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.

New Sides of Aldosterone Action in Cardiovascular System as Potential Targets for Therapeutic Intervention.

PubMed

Kolodziejczyk, Patrycjusz; Gromotowicz-Poplawska, Anna; Aleksiejczuk, Michal; Chabielska, Ewa; Tutka, Piotr; Miltyk, Wojciech

2018-03-26

Aldosterone, the main mineralocorticoid hormone, plays a crucial role in the regulation of electrolyte homeostasis and blood pressure. Although, this role is undoubtedly important, it is not a hormonal action that attracts the most attention. Aldosterone seems to be very important important as a local messenger in the pathology of cardiovascular diseases (CVD). In the last few years, the attention was focused on the correlation between raised aldosterone level and increased risk of cardiovascular events. It has been demonstrated that aldosterone contributes to fibrosis, inflammation, endothelial dysfunction, fibrinolytic disordes, and oxidative stress leading to CVD development and progression. It used to be thought that the effects of aldosterone are mediated via classic nuclear receptors - mineralocorticoid receptors (MR). Now we know that the mechanism of aldosterone action in cardiovascular system is much more complex, since experimental and clinical studies indicate that MR blockade may be not sufficient to abolish aldosterone-incuced harmful effects in the cardiovascular system. Therefore, the involvement of some other than MR, receptors and factors is suggested. Moreover, in addition to the generally known genomic action of aldosterone, which involves MR activation, the nongenomic pathways are postulated in the mode of hormone action. More and more attention is focused on the membrane-coupled receptors, which mediate the rapid effects of aldosterone and have been already confirmed in different cells and tissues of a cardiovascular system. The confirmation of multiple mechanisms of aldosterone action opens a new perspective for more effective therapeutic intervention in aldosterone-related CVD. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The renin-angiotensin-aldosterone system blockade in patients with advanced diabetic kidney disease.

PubMed

Bermejo, Sheila; García, Carles Oriol; Rodríguez, Eva; Barrios, Clara; Otero, Sol; Mojal, Sergi; Pascual, Julio; Soler, María José

Diabetic kidney disease is the leading cause of end-stage chronic kidney disease. The renin-angiotensin-aldosterone system (RAAS) blockade has been shown to slow the progression of diabetic kidney disease. Our objectives were: to study the percentage of patients with diabetic kidney disease treated with RAAS blockade, to determine its renal function, safety profile and assess whether its administration is associated with increased progression of CKD after 3 years of follow-up. Retrospective study. 197 diabetic kidney disease patients were included and divided into three groups according to the treatment: patients who had never received RAAS blockade (non-RAAS blockade), patients who at some point had received RAAS blockade (inconstant-RAAS blockade) and patients who received RAAS blockade (constant-RAAS blockade). Clinical characteristics and analytical variables such as renal function, electrolytes, glycosylated haemoglobin and glomerular filtration rate according to chronic kidney disease -EPI and MDRD formulas were assessed. We also studied their clinical course (baseline, 1 and 3 years follow-up) in terms of treatment group, survival, risk factors and renal prognosis. Non-RAAS blockade patients had worse renal function and older age (p<0.05) at baseline compared to RAAS blockade patients. Patients who received RAAS blockade were not found to have greater toxicity or chronic kidney disease progression and no differences in renal prognosis were identified. Mortality was higher in non-RAAS blockade patients, older patients and patients with worse renal function (p<0.05). In the multivariate analysis, older age and worse renal function were risk factors for mortality. Treatment with RAAS blockade is more common in diabetic kidney disease patients with eGFR≥30ml/min/1.73m 2 . In our study, there were no differences in the evolution of renal function between the three groups. Older age and worse renal function were associated with higher mortality in patients who did not receive RAAS blockade. Copyright © 2017 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

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.

Adipocyte-Derived Hormone Leptin Is a Direct Regulator of Aldosterone Secretion, Which Promotes Endothelial Dysfunction and Cardiac Fibrosis.

PubMed

Huby, Anne-Cécile; Antonova, Galina; Groenendyk, Jake; Gomez-Sanchez, Celso E; Bollag, Wendy B; Filosa, Jessica A; Belin de Chantemèle, Eric J

2015-12-01

In obesity, the excessive synthesis of aldosterone contributes to the development and progression of metabolic and cardiovascular dysfunctions. Obesity-induced hyperaldosteronism is independent of the known regulators of aldosterone secretion, but reliant on unidentified adipocyte-derived factors. We hypothesized that the adipokine leptin is a direct regulator of aldosterone synthase (CYP11B2) expression and aldosterone release and promotes cardiovascular dysfunction via aldosterone-dependent mechanisms. Immunostaining of human adrenal cross-sections and adrenocortical cells revealed that adrenocortical cells coexpress CYP11B2 and leptin receptors. Measurements of adrenal CYP11B2 expression and plasma aldosterone levels showed that increases in endogenous (obesity) or exogenous (infusion) leptin dose-dependently raised CYP11B2 expression and aldosterone without elevating plasma angiotensin II, potassium or corticosterone. Neither angiotensin II receptors blockade nor α and β adrenergic receptors inhibition blunted leptin-induced aldosterone secretion. Identical results were obtained in cultured adrenocortical cells. Enhanced leptin signaling elevated CYP11B2 expression and plasma aldosterone, whereas deficiency in leptin or leptin receptors blunted obesity-induced increases in CYP11B2 and aldosterone, ruling out a role for obesity per se. Leptin increased intracellular calcium, elevated calmodulin and calmodulin-kinase II expression, whereas calcium chelation blunted leptin-mediated increases in CYP11B2, in adrenocortical cells. Mineralocorticoid receptor blockade blunted leptin-induced endothelial dysfunction and increases in cardiac fibrotic markers. Leptin is a newly described regulator of aldosterone synthesis that acts directly on adrenal glomerulosa cells to increase CYP11B2 expression and enhance aldosterone production via calcium-dependent mechanisms. Furthermore, leptin-mediated aldosterone secretion contributes to cardiovascular disease by promoting endothelial dysfunction and the expression of profibrotic markers in the heart. © 2015 American Heart Association, Inc.

Aldosterone and parathyroid hormone: a precarious couple for cardiovascular disease.

PubMed

Tomaschitz, Andreas; Ritz, Eberhard; Pieske, Burkert; Fahrleitner-Pammer, Astrid; Kienreich, Katharina; Horina, Jörg H; Drechsler, Christiane; März, Winfried; Ofner, Michael; Pieber, Thomas R; Pilz, Stefan

2012-04-01

Animal and human studies support a clinically relevant interaction between aldosterone and parathyroid hormone (PTH) levels and suggest an impact of the interaction on cardiovascular (CV) health. This review focuses on mechanisms behind the bidirectional interactions between aldosterone and PTH and their potential impact on the CV system. There is evidence that PTH increases the secretion of aldosterone from the adrenals directly as well as indirectly by activating the renin-angiotensin system. Upregulation of aldosterone synthesis might contribute to the higher risk of arterial hypertension and of CV damage in patients with primary hyperparathyroidism. Furthermore, parathyroidectomy is followed by decreased blood pressure levels and reduced CV morbidity as well as lower renin and aldosterone levels. In chronic heart failure, the aldosterone activity is inappropriately elevated, causing salt retention; it has been argued that the resulting calcium wasting causes secondary hyperparathyroidism. The ensuing intracellular calcium overload and oxidative stress, caused by PTH and amplified by the relative aldosterone excess, may increase the risk of CV events. In the setting of primary aldosteronism, renal and faecal calcium loss triggers increased PTH secretion which in turn aggravates aldosterone secretion and CV damage. This sequence explains why adrenalectomy and blockade of the mineralocorticoid receptor tend to decrease PTH levels in patients with primary aldosteronism. In view of the reciprocal interaction between aldosterone and PTH and the potentially ensuing CV damage, studies are urgently needed to evaluate diagnostic and therapeutic strategies addressing the interaction between the two hormones.

Significant hyperkalemia and hyponatremia secondary to telmisartan/hydrochlorothiazide treatment.

PubMed

Cakir, Mehtap

2010-12-01

The renin-angiotensin-aldosterone system (RAAS) has crucial importance in maintaining blood pressure; thus blockade of RAAS is an effective antihypertensive treatment choice. The final step in RAAS stimulation is aldosterone secretion by angiotensin II, which leads to increased renal tubular sodium absorption and potassium secretion. Angiotensin II receptor blockers (ARBs) allow blockade of RAAS by blocking binding of angiotensin II to the AT(1) receptors. There are several fixed-dose combinations of ARBs with hydrochlorothiazide in the market, providing antihypertensive therapies with complimentary mechanisms of action. With such combinations, while ARB inhibits the vasoconstricting action and aldosterone-secreting effects of angiotensin II, hydrochlorothiazide affects the renal tubular mechanisms of electrolyte reabsorption and directly increases excretion of sodium and chloride in the distal tubule, and promotes water excretion. Also, hypokalemia, which may be triggered by increased urinary potassium loss induced by hydrochlorothiazide, is opposed by ARB use and hence ARB/hydrochlorothiazide combination is known to be safe in terms of potassium imbalance. In this case report, significant hyperkalemia and hyponatremia related to telmisartan/hydrochlorothiazide use in a diabetic patient has been presented.

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

Predictors of hyperkalemia risk following hypertension control with aldosterone blockade.

PubMed

Khosla, Nitin; Kalaitzidis, Rigas; Bakris, George L

2009-01-01

Aldosterone antagonists have proven efficacy for management of resistant hypertension and proteinuria reduction; however, they are not widely used due to risk of hyperkalemia. This study assesses the risk factors for hyperkalemia in patients with chronic kidney disease (CKD) and resistant hypertension whose blood pressure (BP) is reduced to a guideline goal. This is a two-center study conducted in university-based hypertension clinics directed by clinical hypertension specialists. Forty-six patients with resistant hypertension and stages 2 or 3 CKD (mean estimated glomerular filtration rate (eGFR) 56.5 + or - 16.2 ml/min/1.73 m(2)) were evaluated for safety and efficacy of aldosterone blockade added to preexisting BP-lowering regimens. All patients were on three mechanistically complementary antihypertensive agents including a diuretic and a renin-angiotensin system blocker. Patients were evaluated after a median of 45 treatment days. The primary endpoint was change in systolic BP. Secondary endpoints included change in serum potassium, creatinine, eGFR, diastolic BP and tolerability. The mean age of the patients studied was 64.9 + or - 10.7 years, all were obese and 86% had type 2 diabetes, with 82% being African-American. Addition of aldosterone antagonism yielded a further mean reduction in systolic BP of 14.7 + or - 5.1 mm Hg (p = 0.001). Females with BMI >30 and those with a baseline systolic BP >160 mm Hg were more likely to have a greater BP reduction to aldosterone antagonism. In total, 39% of the patients had a >30% decrease in eGFR when the BP goal was achieved. The mean increase in serum potassium was 0.4 mEq/l above baseline (p = 0.001), with 17.3% manifesting hyperkalemia, i.e. serum potassium >5.5 mEq/l. Predictors of hyperkalemia included a baseline eGFR of < or = 45 ml/min/1.73 m(2) in whom serum potassium was >4.5 mEq/l on appropriately dosed diuretics. Contributing risks in this subgroup included a systolic BP reduction of >15 mm Hg associated with an eGFR fall of >30%. Aldosterone antagonism is effective and safe for achieving a BP goal among people with diabetic nephropathy when added to a triple antihypertensive regimen that includes a blocker of the renin-angiotensin system and an appropriately selected and dosed diuretic. Caution is advised when using aldosterone blockade for BP control in people with advanced stage 3 nephropathy with a serum potassium of >4.5 mEq/l for safety reasons. Copyright 2009 S. Karger AG, Basel.

Aldosterone breakthrough during aliskiren, valsartan, and combination (aliskiren + valsartan) therapy.

PubMed

Bomback, Andrew S; Rekhtman, Yelena; Klemmer, Philip J; Canetta, Pietro A; Radhakrishnan, Jai; Appel, Gerald B

2012-01-01

Aldosterone levels increase in 30%-40% of patients on angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers over the long term. This "aldosterone breakthrough" may carry important clinical consequences given aldosterone's nonepithelial, pro-fibrotic actions. The renin inhibitor, aliskiren, by suppressing the renin-angiotensin-aldosterone system (RAAS) proximally, may limit breakthrough compared to conventional RAAS blockade. This open-label study (NCT01129557) randomized subjects to aliskiren 300 mg daily (A), valsartan 320 mg daily (V), or aliskiren 150 mg + valsartan 160 mg daily (A+V) for 9 months. Eligible subjects had proteinuria >300 mg/day, estimated glomerular filtration rate (eGFR) >45 mL/min/1.73 m(2), and systolic blood pressure (BP) >130 or diastolic BP >80 mm Hg. Serum and 24-hour urine aldosterone (indexed to 24-hour urine Na) were checked before initiation of therapy and at 3, 6, and 9 months. Aldosterone breakthrough was defined as a sustained increase from baseline aldosterone by study end. The study was intended to enroll 120 subjects but was terminated early by the sponsor. We present here the results of 33 subjects who completed the protocol, of which 12 were randomized to A, 11 were randomized to V, and 10 were randomized to A+V. Mean baseline eGFR was 75.5 (±23.3) mL/min/1.73 m(2); baseline proteinuria was 3104 (±2943) mg/day; and baseline BP was 134.7 (±10.5)/84.8 (±8.4) mm Hg. Three (27%) subjects on V, three (25%) subjects on A, and three (30%) subjects on A+V had aldosterone breakthrough. Mean proteinuria reduction was 31% from baseline in all subjects: 30% in subjects with breakthrough vs. 32% in subjects without breakthrough. Mean BP reduction was 11.0/8.8 mm Hg in all subjects: 8.4/6.1 mm Hg in subjects with breakthrough vs. 12.0/9.8 mm Hg in subjects without breakthrough. Aliskiren, alone or in combination with valsartan, did not reduce the incidence of aldosterone breakthrough in subjects with hypertension and proteinuria compared with conventional RAAS blockade. Copyright © 2012 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Aldosterone antagonists in heart failure.

PubMed

Miller, Susan E; Alvarez, René J

2013-01-01

Chronic, systolic heart failure is an increasing and costly health problem, and treatments based on pathophysiology have evolved that include the use of aldosterone antagonists. Advances in the understanding of neurohormonal responses to heart failure have led to better pharmacologic treatments. The steroid hormone aldosterone has been associated with detrimental effects on the cardiovascular system, such as ventricular remodeling and endothelial dysfunction. This article will review the literature and guidelines that support the use of aldosterone antagonists in the treatment of chronic, systolic heart failure. Aldosterone antagonists are life-saving drugs that have been shown to decrease mortality in patients with New York Heart Association class III to IV heart failure and in patients with heart failure after an acute myocardial infarction. Additional studies are being conducted to determine if the role of aldosterone antagonists can be expanded to patients with less severe forms of heart failure. Aldosterone antagonists are an important pharmacologic therapy in the neurohormonal blockade necessary in the treatment of systolic heart failure. These drugs have been shown to decrease mortality and reduce hospital readmission rates. The major complication of aldosterone antagonists is hyperkalemia, which can be avoided with appropriate patient selection and diligent monitoring.

Neurohormonal Blockade in Heart Failure

PubMed Central

Kotecha, Dipak; Atar, Dan; Hopper, Ingrid

2017-01-01

A key feature of chronic heart failure (HF) is the sustained activation of endogenous neurohormonal systems in response to impaired cardiac pumping and/or filling properties. The clinical use of neurohormonal blockers has revolutionised the care of HF patients over the past three decades. Drug therapy that is active against imbalance in both the autonomic and renin–angiotensin–aldosterone systems consistently reduces morbidity and mortality in chronic HF with reduced left ventricular ejection fraction and in sinus rhythm. This article provides an assessment of the major neurohormonal systems and their therapeutic blockade in patients with chronic HF. PMID:28785471

[RAAS and insulin resistance].

PubMed

Motoshima, Hiroyuki; Araki, Eiichi

2012-09-01

The role of the renin-angiotensin-aldosterone system (RAAS) on the development of insulin resistance and type 2 diabetes (T2DM) is an area of growing interest. Most of the deleterious actions of the RAAS on insulin signals appear to be mediated through activation of the serine/threonine kinase, oxidative stress and tissue-inflammation in insulin-sensitive organs. Both experimental and clinical studies demonstrated that angiotensin II (Ang II) and aldosterone could play a role in the development of insulin resistance, diabetes and cardiovascular diseases. Large randomized clinical trials revealed that blockade of the RAAS with either angiotensin I converting enzyme inhibitors or AT1 receptor blockers results in decreased T2DM incidence, with a minor attenuation of markers for insulin resistance. This review focuses on the role of RAAS in the pathogenesis of insulin resistance, as well as on clinical relevance of RAAS blockade in the prevention and treatment of the metabolic syndrome and pre-diabetes.

The Role of Aldosterone in Obesity-Related Hypertension

PubMed Central

Kawarazaki, Wakako

2016-01-01

Obese subjects often have hypertension and related cardiovascular and renal diseases, and this has become a serious worldwide health problem. In obese subjects, impaired renal-pressure natriuresis causes sodium retention, leading to the development of salt-sensitive hypertension. Physical compression of the kidneys by visceral fat and activation of the sympathetic nervous system, renin–angiotensin systems (RAS), and aldosterone/mineralocorticoid receptor (MR) system are involved in this mechanism. Obese subjects often exhibit hyperaldosteronism, with increased salt sensitivity of blood pressure (BP). Adipose tissue excretes aldosterone-releasing factors, thereby stimulating aldosterone secretion independently of the systemic RAS, and aldosterone/MR activation plays a key role in the development of hypertension and organ damage in obesity. In obese subjects, both salt sensitivity of BP, enhanced by obesity-related metabolic disorders including aldosterone excess, and increased dietary sodium intake are closely related to the incidence of hypertension. Some salt sensitivity-related gene variants affect the risk of obesity, and together with salt intake, its combination is possibly associated with the development of hypertension in obese subjects. With high salt levels common in modern diets, salt restriction and weight control are undoubtedly important. However, not only MR blockade but also new diagnostic modalities and therapies targeting and modifying genes that are related to salt sensitivity, obesity, or RAS regulation are expected to prevent obesity and obesity-related hypertension. PMID:26927805

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.

