of ACEI and ARB drugs in non-transplant patients, this effect has not been studied in kidney transplant recipients. To analyse the relationship between sodium intake and the antiproteinuric effect of ACEI/ARB drugs in kidney transplant recipients. We selected 103 kidney transplant recipients receiving ACEI/ARB drugs for more than 6 months due to proteinuria>1 g/day. Proteinuria was analysed at baseline and at 6 months after starting ACEI/ARB treatment. Salt intake was estimated by urinary sodium to creatinine ratio (uNa/Cr). Proteinuria fell to less than 1g/day in 46 patients (44.7%). High uNa/Cr was associated with a smaller proteinuria decrease (r=-0.251, P=.011). The percentage proteinuria reduction was significantly lower in patients in the highest uNa/Cr tertile [63.9% (IQR 47.1%), 60.1% (IQR 55.4%), 38.9% (IQR 85.5%), P=.047]. High uNa/Cr independently relates (OR 2.406 per 100 mEq/g, 95% CI: 1.008-5.745, P=.048) to an antiproteinuric response <50% after renin-angiotensin-aldosterone system blockade. A high salt intake results in a smaller proteinuria decrease in kidney transplant recipients with proteinuria treated with ACEI/ARB drugs. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Dietary Sodium Restriction Increases the Risk of Misinterpreting Mild Cases of Primary Aldosteronism

PubMed Central

Guarda, Francisco J.; Torrey, Jasmine; Williams, Gordon

2016-01-01

Context: The aldosterone to renin ratio (ARR) is recommended to screen for primary aldosteronism (PA). Objective: To evaluate whether dietary sodium restriction results in misinterpretation of PA screening. Participants: Untreated hypertensives with ARR more than 20 on a high dietary sodium intake (HS) were also evaluated on a low dietary sodium intake (LS) (n = 241). Positive screening for PA was defined as: plasma renin activity (PRA) less than or equal to 1.0 ng/mL · h with serum aldosterone more than or equal to 6 ng/dL. PA was confirmed by a 24-hour urinary aldosterone excretion more than or equal to 12 mcg with urinary sodium more than 200 mmol. Results: Only 33% (79/241) of participants with an ARR more than 20 had a positive PA screen on HS. On LS, 56% (44/79) of these participants no longer met criteria for positive PA screening. When compared with participants with positive PA screening on both diets, participants with a positive screen on HS but negative on LS exhibited a significantly higher PRA on both diets. Remarkably, of the 48/79 participants who had PA confirmed, 52% had negative PA screening on LS. The distinguishing feature of these participants with “discordant” screening results was a larger rise in PRA on LS resulting in normalization of the ARR and higher Caucasian race prevalence. Conclusions: Sodium restriction is recommended in hypertension; however, it can significantly raise PRA, normalize the ARR, and result in false interpretation of PA screening. Milder phenotypes of PA, where PRA is not as suppressed, are most susceptible to dietary sodium influences on renin and ARR. Optimal screening for PA should occur under conditions of HS. PMID:27428770

Dietary Sodium Restriction Increases the Risk of Misinterpreting Mild Cases of Primary Aldosteronism.

PubMed

Baudrand, Rene; Guarda, Francisco J; Torrey, Jasmine; Williams, Gordon; Vaidya, Anand

2016-11-01

The aldosterone to renin ratio (ARR) is recommended to screen for primary aldosteronism (PA). To evaluate whether dietary sodium restriction results in misinterpretation of PA screening. Untreated hypertensives with ARR more than 20 on a high dietary sodium intake (HS) were also evaluated on a low dietary sodium intake (LS) (n = 241). Positive screening for PA was defined as: plasma renin activity (PRA) less than or equal to 1.0 ng/mL · h with serum aldosterone more than or equal to 6 ng/dL. PA was confirmed by a 24-hour urinary aldosterone excretion more than or equal to 12 mcg with urinary sodium more than 200 mmol. Only 33% (79/241) of participants with an ARR more than 20 had a positive PA screen on HS. On LS, 56% (44/79) of these participants no longer met criteria for positive PA screening. When compared with participants with positive PA screening on both diets, participants with a positive screen on HS but negative on LS exhibited a significantly higher PRA on both diets. Remarkably, of the 48/79 participants who had PA confirmed, 52% had negative PA screening on LS. The distinguishing feature of these participants with "discordant" screening results was a larger rise in PRA on LS resulting in normalization of the ARR and higher Caucasian race prevalence. Sodium restriction is recommended in hypertension; however, it can significantly raise PRA, normalize the ARR, and result in false interpretation of PA screening. Milder phenotypes of PA, where PRA is not as suppressed, are most susceptible to dietary sodium influences on renin and ARR. Optimal screening for PA should occur under conditions of HS.

Molecular characterization and transcriptional regulation of the renin-angiotensin system genes in Senegalese sole (Solea senegalensis Kaup, 1858): differential gene regulation by salinity.

PubMed

Armesto, Paula; Cousin, Xavier; Salas-Leiton, Emilio; Asensio, Esther; Manchado, Manuel; Infante, Carlos

2015-06-01

In this work, the complete cDNA sequence encoding angiotensinogen (agt) in the euryhaline flatfish Senegalese sole was obtained. Additionally, putative coding sequences belonging to other renin-angiotensin system (RAS) genes including renin (ren), angiotensin-converting enzyme (ace), angiotensin-converting enzyme 2 (ace2), as well as angiotensin II receptor type I (agtr1) and type II (agtr2), were also identified. In juvenile tissues, agt transcripts were mainly detected in liver, ren in kidney, ace and ace2 in intestine, agtr1 in kidney and brain, and agtr2 in liver and kidney. Expression analysis of the six RAS genes after a salinity shift revealed a clear increase of agt mRNA abundance in liver just after transferring soles to high salinity water (60 ppt) with a peak at 48 h. Moreover, gene expression analysis in gills showed transcriptional regulation of ace and agtr1 at 48 h and agtr2 at 96 h after transferring soles to 60 ppt. Incubation of larvae before mouth opening (until 3 days post hatch; dph) at low salinity (10 ppt) resulted in a coordinated transcriptional up-regulation of RAS genes. Nevertheless, no differences in mRNA abundance between salinities were observed when larvae were cultivated to low salinity after mouth opening. Whole-mount in situ hybridization (WISH) signal for agt and ace in 3 dph larvae incubated at 10 ppt and 35 ppt confirmed that the former gene was mainly expressed in liver whereas the later gene was mainly located in pharynx and posterior gut, without pronounced differences in intensity between salinities. Possible physiological significance of all these results is discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

New evidence on the importance of the renin-angiotensin system in the treatment of higher-risk patients with hypertension.

PubMed

Sleight, Peter; Yusuf, Salim

2003-09-01

We reviewed the drug treatment of hypertension in the light of recent trials. beta-Blockers and diuretics clearly reduce mortality, strokes, and coronary heart disease (CHD) in hypertension. Recent trials assessed whether newer agents that block the renin-angiotensin-aldosterone system, or calcium blockers, offer any additional advantage, or have benefits in high-risk individuals with conventionally 'normal' blood pressure. The recent ALLHAT study claimed no differences in CHD or mortality when chlorthalidone, amlodipine, and lisinopril were compared. However, the decrease in blood pressure was not the same with the three agents, and a substantial proportion of patients enrolled did not have clinical disease. In contrast, the LIFE study (comparing losartan and a beta-blocker) and the ANBP-2 study [comparing angiotensin-converting enzyme (ACE) inhibition and a diuretic] reduced blood pressure similarly, yet demonstrated benefits in favour of angiotensin II type 1 receptor blockers (ARBs) and ACE inhibitors. Other trials indicated similar advantages of ACE inhibitors or ARBs in patients with diabetic nephropathy. Among high-risk patients with initial blood pressure in the 'normal' range, ACE inhibitors significantly reduce clinical events (mortality, strokes, and myocardial infarction), despite modest decreases in blood pressure, suggesting that additional mechanisms are responsible. Recent results of the Prospective Studies Collaboration show lower risk, even in the normal blood pressure range; high-risk patients will benefit further from ACE inhibitors and ARBs (and beta-blockers after myocardial infarction). Data for other blood pressure decreasing agents are unavailable in such populations. We conclude that blood pressure decreasing per se is of clinical benefit, but drugs that block the renin-angiotensin system offer additional advantages. Drug choice is best determined by the patient's clinical condition.

Vasoactive neuroendocrine responses associated with tolerance to lower body negative pressure in humans

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Sather, T. M.

2000-01-01

The purpose of this investigation was to test the hypothesis that peripheral vasoconstriction and orthostatic tolerance are associated with increased circulating plasma concentrations of noradrenaline, vasopressin and renin-angiotensin. Sixteen men were categorized as having high (HT, n=9) or low (LT, n=7) tolerance to lower body negative pressure (LBNP) based on whether the endpoint of their pre-syncopal-limited LBNP (peak LBNP) exposure exceeded -60 mmHg. The two groups were matched for age, height, weight, leg volume, blood volume and maximal oxygen uptake, as well as baseline blood volume and plasma concentrations of vasoactive hormones. Peak LBNP induced similar reductions in mean arterial pressure in both groups. The reduction in leg arterial pulse volume (measured by impedance rheography), an index of peripheral vascular constriction, from baseline to peak LBNP was greater (P<0.05) in the HT group (-0.041 +/- 0.005 ml 100 ml-1) compared to the reduction in the LT group (-0. 025 +/- 0.003 ml 100 ml-1). Greater peak LBNP in the HT group was associated with higher (P<0.05) average elevations in plasma concentrations of vasopressin (pVP, Delta=+7.2 +/- 2.0 pg ml-1) and plasma renin-angiotensin (PRA, Delta=+2.9 +/- 1.3 ng Ang II ml-1 h-1) compared to average elevations of pVP (+2.2 +/- 1.0 pg ml-1) and PRA (+0.1 +/- 0.1 ng Ang II ml-1 h-1) in the LT group. Plasma noradrenaline concentrations were increased (P<0.05) from baseline to peak LBNP in both HT and LT groups, with no statistically distinguishable difference between groups. These data suggest that the renin-angiotensin and vasopressin systems may contribute to sustaining arterial pressure and orthostatic tolerance by their vasoconstrictive actions.

[Elevated serum aldosterone levels in dialysis patients: Are we underusing renin-angiotensin-aldosterone system blockers?

PubMed

Fernández-Reyes, M J; Velasco, S; Gutierrez, C; Gonzalez Villalba, M J; Heras, M; Molina, A; Callejas, R; Rodríguez, A; Calle, L; Lopes, V

Serum aldosteronelevels (SA) are a marker of cardiovascular (CV) risk in the general population. To analyze SA levels in dialysis patients and its relationship with characteristics of dialysis; comorbidity; blood pressure and the use of blocking renin-angiotensin-aldosterone system agents (BSRAA). We determined SA in 102 patients: 81 on hemodialysis (HD) and 21 on peritoneal dialysis. Mean age 71.4±12 years; 54.9% male; 29.4% diabetics. Mean time on dialysis 59.3±67 months. In 44 HD patients plasma renin activity (PRA) was measured. Mean SA was 72.6±114.9ng/dl (normal range 1.17-23.6ng/dl). A total of 57.8% of patients had above normal levels which were not related to dialysis characteristics or comorbidity. Only 21% of patients with heart failure and 19.2% with ischemic heart disease used BSRAA. A number of 25 patients treated with BSRAA had significantly lower levels of SA. There was an inverse correlation between AS and systolic blood pressure (SBP), and direct with PRA. The logistic regression analysis conducted to find SA levels above the median associated factors showed that SBP was the only independent risk variable in the overall population (OR 0.97; P=.022); in the 44 patients in whom PRA was determined this was the only independent risk factor (OR 2.24; P=.012). A high percentage of dialysis patients have elevated levels of SA that are associated to diminished SBP and activated PRA and not to dialysis characteristics. In patients with a history of heart disease we underuse BSRAA. Copyright © 2016 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

Nocturnal diastolic blood pressure decline is associated with higher 25-hydroxyvitamin D level and standing plasma renin activity in a hypertensive population.

PubMed

Zhang, Mingchen; Xu, Xinjuan; Liu, Haiming; Li, Haixia; Zhang, Junshi; Gao, Min

2017-01-01

Patients with nondipper hypertension are known to carry a high risk of cardiovascular complications. Vitamin D deficiency is associated with hypertension. Because vitamin D deficiency activates the renin-angiotensin-aldosterone system (RAAS), we hypothesized that this vitamin would interact with the RAAS to influence blood pressure (BP) in nondipper hypertensive patients. We performed a cross-sectional analysis of 1,007 outpatients with hypertension (HTN). Dipper and nondipper patterns were detected, and the two groups were matched for clinical, laboratory, 25-hydroxyvitamin D (25OHD) levels, and ambulatory blood pressure recording. Plasma renin activity (PRA), angiotensin II, and plasma aldosterone concentration (PAC) were assessed in 174 patients treated with calcium channel blockers or no medication. The mean 25OHD concentration in the entire study population was 12.3ng/dL, and the prevalence of vitamin D deficiency was 87.0%. Dipper and nondipper HTN were noted in 187 patients (24.6%) and 573 patients (75.4%). 25OHD levels were similar between nondipper and dipper HTN groups. Forward stepwise logistic regression analysis showed that BMI and age were independent predictors of nondipper HTN. Neither 25OHD levels nor RAAS components were included in the model. In correlation analyses, nocturnal decline of diastolic BP was positively associated with 25OHD levels and standing PRA (r = 0.152 p = 0.045, r = 0.165 p = 0.038, respectively). The present study showed that vitamin D deficiency was astonishingly prevalent in hypertensive subjects residing in Xinjiang, China. There may be a weakly association of nocturnal DBP decline with 25OHD levels and standing PRA levels. We found no association between vitamin D deficiency and nondipper HTN.