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

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.

Mechanisms underlying very-low-frequency RR-interval oscillations in humans

NASA Technical Reports Server (NTRS)

Taylor, J. A.; Carr, D. L.; Myers, C. W.; Eckberg, D. L.

1998-01-01

BACKGROUND: Survival of post-myocardial infarction patients is related inversely to their levels of very-low-frequency (0.003 to 0.03 Hz) RR-interval variability. The physiological basis for such oscillations is unclear. In our study, we used blocking drugs to evaluate potential contributions of sympathetic and vagal mechanisms and the renin-angiotensin-aldosterone system to very-low-frequency RR-interval variability in 10 young healthy subjects. METHODS AND RESULTS: We recorded RR intervals and arterial pressures during three separate sessions, with the patient in supine and 40 degree upright tilt positions, during 20-minute frequency (0.25 Hz) and tidal volume-controlled breathing after intravenous injections: saline (control), atenolol (0.2 mg/kg, beta-adrenergic blockade), atropine sulfate (0.04 mg/kg, parasympathetic blockade), atenolol and atropine (complete autonomic blockade), and enalaprilat (0.02 mg/kg, ACE blockade). We integrated fast Fourier transform RR-interval spectral power at very low (0.003 to 0.03 Hz), low (0.05 to 0. 15 Hz), and respiratory (0.2 to 0.3 Hz) frequencies. Beta-adrenergic blockade had no significant effect on very-low- or low-frequency RR-interval power but increased respiratory frequency power 2-fold. ACE blockade had no significant effect on low or respiratory frequency RR-interval power but modestly (approximately 21%) increased very-low-frequency power in the supine (but not upright tilt) position (P<0.05). The most profound effects were exerted by parasympathetic blockade: Atropine, given alone or with atenolol, abolished nearly all RR-interval variability and decreased very-low-frequency variability by 92%. CONCLUSIONS: Although very-low-frequency heart period rhythms are influenced by the renin-angiotensin-aldosterone system, as low and respiratory frequency RR-interval rhythms, they depend primarily on the presence of parasympathetic outflow. Therefore the prognostic value of very-low-frequency heart period oscillations may derive from the fundamental importance of parasympathetic mechanisms in cardiovascular health.

Efficacy and Safety of Combined vs. Single Renin–Angiotensin–Aldosterone System Blockade in Chronic Kidney Disease: A Meta-Analysis

PubMed Central

2013-01-01

BACKGROUND Although dual blockade of the renin–angiotensin–aldosterone system (RAAS) has gained popularity for the treatment of kidney disease, its benefits and potential risks have not been fully elucidated. We conducted a meta-analysis of all randomized controlled trials comparing the efficacy and safety of combined vs. single RAAS blockade therapy in chronic kidney disease (CKD). METHODS We performed a literature search using MEDLINE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, scientific abstracts from meetings, and bibliographies of retrieved articles. We used random-effects models to compute net changes and rate differences in variables. RESULTS Fifty-nine (25 crossover and 34 parallel-arm) randomized controlled trials (RCTs) comparing the efficacy and safety of combined vs. single RAAS blockade therapy in CKD were identified (4,975 patients). Combined RAAS blockade therapy was associated with a significant net decrease in glomerular filtration rate (GFR) (–1.8ml/min or ml/min/1.73 m2; P = 0.005), albuminuria (–90mg/g of creatinine; P = 0.001 or –32mg/day; P = 0.03), and proteinuria (–291mg/g; P = 0.003 or –363mg/day; P < 0.001). Combined RAAS blockade therapy was associated with a 9.4% higher rate of regression to normoalbuminuria and a 5% higher rate of achieving the blood pressure (BP) goal (as defined in individual trials). However, combined RAAS blockade therapy was associated with a significant net increase in serum potassium level, a 3.4% higher rate of hyperkalemia, and a 4.6% higher rate of hypotension. There was no effect on doubling of the serum creatinine level, hospitalization, or mortality. CONCLUSIONS Although combined RAAS blockade therapy in CKD is associated with a decrease in albuminuria and proteinuria, it is associated with a decrease in GFR and a higher incidence of hyperkalemia and hypotension relative to monotherapy. The potential long-term kidney benefits of combined RAAS blockade therapy require further study. PMID:23382494

GPER-1 and estrogen receptor-β ligands modulate aldosterone synthesis.

PubMed

Caroccia, Brasilina; Seccia, Teresa M; Campos, Abril Gonzalez; Gioco, Francesca; Kuppusamy, Maniselvan; Ceolotto, Giulio; Guerzoni, Eugenia; Simonato, Francesca; Mareso, Sara; Lenzini, Livia; Fassina, Ambrogio; Rossi, Gian Paolo

2014-11-01

Fertile women have lower blood pressure and cardiovascular risk than age-matched men, which suggests that estrogens exert cardiovascular protective effects. However, whether 17 β-estradiol (E2) blunts aldosterone secretion, and thereby affects the gender dimorphism of blood pressure, is unknown. We therefore sought for the estrogen receptor (ER) subtypes in human adrenocortical tissues ex vivo by performing gene and protein expression studies. We also investigated the effect of E2 on aldosterone synthesis and the involved receptors through in vitro functional experiments in the adrenocortical cells HAC15. We found that in the human adrenal cortex and aldosterone-producing adenoma cells, the most expressed ERs were the ERβ and the G protein-coupled receptor-1 (GPER-1), respectively. After selective ERβ blockade, E2 (10 nmol/L) markedly increased both the expression of aldosterone synthase and the production of aldosterone (+5- to 7-fold vs baseline, P < .001). Under the same condition, the GPER-1 receptor agonist 1-[4-(6-bromo-benzo (1, 3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c] quinolin-8-yl]-ethanone (G-1) (10 nmol/L) mimicked this effect, which was abrogated by cotreatment with either the GPER-1 receptor antagonist (3aS*,4R*,9bR*)-4-(6-Bro-mo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta[c]quinoline (G-15), or a selective protein kinase A inhibitor 8-Bromo-2-monobutyryladenosine-3,5-cyclic mono-phosphorothioate, Rp-isomer. Silencing of the ERβ significantly raised aldosterone synthase expression and aldosterone production. Conversely, silencing of the GPER-1 lowered aldosterone synthase gene and protein expression. Moreover, it blunted the stimulatory effect of E2 on aldosterone synthase that was seen during ERβ blockade. These results support the conclusion that in humans, E2 inhibits aldosterone synthesis by acting via ERβ. Pharmacologic disinhibition of ERβ unmasks a potent secretagogue effect of E2 that involves GPER-1 and protein kinase A signaling.

[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.

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.

Association between renin–angiotensin–aldosterone system blockade and future osteoporotic fracture risk in hypertensive population

PubMed Central

Chen, Chang-I.; Yeh, Jong-Shiuan; Tsao, Nai-Wen; Lin, Fen-Yen; Shih, Chun-Ming; Chiang, Kuang-Hsing; Kao, Yung-Ta; Fang, Yu-Ann; Tsai, Lung-Wen; Liu, Wen-Chi; Nakagami, Hironori; Morishita, Ryuichi; Kuo, Yi-Jie; Huang, Chun-Yao

2017-01-01

Abstract Tissue renin–angiotensin–aldosterone system (RAAS) activation in sites of osteoporosis had been demonstrated in animal studies; however, the possibility of RAAS blockade to prevent future osteoporotic fracture had rarely been verified in clinical studies. We Used the Taiwan Longitudinal Health insurance database 2000 to 2008, the cohort study comprised patients age over 40 with a recorded new diagnosis of hypertension between January 1, 2000 to December 31, 2008, in addition, patients who had diagnosis of osteoporosis before the date of cohort enter were excluded. After the definite diagnosis of hypertension, each patient was followed until osteoporotic fracture happened or the end of 2008. The occurrence of osteoporotic fracture was evaluated in patients who either were or without taking RAAS blockade agents. Cox proportional hazard regressions were used to evaluate the osteoporotic fracture incidence after adjusting for known confounding factors. In total, 57,132 hypertensive patients comprised the study cohort. Our study results showed that the incidence of osteoporosis fracture in the whole cohort was significantly higher in the RAAS blockade non-user group than the user group. This phenomenon was observed in both sex and all age categories. Sensitivity analysis further showed the concordant lower osteoporosis fracture risk in patients with various RAAS blockers usage durations; the risk of osteoporosis fracture was the lowest in those drug use >365 days when compared with the non-user cohort. In conclusion, our study result demonstrated the lower future osteoporotic fracture risk in hypertensive subjects who received long term RAAS blocker treatment. PMID:29145244

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.

Rapid stimulation of sodium intake combining aldosterone into the 4th ventricle and the blockade of the lateral parabrachial nucleus.

PubMed

Gasparini, S; Melo, M R; Leite, G F; Nascimento, P A; Andrade-Franzé, G M F; Menani, J V; Colombari, E

2017-03-27

Chronic infusion of aldosterone into the 4th ventricle (4th V) induces robust daily sodium intake, whereas acute injection of aldosterone into the 4th V produces no sodium intake. The inhibitory mechanism of the lateral parabrachial nucleus (LPBN) restrains sodium intake induced by different natriorexigenic stimuli and might affect the acute response to aldosterone into the 4th V. In the present study, 1.8% NaCl and water intake was tested in rats treated with acute injections of aldosterone into the 4th V combined with the blockade of the inhibitory mechanisms with injections of moxonidine (α 2 adrenergic/imidazoline agonist) or methysergide (a serotonergic antagonist) into the LPBN. Male Holtzman rats with stainless steel cannulas implanted in the 4th V and bilaterally in the LPBN were used. Aldosterone (250 or 500ng) into the 4th V combined with vehicle into the LPBN induced no 1.8% NaClintake compared to control (1.5±1.1 and 1.1±0.4, respectively, vs. vehicle into 4th V: 1.0±0.5ml/2h). However, aldosterone (250 or 500ng) into the 4th V combined with moxonidine (0.5nmol) into the LPBN induced strong ingestion of 1.8% NaCl (12.7±4.6 and 17.6±3.7ml/2h, respectively). Aldosterone (250ng) into the 4th V combined with methysergide (4μg) into the LPBN also induced 1.8% NaCl intake (17.6±5.4ml/2h). These data suggest that the inhibitory mechanisms of the LPBN counteract the facilitation of sodium intake produced by aldosterone injected into the 4th, restraining sodium intake in this condition. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

It is time to reconsider the cardiovascular protection afforded by RAAS blockade -- overview of RAAS systems.

PubMed

Tsukamoto, Osamu; Kitakaze, Masafumi

2013-04-01

More than a century has passed since the renin-angiotensin-aldosterone system (RAAS) was discovered in 1897. Both circulatory and tissue RAAS have been found to be essential for regulation of the functions of the whole body, organs, tissues and cells. There is no doubt that the RAAS plays fundamental physiological roles in maintaining homeostasis, but it can also contribute to organ pathophysiology and tissue damages in some situations. Today, the usefulness of RAAS blockade is well-established in the management of a variety of cardiovascular disorders worldwide. However, the latest findings in this field are still providing us with new and unexpected insights into the pathophysiology of cardiovascular diseases. Such developments include dual blockade therapy with angiotensin I converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs), and a new class of RAAS blockers, renin inhibitors. These give us the opportunity to revisit the basic principles of the RAAS and reconsider the strategies of RAAS blockade for cardiovascular protection.

Aldosterone blockade and left ventricular dysfunction: a systematic review of randomized clinical trials.

PubMed

Ezekowitz, Justin A; McAlister, Finlay A

2009-02-01

Aldosterone blockade has been used to treat acute myocardial infarction (MI) and chronic heart failure. The aim of this study is to summarize the evidence on the efficacy of spironolactone (SP), eplerenone (EP), or canrenoate (CAN) in patients with left ventricular dysfunction. A search of multiple electronic databases until June 2008 was supplemented by hand searches of reference lists of included studies and review articles, meeting abstracts, FDA reports, and contact with study authors and drug manufacturers. Studies were eligible for inclusion if they included patients with left ventricular systolic or diastolic dysfunction, treatment with SP, EP, or CAN vs. control, and reported clinical outcomes. Nineteen randomized controlled trials (four in acute MI and 15 in heart failure, n = 10 807 patients) were included -- 14 of SP, three of EP, and three of CAN. Analysis was performed using relative risks (RRs) with 95% confidence intervals (CIs) and a random effects model with statistical heterogeneity assessed by I(2). Aldosterone blockade reduced all-cause mortality by 20% (RR 0.80, 95% CI 0.74-0.87). All-cause mortality was reduced in both heart failure (RR = 0.75, 95% CI 0.67-0.84) and post-MI (RR 0.85, 95% CI 0.76-0.95) patients. Only nine trials reported hospitalizations, and the RR reduction was 23% (RR 0.77, 95% CI 0.68-0.87), although 98% of the outcomes came from two trials. Ejection fraction (EF) improved in the seven heart failure trials, which assessed this outcome (weighted mean difference 3.1%, 95% CI 1.6-4.5). We demonstrated a 20% reduction in all-cause mortality with the use of aldosterone blockade in a clinically heterogeneous group of clinical trial participants with heart failure and post-MI. In addition, we found a 3.1% improvement in EF. Further study in those with less severe symptoms or preserved systolic function is warranted.

Responses to dehydration in the one-humped camel and effects of blocking the renin-angiotensin system.

PubMed

Ali, Mahmoud Alhaj; Adem, Abdu; Chandranath, Irwin S; Benedict, Sheela; Pathan, Javed Y; Nagelkerke, Nicolas; Nyberg, Fred; Lewis, Lynley K; Yandle, Tim G; Nicholls, Gary M; Frampton, Chris M; Kazzam, Elsadig

2012-01-01

Our objectives were to compare the levels of circulating electrolytes, hormones, and renal function during 20 days of dehydration in camels versus the level in non-dehydrated camels and to record the effect of blocking angiotensin II AT1 receptors with losartan during dehydration. Dehydration induced significant increments in serum sodium, creatinine, urea, a substantial fall in body weight, and a doubling in plasma arginine vasopressin (AVP) levels. Plasma aldosterone, however, was unaltered compared with time-matched controls. Losartan significantly enhanced the effect of dehydration to reduce body weight and increase serum levels of creatinine and urea, whilst also impairing the rise in plasma AVP and reducing aldosterone levels. We conclude that dehydration in the camel induces substantial increments in serum sodium, creatinine, urea and AVP levels; that aldosterone levels are altered little by dehydration; that blockade of angiotensin II type 1 receptors enhances the dehydration-induced fall in body weight and increase in serum creatinine and urea levels whilst reducing aldosterone and attenuating the rise in plasma AVP.

Responses to Dehydration in the One-Humped Camel and Effects of Blocking the Renin-Angiotensin System

PubMed Central

Ali, Mahmoud Alhaj; Adem, Abdu; Chandranath, Irwin S.; Benedict, Sheela; Pathan, Javed Y.; Nagelkerke, Nicolas; Nyberg, Fred; Lewis, Lynley K.; Yandle, Tim G.; Nicholls, Gary M.; Frampton, Chris M.; Kazzam, Elsadig

2012-01-01

Our objectives were to compare the levels of circulating electrolytes, hormones, and renal function during 20 days of dehydration in camels versus the level in non-dehydrated camels and to record the effect of blocking angiotensin II AT1 receptors with losartan during dehydration. Dehydration induced significant increments in serum sodium, creatinine, urea, a substantial fall in body weight, and a doubling in plasma arginine vasopressin (AVP) levels. Plasma aldosterone, however, was unaltered compared with time-matched controls. Losartan significantly enhanced the effect of dehydration to reduce body weight and increase serum levels of creatinine and urea, whilst also impairing the rise in plasma AVP and reducing aldosterone levels. We conclude that dehydration in the camel induces substantial increments in serum sodium, creatinine, urea and AVP levels; that aldosterone levels are altered little by dehydration; that blockade of angiotensin II type 1 receptors enhances the dehydration-induced fall in body weight and increase in serum creatinine and urea levels whilst reducing aldosterone and attenuating the rise in plasma AVP. PMID:22624009

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

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.

Phosphate and FGF23 in the renoprotective benefit of RAAS inhibition.

PubMed

de Seigneux, Sophie; Martin, Pierre-Yves

2016-04-01

Renin angiotensin-aldosterone system (RAAS) blockade is a mainstay of chronic kidney disease (CKD) treatment given its beneficial effects on proteinuria, nephroprotection, heart disease and global mortality. The FGF23/Klotho/phosphate axis is crucial for phosphate excretion. During CKD, loss of Klotho, decreased phosphate excretion and FGF23 elevation are early events contributing both to renal disease progression and to cardiovascular complications. Experimental evidence suggests that Klotho replacement may improve renal and cardiovascular disease during CKD. Recent evidence suggests that both RAAS activation and proteinuria decrease Klotho expression and lead to phosphate retention and FGF23 elevation. In opposition RAAS blockade may reverse Klotho loss during CKD in both experimental and human studies, with direct and indirect expected beneficial effects on the kidney and cardiovascular system. This effect of RAAS blockade on the FGF23/Klotho/phosphate axis may participate in explaining some of the beneficial effects of these drugs during CKD. In this article we review the evidence linking RAAS blockade to modulation of the FGF23/Klotho/phosphate axis and the beneficial effects of these regulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Role of RAAS inhibitors for the treatment of heart failure].

PubMed

Murohara, Toyoaki

2012-09-01

Heart failure (HF) is defined as an inability of the heart to supply sufficient blood flow to meet demand of the body. HF is characterized by an activation of various neurohumoral factors including the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS). Thus, medical treatments mainly consist of the blockade of the RAAS and/or SNS. In this chapter, the role of the RAAS inhibitors is discussed for the treatment of patients with HF.