Effect of propranolol on the splanchnic and peripheral renin angiotensin system in cirrhotic patients

PubMed Central

Vilas-Boas, Walkíria Wingester; Jr, Antônio Ribeiro-Oliveira; da Cunha Ribeiro, Renata; Vieira, Renata Lúcia Pereira; Almeida, Jerusa; Nadu, Ana Paula; Silva, Ana Cristina Simões e; Santos, Robson Augusto Souza

2008-01-01

AIM: To evaluate the effect of β-blockade on angiotensins in the splanchnic and peripheral circulation of cirrhotic patients and also to compare hemodynamic parameters during liver transplantation according to propranolol pre-treatment or not. METHODS: Patients were allocated into two groups: outpatients with advanced liver disease(LD) and during liver transplantation(LT). Both groups were subdivided according to treatment with propranolol or not. Plasma was collected through peripheral venipuncture to determine plasma renin activity(PRA), Angiotensin(Ang) I, Ang II, and Ang-(1-7) levels by radioimmunoassay in LD group. During liver transplantation, hemodynamic parameters were determined and blood samples were obtained from the portal vein to measure renin angiotensin system(RAS) components. RESULTS: PRA, Ang I, Ang II and Ang-(1-7) were significantly lower in the portal vein and periphery in all subgroups treated with propranolol as compared to non-treated. The relationships between Ang-(1-7) and Ang I levels and between Ang II and Ang I were significantly increased in LD group receiving propranolol. The ratio between Ang-(1-7) and Ang II remained unchanged in splanchnic and peripheral circulation in patients under β-blockade, whereas the relationship between Ang II and Ang I was significantly increased in splanchnic circulation of LT patients treated with propranolol. During liver transplantation, cardiac output and index as well systemic vascular resistance and index were reduced in propranolol-treated subgroup. CONCLUSION: In LD group, propranolol treatment reduced RAS mediators, but did not change the ratio between Ang-(1-7) and Ang II in splanchnic and peripheral circulation. Furthermore, the modification of hemodynamic parameters in propranolol treated patients was not associated with changes in the angiotensin ratio. PMID:19058308

A randomised controlled trial evaluating the effect of potassium supplementation on vascular function and the renin-angiotensin-aldosterone system.

PubMed

Graham, U M; McCance, D R; Young, I S; Mullan, K R

2014-05-01

There is limited evidence on the effect of potassium supplementation on the vasculature in patients at increased cardiovascular risk. Potassium increases aldosterone and there is a strong association of hyperaldosteronism with poor cardiac outcomes. We aimed to determine whether potassium supplementation has a significant medium-term effect on aldosterone levels and, if so, what the overall effect of this is on vascular function in patients at moderate cardiovascular disease risk. Forty patients at moderate cardiovascular disease risk were included in a randomised placebo-controlled crossover study. Patients were assigned to 64 mmol potassium chloride or placebo for 6 weeks. Vascular function was assessed using pulse-wave analysis including the detection of a change in augmentation index to salbutamol and nitroglycerine-induced vasodilation. There was no change in augmentation index with potassium vs placebo (25.2±1.4 vs. 26.0±1.3%, respectively). Potassium improved brachial systolic blood pressure (131.8±2.2 vs. 137.1±2.4 mm Hg; P=0.013), central systolic blood pressure (123.2±2.3 vs. 128.4±2.3 mm Hg; P=0.011) and central diastolic blood pressure (80.3±1.3 vs. 83.7±1.4 mm Hg; P=0.019). Plasma renin activity and serum aldosterone both increased with potassium (P=0.001 and P=0.048 respectively). We found that potassium supplementation had no effect on endothelial function or pulse-wave analysis. It lowered brachial systolic and central blood pressure. It was associated with increased plasma renin activity and serum aldosterone.

Endogenous ouabain and the renin-angiotensin-aldosterone system: distinct effects on Na handling and blood pressure in human hypertension.

PubMed

Manunta, Paolo; Hamlyn, John M; Simonini, Marco; Messaggio, Elisabetta; Lanzani, Chiara; Bracale, Maria; Argiolas, Giuseppe; Casamassima, Nunzia; Brioni, Elena; Glorioso, Nicola; Bianchi, Giuseppe

2011-02-01

To evaluate whether the renin-angiotensin-aldosterone system (RAAS) and endogenous ouabain system differently affect renal Na handling and blood pressure. Three hundred and one patients in whom we compared blood pressure, and renal Na tubular reabsorption in the basal condition and 2 h (T120) after saline infusion. Following multivariate-adjusted linear and quartiles analysis, baseline mean blood pressure (MBP) was significantly higher (113.7 ± 1.33 mmHg) in the fourth versus the first endogenous ouabain quartile (103.8 ± 1.04 mmHg) and the trend across the quartiles was highly significant (β = 0.23, P = 3.53e-04). In contrast, an inverse relationship was present in the renin activity (PRA) quartiles with MBP highest in the first (112.5 ± 1.26) and lowest in the fourth PRA quartile (107.6 ± 1.48, P = 0.039). Following an acute saline load, changes in MBP and the slope of the pressure-natriuresis relationship were inversely related across the PRA quartiles. The fractional excretion of sodium (FENa) showed a negative linear trend going from the first to the third endogenous ouabain quartiles (2.35 ± 0.17 and 1.90 ± 0.14%, P = 0.05). Patients in the fourth endogenous ouabain quartile (>323 pmol/l) showed increased FENa T120 (2.78 ± 0.18%, P < 0.01) and increased Na tubular rejection fraction (P = 0.007) after Na load. After the saline load, there was a biphasic relationship between plasma endogenous ouabain and FENa favoring Na retention at low endogenous ouabain and Na excretion at high endogenous ouabain levels. The RAAS and endogenous ouabain system are two independent and complementary systems having an inverse (RAAS) or a direct (endogenous ouabain system) relationship with hemodynamic parameters.

Ovariectomy modify local renin-angiotensin-aldosterone system gene expressions in the heart of ApoE (-/-) mice.

PubMed

Borges, Celina Carvalho; Penna-de-Carvalho, Aline; Medeiros Junior, Jorge L; Aguila, Marcia Barbosa; Mandarim-de-Lacerda, Carlos A

2017-12-15

The evaluation of the local Renin-Angiotensin-Aldosterone system (RAAS) gene expressions in the heart of ovariectomized (OVX) apolipoprotein E deficient mice (ApoE). Four-months old C57BL/6 female mice (wild-type, wt, n=20), and ApoE female mice (n=20), were submitted to OVX or a surgical procedure without ovary removal (SHAM) and formed four groups (n=10/group): SHAM/wt, SHAM/ApoE, OVX/wt, and OVX/ApoE. OVX led to greater body mass, plasma triglycerides (TG) and total cholesterol, and resulted in insulin resistance and altered RAAS gene expressions in the heart tissue. The gene expression of angiotensin-converting enzyme (ACE)-2 was lower in OVX/wt than in SHAM/wt (P=0.0004), Mas receptor (MASr) was lower in OVX/wt compared to SHAM/wt (P<0.0001). Also, angiotensin II receptor type 1 (AT1r) was higher in OVX/wt than in SHAM/wt (P=0.0229), and AT2r was lower in OVX/wt than in SHAM/wt (P=0.0121). OVX and ApoE deficiency showed interaction potentializing the insulin resistance, increasing TG levels and altering ACE and MASr gene expressions. ACE gene expression was higher in OVX/ApoE than in OVX/wt (P<0.0001), and MASr gene expression was lower in OVX/ApoE than in OVX/wt (P<0.0001). The impact of OVX on local RAAS cascade in the heart of ApoE deficient animals, besides the metabolic changes culminating with insulin resistance, involves an upregulation of renin, ACE, and AT1r gene expressions. The findings may contribute to clarify the mechanisms of development of postmenopausal hypertension and the link between RAAS and apolipoprotein E. Copyright © 2017 Elsevier Inc. All rights reserved.

The renin-angiotensin-aldosterone system (RAAS) - physiology and molecular mechanisms of functioning.

PubMed

Chaszczewska-Markowska, Monika; Sagan, Maria; Bogunia-Kubik, Katarzyna

2016-09-13

Secretion of renin juxtaglomerular cells into bloodstream initiates activation of an enzymatic-hormonal cascade known as the RAAS (renin - angiotensin - aldosterone system). As a result, blood pressure is increased by the means several interrelated mechanisms. Mechanism of Zjednoczoaction of this system has been known for decades, but a few previously unknown components were recently added, such as ACE-2 and Ang(1-7), and their role often seems to be opposite to that of the conventional components. Local tissue systems also have important biological functions. They operate largely independently of the systemic activity, and their activity is observed primarily in the kidney, heart, in blood vessels, adrenal gland and nervous system. Angiotensin-2 (Ang-2), the main RAAS effector, has a wide scope of action, and thus abnormalities in its functioning have many consequences. Excessive activation is accompanied by chronic inflammation, as Ang-2 stimulates inflammatory mediators. As a result, degenerative processes and atherosclerosis are initiated. RAAS imbalance is associated with the most common diseases of civilization, such as cardio-vascular diseases, diabetes, kidney diseases, preeclampsia, osteoporosis and even neurodegenerative diseases. Many of these pathological processes are attributed to the excessive activation of tissue RA system. Therapeutic strategies based on inhibition of the RAAS are commonly used mainly in the treatment of hypertension and other cardiovascular disorders. The benefits of this class of drugs is primarily a decrease in blood pressure, but also the suppression of inflammatory processes and other pathological phenomena resulting from excessive activation of the RAAS. For that reason, some consider to use RAAS inhibitors in other diseases, e.g. Parkinson's disease. Further studies give hope for the improvement of RAAS inhibitor therapy and the development of new therapeutic strategies.

Effect of RAAS blockers on adverse clinical outcomes in high CVD risk subjects with atrial fibrillation: A meta-analysis and systematic review of randomized controlled trials.

PubMed

Chaugai, Sandip; Sherpa, Lhamo Yanchang; Sepehry, Amir A; Arima, Hisatomi; Wang, Dao Wen

2016-06-01

Recent studies have demonstrated that atrial fibrillation significantly increases the risk of adverse clinical outcomes in high cardiovascular disease risk subjects. Application of renin-angiotensin-aldosterone system blockers for prevention of recurrence of atrial fibrillation and adverse clinical outcomes in subjects with atrial fibrillation is a theoretically appealing concept. However, results of clinical trials evaluating the effect of renin-angiotensin-aldosterone blockers on adverse clinical outcomes in high cardiovascular disease risk subjects with atrial fibrillation remain inconclusive.A pooled study of 6 randomized controlled trials assessing the efficacy of renin-angiotensin-aldosterone blockers on subjects with atrial fibrillation was performed.A total of 6 randomized controlled trials enrolled a total of 53,510 patients followed for 1 to 5 years. RAAS blockade therapy was associated with 14% reduction in the incidence of heart failure (OR: 0.86, [95%CI: 0.76- 0.97], P=0.018) and 17% reduction in the incidence of CVE (OR: 0.83, [95%CI: 0.70-0.99], P = 0.038). The corresponding decline in absolute risk against heart failure (ARR: 1.4%, [95%CI: 0.2-2.6%], P = 0.018) and CVE (ARR: 3.5%, [95%CI: 0.0-6.9%], P = 0.045) in the AF group was much higher than the non-AF group for heart failure (ARR: 0.4%, [95%CI: 0.0-0.7%], P = 0.057) and CVE (ARR: 1.6%, [95%CI: -0.1% to 3.3%], P = 0.071). No significant effect was noted on all-cause or cardiovascular mortality, stroke, or myocardial infarction.This study suggests that RAAS blockade offers protection against heart failure and cardiovascular events in high cardiovascular disease risk subjects with atrial fibrillation.

Decongestion Strategies and Renin-Angiotensin-Aldosterone System Activation in Acute Heart Failure

PubMed Central

Mentz, Robert J.; Stevens, Susanna R.; DeVore, Adam D.; Lala, Anuradha; Vader, Justin M.; AbouEzzeddine, Omar F.; Khazanie, Prateeti; Redfield, Margaret M.; Stevenson, Lynne W.; O'Connor, Christopher M.; Goldsmith, Steven R.; Bart, Bradley A.; Anstrom, Kevin J.; Hernandez, Adrian F.; Braunwald, Eugene; Felker, G. Michael