Fibroblast growth factor 23 and the antiproteinuric response to dietary sodium restriction during renin-angiotensin-aldosterone system blockade.

PubMed

Humalda, Jelmer K; Lambers Heerspink, Hiddo J; Kwakernaak, Arjan J; Slagman, Maartje C J; Waanders, Femke; Vervloet, Marc G; Ter Wee, Pieter M; Navis, Gerjan; de Borst, Martin H

2015-02-01

Residual proteinuria during renin-angiotensin-aldosterone system (RAAS) blockade is a major renal and cardiovascular risk factor in chronic kidney disease. Dietary sodium restriction potentiates the antiproteinuric effect of RAAS blockade, but residual proteinuria remains in many patients. Previous studies linked high fibroblast growth factor 23 (FGF-23) levels with volume overload; others linked higher serum phosphate levels with impaired RAAS-blockade efficacy. We hypothesized that FGF-23 reduces the capacity of dietary sodium restriction to potentiate RAAS blockade, impairing the antiproteinuric effect. Post hoc analysis of cohort data from a randomized crossover trial with two 6-week study periods comparing proteinuria after a regular-sodium diet with proteinuria after a low-sodium diet, both during background angiotensin-converting enzyme inhibition. 47 nondiabetic patients with CKD with residual proteinuria (median protein excretion, 1.9 [IQR, 0.8-3.1] g/d; mean age, 50±13 [SD] years; creatinine clearance, 69 [IQR, 50-110] mL/min). Plasma carboxy-terminal FGF-23 levels. Difference in residual proteinuria at the end of the regular-sodium versus low-sodium study period. Residual proteinuria during the low-sodium diet period adjusted for proteinuria during the regular-sodium diet period. Higher baseline FGF-23 level was associated with reduced antiproteinuric response to dietary sodium restriction (standardized β=-0.46; P=0.001; model R(2)=0.71). For every 100-RU/mL increase in FGF-23 level, the antiproteinuric response to dietary sodium restriction was reduced by 10.6%. Higher baseline FGF-23 level was a determinant of more residual proteinuria during the low-sodium diet (standardized β=0.27; P=0.003) in linear regression analysis adjusted for baseline proteinuria (model R(2)=0.71). There was no interaction with creatinine clearance (P interaction=0.5). Baseline FGF-23 level did not predict changes in systolic or diastolic blood pressure upon intensified antiproteinuric treatment. Observational study, limited sample size. FGF-23 levels are associated independently with impaired antiproteinuric response to sodium restriction in addition to RAAS blockade. Future studies should address whether FGF-23-lowering strategies may further optimize proteinuria reduction by RAAS blockade combined with dietary sodium restriction. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

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

PubMed

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

2013-02-01

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

Vitamin D analogues to target residual proteinuria: potential impact on cardiorenal outcomes

PubMed Central

Humalda, Jelmer K.; Goldsmith, David J. A.; Thadhani, Ravi; de Borst, Martin H.

2015-01-01

Residual proteinuria, the amount of proteinuria that remains during optimally dosed renin-angiotensin-aldosterone system (RAAS) blockade, is an independent risk factor for progressive renal function loss and cardiovascular complications in chronic kidney disease (CKD) patients. Dual RAAS blockade may reduce residual proteinuria but without translating into improved cardiorenal outcomes at least in diabetic nephropathy; rather, dual RAAS blockade may increase the risk of adverse events. These findings have challenged the concept of residual proteinuria as an absolute treatment target. Therefore, new strategies must be explored to address whether by further reduction of residual proteinuria using interventions not primarily targeting the RAAS benefit in terms of cardiorenal risk reduction would accrue. Both clinical and experimental intervention studies have demonstrated that vitamin D can reduce residual proteinuria through both RAAS-dependent and RAAS-independent pathways. Future research should prospectively explore vitamin D treatment as an adjunct to RAAS blockade in an interventional trial exploring clinically relevant cardiorenal end points. PMID:25609737

Dual blockade of aldosterone and angiotensin II additively suppresses TGF-beta and NADPH oxidase in the hypertensive kidney.

PubMed

Onozato, Maristela Lika; Tojo, Akihiro; Kobayashi, Naohiko; Goto, Atsuo; Matsuoka, Hiroaki; Fujita, Toshiro

2007-05-01

Angiotensin II blockade and spironolactone effectively reduces proteinuria in humans. To clarify the mechanisms of the beneficial effect of blockade of both aldosterone and angiotensin II, we associated the aldosterone antagonist eplerenone to an angiotensin-converting enzyme inhibitor (ACEI) and examined the effect on renal transforming growth factor (TGF)-beta expression and oxidative stress by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the Dahl salt-sensitive rat with heart failure (DSHF). Dahl salt-resistant control rats and DSHF rats were fed with 8% NaCl diet and at 11 weeks the DSHF rats were treated with vehicle, eplerenone (Epl), trandolapril or a combination of both drugs for 7 weeks. DSHF rats showed increased NADPH oxidase and decreased superoxide dismutase (SOD) resulting in increased oxidative stress. ACEI and Epl reduced NADPH oxidase showing an additive effect in their combination; ACEI increased manganese SOD (MnSOD) and Epl increased MnSOD, copper-zinc SOD and catalase, resulting in the lowest levels of oxidative stress with the combination therapy. Glomerulosclerosis and proteinuria were increased in the DSHF rats, and Epl suppressed them more effectively than ACEI to levels not different from the combination of both, showing a positive correlation with NADPH oxidase expression and TGF-beta. Renal TGF-beta was specifically suppressed with Epl The association of Epl to ACEI is beneficial due to further reduction of NADPH oxidase and specific inhibition of TGF-beta resulting in improvement of renal damage.

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.

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

Modulating kidney transplant interstitial fibrosis and tubular atrophy: is the RAAS an important target?

PubMed

Amer, Hatem; Griffin, Matthew D

2014-02-01

In follow-up to a recently published randomized controlled clinical trial, Issa et al. provide evidence that systemic activity and physiological responsiveness of the renin aldosterone angiotensin system (RAAS) are well within normal limits in most kidney recipients during the first 5 years post-transplant. Implications of the results include the need to better understand intra-renal RAAS activity in transplanted kidneys and to identify patients in which the graft-protective effects of RAAS blockade are most relevant.

Plasma soluble (pro)renin receptor is independent of plasma renin, prorenin, and aldosterone concentrations but is affected by ethnicity.

PubMed

Nguyen, Geneviève; Blanchard, Anne; Curis, Emmanuel; Bergerot, Damien; Chambon, Yann; Hirose, Takuo; Caumont-Prim, Aurore; Tabard, Sylvie Brailly; Baron, Stéphanie; Frank, Michael; Totsune, Kazuhito; Azizi, Michel

2014-02-01

A soluble (pro)renin receptor (sPRR) circulates in plasma and is able to bind renin and prorenin. It is not known whether plasma sPRR concentrations vary with the activity of the renin-angiotensin system. We measured plasma sPRR, renin, prorenin, and aldosterone concentrations in 121 white and 9 black healthy subjects, 40 patients with diabetes mellitus, 41 hypertensive patients with or without renin-angiotensin system blockers, 9 patients with primary aldosteronism, and 10 patients with Gitelman syndrome. Median physiological plasma sPRR concentration was 23.5 ng/mL (interquartile range, 20.9-26.5) under usual uncontrolled sodium diet. sPRR concentration in healthy subjects, unlike renin and prorenin, did not display circadian variation or dependence on age, sex, posture, or hormonal status. sPRR concentrations were ≈25% lower in black than in white subjects, whereas renin concentrations were ≈40% lower. Patients with diabetes mellitus (average renin-high prorenin levels) and with hypertension only (average renin-average prorenin levels) had sPRR concentrations similar to healthy subjects. Renin-angiotensin system blockade was associated with increase of sPRR concentration by ≈12%. sPRR in patients with primary aldosteronism (low renin-low prorenin) and Gitelman syndrome (high renin-high prorenin) were similar and ≈10% higher than in healthy subjects. There was no correlation between sPRR and renin or prorenin. In conclusion, our results show that plasma sPRR concentrations are dependent on ethnicity and independent of renin, prorenin, and aldosterone concentrations in healthy subjects and in patients with contrasted degrees of renin-angiotensin system activity.

Combined renin-angiotensin-aldosterone system blockade and statin therapy effectively reduces the risk of cerebrovascular accident in autosomal dominant polycystic kidney disease: a nationwide population-based cohort study

PubMed Central

Sung, Pei-Hsun; Chiang, Hsin-Ju; Lee, Mel S.; Chiang, John Y.; Yip, Hon-Kan; Yang, Yao-Hsu

2017-01-01

Fairly limited data reported the incidence and risk of cerebrovascular accident (CVA) in autosomal dominant polycystic kidney disease (ADPKD). Additionally, little is known regarding the therapeutic impact of renin-angiotensin-aldosterone system (RAAS) blockade and statin on reducing the occurrence of CVA in ADPKD. We utilized the data from Taiwan National Health Insurance Research Database (NHIRD) to perform a population-based cohort study (1997-2013). A total of 2,647 patients with ADPKD were selected from 1,000,000 general population after excluding patients with age<18, renal replacement therapy and concomitant diagnosis of CVA. Additionally, non-ADPKD subjects were assigned as comparison group by matching study cohort with age, gender, income and urbanization in 1:10 ratio (n=26,470). The results showed that ADPKD group had significantly higher frequency rate and cumulative incidence of CVA as compared with the non-ADPKD group (8.73% v.s. 3.93%, p<0.0001). Furthermore, the frequencies of both hemorrhagic and ischemic strokes were also significantly higher in the ADPKD than non-ADPKD group (all p-values <0.0001). After adjusting for age, gender and atherosclerotic risk factors with multivariate analysis, ADPKD independently carried 2.34- and 5.12-fold risk for occurrence of CVA and hemorrhagic stroke (95% CI: 2.02-2.72 and 4.01-6.54), respectively. Combination therapy [adjusted (a) HR=0.19, 95% CI: 0.11-0.31] was superior to either RAAS blockade (aHR=0.37, 95% CI, 0.28-0.5) or statin (aHR=0.44, 95% CI, 0.24-0.79) alone for reducing the CVA occurrence in the ADPKD population. In conclusion, ADPKD was associated with an increased risk of CVA occurrence. Combined RAAS blockade and statin therapy effectively reduces the risk of CVA in ADPKD. PMID:28977886

Aldosterone Promotes Cardiac Endothelial Cell Proliferation In Vivo

PubMed Central

Gravez, Basile; Tarjus, Antoine; Pelloux, Véronique; Ouvrard‐Pascaud, Antoine; Delcayre, Claude; Samuel, Janelise; Clément, Karine; Farman, Nicolette; Jaisser, Fréderic; Messaoudi, Smail

2015-01-01

Background Experimentally, aldosterone in association with NaCl induces cardiac fibrosis, oxidative stress, and inflammation through mineralocorticoid receptor activation; however, the biological processes regulated by aldosterone alone in the heart remain to be identified. Methods and Results Mice were treated for 7 days with aldosterone, and then cardiac transcriptome was analyzed. Aldosterone regulated 60 transcripts (51 upregulated and 9 downregulated) in the heart (fold change ≥1.5, false discovery rate <0.01). To identify the biological processes modulated by aldosterone, a gene ontology analysis was performed. The majority of aldosterone‐regulated genes were involved in cell division. The cardiac Ki‐67 index (an index of proliferation) of aldosterone‐treated mice was higher than that of nontreated mice, confirming microarray predictions. Costaining of Ki‐67 with vinculin, CD68, α‐smooth muscle actin, CD31, or caveolin 1 revealed that the cycling cells were essentially endothelial cells. Aldosterone‐induced mineralocorticoid receptor–dependent proliferation was confirmed ex vivo in human endothelial cells. Moreover, pharmacological‐specific blockade of mineralocorticoid receptor by eplerenone inhibited endothelial cell proliferation in a preclinical model of heart failure (transverse aortic constriction). Conclusions Aldosterone modulates cardiac gene expression and induces the proliferation of cardiac endothelial cells in vivo. PMID:25564371

Aldosterone increases cardiac vagal tone via G protein-coupled oestrogen receptor activation

PubMed Central

Brailoiu, G Cristina; Benamar, Khalid; Arterburn, Jeffrey B; Gao, Erhe; Rabinowitz, Joseph E; Koch, Walter J; Brailoiu, Eugen

2013-01-01

In addition to acting on mineralocorticoid receptors, aldosterone has been recently shown to activate the G protein-coupled oestrogen receptor (GPER) in vascular cells. In light of the newly identified role for GPER in vagal cardiac control, we examined whether or not aldosterone activates GPER in rat nucleus ambiguus. Aldosterone produced a dose-dependent increase in cytosolic Ca2+ concentration in retrogradely labelled cardiac vagal neurons of nucleus ambiguus; the response was abolished by pretreatment with the GPER antagonist G-36, but was not affected by the mineralocorticoid receptor antagonists, spironolactone and eplerenone. In Ca2+-free saline, the response to aldosterone was insensitive to blockade of the Ca2+ release from lysosomes, while it was reduced by blocking the Ca2+ release via ryanodine receptors and abolished by blocking the IP3 receptors. Aldosterone induced Ca2+ influx via P/Q-type Ca2+ channels, but not via L-type and N-type Ca2+ channels. Aldosterone induced depolarization of cardiac vagal neurons of nucleus ambiguus that was sensitive to antagonism of GPER but not of mineralocorticoid receptor. in vivo studies, using telemetric measurement of heart rate, indicate that microinjection of aldosterone into the nucleus ambiguus produced a dose-dependent bradycardia in conscious, freely moving rats. Aldosterone-induced bradycardia was blocked by the GPER antagonist, but not by the mineralocorticoid receptor antagonists. In summary, we report for the first time that aldosterone decreases heart rate by activating GPER in cardiac vagal neurons of nucleus ambiguus. PMID:23878371

Aldosterone and parathyroid hormone interactions as mediators of metabolic and cardiovascular disease.

PubMed

Tomaschitz, Andreas; Ritz, Eberhard; Pieske, Burkert; Rus-Machan, Jutta; Kienreich, Katharina; Verheyen, Nicolas; Gaksch, Martin; Grübler, Martin; Fahrleitner-Pammer, Astrid; Mrak, Peter; Toplak, Hermann; Kraigher-Krainer, Elisabeth; März, Winfried; Pilz, Stefan

2014-01-01

Inappropriate aldosterone and parathyroid hormone (PTH) secretion is strongly linked with development and progression of cardiovascular (CV) disease. Accumulating evidence suggests a bidirectional interplay between parathyroid hormone and aldosterone. This interaction may lead to a disproportionally increased risk of CV damage, metabolic and bone diseases. This review focuses on mechanisms underlying the mutual interplay between aldosterone and PTH as well as their potential impact on CV, metabolic and bone health. PTH stimulates aldosterone secretion by increasing the calcium concentration in the cells of the adrenal zona glomerulosa as a result of binding to the PTH/PTH-rP receptor and indirectly by potentiating angiotensin 2 induced effects. This may explain why after parathyroidectomy lower aldosterone levels are seen in parallel with improved cardiovascular outcomes. Aldosterone mediated effects are inappropriately pronounced in conditions such as chronic heart failure, excess dietary salt intake (relative aldosterone excess) and primary aldosteronism. PTH is increased as a result of (1) the MR (mineralocorticoid receptor) mediated calciuretic and magnesiuretic effects with a trend of hypocalcemia and hypomagnesemia; the resulting secondary hyperparathyroidism causes myocardial fibrosis and disturbed bone metabolism; and (2) direct effects of aldosterone on parathyroid cells via binding to the MR. This adverse sequence is interrupted by mineralocorticoid receptor blockade and adrenalectomy. Hyperaldosteronism due to klotho deficiency results in vascular calcification, which can be mitigated by spironolactone treatment. In view of the documented reciprocal interaction between aldosterone and PTH as well as the potentially ensuing target organ damage, studies are needed to evaluate diagnostic and therapeutic strategies to address this increasingly recognized pathophysiological phenomenon. © 2013.

Aldosterone Upregulates Transient Receptor Potential Melastatin 7 (TRPM7)*

PubMed Central

Valinsky, William C.; Jolly, Anna; Miquel, Perrine

2016-01-01

Transient receptor potential melastatin 7 (TRPM7) is a ubiquitously expressed Mg2+-permeable ion channel fused to a C-terminal α-kinase domain. Recently, aldosterone was shown to increase intracellular Mg2+ levels and alter inflammatory signaling in TRPM7-expressing HEK293 cells. This study was undertaken to assess whether these effects were related to an aldosterone-mediated increase of TRPM7 current and/or plasma membrane localization. Using HEK293 cells stably expressing WT-TRPM7, we found that 18-h application of aldosterone significantly increased TRPM7 current and TRPM7 plasma membrane protein expression by 48% and 34%, respectively. The aldosterone-mediated increase of TRPM7 current was inhibited by eplerenone, a mineralocorticoid receptor (MR) blocker, and GSK-650394, an inhibitor of the serum- and glucocorticoid-regulated kinase 1 (SGK1). SGK1 blockade also prevented the aldosterone-induced increase of TRPM7 plasma membrane protein. It was further determined that K1648R-TRPM7, the phosphotransferase-inactive TRPM7 mutant, was unresponsive to aldosterone. Therefore, chronic aldosterone treatment increases the plasma membrane expression of TRPM7, which is associated with an increase of TRPM7 current. This process occurs via an MR-dependent, genomic signaling cascade involving SGK1 and a functioning TRPM7 α-kinase domain. We suggest that this mechanism may be of general relevance when interpreting the effects of aldosterone because the MR receptor is found in multiple tissues, and TRPM7 and SGK1 are ubiquitously expressed. PMID:27466368

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.