2014-01-01

Background High dose diuretics in patients with acute heart failure (AHF) are thought to activate the renin-angiotensin-aldosterone system (RAAS), and alternative decongestion strategies, such as ultrafiltration (UF), have been proposed to mitigate this RAAS activation. Methods We analyzed 427 AHF patients enrolled in the DOSE-AHF and CARRESS-HF trials. We assessed the relationship between two markers of RAAS activation (plasma renin activity [PRA] and aldosterone) from baseline to 72-96h and decongestion strategy; high vs. low-dose and continuous infusion vs. bolus furosemide for DOSE-AHF and UF vs. stepped pharmacologic care for CARRESS-HF. We determined the relationship between RAAS biomarkers and 60-day outcomes. Results Patients with greater RAAS activation at baseline had lower blood pressures, lower serum sodium, and higher BUN. Continuous infusion furosemide and UF were associated with greater PRA increases (median +1.66 vs. +0.66 ng/mL/h with continuous vs. bolus, P=0.021; +4.05 vs. +0.56 ng/mL/h with UF vs. stepped care, P=0.014). There was no significant difference in RAAS biomarker change with high vs. low-dose diuretics (both P>0.5). Neither baseline log PRA nor log aldosterone was associated with increased death/HF hospitalization (HR for a doubling 1.05; 95% CI: 0.98-1.13, P=0.18 and HR 1.13; 95% CI: 0.99-1.28, P=0.069, respectively). The change in RAAS biomarkers from baseline to 72-96 h was not associated with outcomes (both P>0.5). Conclusions High-dose loop diuretics did not result in greater RAAS activation than low-dose diuretics. UF resulted in greater PRA increase than stepped pharmacologic care. Neither PRA nor aldosterone was significantly associated with short-term outcomes in this cohort. PMID:25543972

Regulation of the renin-angiotensin-aldosterone system in fibromyalgia.

PubMed

Maliszewski, Anne M; Goldenberg, Don L; Hurwitz, Shelley; Adler, Gail K

2002-07-01

To assess the function of the renin-angiotensin-aldosterone (RAA) system in women with fibromyalgia (FM) compared to healthy women. Women with FM [n = 14, age 41.0+/-7.2 yrs, body mass index (BMI) 26.4+/-5.4 kg/m2] and healthy women (n = 13, age 40.0+/-7.7 yrs, BMI 25.0+/-5.0 kg/m2) were placed on a low sodium diet (10 mEq sodium/day) for 5 days. After being supine and fasting overnight, subjects received an intravenous infusion of angiotensin II at successive doses of 1, 3, and 10 ng/kg/min for 45 min per dose. Blood pressure (BP), plasma renin activity (PRA), aldosterone, and cortisol were measured at baseline and after each dose of angiotensin II. Prior to sodium restriction, women with FM completed the Hopkins Symptom Checklist-90, which included a question grading the extent of dizziness/faintness on a scale of 0 (none) to 4 (extremely). After dietary sodium restriction, baseline PRA, aldosterone, and supine BP were similar in healthy women and women with FM. Aldosterone and BP rose in response to infused angiotensin II; these responses did not differ significantly between healthy women and women with FM. In women with FM, symptoms of dizziness correlated inversely with BMI (r = -0.81, p < 0.001) and the systolic BP response to 10 ng/kg/min angiotensin II (r = -0.81, p < 0.001). The functioning of the RAA system, including the vascular response to angiotensin II, was intact in women with FM compared to healthy women. However, women with FM who complained of dizziness had a blunted vascular response to angiotensin II. This blunted vascular response may indicate intravascular volume depletion in women with symptoms of dizziness.

Angiotensin-(1-7): A Novel Peptide to Treat Hypertension and Nephropathy in Diabetes?

PubMed

Padda, Ranjit Singh; Shi, Yixuan; Lo, Chao-Sheng; Zhang, Shao-Ling; Chan, John S D

2015-10-14

The renin-angiotensin system (RAS) plays a pivotal role in mammalian homeostasis physiology. The RAS can be delineated into a classical RAS (the pressor arm) including angiotensinogen (Agt), renin, angiotensin-converting enzyme (ACE), angiotensin II (Ang II) and angiotensin type 1 receptor (AT1R), and a counterbalancing novel RAS (the depressor arm) including Agt, renin, angiotensin-converting enzyme-2 (ACE-2), angiotensin-(1-7) (Ang 1-7) and Ang 1-7 receptor (or Mas receptor (MasR)). Hyperglycemia (diabetes) induces severe tissue oxidative stress, which stimulates the pressor arm of the renal RAS axis and leads to an increase in ACE/ACE-2 ratio, with excessive formation of Ang II. There is a growing body of evidence for beneficial effects of the depressor arm of RAS (ACE-2/Ang 1-7/MasR) axis in diabetes, hypertension and several other diseased conditions. Evidence from in vitro, in vivo and clinical studies reflects anti-oxidant, anti-fibrotic, and anti-inflammatory properties of Ang 1-7. Most of the currently available therapies only target suppression of the pressor arm of RAS with angiotensin receptor blockers (ARBs) and ACE inhibitors (ACEi). However, it is time to consider simultaneous activation of the depressor arm for more effective outcomes. This review summarizes the recent updates on the protective role of Ang 1-7 in hypertension and kidney injury in diabetes, as well as the possible underlying mechanism(s) of Ang 1-7 action, suggesting that the ACE-2/Ang 1-7/MasR axis can be developed as a therapeutic target for the treatment of diabetes-induced hypertension and renal damage.

Angiotensin-(1-7): A Novel Peptide to Treat Hypertension and Nephropathy in Diabetes?

PubMed Central

Padda, Ranjit Singh; Shi, Yixuan; Lo, Chao-Sheng; Zhang, Shao-Ling; Chan, John S.D.

2015-01-01

The renin-angiotensin system (RAS) plays a pivotal role in mammalian homeostasis physiology. The RAS can be delineated into a classical RAS (the pressor arm) including angiotensinogen (Agt), renin, angiotensin-converting enzyme (ACE), angiotensin II (Ang II) and angiotensin type 1 receptor (AT1R), and a counterbalancing novel RAS (the depressor arm) including Agt, renin, angiotensin-converting enzyme-2 (ACE-2), angiotensin-(1-7) (Ang 1-7) and Ang 1-7 receptor (or Mas receptor (MasR)). Hyperglycemia (diabetes) induces severe tissue oxidative stress, which stimulates the pressor arm of the renal RAS axis and leads to an increase in ACE/ACE-2 ratio, with excessive formation of Ang II. There is a growing body of evidence for beneficial effects of the depressor arm of RAS (ACE-2/Ang 1-7/MasR) axis in diabetes, hypertension and several other diseased conditions. Evidence from in vitro, in vivo and clinical studies reflects anti-oxidant, anti-fibrotic, and anti-inflammatory properties of Ang 1-7. Most of the currently available therapies only target suppression of the pressor arm of RAS with angiotensin receptor blockers (ARBs) and ACE inhibitors (ACEi). However, it is time to consider simultaneous activation of the depressor arm for more effective outcomes. This review summarizes the recent updates on the protective role of Ang 1-7 in hypertension and kidney injury in diabetes, as well as the possible underlying mechanism(s) of Ang 1-7 action, suggesting that the ACE-2/Ang 1-7/MasR axis can be developed as a therapeutic target for the treatment of diabetes-induced hypertension and renal damage. PMID:26793405

Regulated expression of the Ren-2 gene in transgenic mice derived from parental strains carrying only the Ren-1 gene.