Effect of RAAS blockers on adverse clinical outcomes in high CVD risk subjects with atrial fibrillation

PubMed Central

Chaugai, Sandip; Sherpa, Lhamo Yanchang; Sepehry, Amir A.; Arima, Hisatomi; Wang, Dao Wen

2016-01-01

Abstract 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. PMID:27368043

AT1 and aldosterone receptors blockade prevents the chronic effect of nandrolone on the exercise-induced cardioprotection in perfused rat heart subjected to ischemia and reperfusion.

PubMed

Marques-Neto, Silvio Rodrigues; Ferraz, Emanuelle Baptista; Rodrigues, Deivid Carvalho; Njaine, Brian; Rondinelli, Edson; Campos de Carvalho, Antônio Carlos; Nascimento, Jose Hamilton Matheus

2014-04-01

Myocardial tolerance to ischaemia/reperfusion (I/R) injury is improved by exercise training, but this cardioprotection is impaired by the chronic use of anabolic androgenic steroids (AAS). The present study evaluated whether blockade of angiotensin II receptor (AT1-R) with losartan and aldosterone receptor (mineralocorticoid receptor, MR) with spironolactone could prevent the deleterious effect of AAS on the exercise-induced cardioprotection. Male Wistar rats were exercised and treated with either vehicle, nandrolone decanoate (10 mg/kg/week i.m.) or the same dose of nandrolone plus losartan or spironolactone (20 mg/kg/day orally) for 8 weeks. Langendorff-perfused hearts were subjected to I/R and evaluated for the postischaemic recovery of left ventricle (LV) function and infarct size. mRNA and protein expression of angiotensin II type 1 receptor (AT1-R), mineralocorticoid receptor (MR), and KATP channels were determined by reverse-transcriptase polymerase chain reaction and Western blotting. Postischaemic recovery of LV function was better and infarct size was smaller in the exercised rat hearts than in the sedentary rat hearts. Nandrolone impaired the exercise-induced cardioprotection, but this effect was prevented by losartan (AT1-R antagonist) and spironolactone (MR antagonist) treatments. Myocardial AT1-R and MR expression levels were increased, and the expression of the KATP channel subunits SUR2a and Kir6.1 was decreased and Kir6.2 increased in the nandrolone-treated rat hearts. The nandrolone-induced changes of AT1-R, MR, and KATP subunits expression was normalized by the losartan and spironolactone treatments. The chronic nandrolone treatment impairs the exercise-induced cardioprotection against ischaemia/reperfusion injury by activating the cardiac renin-angiotensin-aldosterone system and downregulating KATP channel expression.

The effect of sugammadex on steroid hormones: A randomized clinical study.

PubMed

Gunduz Gul, Gulay; Ozer, Ayse B; Demirel, Ismail; Aksu, Ahmet; Erhan, Omer L

2016-11-01

Sugammadex is an alternative drug to traditional decurarization by cholinesterase inhibitors. It has been examined the effect of sugammadex on steroid hormones in this study. Randomized clinical trial. The study was conducted in a University Teaching Hospital from January 2013 to May 2014. Fifty male patients between 18 and 45years of age with an American Society of Anesthesiology (ASA) class I or II undergoing elective lower extremity surgery were included in this study. Patients were categorized into two groups (neostigmin group, Group N; and sugammadex group, Group S). In addition to standard monitorization, train-of-four (TOF) was also used to monitorize the level of neuromuscular blockade. Standard induction and maintenance of anesthesia were performed. At the termination of surgery, neuromuscular blockade was antagonized using 0.05mg/kg of neostigmine and 0.01mg/kg of atropin when spontaneous recovery of neuromuscular blockade occurred with the reappearance of T2 in Group N and using 4mg/kg sugammadex in Group S. The primary outcome in this study was to determine serum aldosterone, cortisol, progesterone, and free testosterone levels. Three blood samples were obtained in each patient just before and 15minutes and 4hours after antagonism, No significant differences were found in demographic characteristics between the groups. While there were no differences in serum progesterone levels, patients in neostigmin group had significantly higher cortisol levels at 15minutes as compared to baseline. Also, patients in sugammadex group had significantly higher serum aldosterone and testosterone levels 15minutes after antagonism as compared to those in the neostigmine group. Our findings suggest that sugammadex is not associated with adverse effects on steroid hormones progesterone and cortisol, while it may lead to a temporary increase in aldosterone and testosterone. Copyright © 2016 Elsevier Inc. All rights reserved.

Excessive Adiposity and Metabolic Dysfunction Relate to Reduced Natriuretic Peptide During RAAS Activation in HIV.

PubMed

Murphy, Caitlin A; Fitch, Kathleen V; Feldpausch, Meghan; Maehler, Patrick; Wong, Kimberly; Torriani, Martin; Adler, Gail K; Grinspoon, Steven K; Srinivasa, Suman

2018-02-01

Natriuretic peptides (NPs) negatively feedback on the renin-angiotensin-aldosterone system (RAAS) and play a critical role in preserving cardiac structure and maintaining metabolic homeostasis. Well-treated HIV-infected individuals are at risk for fat redistribution and demonstrate evidence of RAAS dysregulation, which relates to metabolic dysfunction. We investigated circulating NPs in relation to RAAS physiology and metrics of body composition for the first time in HIV. We assessed atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and amino terminal pro B-type natriuretic peptide (NT-proBNP) during acute activation of the RAAS using a low sodium controlled diet among 20 HIV-infected and 10 non-HIV-infected individuals well-phenotyped for body composition. BNP(60[44,152] vs. 196[91,251], P=.04) was significantly lower and serum aldosterone higher among HIV-infected vs. non-HIV-infected individuals. BNP was significantly and inversely associated with body composition [waist circumference(r=-0.46, P=.04), BMI(r=-0.55, P=.01), body adiposity index (r=-0.49, P=.03)], metabolic indices [total cholesterol(r=-0.44, P=.05), HOMA-IR(r=-0.44, P=.05), MAP (r=-0.44, P=.05)], and serum aldosterone(r=-0.49,P=.03) among the HIV group. These relationships were not demonstrated in the non-HIV group. In a four-group comparison stratifying by HIV serostatus and above/below BMI 25 kg/m2, BNP decreased significantly across groups, being highest in non-HIV with BMI<25 kg/m2 and lowest in HIV with BMI >25 kg/m2 (overall P=.01). Relatively reduced NP, particularly BNP, among HIV-infected individuals with excess adiposity may contribute to reduced suppression of aldosterone and potentially drive aldosterone-mediated metabolic complications. Novel strategies which target RAAS blockade and/or augment NPs may be potentially useful to reduce cardiometabolic disease among HIV-infected individuals in whom these systems are perturbed. Copyright © 2018 Endocrine Society

Effects of Dietary Sodium Restriction in Kidney Transplant Recipients Treated With Renin-Angiotensin-Aldosterone System Blockade: A Randomized Clinical Trial.

PubMed

de Vries, Laura V; Dobrowolski, Linn C; van den Bosch, Jacqueline J O N; Riphagen, Ineke J; Krediet, C T Paul; Bemelman, Frederike J; Bakker, Stephan J L; Navis, Gerjan

2016-06-01

In patients with chronic kidney disease receiving renin-angiotensin-aldosterone system (RAAS) blockade, dietary sodium restriction is an often-used treatment strategy to reduce blood pressure (BP) and albuminuria. Whether these effects extend to kidney transplant recipients is unknown. We therefore studied the effects of dietary sodium restriction on BP and urinary albumin excretion (UAE) in kidney transplant recipients receiving RAAS blockade. Two-center randomized crossover trial. Stable outpatient kidney transplant recipients with creatinine clearance > 30mL/min, BP ≥120/80mmHg, receiving stable RAAS blockade therapy. 6-week regular-sodium diet (target, 150mmol/24 h) and a 6-week low-sodium diet (target, 50mmol/24 h). Main outcome parameters were systolic and diastolic BP, UAE, and estimated glomerular filtration rate (eGFR) at the end of each diet period. Dietary adherence was assessed by 24-hour urinary sodium excretion. We randomly assigned 23 kidney transplant recipients, of whom 22 (mean age, 58±8 [SD] years; 50% men; mean eGFR, 51±21mL/min/1.73m(2)) completed the study. One patient withdrew from the study because of concerns regarding orthostatic hypotension on the low-sodium diet. Sodium excretion decreased from 164±50mmol/24 h during the regular-sodium diet to 87±55mmol/24 h during the low-sodium diet (mean difference, -77 [95% CI, -110 to -44] mmol/24 h; P<0.001). Sodium restriction significantly reduced systolic BP from 140±14 to 129±12mmHg (mean difference, -11 [95% CI, -14 to -7] mmHg; P<0.001), diastolic BP from 86±8 to 79±8mmHg (mean difference, -7 [95% CI, -10 to -5] mmHg; P<0.001). We found no significant effect on natural log (ln)-transformed UAE (mean difference, -0.03 [95% CI, -0.6 to 0.6] ln(mg/24 h); P=0.9) or eGFR. No hard end points; small study; small proportion of patients willing to test the intervention; adherence to sodium diet was achieved in 86% of patients. In stable kidney transplant recipients receiving RAAS blockade, dietary sodium restriction effectively reduces BP without affecting eGFR. Dietary sodium restriction is relevant to BP management in kidney transplant recipients receiving RAAS blockade. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Aldosterone Upregulates Transient Receptor Potential Melastatin 7 (TRPM7).

PubMed

Valinsky, William C; Jolly, Anna; Miquel, Perrine; Touyz, Rhian M; Shrier, Alvin

2016-09-16

Transient receptor potential melastatin 7 (TRPM7) is a ubiquitously expressed Mg(2+)-permeable ion channel fused to a C-terminal α-kinase domain. Recently, aldosterone was shown to increase intracellular Mg(2+) levels and alter inflammatory signaling in TRPM7-expressing HEK293 cells. This study was undertaken to assess whether these effects were related to an aldosterone-mediated increase of TRPM7 current and/or plasma membrane localization. Using HEK293 cells stably expressing WT-TRPM7, we found that 18-h application of aldosterone significantly increased TRPM7 current and TRPM7 plasma membrane protein expression by 48% and 34%, respectively. The aldosterone-mediated increase of TRPM7 current was inhibited by eplerenone, a mineralocorticoid receptor (MR) blocker, and GSK-650394, an inhibitor of the serum- and glucocorticoid-regulated kinase 1 (SGK1). SGK1 blockade also prevented the aldosterone-induced increase of TRPM7 plasma membrane protein. It was further determined that K1648R-TRPM7, the phosphotransferase-inactive TRPM7 mutant, was unresponsive to aldosterone. Therefore, chronic aldosterone treatment increases the plasma membrane expression of TRPM7, which is associated with an increase of TRPM7 current. This process occurs via an MR-dependent, genomic signaling cascade involving SGK1 and a functioning TRPM7 α-kinase domain. We suggest that this mechanism may be of general relevance when interpreting the effects of aldosterone because the MR receptor is found in multiple tissues, and TRPM7 and SGK1 are ubiquitously expressed. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Sequential RAAS blockade: is it worth the risk?

PubMed

Persson, Frederik; Rossing, Peter

2014-03-01

Soon after the emergence of the renin-angiotensin-aldosterone system (RAAS) blocking treatment as the cornerstone of renoprotective treatment in the prevention and treatment of diabetic and nondiabetic CKD, it was investigated if a higher degree of achievable RAAS blockade by combining more than one compound is feasible and advantageous. Regardless of the benefits from using monotherapy for diabetic kidney disease, there is still much improvement to wish for in terms of kidney prognosis in these populations. A great deal of research has gone into evaluating combinations of the RAAS blocking treatments in different populations and with different drugs and doses. Studies have mostly been short-term and use surrogate endpoints such as albuminuria. Side effects have been well known and expected in terms of increasing potassium levels and hypotension, but to an acceptable extent. With recent disappointing results from major hard endpoint trials using dual RAAS blockade the concept is now under scrutiny. In this review we will discuss the pros and cons of dual RAAS blockade, with facts and findings from smaller studies, endpoint trials, and meta-analyses. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Aldosterone stimulates vacuolar H+-ATPase activity in renal acid-secretory intercalated cells mainly via a protein kinase C-dependent pathway

PubMed Central

Winter, Christian; Kampik, Nicole B.; Vedovelli, Luca; Rothenberger, Florina; Păunescu, Teodor G.; Stehberger, Paul A.; Brown, Dennis; John, Hubert

2011-01-01

Urinary acidification in the collecting duct is mediated by the activity of H+-ATPases and is stimulated by various factors including angiotensin II and aldosterone. Classically, aldosterone effects are mediated via the mineralocorticoid receptor. Recently, we demonstrated a nongenomic stimulatory effect of aldosterone on H+-ATPase activity in acid-secretory intercalated cells of isolated mouse outer medullary collecting ducts (OMCD). Here we investigated the intracellular signaling cascade mediating this stimulatory effect. Aldosterone stimulated H+-ATPase activity in isolated mouse and human OMCDs. This effect was blocked by suramin, a general G protein inhibitor, and GP-2A, a specific Gαq inhibitor, whereas pertussis toxin was without effect. Inhibition of phospholipase C with U-73122, chelation of intracellular Ca2+ with BAPTA, and blockade of protein kinase C prevented the stimulation of H+-ATPases. Stimulation of PKC by DOG mimicked the effect of aldosterone on H+-ATPase activity. Similarly, aldosterone and DOG induced a rapid translocation of H+-ATPases to the luminal side of OMCD cells in vivo. In addition, PD098059, an inhibitor of ERK1/2 activation, blocked the aldosterone and DOG effects. Inhibition of PKA with H89 or KT2750 prevented and incubation with 8-bromoadenosine-cAMP mildly increased H+-ATPase activity. Thus, the nongenomic modulation of H+-ATPase activity in OMCD-intercalated cells by aldosterone involves several intracellular pathways and may be mediated by a Gαq protein-coupled receptor and PKC. PKA and cAMP appear to have a modulatory effect. The rapid nongenomic action of aldosterone may participate in the regulation of H+-ATPase activity and contribute to final urinary acidification. PMID:21832245

Sodium intake, RAAS-blockade and progressive renal disease.

PubMed

de Borst, Martin H; Navis, Gerjan

2016-05-01

Pharmacological blockade of the renin-angiotensin-aldosterone system (RAAS) by angiotensin converting enzyme inhibitors or angiotensin receptor blockers is the current standard treatment to prevent progressive renal function loss in patients with chronic kidney disease. Yet in many patients the renal protective effect of RAAS-blockade is incomplete. Short-term clinical studies have demonstrated that dietary sodium restriction potentiates the antiproteinuric effect of RAAS-blockade. More recently, it was shown that this effect is accompanied by a lower risk of end-stage renal disease and adverse cardiovascular outcomes. The modulation of RAAS-blockade efficacy by sodium intake is likely multifactorial, and is mediated by effects of sodium on local tissue RAAS in kidney, vasculature and brain, and by effects on the immune system. Despite the evidence showing the beneficial effects of even a moderate sodium restriction (∼2.5g/d), it remains difficult to realize in clinical practice. In an analysis based on 24-h urinary sodium excretion data from more than 10,000 CKD patients and renal transplant recipients, we found that sodium intake in these patients is on average 3.8g/d, closely resembling the global general population (3.95g/d). Behavioral approaches including the use of online dietary coaching (ehealth) and feedback using data from 24-h urine collections may be useful to successfully lower dietary sodium intake, aiming to improve cardio-renal outcomes in patients with CKD. Copyright © 2016 Elsevier Ltd. All rights reserved.

The antihypertensive effectiveness and safety of dual RAAS blockade with aliskiren and valsartan.

PubMed

Chrysant, Steven G

2010-03-01

The renin-angiotensin-aldosterone system (RAAS) is a major factor for the development and maintenance of hypertension and a major cause for cardiovascular remodeling and cardiovascular complications through its active peptide angiotensin (Ang) II. Blockade of RAAS with ACE inhibitors (ACEIs) results in suppression of Ang II levels, which eventually return to baseline levels after prolonged ACEI administration. This leads to an escape phenomenon through generation of Ang II from enzymes other than ACE and led to the hypothesis that dual blockade of RAAS with an ACEI/Ang receptor blocker (ARB) combination could lead to total blockade of RAAS, since ARBs block the action of Ang II at the AT1 receptor level, irrespective of the mechanism of Ang II generation and will have an additive blood pressure (BP)-lowering effect. However, this hypothesis has not materialized clinically, as the ACEI/ARB combination produces modest BP reductions that are not significantly greater than monotherapy with the component drugs, and is frequently associated with higher incidence of side effects. A new dual RAAS blockade with the direct renin inhibitor aliskiren and the ARB valsartan produces greater BP reductions than monotherapy with the component drugs and is safe and well tolerated. The combination of aliskiren with valsartan, and with other antihypertensive drugs is discussed. Copyright 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

Elevations in serum creatinine with RAAS blockade: why isn't it a sign of kidney injury?

PubMed

Ryan, Michael J; Tuttle, Katherine R

2008-09-01

The aim of this article is to review the pertinent physiology and pathophysiology of the renin-angiotensin-aldosterone system (RAAS), summarize the proven beneficial cardiovascular and renal effects of RAAS blockade, examine clinical situations in which RAAS blockade may induce reductions in glomerular filtration rate, and explore why increases in serum creatinine in the setting of angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) therapy do not necessarily signify the presence of clinically relevant kidney failure. RAAS inhibition appears to reduce the likelihood of atrial fibrillation. RAAS inhibition leads to improved insulin sensitivity and glycemic control, but does not appear to prevent diabetes. The beneficial effects of ACEi/ARB therapy extend to those with significant renal disease. Combination ACEi/ARB is safe, and reduces proteinuria more than either agent alone in patients with macroalbuminuric nephropathy. Acute deteriorations in renal function that result from RAAS inhibition are usually reversible. RAAS blockade exerts potent hemodynamic, antihypertensive, and antiinflammatory effects, and slows progression of kidney disease beyond that due to lowering of blood pressure. The benefit extends to those with advanced disease. In spite of established benefit, ACEi and ARB therapy remains underutilized, in part due to concerns about acute deteriorations in renal function that result from interruption of the RAAS.