PubMed Central

Tronik, D; Dreyfus, M; Babinet, C; Rougeon, F

1987-01-01

The Ren-2 gene encoding the mouse submaxillary gland (SMG) renin was microinjected into the pronuclei of fertilized eggs from mice carrying only the Ren-1 gene. In addition to the whole transcription unit, the injected DNA contained 2.5 and 3 kb of upstream and downstream flanking sequences, respectively. Three independent transgenic mice lines were obtained; two of them had integrated one copy of the Ren-2 gene, the last one had integrated five and eleven copies at two independent sites. Independently of the number of Ren-2 copies integrated, the pattern of Ren-2 gene expression in all the transgenic mice was identical to that observed in wild-type animals in which Ren-1 and Ren-2 are closely linked on chromosome 1. In particular, the exogenous Ren-2 gene was only transcribed in the kidney and in the SMG. In the kidney, Ren-1 and Ren-2 mRNAs were present at a comparable level, whereas in the SMG Ren-2 mRNA was at least 100-fold more abundant than Ren-1 mRNA. Moreover, Ren-2 expression in the SMG was positively regulated by androgens. Only one difference between transgenic mice and wild-type mice carrying the Ren-2 gene has been observed: the basal level of Ren-2 transcription in the SMG of transgenic females was lower than in two-gene strain females. Androgen treatment of transgenic females induced SMG renin mRNA to a level identical to that of transgenic males. This suggests that the basal level of SMG renin mRNA is dependent upon cis-acting elements which are not present in the microinjected fragment. Images Fig. 1. Fig. 2. Fig. 3. PMID:3297677

Angiotensinogen concentration in the cerebrospinal fluid in different experimental conditions in the rat.

PubMed

Ruiz, P; Basso, N; Grinspon, D; Mangiarua, E; Cannata, M A

1983-01-01

Angiotensinogen is the most important component of the renin-angiotensin system present in the cerebrospinal fluid (CSF) of the rat. Its physiological significance as well as its origin have not been clearly elucidated. In this experiment we have examined plasma renin activity (PRA) and plasma and CSF angiotensinogen concentration under the following experimental conditions in male rats of the Wistar strain: 1) adrenalectomy (Adx) 4 days prior to sample collection; controls were sham Adx animals; 2) nephrectomy (Nx) 48 hours before blood and CSF collection; controls were sham Nx rats; 3) DOC-salt treatment (Cortexon depot, 50 mg/kg.s.c. twice a week) plus saline to drink was given during 4 weeks; controls were intact rats; 4) DOC-salt plus captopril: captopril (100 mg/kg/day) in the drinking fluid was added to the treatment of experimental and control animals of Group 3; 5) two-kidney, two clip hypertension: silver clips placed in both renal arteries 8 weeks before samples collection; control: sham-operated rats; 6) water deprivation: rats deprived of water for 5 days; controls: intact rats; 7) peripheral sympathectomy: 6-hydroxydopamine (6-HODA) injected s.c. from birth until 16 weeks of age, adrenodemedullectomy and adrenal denervation performed at 8 weeks; controls were vehicle-injected animals. Determination of angiotensinogen concentration in plasma and CSF was accomplished by incubation of the samples with excess hog renin. The angiotensin I released as well as PRA were evaluated using an specific radioimmunoassay technique. PRA was significantly increased by Adx, captopril treatment, and water deprivation, and was almost suppressed by Nx, DOC-salt, and DOC-salt plus captopril treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

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,…

Molecular recognition and regulation of human angiotensin-I converting enzyme (ACE) activity by natural inhibitory peptides

PubMed Central

Masuyer, Geoffrey; Schwager, Sylva L. U.; Sturrock, Edward D.; Isaac, R. Elwyn; Acharya, K. Ravi

2012-01-01

Angiotensin-I converting enzyme (ACE), a two-domain dipeptidylcarboxypeptidase, is a key regulator of blood pressure as a result of its critical role in the renin-angiotensin-aldosterone and kallikrein-kinin systems. Hence it is an important drug target in the treatment of cardiovascular diseases. ACE is primarily known for its ability to cleave angiotensin I (Ang I) to the vasoactive octapeptide angiotensin II (Ang II), but is also able to cleave a number of other substrates including the vasodilator bradykinin and N-acetyl-Ser-Asp-Lys-Pro (Ac-SDKP), a physiological modulator of hematopoiesis. For the first time we provide a detailed biochemical and structural basis for the domain selectivity of the natural peptide inhibitors of ACE, bradykinin potentiating peptide b and Ang II. Moreover, Ang II showed selective competitive inhibition of the carboxy-terminal domain of human somatic ACE providing evidence for a regulatory role in the human renin-angiotensin system (RAS). PMID:23056909

Farmácia Popular Program: pharmaceutical market analysis of antihypertensive acting on the renin-angiotensin system medicines.

PubMed

Silva, Rondineli Mendes da; Chaves, Gabriela Costa; Chaves, Luisa Arueira; Campos, Mônica Rodrigues; Luiza, Vera Lucia; Bertoldi, Andréa Dâmaso; Ross-Degnan, Dennis; Emmerick, Isabel Cristina Martins

2017-08-01

This paper aims to analyse changes in the retail pharmaceutical market following policy changes in the Farmácia Popular Program (FP), a medicines subsidy program in Brazil. The retrospective longitudinal analyses focus on therapeutic class of agents acting on the renin-angiotensin system. Data obtained from QuintilesIMS (formerly IMS Health) included private retail pharmacy sales volume (pharmaceutical units) and sales values from 2002 to 2013. Analyses evaluated changes in market share following key FP policy changes. The therapeutic class was selected due to its relevance to hypertension treatment. Market share was analysed by therapeutic sub-classes and by individual company. Losartan as a single product accounted for the highest market share among angiotensin II antagonists. National companies had higher sales volume during the study period, while multinational companies had higher sales value. Changes in pharmaceutical market share coincided with the inclusion of specific products in the list of medicines covered by FP and with increases in or exemption from patient copayment.

THE RENIN-ANGIOTENSIN SYSTEM AND THE BIOLOGY OF SKELETAL MUSCLE: MECHANISMS OF MUSCLE WASTING IN CHRONIC DISEASE STATES.