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.

Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis

PubMed Central

Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han

2016-01-01

Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate–limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/−) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency–induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/−) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency–induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis. PMID:26471128

Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER).

PubMed

Feldman, Ross D; Ding, Qingming; Hussain, Yasin; Limbird, Lee E; Pickering, J Geoffrey; Gros, Robert

2016-06-01

Although aldosterone is a known regulator of renal and cardiovascular function, its role as a regulator of cancer growth and spread has not been widely considered. This study tested the hypothesis that aldosterone regulates cancer cell growth/spread via G protein-coupled estrogen receptor (GPER) activation. In vitro in murine renal cortical adenocarcinoma (RENCA) cells, a widely used murine in vitro model for the study of renal cell adenocarcinoma, aldosterone increased RENCA cell proliferation to a maximum of 125 ± 3% of control at a concentration of 10 nM, an effect blocked by the GPER antagonist G15 or by GPER knockdown using short interfering (sh) RNA techniques. Further, aldosterone increased RENCA cell migration to a maximum of 170 ± 20% of control at a concentration of 100 nM, an effect also blocked by G15 or by GPER down-regulation. In vivo, after orthotopic RENCA cell renal transplantation, pulmonary tumor spread was inhibited by pharmacologic blockade of aldosterone effects with spironolactone (percentage of lung occupied by metastasis: control = 68 ± 13, spironolactone = 26 ± 8, P < 0.05) or inhibition of aldosterone synthesis with a high dietary salt diet (percentage of lung: control = 44 ± 6, high salt = 12 ± 3, P < 0.05), without reducing primary tumor size. Additionally, adrenalectomy significantly reduced the extent of pulmonary tumor spread, whereas aldosterone infusion recovered pulmonary metastatic spread toward baseline levels. Finally, inhibition of GPER either with the GPER antagonist G15 or by GPER knockdown comparably inhibited RENCA cell pulmonary metastatic cancer spread. Taken together, these findings provide strong evidence for aldosterone serving a causal role in renal cell cancer regulation via its GPER receptor; thus, antagonism of GPER represents a potential new target for treatment to reduce metastatic spread.-Feldman, R. D., Ding, Q., Hussain, Y., Limbird, L. E., Pickering, J. G., Gros, R. Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER). © FASEB.

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.

The necessity and effectiveness of mineralocorticoid receptor antagonist in the treatment of diabetic nephropathy.

PubMed

Sato, Atsuhisa

2015-06-01

Diabetes mellitus is a major cause of chronic kidney disease (CKD), and diabetic nephropathy is the most common primary disease necessitating dialysis treatment in the world including Japan. Major guidelines for treatment of hypertension in Japan, the United States and Europe recommend the use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, which suppress the renin-angiotensin system (RAS), as the antihypertensive drugs of first choice in patients with coexisting diabetes. However, even with the administration of RAS inhibitors, failure to achieve adequate anti-albuminuric, renoprotective effects and a reduction in cardiovascular events has also been reported. Inadequate blockade of aldosterone may be one of the reasons why long-term administration of RAS inhibitors may not be sufficiently effective in patients with diabetic nephropathy. This review focuses on treatment in diabetic nephropathy and discusses the significance of aldosterone blockade. In pre-nephropathy without overt nephropathy, a mineralocorticoid receptor antagonist can be used to enhance the blood pressure-lowering effects of RAS inhibitors, improve insulin resistance and prevent clinical progression of nephropathy. In CKD categories A2 and A3, the addition of a mineralocorticoid receptor antagonist to an RAS inhibitor can help to maintain 'long-term' antiproteinuric and anti-albuminuric effects. However, in category G3a and higher, sufficient attention must be paid to hyperkalemia. Mineralocorticoid receptor antagonists are not currently recommended as standard treatment in diabetic nephropathy. However, many studies have shown promise of better renoprotective effects if mineralocorticoid receptor antagonists are appropriately used.

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.

FAD286, an aldosterone synthase inhibitor, reduced atherosclerosis and inflammation in apolipoprotein E-deficient mice.

PubMed

Gamliel-Lazarovich, Aviva; Gantman, Anna; Coleman, Raymond; Jeng, Arco Y; Kaplan, Marielle; Keidar, Shlomo

2010-09-01

Aldosterone is known to be involved in atherosclerosis and cardiovascular disease and blockade of its receptor was shown to improve cardiovascular function. It was, therefore, hypothesized that inhibition of aldosterone synthesis would also reduce atherosclerosis development. To test this hypothesis, we examined the effect of FAD286 (FAD), an aldosterone synthase inhibitor, on the development of atherosclerosis in spontaneous atherosclerotic apolipoprotein E-deficient mice. Mice were divided into three treatment groups: normal diet, low-salt diet (LSD) and LSD treated with FAD at 30 mg/kg per day (LSD + FAD) for 10 weeks. Histomorphometry of the aortas obtained from these mice showed that atherosclerotic lesion area increased by three-fold under LSD compared with normal diet and FAD significantly reduced lesion area to values similar to normal diet. Changes in atherosclerosis were paralleled by changes in the expression of the inflammation markers (C-reactive protein, monocyte chemotactic protein-1, interleukin-6, nuclear factor kappa B and intercellular adhesion molecule-1) in peritoneal macrophages obtained from these mice. Surprisingly, whereas LSD increased serum or urine aldosterone levels, FAD did not alter these levels when evaluated at the end of the study. In J774A.1 macrophage-like cell line stimulated with lipopolysaccharide, FAD was shown to have a direct dose-dependent anti-inflammatory effect. In apolipoprotein E-deficient mice, FAD reduces atherosclerosis and inflammation. However, these actions appeared to be dissociated from its effect on inhibition of aldosterone synthesis.

Prognostic Impact of Loop Diuretics in Patients With Chronic Heart Failure　- Effects of Addition of Renin-Angiotensin-Aldosterone System Inhibitors and β-Blockers.

PubMed

Miura, Masanobu; Sugimura, Koichiro; Sakata, Yasuhiko; Miyata, Satoshi; Tadaki, Soichiro; Yamauchi, Takeshi; Onose, Takeo; Tsuji, Kanako; Abe, Ruri; Oikawa, Takuya; Kasahara, Shintaro; Nochioka, Kotaro; Takahashi, Jun; Shimokawa, Hiroaki

2016-05-25

It remains to be elucidated whether addition of renin-angiotensin-aldosterone system (RAAS) inhibitors and/or β-blockers to loop diuretics has a beneficial prognostic impact on chronic heart failure (CHF) patients. From the Chronic Heart failure Analysis and Registry in the Tohoku district 2 (CHART-2) Study (n=10,219), we enrolled 4,134 consecutive patients with symptomatic stage C/D CHF (mean age, 69.3 years, 67.7% male). We constructed Cox models for composite of death, myocardial infarction, stroke and HF admission. On multivariate inverse probability of treatment weighted (IPTW) Cox modeling, loop diuretics use was associated with worse prognosis with hazard ratio (HR) 1.28 (P<0001). Furthermore, on IPTW multivariate Cox modeling for multiple treatments, both low-dose (<40 mg/day) and high-dose (≥40 mg/day) loop diuretics were associated with worse prognosis with HR 1.32 and 1.56, respectively (both P<0.001). Triple blockade with RAS inhibitor(s), mineral corticoid (aldosterone) receptor antagonist(s) (MRA), and β-blocker(s) was significantly associated with better prognosis in those on low-dose but not on high-dose loop diuretics. Chronic use of loop diuretics is significantly associated with worse prognosis in CHF patients in a dose-dependent manner, whereas the triple combination of RAAS inhibitor(s), MRA, and β-blocker(s) is associated with better prognosis when combined with low-dose loop diuretics. (Circ J 2016; 80: 1396-1403).

Has RAAS Blockade Reached Its Limits in the Treatment of Diabetic Nephropathy?

PubMed

Majewski, Collen; Bakris, George L

2016-04-01

Medications that block the renin-angiotensin-aldosterone system (RAAS) are a cornerstone of diabetic nephropathy treatment. These agents play an important role in slowing the nephropathy progression in patients with diabetes. Clinical outcome trials that investigated use of these drug classes in patients with diabetic nephropathy have demonstrated clinical significant benefit in slowing nephropathy progression only in people with >300 mg/day of proteinuria. Thus, guidelines mandate their use in such patients. Conversely, combinations of RAAS blocking agents in these patients can worsen renal outcomes. Moreover, use of RAAS blockers in patients with a glomerular filtration rate below 45 mL/min/1.73 m(2) is limited by hyperkalemia. New agents that predictably bind excess potassium in the colon offer the possibility of extending RAAS inhibitor use in advanced chronic kidney disease (CKD) to allow evaluation of RAAS blockade for nephropathy and cardiovascular outcomes. These new potassium-binding agents may provide an opportunity to continue full-dose RAAS inhibition and assess if the benefits of RAAS blockade seen in stage 3 CKD can be extrapolated to persons with stages 4 and 5 CKD, not previously tested due to hyperkalemia.

Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis.

PubMed

Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han; Sun, Zhongjie

2016-06-01

Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis. Copyright © 2016 by the American Society of Nephrology.

Transient Receptor Potential Canonical (TRPC)/Orai1-dependent Store-operated Ca2+ Channels: NEW TARGETS OF ALDOSTERONE IN CARDIOMYOCYTES.

PubMed

Sabourin, Jessica; Bartoli, Fiona; Antigny, Fabrice; Gomez, Ana Maria; Benitah, Jean-Pierre

2016-06-17

Store-operated Ca(2+) entry (SOCE) has emerged as an important mechanism in cardiac pathology. However, the signals that up-regulate SOCE in the heart remain unexplored. Clinical trials have emphasized the beneficial role of mineralocorticoid receptor (MR) signaling blockade in heart failure and associated arrhythmias. Accumulated evidence suggests that the mineralocorticoid hormone aldosterone, through activation of its receptor, MR, might be a key regulator of Ca(2+) influx in cardiomyocytes. We thus assessed whether and how SOCE involving transient receptor potential canonical (TRPC) and Orai1 channels are regulated by aldosterone/MR in neonatal rat ventricular cardiomyocytes. Molecular screening using qRT-PCR and Western blotting demonstrated that aldosterone treatment for 24 h specifically increased the mRNA and/or protein levels of Orai1, TRPC1, -C4, -C5, and stromal interaction molecule 1 through MR activation. These effects were correlated with a specific enhancement of SOCE activities sensitive to store-operated channel inhibitors (SKF-96365 and BTP2) and to a potent Orai1 blocker (S66) and were prevented by TRPC1, -C4, and Orai1 dominant negative mutants or TRPC5 siRNA. A mechanistic approach showed that up-regulation of serum- and glucocorticoid-regulated kinase 1 mRNA expression by aldosterone is involved in enhanced SOCE. Functionally, 24-h aldosterone-enhanced SOCE is associated with increased diastolic [Ca(2+)]i, which is blunted by store-operated channel inhibitors. Our study provides the first evidence that aldosterone promotes TRPC1-, -C4-, -C5-, and Orai1-mediated SOCE in cardiomyocytes through an MR and serum- and glucocorticoid-regulated kinase 1 pathway. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Unilateral adrenalectomy improves urinary protein excretion but does not abolish its relationship to sodium excretion in patients with aldosterone-producing adenoma.

PubMed

Pimenta, E; Gordon, R D; Ahmed, A H; Cowley, D; Robson, D; Kogovsek, C; Stowasser, M

2011-10-01

Experimental and human data suggest that adverse cardiovascular (CV) and renal effects of aldosterone excess are dependent on concomitant dietary salt intake. Increased urinary protein (Uprot) is an early sign of nephropathy independently associated with CV risk. We have previously reported a positive association between Uprot and urinary sodium (UNa) in patients with hyperaldosteronism, but not in patients with normal aldosterone levels. We aimed to determine whether Uprot is related to UNa in patients with aldosterone-producing adenoma (APA) and whether the degree of Uprot and strength of this relationship is reduced following correction of hyperaldosteronism. Subjects with APA (n=24) underwent measurement of 24 h Uprot and UNa before and after unilateral adrenalectomy (follow-up 15.0±11.9 months). Following surgery, mean clinic systolic blood pressure fell (150.4±18.2 vs 134.5±14.5 mm Hg, P=0.0008), despite a reduction in number of antihypertensive medications, and Uprot (211.2±101.6 vs 106.0±41.8 mg per day, P<0.0001) decreased. There was a positive correlation between Uprot and UNa both before (r=0.5477, P=0.0056) and after (r=0.5097, P=0.0109) adrenalectomy. Changes in UNa independently predicted Uprot reduction (P=0.0189). These findings suggest that both aldosterone levels and dietary salt contribute to renal damage, and that once glomerular damage occurs it is not completely resolved following correction of hyperaldosteronism. Our study suggests that treatment strategies based on reduction of aldosterone effects, by adrenalectomy or mineralocorticoid receptor blockade, in conjunction with low-salt diet would provide additional target-organ protection in patients with primary aldosteronism.

[Effect of RAAS inhibition on stroke prevention].

PubMed

Tanahashi, Norio

2012-09-01

Recently, molecular and experimental studies revealed that the brain possesses its own renin-angiotensin-aldosterone system(RAAS) and the brain angiotensin(Ang) II plays an important role on stroke protection, mediating its effects through stimulation of AT2 and possibly the AT4 receptors. Moreover, the novel ACE2/Ang-(1-7)/Mas receptor axis was found to counterbalance the vasoconstrictive actions of the ACE/Ang II/AT1 receptor. Recent clinical trials indicate that blockade of RAAS has a potential role in stroke prevention, but was not conclusive. More carefully designed large clinical trial are needed to verify blood pressure-independent stroke prevention effect by RAAS inhibition.

Early RAAS Blockade Exerts Renoprotective Effects in Autosomal Recessive Alport Syndrome.

PubMed

Uchida, Nao; Kumagai, Naonori; Nozu, Kandai; Fu, Xue Jun; Iijima, Kazumoto; Kondo, Yoshiaki; Kure, Shigeo

2016-11-01

Alport syndrome is a progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes that encode collagen type IV alpha 3, alpha 4, and alpha 5 chains, respectively. Because of abnormal collagen chain, glomerular basement membrane becomes fragile and most of the patients progress to end-stage renal disease in early adulthood. COL4A5 mutation causes X-linked form of Alport syndrome, and two mutations in either COL4A3 or COL4A4 causes an autosomal recessive Alport syndrome. Recently, renin-angiotensin-aldosterone system (RAAS) blockade has been shown to attenuate effectively disease progression in Alport syndrome. Here we present three Japanese siblings and their father all diagnosed with autosomal recessive Alport syndrome and with different clinical courses, suggesting the importance of the early initiation of RAAS blockade. The father was diagnosed with Alport syndrome. His consanguineous parents and his wife were healthy. All three siblings showed hematuria since infancy. Genetic analysis revealed that they shared the same gene mutations in COL4A3 in a compound heterozygous state: c.2330G>A (p.Gly777Ala) from the mother and c.4354A>T (p.Ser1452Cys) from the father. Although RAAS blockade was initiated for the older sister and brother when their renal function was already impaired, it did not attenuate disease progression. In the youngest brother, RAAS blockade was initiated during normal renal function stage. After the initiation, his renal function has been normal with the very mild proteinuria to date at the age of 17 years. We propose that in Alport syndrome, RAAS blockade should be initiated earlier than renal function is impaired.

Effects of calcium channel blockers comparing to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients with hypertension and chronic kidney disease stage 3 to 5 and dialysis: A systematic review and meta-analysis

PubMed Central

Lin, Yen-Chung; Lin, Jheng-Wei; Wu, Mai-Szu; Chen, Kuan-Chou; Peng, Chiung-Chi

2017-01-01

Background Calcium channel blocker (CCB) or two renin angiotensin aldosterone system blockades (RAAS), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are major potent and prevalently used as initial antihypertensive agents for mild to moderate hypertension, but no uniform agreement as to which antihypertensive drugs should be given for initial therapy, especially among chronic kidney disease (CKD) patients. Design A systematic review and meta-analysis comparing CCBs and the two RAAS blockades for hypertensive patients with CKD stage 3 to 5D. The inclusion criteria for this systematic review was RCT that compared the effects of CCBs and the two RAAS blockades in patients with hypertension and CKD. The exclusion criteria were (1) renal transplantation, (2) CKD stage 1 or 2, (3) combined therapy (data cannot be extracted separately). Outcomes were blood pressure change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes. Results 21 randomized controlled trials randomized 9,492 patients with hypertensive and CKD into CCBs and the two RAAS blockades treatments. The evidence showed no significant differences in blood presser change, mortality, heart failure, stroke or cerebrovascular events, and renal outcomes between CCBs group and the two RAAS blockades group. The publication bias of pooled mean blood presser change that was detected by Egger’s test was non-significant. Conclusions CCBs has similar effects on long term blood pressure, mortality, heart failure, stroke or cerebrovascular events, and renal function to RAAS blockades in patients CKD stage 3 to 5D and hypertension. PMID:29240784

Comparison of dual RAAS blockade and higher-dose RAAS inhibition on nephropathy progression.

PubMed

Bakris, George L; Weir, Matthew R

2008-04-01

Although the risk of dying from cardiovascular disease (CVD) is greater than for progressing to end-stage renal disease (ESRD), the increasing prevalence of diabetes mellitus and reduced mortality from CVD have contributed to an increased incidence of ESRD. Use of renin-angiotensin-aldosterone system (RAAS) blockers to reduce blood pressure is proven to reduce the rate of nephropathy progression. Theoretically, more complete RAAS inhibition may enhance the ability to slow nephropathy progression. Combining an angiotensin-converting enzyme inhibitor (ACEI) and an angiotensin receptor blocker (ARB) more completely inhibits the RAAS, potentially providing greater opportunity for renoprotection. Proteinuria is a strong independent predictor of poor renal and cardiovascular outcomes. Therefore, targeting interventions that further reduce proteinuria may yield better outcomes. This review presents evidence supporting the hypothesis that higher doses of RAAS inhibition or dual RAAS blockade are more effective in reducing proteinuria. Clinical data and ongoing trials will be discussed in the context of this hypothesis.

Aldosterone breakthrough in dogs with naturally occurring myxomatous mitral valve disease.

PubMed

Ames, M K; Atkins, C E; Eriksson, A; Hess, A M

2017-06-01

Aldosterone breakthrough (ABT) is the condition in which angiotensin converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers fail to effectively suppress the activity of the renin angiotensin aldosterone system. The objective of this study was to determine if ABT occurs in dogs with naturally occurring myxomatous mitral valve disease receiving an ACEI, using the urine aldosterone to creatinine ratio (UAldo:C) as a measure of renin angiotensin aldosterone system activation. This study includes 39 dogs with myxomatous mitral valve disease. A UAldo:C cut-off definition (derived from a normal population of healthy, adult, and client-owned dogs) was used to determine the prevalence of ABT in this population. Spearman analysis and univariate logistic regression were used to evaluate the relationship between UAldo:C and ABT (yes/no) and eight variables (age, serum K + concentration, serum creatinine concentration, ACEI therapy duration and ACEI dosage, furosemide therapy duration and furosemide dosage, and urine sample storage time). Finally, the UAldo:C in dogs receiving spironolactone, as part congestive heart failure (CHF) therapy, was compared to dogs with CHF that were not receiving spironolactone. The prevalence of ABT was 32% in dogs with CHF and 30% in dogs without CHF. There was no relationship between either the UAldo:C or the likelihood of ABT and the eight variables. Therapy with spironolactone lead to a significant elevation of the UAldo:C. Using the UAldo:C and a relatively stringent definition of ABT, it appears that incomplete RAAS blockade is common in dogs with MMVD receiving an ACEI. The prevalence of ABT in this canine population mirrors that reported in humans. While the mechanism of ABT is likely multifactorial and still poorly understood, the proven existence of ABT in dogs offers the potential to improve the prognosis for MMVD with the addition of a mineralocorticoid receptor blocker to current therapeutic regimens. Approximately 30% of dogs being treated for heart disease and CHF satisfied the definition of ABT. Identifying patient subpopulations experiencing ABT may help guide future study design and clinical decision-making. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Transient Receptor Potential Canonical (TRPC)/Orai1-dependent Store-operated Ca2+ Channels

PubMed Central

Sabourin, Jessica; Bartoli, Fiona; Antigny, Fabrice; Gomez, Ana Maria; Benitah, Jean-Pierre

2016-01-01

Store-operated Ca2+ entry (SOCE) has emerged as an important mechanism in cardiac pathology. However, the signals that up-regulate SOCE in the heart remain unexplored. Clinical trials have emphasized the beneficial role of mineralocorticoid receptor (MR) signaling blockade in heart failure and associated arrhythmias. Accumulated evidence suggests that the mineralocorticoid hormone aldosterone, through activation of its receptor, MR, might be a key regulator of Ca2+ influx in cardiomyocytes. We thus assessed whether and how SOCE involving transient receptor potential canonical (TRPC) and Orai1 channels are regulated by aldosterone/MR in neonatal rat ventricular cardiomyocytes. Molecular screening using qRT-PCR and Western blotting demonstrated that aldosterone treatment for 24 h specifically increased the mRNA and/or protein levels of Orai1, TRPC1, -C4, -C5, and stromal interaction molecule 1 through MR activation. These effects were correlated with a specific enhancement of SOCE activities sensitive to store-operated channel inhibitors (SKF-96365 and BTP2) and to a potent Orai1 blocker (S66) and were prevented by TRPC1, -C4, and Orai1 dominant negative mutants or TRPC5 siRNA. A mechanistic approach showed that up-regulation of serum- and glucocorticoid-regulated kinase 1 mRNA expression by aldosterone is involved in enhanced SOCE. Functionally, 24-h aldosterone-enhanced SOCE is associated with increased diastolic [Ca2+]i, which is blunted by store-operated channel inhibitors. Our study provides the first evidence that aldosterone promotes TRPC1-, -C4-, -C5-, and Orai1-mediated SOCE in cardiomyocytes through an MR and serum- and glucocorticoid-regulated kinase 1 pathway. PMID:27129253

Aerobic Exercise and Pharmacological Therapies for Skeletal Myopathy in Heart Failure: Similarities and Differences

PubMed Central

Bacurau, Aline V.; Cunha, Telma F.; Souza, Rodrigo W.; Voltarelli, Vanessa A.; Gabriel-Costa, Daniele; Brum, Patricia C.

2016-01-01

Skeletal myopathy has been identified as a major comorbidity of heart failure (HF) affecting up to 20% of ambulatory patients leading to shortness of breath, early fatigue, and exercise intolerance. Neurohumoral blockade, through the inhibition of renin angiotensin aldosterone system (RAS) and β-adrenergic receptor blockade (β-blockers), is a mandatory pharmacological therapy of HF since it reduces symptoms, mortality, and sudden death. However, the effect of these drugs on skeletal myopathy needs to be clarified, since exercise intolerance remains in HF patients optimized with β-blockers and inhibitors of RAS. Aerobic exercise training (AET) is efficient in counteracting skeletal myopathy and in improving functional capacity and quality of life. Indeed, AET has beneficial effects on failing heart itself despite being of less magnitude compared with neurohumoral blockade. In this way, AET should be implemented in the care standards, together with pharmacological therapies. Since both neurohumoral inhibition and AET have a direct and/or indirect impact on skeletal muscle, this review aims to provide an overview of the isolated effects of these therapeutic approaches in counteracting skeletal myopathy in HF. The similarities and dissimilarities of neurohumoral inhibition and AET therapies are also discussed to identify potential advantageous effects of these combined therapies for treating HF. PMID:26904163

Calibrating the impact of dual RAAS blockade on the heart and the kidney - balancing risks and benefits.

PubMed

Ziff, O J; Covic, A; Goldsmith, D

2016-07-01

Overactivity of the renin-angiotensin-aldosterone system (RAAS) plays a key role in the pathophysiology of heart failure (HF) and chronic kidney disease (CKD). RAAS antagonists can significantly improve clinical outcomes, but monotherapy blocks but one step of the RAAS and can be bypassed through compensatory mechanisms. Providing more complete RAAS blockade by deploying drugs with complementary actions seemed logical - hence the practice of using dual (or triple) RAAS inhibitors. However, RAAS antagonists also exhibit dose-limiting side effects, including acute kidney injury, hyperkalaemia and hypotension, which blunt their overall effectiveness. Despite achieving better RAAS blockade, several trials failed to show clinical outcome improvements. Patients with concomitant CKD and HF (cardiorenal syndrome) are at the greatest risk of these adverse events and therefore the least able to benefit, yet they also have the worst prognosis. This paradox, where those most in need have fewest therapeutic options, poses three questions which are the focus of this review: whether (i) novel therapies that prevent adverse effects can restore therapeutic benefits to patients who would otherwise be RAAS-therapy intolerant, (ii) there are any validated alternatives to their use and (iii) newer approaches to the detection of fluid congestion are ready for implementation. © 2016 John Wiley & Sons Ltd.

Dietary sodium restriction: a neglected therapeutic opportunity in chronic kidney disease

PubMed Central

Humalda, Jelmer K.; Navis, Gerjan

2014-01-01

Purpose of review Restriction of dietary sodium is recommended at a population level as well as for groups at high cardiovascular risk, and chronic kidney disease (CKD). This review addresses recent evidence for the protective effect of dietary sodium restriction in CKD patients specifically. Recent findings Sodium intake in CKD populations is generally high, and often above population average. Recent data demonstrated that moderately lower sodium intake in CKD patients is associated with substantially better long-term outcome of renin–angiotensin–aldosterone system (RAAS)-blockade, in diabetic and nondiabetic CKD, related to better effects of RAAS-blockade on proteinuria, independent of blood pressure. This is in line with better short-term efficacy of RAAS-blockade during moderate sodium restriction in diabetic and nondiabetic CKD. This effect of sodium restriction is likely mediated by its effects on volume status. Sustainable sodium restriction can be achieved by approaches on the basis of behavioral sciences. Summary Moderate restriction of dietary sodium can substantially improve the protective effects of RAAS-blockade in CKD, by specific renal effects apparent from proteinuria reduction. The latter precludes straightforward extrapolation of data from nonrenal populations to CKD. Concerns regarding the adverse effects of a very low sodium intake should not distract from the protective effects of moderate sodium restriction. Prospective studies should assess the efficacy and sustainability of different strategies to target high sodium intake in CKD, along with measures at population level. Video abstract http://links.lww.com/CONH/A14 PMID:25222815

[Salt-induced inappropriate augmentation of intrarenal RAAS and its treatment in patients with chronic kidney disease].

PubMed

Konishi, Yoshio

2012-09-01

Focus on the role of the renin-angiotensin-aldosterone system (RAAS) in the pathophysiology of hypertension and renal damage has shifted recently to the role of the local RAAS in the kidneys. Inappropriate augmentation of intrarenal RAAS activity in patients with chronic kidney disease has suggested playing important roles in the development of hypertension and renal injury. In this article, I show the recent findings that salt-induced this augmentation may contribute to the development of salt-sensitive hypertension and play a key role in cardiorenal syndrome (CRS), and that blockade of intrarenal RAAS may be an important strategy for salt-sensitive hypertension and CRS.

Evaluation of subacute change in RAAS activity (as indicated by urinary aldosterone:creatinine, after pharmacologic provocation) and the response to ACE inhibition.

PubMed

Ames, Marisa K; Atkins, Clarke E; Lantis, Andrea C; zum Brunnen, James

2016-01-01

The objective of this study was to evaluate subacute changes in renin-angiotensin-aldosterone system (RAAS) activity during angiotensin-converting enzyme inhibitor (ACEI) therapy in dogs with experimental RAAS activation. Analysis of data (urine aldosterone:creatinine ratio (UAldo:C) and serum angiotensin-converting enzyme activity), in 31 healthy dogs with furosemide or amlodipine-activated RAAS that received an ACEI. When furosemide or amlodipine activation of RAAS preceded ACEI administration, incomplete RAAS blockade (IRB) was defined as a UAldo:C greater than (a) the dog's 'activated' baseline value or (b) a population-derived cut-off value (mean + 2 SD (>1.0 μg/g) of pretreatment UAldo:C from our population of research dogs). In studies where RAAS activation occurred concurrently with ACEIs, IRB was defined as (a) a UAldo:C greater than either twofold the dog's prestimulation baseline value or (b) 1.0 µg/g. Dogs were followed for 7-17 days. Serum angiotensin-converting enzyme activity was measured in 19 dogs and was significantly reduced (P<0.0001) after ACEI administration. The overall incidence of IRB, when RAAS activation preceded ACEI administration, was 33% and 8% for definitions (a) and (b), respectively. The overall incidence of IRB, when ACEIs were concurrent with RAAS activation, was 65% and 61% for definitions (a) and (b), respectively. Increases in UAldo:C, despite ACEI administration, is evidence of IRB in this subacute model of experimental RAAS activation and suppression. © The Author(s) 2016.

Management of diabetic nephropathy: Recent progress and future perspective.

PubMed

Ahmad, Jamal

2015-01-01

Diabetic nephropathy (DN), a leading cause of end-stage renal disease (ESRD) affecting ∼20-30% diabetics, is associated with increased cardiovascular mortality. The progression of kidney disease in patients with diabetes can take many years. It occurs as a result of interaction between both genetic and environmental factors in individuals with both type 1 and type 2 diabetes. Hyperglycaemia, hypertension, and genetic pre-disposition are the main risk factors besides elevated serum lipids, smoking habits, and the amount of dietary proteins. Interventions such as glycaemic control, blood pressure control and inhibition of the renin-angiotensin-aldosterone system have been shown to slow this progression. Despite the implementation of these strategies, the number of patients with diabetes that ultimately develop end-stage renal disease remains high. The treatment of DN, therefore, has posed a formidable challenge besides optimization of renin-angiotensin-aldosterone system blockade in patients with DN; additional investigation has focused on the potential of novel therapies that target various pathways upregulated by hyperglycaemia or other targets believed to promote the progression of DN such as oxidative stress, inflammation, endothelin system and vitamin D receptors. This review article addresses the pathogenesis and some of the well established principles regarding the progression and accepted management of DN, and also includes the perspectives of novel anti-DN agents and the future directions for the prevention of DN. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Dual RAAS blockade is desirable in kidney disease: con.

PubMed

Bakris, George L

2010-09-01

Dual renin-angiotensin aldosterone (RAAS) blockade is associated with higher risk of hyperkalemia and has not been shown, in any outcome trial of validated renal end points, that is, doubling of creatinine, time to dialysis, or death, to be superior over other approaches. It shows promise in advanced proteinuric nephropathy for additional proteinuria reduction. Whether this additional proteinuria reduction translates into meaningful outcomes of chronic kidney disease (CKD) is unknown, as proteinuria change is not a validated surrogate end point. Until we know the answer to this question, only those with very high levels of proteinuria should receive combination RAAS blocking therapy, and they need to be carefully monitored. Such individuals should be evaluated for risk of hyperkalemia and should consider use of a non-dihydropyridine calcium antagonist added to the single RAAS agent as an alternative for proteinuria reduction. This provides a safe and effective option for those patients with advanced nephropathic disease who need additional proteinuria reduction. In all cases other than advanced proteinuric nephropathy, there is no evidence of any positive CKD outcome with dual RAAS blockade. Thus, dual RAAS blockade cannot be recommended for all CKD patients.

We Avoid RAAS Inhibitors in PD Patients with Residual Renal Function.

PubMed

Turner, Jeffrey M

2016-07-01

Preserving residual renal function in patients on peritoneal dialysis (PD) positively impacts mortality. While it is important to avoid nephrotoxic agents in this setting, clinicians should appreciate that inhibitors of the renin-angiotensin-aldosterone system (RAAS), including angiotensin converting enzyme inhibitors, and angiotensin receptor blockers are likely to preserve glomerular filtration rate and prolong the time until patients on PD reach anuria, and this may improve mortality in these patients. In addition, RAAS blockade favorably affects the peritoneal membrane by reducing morphologic changes that can lead to ultrafiltration failure. This in turn may delay or prevent modality failure in patients on PD. Thus, clinicians should avoid the impulse to stop RAAS inhibitors in the PD population. © 2016 Wiley Periodicals, Inc.

Evaluation of subacute change in RAAS activity (as indicated by urinary aldosterone:creatinine, after pharmacologic provocation) and the response to ACE inhibition

PubMed Central

Ames, Marisa K; Atkins, Clarke E; Lantis, Andrea C; zum Brunnen, James

2016-01-01

Objective: The objective of this study was to evaluate subacute changes in renin–angiotensin–aldosterone system (RAAS) activity during angiotensin-converting enzyme inhibitor (ACEI) therapy in dogs with experimental RAAS activation. Methods: Analysis of data (urine aldosterone:creatinine ratio (UAldo:C) and serum angiotensin-converting enzyme activity), in 31 healthy dogs with furosemide or amlodipine-activated RAAS that received an ACEI. When furosemide or amlodipine activation of RAAS preceded ACEI administration, incomplete RAAS blockade (IRB) was defined as a UAldo:C greater than (a) the dog’s ‘activated’ baseline value or (b) a population-derived cut-off value (mean + 2 SD (>1.0 μg/g) of pretreatment UAldo:C from our population of research dogs). In studies where RAAS activation occurred concurrently with ACEIs, IRB was defined as (a) a UAldo:C greater than either twofold the dog’s prestimulation baseline value or (b) 1.0 µg/g. Dogs were followed for 7–17 days. Results: Serum angiotensin-converting enzyme activity was measured in 19 dogs and was significantly reduced (P<0.0001) after ACEI administration. The overall incidence of IRB, when RAAS activation preceded ACEI administration, was 33% and 8% for definitions (a) and (b), respectively. The overall incidence of IRB, when ACEIs were concurrent with RAAS activation, was 65% and 61% for definitions (a) and (b), respectively. Conclusion: Increases in UAldo:C, despite ACEI administration, is evidence of IRB in this subacute model of experimental RAAS activation and suppression. PMID:27009288

Blood Pressure Lowering and Safety Improvements With Liver Angiotensinogen Inhibition in Models of Hypertension and Kidney Injury.

PubMed

Mullick, Adam E; Yeh, Steve T; Graham, Mark J; Engelhardt, Jeffery A; Prakash, Thazha P; Crooke, Rosanne M

2017-09-01

Uncontrolled hypertension is an important contributor to cardiovascular disease. Despite the armamentarium of antihypertensive treatments, there remains a need for novel agents effective in individuals who cannot reach acceptable blood pressure levels. Inhibitors targeting the renin-angiotensin-aldosterone system (RAAS) are widely used but may not optimally inhibit RAAS and demonstrate an acceptable safety profile. Experiments were conducted to characterize a series of AGT (angiotensinogen) antisense oligonucleotides (ASOs) and compare their efficacy and tolerability to traditional RAAS blockade. AGT ASOs which target multiple systemic sites of AGT versus an N-acetylgalactosamine-conjugated AGT ASO that targets the liver were compared with captopril and losartan. Spontaneously hypertensive rats fed an 8% NaCl diet, a model of malignant hypertension resistant to standard RAAS inhibitors, demonstrated robust and durable blood pressure reductions with AGT ASO treatments, which was not observed with standard RAAS blockade. Studies in rat models of acute kidney injury produced by salt deprivation revealed kidney injury with ASO treatment that reduced kidney-expressed AGT, but not in animals treated with the N-acetylgalactosamine AGT ASO despite comparable plasma AGT reductions. Administration of either captopril or losartan also produced acute kidney injury during salt deprivation. Thus, intrarenal RAAS derived from kidney AGT, and inhibited by the standard of care, contributes to the maintenance of renal function during severe RAAS challenge. Such improvements in efficacy and tolerability by a liver-selective AGT inhibitor could be desirable in individuals not at their blood pressure goal with existing RAAS blockade. © 2017 American Heart Association, Inc.