PubMed

Delafontaine, Patrice; Yoshida, Tadashi

2016-01-01

Sarcopenia and cachexia are muscle-wasting syndromes associated with aging and with many chronic diseases such as congestive heart failure, diabetes, cancer, chronic obstructive pulmonary disease, and renal failure. While mechanisms are complex, these conditions are often accompanied by elevated angiotensin II (Ang II). We found that Ang II infusion in rodents leads to skeletal muscle wasting via alterations in insulin-like growth factor-1 signaling, increased apoptosis, enhanced muscle protein breakdown via the ubiquitin-proteasome system, and decreased appetite resulting from downregulation of hypothalamic orexigenic neuropeptides orexin and neuropeptide Y. Furthermore, Ang II inhibits skeletal muscle stem cell proliferation, leading to lowered muscle regenerative capacity. Distinct stem cell Ang II receptor subtypes are critical for regulation of muscle regeneration. In ischemic mouse congestive heart failure model skeletal muscle wasting and attenuated muscle regeneration are Ang II dependent. These data suggest that the renin-angiotensin system plays a critical role in mechanisms underlying cachexia in chronic disease states.

Expanding the spectrum of genetic mutations in antenatal Bartter syndrome type II.

PubMed

Fretzayas, Andreas; Gole, Evangelia; Attilakos, Achilleas; Daskalaki, Anna; Nicolaidou, Polyxeni; Papadopoulou, Anna

2013-06-01

Bartter syndrome (BS) is a group of genetic disorders characterized by hypokalemic metabolic alkalosis, hyponatremia and elevated renin and aldosterone plasma concentrations. BS type II is caused by mutations in the KCNJ1 gene and usually presents with transient hyperkalemia. We report here a novel KCNJ1 mutation in a male neonate, prematurely born after a pregnancy complicated by polyhydramnios. The infant presented with typical clinical and laboratory findings of BS type II, such as hyponatremia, hypochloremic metabolic alkalosis, severe weight loss, elevated renin and aldosterone levels and transient hyperkalemia in the early postnatal period, which were later normalized. Molecular analysis revealed a compound heterozygous mutation in the KCNJ1 gene, consisting of a novel K76E and an already described V315G mutation, both affecting functional domains of the channel protein. Typical manifestations of antenatal BS in combination with hyperkalemia should prompt the clinician to search for mutations in the KCNJ1 gene first. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

Blood pressure and plasma renin activity as predictors of orthostatic intolerance

NASA Technical Reports Server (NTRS)

Harrison, M. H.; Kravik, S. E.; Geelen, G.; Keil, L.; Greenleaf, J. E.

1985-01-01

The effect of 3 h standing, followed by a period of head-up tilt (HUT) on physiological response (orthostatic tolerance, blood pressure and heart rate), as well as on plasma vasopressin (PVP) and renin activity (PRA) were studied in 13 dehydrated (to 2.4 pct loss of body weight) subjects. Seven subjects showed signs of orthostatic intolerance (INT), manifested by sweating, pallor, nausea and dizziness. Prior to these symptoms, the INT subjects exhibited lower systolic (SP) and pulse (PP) pressures, and an elevated PRA, compared to the tolerant (TOL) subjects. HUT has aggravated increases of RPA in the INT subjects and caused an increase, higher than in TOL subjects, in PVP, while rehydration has greatly attenuated the PVP response to the HUT and decreased the PRA response. It is concluded that dehydration, together with measurements of SP, PP and PRA, may serve as a means of predicting orthostatic intolerance and may provide a physiological model for studying the causes of intolerance.

Effector peptides of the renin-angiotensin system in the central mechanisms of acquired and innate behavior in thirst in rats.

PubMed

Vlasenko, R Ya; Kotov, A V

2007-03-01

We report here a comparative analysis of the involvement of a number of components of the renin-angiotensin system in the performance of simple and complex forms of drinking behavior and thirst-associated non-drinking types of behavior. On central (intracerebroventricular) microinjection, [des-Asp1]-angiotensin I at doses equieffective to those of angiotensins II and III was found to be involved only in the performance of simple (taking water from the bowl) and linked forms of activity (comfort behavior, stress grooming, orientational-investigative, and feeding behavior). Angiotensin II was involved in the central mechanisms of complex acquired drinking behavior, selectively modulating its key stages (initial, final), while angiotensin III was involved only in the mechanisms of reproduction of the complex skill. All three substances induced "innate patterns of behavior" specific for each compound, these occurring at fixed periods of time after intracerebral microinjection. The effects of these substances were selectively suppressed by the AT1 receptor blocker losartan potassium.

AT1 receptor signaling pathways in the cardiovascular system.

PubMed

Kawai, Tatsuo; Forrester, Steven J; O'Brien, Shannon; Baggett, Ariele; Rizzo, Victor; Eguchi, Satoru

2017-11-01

The importance of the renin angiotensin aldosterone system in cardiovascular physiology and pathophysiology has been well described whereas the detailed molecular mechanisms remain elusive. The angiotensin II type 1 receptor (AT1 receptor) is one of the key players in the renin angiotensin aldosterone system. The AT1 receptor promotes various intracellular signaling pathways resulting in hypertension, endothelial dysfunction, vascular remodeling and end organ damage. Accumulating evidence shows the complex picture of AT1 receptor-mediated signaling; AT1 receptor-mediated heterotrimeric G protein-dependent signaling, transactivation of growth factor receptors, NADPH oxidase and ROS signaling, G protein-independent signaling, including the β-arrestin signals and interaction with several AT1 receptor interacting proteins. In addition, there is functional cross-talk between the AT1 receptor signaling pathway and other signaling pathways. In this review, we will summarize an up to date overview of essential AT1 receptor signaling events and their functional significances in the cardiovascular system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dehydration-induced drinking in humans

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.

1982-01-01

The human tendency to experience a delay in rehydration (involuntary dehydration) after fluid loss is considered. The two primary factors contributing to involuntary dehydration are probably upright posture, and extracellular fluid and electrolyte loss by sweating from exercise and heat exposure. First, as the plasma sodium and osmotic concentrations remain virtually unchanged for supine to upright postural changes, the major stimuli for drinking appear to be associated with the hypovolemia and increase in the renin-angiotension system. Second, voluntary drinking during the heat experiments was 146% greater than in cool experiments; drinking increased by 109% with prior dehydration as opposed to normal hydration conditions; and drinking was increased by 41% after exercise as compared with the resting condition. Finally, it is concluded that the rate of sweating and the rate of voluntary fluid intake are highly correlated, and that the dispogenic factors of plasma volume, osmolality, and plasma renin activity are unrelated to sweat rate, but are likely to induce drinking in humans.

Hyperkalemia in Heart Failure.