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 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.

Advances in treatment of hyperkalemia in chronic kidney disease.

PubMed

Sarafidis, Pantelis A; Georgianos, Panagiotis I; Bakris, George L

2015-01-01

Hyperkalemia is a frequent electrolyte disorder associated with life-threatening cardiac arrhythmias and sudden death. Patients prone to hyperkalemia have chronic kidney disease (CKD) either alone or in conjunction with diabetes or heart failure (HF). Although agents inhibiting the renin-angiotensin-aldosterone-system (RAAS) are currently the first-line treatments toward cardio- and nephroprotection, their administration often leads to potassium elevation in such patients and results in high rates of treatment discontinuation. This article provides an overview of factors interfering with potassium homeostasis and discusses emerging potassium-lowering therapies for long-term management of hyperkalemia. In recent randomized clinical studies, two new oral potassium-exchanging compounds, patiromer and sodium zirconium cyclosilicate, were shown to effectively normalize elevated serum potassium and chronically maintain potassium homeostasis in hyperkalemic patients treated with RAAS blockers. Both agents exhibit good tolerability and were not associated with serious adverse effects. Although additional research is required, these drugs are promising for lowering the risk of incident hyperkalemia associated with RAAS blockade use in people with diabetes or HF who have CKD. They also provide the opportunity to test whether patients who could not previously receive RAAS blockade may benefit from their cardio- and renoprotective effects.

Revisiting RAAS blockade in CKD with newer potassium-binding drugs.

PubMed

Georgianos, Panagiotis I; Agarwal, Rajiv

2018-02-01

Among patients with proteinuric chronic kidney disease (CKD), current guideline recommendations mandate the use of agents blocking the renin angiotensin aldosterone system (RAAS) as first-line antihypertensive therapy based on randomized trials demonstrating that RAAS inhibitors are superior to other antihypertensive drug classes in slowing nephropathy progression to end-stage renal disease. However, the opportunities for adequate RAAS blockade in CKD are often limited, and an important impediment is the risk of hyperkalemia, especially when RAAS inhibitors are used in maximal doses or are combined. Accordingly, a large proportion of patients with proteinuric CKD may not have the anticipated renoprotective benefits since RAAS blockers are often discontinued due to incident hyperkalemia or are administered at suboptimal doses for fear of the development of hyperkalemia. Two newer potassium binders, patiromer and sodium zirconium cyclosilicate (ZS-9), have been shown to effectively and safely reduce serum potassium levels and maintain long-term normokalemia in CKD patients receiving background therapy with RAAS inhibitors. Whether these novel potassium-lowering therapies can overcome the barrier of hyperkalemia and enhance the tolerability of RAAS inhibitor use in proteinuric CKD awaits randomized trials. Published by Elsevier Inc.

Diuretic use, RAAS blockade and morbidity in elderly patients presenting to the Emergency Department with non-specific complaints.

PubMed

Ruedinger, Juliane M; Nickel, Christian H; Maile, Silke; Bodmer, Michael; Kressig, Reto W; Bingisser, Roland

2012-05-09

Up to 20% of elderly patients present to the emergency department (ED) with non-specific complaints (NSC), such as "generalised weakness", the majority suffering from serious conditions requiring timely intervention. Little is known about the use and influence of diuretics and renin-angiotensin-aldosterone (RAAS) blockade on morbidity in those patients. The hypothesis was tested that the use of diuretics and RAAS blockade could be associated with an increased incidence of serious conditions in those patients. During a 23-month period, all adult non-trauma patients with an Emergency Severity Index (ESI) of 2 or 3 were prospectively enrolled. Serious conditions were defined as potentially life-threatening conditions or conditions requiring early intervention to prevent further morbidity and mortality. Study population consisted of 633 patients with median age 82 years, median Charlson comorbidity index 2. 59% of all subjects suffered from a serious condition. 299 subjects (47.2%) used diuretics, of which 65.6% suffered from a serious condition. Combination therapy of RAAS blockade and diuretics was found in 158 subjects (24.9%), 70.3% of which suffered from a serious condition. The intake of two or more diuretics, loop diuretics and a combination therapy with diuretics and RAAS blockade were associated with an increased risk for serious condition (p = 0.036; p = 0.021; p = 0.004). Treatment with two or more diuretics, loop diuretics, or a combination therapy with RAAS blockade and diuretics are independently associated with serious condition and therefore should be recognized as "red flags" in elderly patients presenting to the ED with NSC.

[Dissociation of antihypertensive and metabolic response to losartan and spironolactone in experimental rats with metabolic sindrome].

PubMed

Machado, Hussen; Pinheiro, Helady Sanders; Terra, Marcella Martins; Guerra, Martha de Oliveira; de Paula, Rogerio Baumgratz; Peters, Vera Maria

2012-01-01

The treatment of arterial hypertension (AH) in patients with metabolic syndrome (MS) is a challenge, since non drug therapies are difficult to implement and optimal pharmacological treatment is not fully established. To assess the blockade of the rennin angiotensin aldosterone system (RAAS) in blood pressure (BP) in renal function and morphology in an experimental model of MS induced by high fat diet. Wistar rats were fed on high fat diet from the fourth week of life, for 20 weeks. The groups received Losartan or Spironolactone from the eighth week of life. We weekly evaluated the body weight and BP by tail plethysmography. At the end of the experiment oral glucose tolerance, lipid profile, creatinine clearance tests, and the direct measurement of BP were performed. A morphometric kidney analysis was performed. The administration of high-fat diet was associated with the development of MS, characterized by central fat accumulation, hypertension, hyperglycemia and hypertriglyceridemia. In this model there were no changes in renal histomorphometry. The blockade of angiotensin II (Ang II) receptor AT1 prevented the development of hypertension. The mineralocorticoid blockage did not have antihypertensive efficacy but was associated with reduction of abdominal fat. The dissociation of the antihypertensive response to the blockades of Ang II receptors and mineralocorticoid indicates the involvement of Ang II in the pathogenesis of hypertension associated with obesity. Reduction of central obesity with Spironolactone suggests the presence of mineralocorticoid adipogenic effect.

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.

Impact of aldosterone antagonists on the substrate for atrial fibrillation: Aldosterone promotes oxidative stress and atrial structural/electrical remodeling

PubMed Central

Mayyas, Fadia; Alzoubi, Karem H.; Van Wagoner, David R.

2014-01-01

Atrial fibrillation (AF), the most common cardiac arrhythmia, is an electrocardiographic description of a condition with multiple and complex underlying mechanisms. Oxidative stress is an important driver of structural remodeling that creates a substrate for AF. Oxidant radicals may promote increase of atrial oxidative damage, electrical and structural remodeling, and atrial inflammation. AF and other cardiovascular morbidities activate angiotensin (Ang-II)-dependent and independent cascades. A key component of the renin–angiotensin-aldosterone system (RAAS) is the mineralocorticoid aldosterone. Recent studies provide evidence of myocardial aldosterone synthesis. Aldosterone promotes cardiac oxidative stress, inflammation and structural/electrical remodeling via multiple mechanisms. In HF patients, aldosterone production is enhanced. In patients and in experimental HF and AF models, aldosterone receptor antagonists have favorable influences on cardiac remodeling and oxidative stress. Therapeutic approaches that seek to reduce AF burden by modulating the aldosterone system are likely beneficial but underutilized. PMID:23993726

Mineralocorticoid receptor antagonism treats obesity-associated cardiac diastolic dysfunction.

PubMed

Bender, Shawn B; DeMarco, Vincent G; Padilla, Jaume; Jenkins, Nathan T; Habibi, Javad; Garro, Mona; Pulakat, Lakshmi; Aroor, Annayya R; Jaffe, Iris Z; Sowers, James R

2015-05-01

Patients with obesity and diabetes mellitus exhibit a high prevalence of cardiac diastolic dysfunction (DD), an independent predictor of cardiovascular events for which no evidence-based treatment exists. In light of renin-angiotensin-aldosterone system activation in obesity and the cardioprotective action of mineralocorticoid receptor (MR) antagonists in systolic heart failure, we examined the hypothesis that MR blockade with a blood pressure-independent low-dose spironolactone (LSp) would treat obesity-associated DD in the Zucker obese (ZO) rat. Treatment of ZO rats exhibiting established DD with LSp normalized cardiac diastolic function, assessed by echocardiography. This was associated with reduced cardiac fibrosis, but not reduced hypertrophy, and restoration of endothelium-dependent vasodilation of isolated coronary arterioles via a nitric oxide-independent mechanism. Further mechanistic studies revealed that LSp reduced cardiac oxidative stress and improved endothelial insulin signaling, with no change in arteriolar stiffness. Infusion of Sprague-Dawley rats with the MR agonist aldosterone reproduced the DD noted in ZO rats. In addition, improved cardiac function in ZO-LSp rats was associated with attenuated systemic and adipose inflammation and an anti-inflammatory shift in cardiac immune cell mRNAs. Specifically, LSp increased cardiac markers of alternatively activated macrophages and regulatory T cells. ZO-LSp rats had unchanged blood pressure, serum potassium, systemic insulin sensitivity, or obesity-associated kidney injury, assessed by proteinuria. Taken together, these data demonstrate that MR antagonism effectively treats established obesity-related DD via blood pressure-independent mechanisms. These findings help identify a particular population with DD that might benefit from MR antagonist therapy, specifically patients with obesity and insulin resistance. © 2015 American Heart Association, Inc.

CCR2 antagonism leads to marked reduction in proteinuria and glomerular injury in murine models of focal segmental glomerulosclerosis (FSGS)

PubMed Central

Miao, Zhenhua; Ertl, Linda S.; Newland, Dale; Zhao, Bin; Wang, Yu; Zang, Xiaoping; Campbell, James J.; Liu, Xiaoli; Dang, Ton; Miao, Shichang; Krasinski, Antoni; Punna, Sreenivas; Zeng, Yibin; McMahon, Jeffrey; Zhang, Penglie; Charo, Israel F.; Schall, Thomas J.

2018-01-01

Focal segmental glomerulosclerosis (FSGS) comprises a group of uncommon disorders that present with marked proteinuria, nephrotic syndrome, progressive renal failure and characteristic glomerular lesions on histopathology. The current standard of care for patients with FSGS include immunosuppressive drugs such as glucocorticoids followed by calcineurin inhibitors, if needed for intolerance or inadequate response to glucocorticoids. Renin-angiotensin-aldosterone (RAAS) blockers are also used to control proteinuria, an important signature of FSGS. Existing treatments, however, achieved only limited success. Despite best care, treatment failure is common and FSGS is causal in a significant proportion of end stage renal disease. Thus, an unmet need exists for novel disease modifying treatments for FSGS. We employed two widely-used murine models of FSGS to test the hypothesis that systemic inhibition of chemokine receptor CCR2 would have therapeutic benefit. Here we report that administration CCX872, a potent and selective small molecule antagonist of CCR2, achieved rapid and sustained attenuation of renal damage as determined by urine albumin excretion and improved histopathological outcome. Therapeutic benefit was present when CCX872 was used as a single therapy, and moreover, the combination of CCX872 and RAAS blockade was statistically more effective than RAAS blockade alone. In addition, the combination of CCR2 and RAAS blockade was equally as effective as endothelin receptor inhibition. We conclude that specific inhibition of CCR2 is effective in the Adriamycin-induced and 5/6 nephrectomy murine models of FSGS, and thus holds promise as a mechanistically distinct therapeutic addition to the treatment of human FSGS. PMID:29561839

Renin-angiotensin-aldosterone-blockade is associated with decreased use of antidepressant therapy in patients with type 1 diabetes and diabetic nephropathy.

PubMed

Ahola, Aila J; Harjutsalo, Valma; Forsblom, Carol; Groop, Per-Henrik

2014-08-01

Hypertension and depression are frequent comorbidities of diabetes. Studies suggest that antihypertensive medication affecting the renin-angiotensin-aldosterone system (RAAS) might also relieve depression. Whether this is also seen in patients with type 1 diabetes is not known. We therefore studied whether use of RAAS-modifying medication is associated with reduced antidepressant use in type 1 diabetes. In all, 1,705 participants in the FinnDiane Study were included (57 % men, mean age 46 ± 11 years). Data on medications were obtained from the Drug Prescription Register. Based on their albumin excretion rate (AER), the patients were classified as having normal AER, microalbuminuria, or macroalbuminuria. Diabetic nephropathy was defined as macroalbuminuria or end-stage renal disease (dialysis or renal transplant). A total of 8.4 and 10.9 % of patients with and without RAAS-modifying medication, respectively, had antidepressant medication purchases (NS). In logistic regression analysis, after adjusting for potential confounding factors, use of RAAS-modifying medication was not associated with antidepressant purchases. However, when patients with and without diabetic nephropathy were analyzed separately, RAAS-modifying medication was associated with lower frequency of antidepressant purchases among patients with established diabetic nephropathy. In conclusion, use of RAAS-modifying medication may improve mood in patients with type 1 diabetes and established diabetic nephropathy.

[Lights and shadows on single and dual RAAS blockade].

PubMed

Cavalli, Andrea; Del Vecchio, Lucia; Locatelli, Francesco

2010-01-01

Angiotensin-converting enzyme inhibitors (ACE-i) and angiotensin II receptor blockers (ARBs) are of paramount importance in everyday clinical practice. Developed as antihypertensive drugs, they soon acquired another important indication as a result of their antiproteinuric activity and capacity to delay the progression of chronic kidney disease. ACE-i and ARBs started out being used as single drugs and were subsequently combined to obtain more complete blocking of the renin-angiotensin-aldosterone system (RAAS). The most evident advantages derived from the administration of these drugs - alone or in combination - have been obtained in proteinuric nephropathies, such as chronic glomerulonephritis and diabetic nephropathy, where they have become the treatment choice. Dual RAAS blockade has been recently evaluated in a large trial of high-risk cardiovascular patients, in whom no related benefits were shown. To the contrary, a higher risk of worsening renal function emerged. It is now quite clear that patients with high proteinuria levels are the ones that benefit most from RAAS inhibition, also with combined ACE-i and ARB. It is very important to pay the utmost attention when these drugs are used in patients in whom no benefit is obtained by RAAS inhibition, such as patients with chronic kidney disease and atherosclerosis, elderly patients, and those without any significant proteinuria.

Therapies on the Horizon for Diabetic Kidney Disease.

PubMed

Khan, Sadaf S; Quaggin, Susan E

2015-12-01

Diabetic nephropathy is rapidly becoming the major cause of end-stage renal disease and cardiovascular mortality worldwide. Standard of care therapies include strict glycemic control and blockade of the renin-angiotensin-aldosterone axis. While these treatments slow progression of diabetic nephropathy, they do not arrest or reverse it. Newer therapies targeting multiple molecular pathways involved in renal inflammation, fibrosis, and oxidative stress have shown promise in animal models. Subsequently, many of these agents have been investigated in clinical human trials with mixed results. In this review, we will discuss recent findings of novel agents used in the treatment of diabetic nephropathy.

Current role of neprilysin inhibitors in hypertension and heart failure.

PubMed

von Lueder, Thomas G; Atar, Dan; Krum, Henry

2014-10-01

Cardiovascular diseases (CVD) continue to represent the major cause of death, morbidity and healthcare expenditure worldwide. Current medical therapy fails to effectively halt disease progression and to reduce adverse clinical outcomes, reflecting incomplete understanding of pathomechanisms as well as the need to expand current pharmacotherapeutic strategies. Hypertension and heart failure, the most important CVD entities, are associated with imbalance in neurohormonal systems activity such as the renin-angiotensin-aldosterone system (RAAS), the sympathetic nervous system and the endothelin system. Blockade of the RAAS constitutes the most successful pharmacotherapeutic concept in hypertension and heart failure to date. The RAAS-opposing natriuretic peptide system constitutes the body's own BP-lowering system, and mediates a multitude of beneficial actions within cardiovascular tissues. The metallopeptidase neprilysin (NEP) hydrolyzes natriuretic peptides. Conceptually, NEP inhibition would increase salutary natriuretic peptide actions in CVD. However, stand-alone NEP inhibitors (NEPi) lacked efficacy beyond standard pharmacotherapy. Combined blockers of NEP and the endothelin system demonstrated efficacy in preclinical studies but have not been evaluated in clinical trials. A decade ago, omapatrilat and other dual-acting NEPi-ACEi (vasopeptidase-inhibitors) were promising agents for hypertension and heart failure. Despite greater efficacy, development of vasopeptidase-inhibitors was halted due to significant off-target effects in some cohorts, most notably increased frequency of angioedema in hypertensive subjects. Novel angiotensin-receptor-neprilysin-inhibitors (ARNi) seek to fully exploit clinical efficacy of combined RAAS-blockade and NEPi-mediated natriuretic peptide augmentation, and hopefully do so with improved clinical safety. We herein review current knowledge of NEPi as stand-alone and combined pharmacotherapeutic agents in hypertension and heart failure. Copyright © 2014. Published by Elsevier Inc.

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.

Hypertension in pediatric patients with chronic kidney disease: management challenges.

PubMed

Gallibois, Claire M; Jawa, Natasha A; Noone, Damien G

2017-01-01

In contrast to adults where hypertension is a leading cause of chronic kidney disease, in pediatrics, hypertension is predominantly a sequela, however, an important one that, like in adults, is likely associated with a more rapid decline in kidney function or progression of chronic kidney disease to end stage. There is a significant issue with unrecognized, or masked, hypertension in childhood chronic kidney disease. Recent evidence and, therefore, guidelines now suggest targeting a blood pressure of <50th percentile for age, sex, and height in children with proteinuria and chronic kidney disease. This often cannot be achieved by monotherapy and additional agents need to be added. Blockade of the renin angiotensin aldosterone system represents the mainstay of therapy, although often limited by the side effect of hyperkalemia. The addition of a diuretic, at least in the earlier stages of chronic kidney disease, might help mitigate this problem.