PubMed

Sarwar, Chaudhry M S; Papadimitriou, Lampros; Pitt, Bertram; Piña, Ileana; Zannad, Faiez; Anker, Stefan D; Gheorghiade, Mihai; Butler, Javed

2016-10-04

Disorders of potassium homeostasis can potentiate the already elevated risk of arrhythmia in heart failure. Heart failure patients have a high prevalence of chronic kidney disease, which further heightens the risk of hyperkalemia, especially when renin-angiotensin-aldosterone system inhibitors are used. Acute treatment for hyperkalemia may not be tolerated in the long term. Recent data for patiromer and sodium zirconium cyclosilicate, used to treat and prevent high serum potassium levels on a more chronic basis, have sparked interest in the treatment of hyperkalemia, as well as the potential use of renin-angiotensin-aldosterone system inhibitors in patients who were previously unable to take these drugs or tolerated only low doses. This review discusses the epidemiology, pathophysiology, and outcomes of hyperkalemia in heart failure; provides an overview of traditional and novel ways to approach management of hyperkalemia; and discusses the need for further research to optimally treat heart failure. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Melatonin, mitochondria and hypertension.

PubMed

Baltatu, Ovidiu C; Amaral, Fernanda G; Campos, Luciana A; Cipolla-Neto, Jose

2017-11-01

Melatonin, due to its multiple means and mechanisms of action, plays a fundamental role in the regulation of the organismal physiology by fine tunning several functions. The cardiovascular system is an important site of action as melatonin regulates blood pressure both by central and peripheral interventions, in addition to its relation with the renin-angiotensin system. Besides, the systemic management of several processes, melatonin acts on mitochondria regulation to maintain a healthy cardiovascular system. Hypertension affects target organs in different ways and cellular energy metabolism is frequently involved due to mitochondrial alterations that include a rise in reactive oxygen species production and an ATP synthesis decrease. The discussion that follows shows the role played by melatonin in the regulation of mitochondrial physiology in several levels of the cardiovascular system, including brain, heart, kidney, blood vessels and, particularly, regulating the renin-angiotensin system. This discussion shows the putative importance of using melatonin as a therapeutic tool involving its antioxidant potential and its action on mitochondrial physiology in the cardiovascular system.

Urinary prostaglandin excretion in pregnancy: the effect of dietary sodium restriction.

PubMed

Delemarre, F M; Thomas, C M; van den Berg, R J; Jongsma, H W; Steegers, E A

2000-10-01

Dietary sodium restriction results in activation of the renin-angiotensin-aldosterone-system. In the non-pregnant situation renin release in response to a low sodium diet is mediated by prostaglandins. We studied the effect of dietary sodium restriction on urinary prostaglandin metabolism in pregnancy. In a randomized, longitudinal study the excretion of urinary metabolites of prostacyclin (6-keto-PGF(1 alpha)and 2,3-dinor-6-keto-PGF(1 alpha)) and thromboxane A(2)(TxB(2)and 2,3-dinor-TxB(2)) was determined throughout pregnancy and post partum in 12 women on a low sodium diet and in 12 controls. In pregnancy the excretion of all urinary prostaglandins is increased. The 6-keto-PGF(1 alpha)/ TxB(2)-ratio as well as the 2, 3-dinor-6-keto-PGF(1 alpha)/ 2,3-dinor-TxB(2)-ratio did not significantly change in pregnancy. CONCLUISION Prostacyclin and thromboxane do not seem to play an important role in sodium balance during pregnancy. Copyright 2000 Harcourt Publishers Ltd.

No evidence for a local renin-angiotensin system in liver mitochondria

PubMed Central

Astin, Ronan; Bentham, Robert; Djafarzadeh, Siamak; Horscroft, James A.; Kuc, Rhoda E.; Leung, Po Sing; Skipworth, James R. A.; Vicencio, Jose M.; Davenport, Anthony P.; Murray, Andrew J.; Takala, Jukka; Jakob, Stephan M.; Montgomery, Hugh; Szabadkai, Gyorgy

2013-01-01

The circulating, endocrine renin-angiotensin system (RAS) is important to circulatory homeostasis, while ubiquitous tissue and cellular RAS play diverse roles, including metabolic regulation. Indeed, inhibition of RAS is associated with improved cellular oxidative capacity. Recently it has been suggested that an intra-mitochondrial RAS directly impacts on metabolism. Here we sought to rigorously explore this hypothesis. Radiolabelled ligand-binding and unbiased proteomic approaches were applied to purified mitochondrial sub-fractions from rat liver, and the impact of AngII on mitochondrial function assessed. Whilst high-affinity AngII binding sites were found in the mitochondria-associated membrane (MAM) fraction, no RAS components could be detected in purified mitochondria. Moreover, AngII had no effect on the function of isolated mitochondria at physiologically relevant concentrations. We thus found no evidence of endogenous mitochondrial AngII production, and conclude that the effects of AngII on cellular energy metabolism are not mediated through its direct binding to mitochondrial targets. PMID:23959064

Resveratrol promotes regression of renal carcinoma cells via a renin-angiotensin system suppression-dependent mechanism.

PubMed

Li, Jianchang; Qiu, Mingning; Chen, Lieqian; Liu, Lei; Tan, Guobin; Liu, Jianjun

2017-02-01

The aim of the present study was to investigate the effect of resveratrol on renal carcinoma cells and explore possible renin-angiotensin system-associated mechanisms. Subsequent to resveratrol treatment, the cell viability, apoptosis rate, cytotoxicity levels, caspase 3/7 activity and the levels of angiotensin II (AngII), AngII type 1 receptor (AT1R), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) were evaluated in renal carcinoma cells. The effects of AngII, AT1R, VEGF and COX-2 on resveratrol-induced cell growth inhibition and apoptosis were also examined. The results indicated that resveratrol treatment may suppress growth, induce apoptosis, and decrease AngII, AT1R, VEGF and COX-2 levels in renal carcinoma ACHN and A498 cells. In addition, resveratrol-induced cell growth suppression and apoptosis were reversed when co-culturing with AT1R or VEGF. Thus, resveratrol may suppress renal carcinoma cell proliferation and induce apoptosis via an AT1R/VEGF pathway.

A potential pathophysiological role for galectins and the renin-angiotensin system in preeclampsia.

PubMed

Blois, Sandra M; Dechend, Ralf; Barrientos, Gabriela; Staff, Anne Cathrine

2015-01-01

This review discusses a potential role of galectins and the renin-angiotensin system (RAS) in the pathophysiology of preeclampsia (PE). Preeclampsia affects between 3 and 5 % of all pregnancies and is a heterogeneous disease, which may be caused by multiple factors. The only cure is the delivery of the placenta, which may result in a premature delivery and baby. Probably due to its heterogeneity, PE studies in human have hitherto only led to the identification of a limited number of factors involved in the pathogenesis of the disease. Animal models, particularly in mice and rats, have been used to gain further insight into the molecular pathology behind PE. In this review, we discuss the picture emerging from human and animal studies pointing to galectins and the RAS being associated with the PE syndrome and affecting a broad range of cellular signaling components. Moreover, we review the epidemiological evidence for PE increasing the risk of future cardiovascular disease later in life.