Candesartan: widening indications for this angiotensin II receptor blocker?

PubMed

Mendis, B; Page, S R

2009-08-01

Candesartan cilexetil is one of a number of drugs of the angiotensin II receptor blocker (ARB) class. Their principal mode of action involves competitive blockade of the angiotensin II type 1 receptor, thereby modulating the activity of the rennin-angiotensin-aldosterone system. Angiotensin II receptor blocker therapy has been proven to be well tolerated and effective in the management of hypertension, chronic heart failure with left ventricular dysfunction and the prevention and progression of diabetic renal disease. Candesartan is a highly potent, long-acting and selective angiotensin II type 1 receptor blocker. It was launched in 1998 for the treatment of hypertension. Its use has increased dramatically, with recently published data suggesting benefit in the treatment of stroke, heart failure, diabetic renal disease and most recently in preventing the development of or delaying the progression of diabetic retinopathy. In this article we review the literature on the use of ARB drugs in general before focusing on candesartan.

RAAS inhibition and renal protection.

PubMed

Leoncini, Giovanna; Giovanna, Leoncini; Viazzi, Francesca; Francesca, Viazzi; Pontremoli, Roberto; Roberto, Pontremoli

2012-01-01

Chronic kidney disease has become a major public health problem worldwide mainly as a consequence of the emerging epidemic of hypertension, diabetes, and obesity. It is currently estimated that nearly 15% of the general population has some degree of renal damage, a figure that reaches 50% in at-risk subgroups. Renin-angiotensin-aldosterone system (RAAS) inhibitors represent the agents of choice to control hypertension and reduce urinary albumin excretion, thereby delaying renal function deterioration. Greater blockade of the RAAS either by the combined use of multiple drugs or by supramaximal doses of single agents may provide greater renal protection. Furthermore, it has been proposed especially in the presence of proteinuria. However, at this time there is insufficient evidence to routinely recommend this therapeutic approach in patients with chronic kidney disease. The present article examines the currently available evidence and practical implications of pharmacological disruption of RAAS activity for renal protection.

RAAS-mediated Redox effects in Chronic Kidney Disease

PubMed Central

Nistala, Ravi; Wei, Yongzhong; Sowers, James R; Whaley-Connell, Adam

2009-01-01

The renin-angiotensin-aldosterone-system (RAAS) is central to the pathogenesis of hypertension, cardiovascular and kidney disease. Emerging evidence support various pathways through which a local renal RAAS can affect kidney function, hypertension, and cardiovascular disease. A prominent mechanism appears to be loss of redox homeostasis and formation of excessive free radicals. Free radicals such as reactive oxygen species (ROS) are necessary in normal physiologic processes including development of nephrons, erythropoeisis and tubular sodium transport. However, loss of redox homeostasis contributes to pro-inflammatory and pro-fibrotic pathways in the kidney that in turn lead to reduced vascular compliance, podocyte pathology and proteinuria. Both blockade of the RAAS and oxidative stress produces salutary effects on hypertension and glomerular filtration barrier injury. Thus, the focus of current research is on understanding the pathophysiology of chronic kidney disease in the context of an elevated RAAS and unbalanced redox mechanisms. PMID:19218092

Elevated N-terminal pro-brain natriuretic peptide levels predict an enhanced anti-hypertensive and anti-proteinuric benefit of dietary sodium restriction and diuretics, but not angiotensin receptor blockade, in proteinuric renal patients.

PubMed

Slagman, Maartje C J; Waanders, Femke; Vogt, Liffert; Damman, Kevin; Hemmelder, Marc; Navis, Gerjan; Laverman, Gozewijn D

2012-03-01

Renin-angiotensin aldosterone system (RAAS) blockade only partly reduces blood pressure, proteinuria and renal and cardiovascular risk in chronic kidney disease (CKD) but often requires sodium targeting [i.e. low sodium diet (LS) and/or diuretics] for optimal efficacy. However, both under- and overtitration of sodium targeting can easily occur. We evaluated whether N-terminal pro-brain natriuretic peptide (NT-proBNP), a biomarker of volume expansion, predicts the benefits of sodium targeting in CKD patients. In a cross-over randomized controlled trial, 33 non-diabetic CKD patients (proteinuria 3.8 ± 0.4 g/24 h, blood pressure 143/86 ± 3/2 mmHg, creatinine clearance 89 ± 5 mL/min) were treated during 6-week periods with placebo, angiotensin receptor blockade (ARB; losartan 100 mg/day) and ARB plus diuretics (losartan 100 mg/day plus hydrochlorothiazide 25 mg/day), combined with LS (93 ± 52 mmol Na(+)/24 h) and regular sodium diet (RS; 193 ± 62 mmol Na(+)/24 h, P < 0.001 versus LS), in random order. As controls, 27 healthy volunteers were studied. NT-proBNP was elevated in patients during placebo + RS [90 (60-137) versus 35 (27-45) pg/mL in healthy controls, P = 0.001]. NT-proBNP was lowered by LS, ARB and diuretics and was normalized by ARB + diuretic + LS [39 (26-59) pg/mL, P = 0.65 versus controls]. NT-proBNP levels above the upper limit of normal (>125 pg/mL) predicted a larger reduction of blood pressure and proteinuria by LS and diuretics but not by ARB, during all steps of the titration regimen. Elevated NT-proBNP levels predict an enhanced anti-hypertensive and anti-proteinuric benefit of sodium targeting, but not RAAS blockade, in proteinuric CKD patients. Importantly, this applies to the untreated condition, as well as to the subsequent treatment steps, consisting of RAAS blockade and even RAAS blockade combined with diuretics. NT-proBNP can be a useful tool to identify CKD patients in whom sodium targeting can improve blood pressure and proteinuria.

Long-term blockade of L/N-type Ca2+ channels by cilnidipine ameliorates repolarization abnormality of the canine hypertrophied heart

PubMed Central

Takahara, A; Nakamura, Y; Wagatsuma, H; Aritomi, S; Nakayama, A; Satoh, Y; Akie, Y; Sugiyama, A

2009-01-01

Background and purpose: The heart of the canine model of chronic atrioventricular block is known to have a ventricular electrical remodelling, which mimics the pathophysiology of long QT syndrome. Using this model, we explored a new pharmacological therapeutic strategy for the prevention of cardiac sudden death. Experimental approach: The L-type Ca2+ channel blocker amlodipine (2.5 mg·day−1), L/N-type Ca2+ channel blocker cilnidipine (5 mg·day−1), or the angiotensin II receptor blocker candesartan (12 mg·day−1) was administered orally to the dogs with chronic atrioventricular block for 4 weeks. Electropharmacological assessments with the monophasic action potential (MAP) recordings and blood sample analyses were performed before and 4 weeks after the start of drug administration. Key results: Amlodipine and cilnidipine decreased the blood pressure, while candesartan hardly affected it. The QT interval, MAP duration and beat-to-beat variability of the ventricular repolarization period were shortened only in the cilnidipine group, but such effects were not observed in the amlodipine or candesartan group. Plasma concentrations of adrenaline, angiotensin II and aldosterone decreased in the cilnidipine group. In contrast, plasma concentrations of angiotensin II and aldosterone were elevated in the amlodipine group, whereas in the candesartan group an increase in plasma levels of angiotensin II and a decrease in noradrenaline and adrenaline concentrations were observed. Conclusions and implications: Long-term blockade of L/N-type Ca2+ channels ameliorated the ventricular electrical remodelling in the hypertrophied heart which causes the prolongation of the QT interval. This could provide a novel therapeutic strategy for the treatment of cardiovascular diseases. PMID:19785655

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.

RAAS Activation Is Associated With Visceral Adiposity and Insulin Resistance Among HIV-infected Patients.

PubMed

Srinivasa, Suman; Fitch, Kathleen V; Wong, Kimberly; Torriani, Martin; Mayhew, Caitlin; Stanley, Takara; Lo, Janet; Adler, Gail K; Grinspoon, Steven K

2015-08-01

Little is known about renin-angiotensin-aldosterone system (RAAS) activation in relationship to visceral adipose tissue (VAT) accumulation in HIV-infected patients, a population at significant risk for insulin resistance and other metabolic disease. Twenty HIV and 10 non-HIV-infected subjects consumed a standardized low sodium or liberal sodium diet to stimulate or suppress the RAAS, respectively. RAAS parameters were evaluated in response to each diet and a graded angiotensin II infusion. Further analyses were performed after groups were substratified by median VAT measured by magnetic resonance imaging. Aldosterone concentrations during the low-sodium diet were higher in HIV than non-HIV-infected subjects [13.8 (9.7, 30.9) vs 9.2 (7.6, 13.6) ng/dL, P = .03] and increased across groups stratified by visceral adipose tissue (VAT) [8.5 (7.1, 12.8), 9.2 (8.1, 21.5), 11.4 (9.4, 13.8), and 27.2 (13.0, 36.9) ng/dL in non-HIV-infected without increased VAT, non-HIV-infected with increased VAT, HIV-infected without increased VAT, HIV-infected with increased VAT, respectively, overall trend P = .02]. Under this condition, plasma renin activity [3.50 (2.58, 4.65) vs 1.45 (0.58, 2.33) ng/mL · h, P = .002] was higher among the HIV-infected subjects with vs without increased VAT. Differences in the suppressibility of plasma renin activity by graded angiotensin infusion were seen stratifying by VAT among the HIV-infected group (P < .02 at each dose). In addition, aldosterone (P = .007) was an independent predictor of insulin resistance in multivariate modeling, controlling for VAT and adiponectin. These data suggest excess RAAS activation in relationship to visceral adiposity in HIV-infected patients that may independently contribute to insulin resistance. Mineralocorticoid blockade may have therapeutic potential to reduce metabolic complications in HIV-infected patients with increased visceral adiposity.

RAAS Activation Is Associated With Visceral Adiposity and Insulin Resistance Among HIV-infected Patients

PubMed Central

Srinivasa, Suman; Fitch, Kathleen V.; Wong, Kimberly; Torriani, Martin; Mayhew, Caitlin; Stanley, Takara; Lo, Janet; Adler, Gail K.

2015-01-01

Context: Little is known about renin-angiotensin-aldosterone system (RAAS) activation in relationship to visceral adipose tissue (VAT) accumulation in HIV-infected patients, a population at significant risk for insulin resistance and other metabolic disease. Design: Twenty HIV and 10 non-HIV-infected subjects consumed a standardized low sodium or liberal sodium diet to stimulate or suppress the RAAS, respectively. RAAS parameters were evaluated in response to each diet and a graded angiotensin II infusion. Further analyses were performed after groups were substratified by median VAT measured by magnetic resonance imaging. Results: Aldosterone concentrations during the low-sodium diet were higher in HIV than non-HIV-infected subjects [13.8 (9.7, 30.9) vs 9.2 (7.6, 13.6) ng/dL, P = .03] and increased across groups stratified by visceral adipose tissue (VAT) [8.5 (7.1, 12.8), 9.2 (8.1, 21.5), 11.4 (9.4, 13.8), and 27.2 (13.0, 36.9) ng/dL in non-HIV-infected without increased VAT, non-HIV-infected with increased VAT, HIV-infected without increased VAT, HIV-infected with increased VAT, respectively, overall trend P = .02]. Under this condition, plasma renin activity [3.50 (2.58, 4.65) vs 1.45 (0.58, 2.33) ng/mL · h, P = .002] was higher among the HIV-infected subjects with vs without increased VAT. Differences in the suppressibility of plasma renin activity by graded angiotensin infusion were seen stratifying by VAT among the HIV-infected group (P < .02 at each dose). In addition, aldosterone (P = .007) was an independent predictor of insulin resistance in multivariate modeling, controlling for VAT and adiponectin. Conclusion: These data suggest excess RAAS activation in relationship to visceral adiposity in HIV-infected patients that may independently contribute to insulin resistance. Mineralocorticoid blockade may have therapeutic potential to reduce metabolic complications in HIV-infected patients with increased visceral adiposity. PMID:26086328

Mineralocorticoid receptor blockade in addition to angiotensin converting enzyme inhibitor or angiotensin II receptor blocker treatment: an emerging paradigm in diabetic nephropathy: a systematic review.

PubMed

Mavrakanas, Thomas A; Gariani, Karim; Martin, Pierre-Yves

2014-02-01

Blockade of the renin-angiotensin-aldosterone system (RAAS) is a standard therapeutic intervention in diabetic patients with chronic kidney disease (CKD). Concomitant mineralocorticoid receptor blockade has been studied as a novel approach to further slow down CKD progression. We used PubMed and EMBASE databases to search for relevant literature. We included in our review eight studies in patients of at least 18 years of age, with a diagnosis of type 1 or type 2 diabetes mellitus and diabetic nephropathy, under an angiotensin converting enzyme inhibitor (ACEI) and/or an angiotensin II receptor blocker (ARB) as standard treatment. A subset of patients in each study also received a mineralocorticoid receptor blocker (MRB) (either spironolactone or eplerenone) in addition to standard treatment. Combined treatment with a mineralocorticoid receptor blocker further reduced albuminuria by 23 to 61% compared with standard treatment. Estimated glomerular filtration rate values upon study completion slightly decreased under combined treatment. Blood pressure levels upon study completion were significantly lower with combined treatment in three studies. Hyperkalemia prevalence increased in patients under combined treatment raising dropout rate up to 17%. Therefore, combined treatment by an ACEI/ARB and a MRB may further decrease albuminuria in diabetic nephropathy. This effect may be due to the specific properties of the MRB treatment. Clinicians should regularly check potassium levels because of the increased risk of hyperkalemia. Available evidence should be confirmed by an adequately powered comparative trial of the standard treatment (ACEI or ARB) versus combined treatment by an ACEI/ARB and a MRB. Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

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

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.

Predominance of AT1 Blockade Over Mas–Mediated Angiotensin-(1–7) Mechanisms in the Regulation of Blood Pressure and Renin–Angiotensin System in mRen2.Lewis Rats

PubMed Central

2013-01-01

BACKGROUND We investigated whether the antihypertensive actions of the angiotensin II (Ang II) receptor (AT1-R) blocker, olmesartan medoxomil, may in part be mediated by increased Ang-(1–7) in the absence of significant changes in plasma Ang II. METHODS mRen2.Lewis congenic hypertensive rats were administered either a vehicle (n = 14) or olmesartan (0.5mg/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 (0.5mg/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. RESULTS 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. CONCLUSIONS Our study highlights the independent regulation of RAS among plasma, heart, and kidney tissue in response to AT1-R blockade. Ang-(1–7) through the mas receptor does not mediate long-term effects of olmesartan besides counterbalancing renin release in response to AT1-R blockade. PMID:23459599

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

Interleukin-33/ST2 system attenuates aldosterone-induced adipogenesis and inflammation.

PubMed

Martínez-Martínez, Ernesto; Cachofeiro, Victoria; Rousseau, Elodie; Álvarez, Virginia; Calvier, Laurent; Fernández-Celis, Amaya; Leroy, Céline; Miana, María; Jurado-López, Raquel; Briones, Ana M; Jaisser, Frederic; Zannad, Faiez; Rossignol, Patrick; López-Andrés, Natalia

2015-08-15

Interleukin-33 (IL-33) but not soluble ST2 (sST2) exerts anti-inflammatory and protective effects in several tissues. Aldosterone, a proinflammatory mediator which promotes adipogenesis, is elevated in obese patients. The aim of this study was to investigate the interactions between IL-33/ST2 system and Aldosterone in adipose tissue. Rats fed a high fat diet presented increased sST2 expression, diminished IL-33/sST2 ratio and enhanced levels of differentiation and inflammation in adipose tissue as compared to controls. A similar pattern was observed in adipose tissue from C57BL/6 Aldosterone-treated mice. In both animal models, Aldosterone was correlated with sST2. Treatment of 3T3-L1 adipocytes with IL-33 delayed adipocyte differentiation diminished lipid accumulation and decreased inflammation. Aldosterone decreased IL-33 and increased sST2 expressions in differentiated adipocytes. Aldosterone-induced adipocyte differentiation and inflammation were blocked by IL-33 treatment, but sST2 did not exert any effects. The crosstalk between IL-33/ST2 and Aldosterone could be relevant in the metabolic consequences of obesity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sacubitril/valsartan: An important piece in the therapeutic puzzle of heart failure.

PubMed

Marques da Silva, Pedro; Aguiar, Carlos

2017-09-01

Sacubitril/valsartan (LCZ696), a supramolecular sodium salt complex of the neprilysin inhibitor prodrug sacubitril and the angiotensin receptor blocker (ARB) valsartan, was recently approved in the EU and the USA for the treatment of chronic heart failure (HF) with reduced ejection fraction (HFrEF) (NYHA class II-IV). Inhibition of chronically activated neurohormonal pathways (the renin-angiotensin-aldosterone system [RAAS] and sympathetic nervous system [SNS]) is central to the treatment of chronic HFrEF. Furthermore, enhancement of the natriuretic peptide (NP) system, with favorable cardiovascular (CV) and renal effects in HF, is a desirable therapeutic goal to complement RAAS and SNS blockade. Sacubitril/valsartan represents a novel pharmacological approach that acts by enhancing the NP system via inhibition of neprilysin (an enzyme that degrades NPs) and by suppressing the RAAS via AT1 receptor blockade, thereby producing more effective neurohormonal modulation than can be achieved with RAAS inhibition alone. In the large, randomized, double-blind PARADIGM-HF trial, replacement of an angiotensin-converting enzyme inhibitor (ACEI) (enalapril) with sacubitril/valsartan resulted in a significant improvement in morbidity and mortality in patients with HFrEF. Sacubitril/valsartan was superior to enalapril in reducing the risk of CV death or HF hospitalization (composite primary endpoint) and all-cause death, and in limiting progression of HF. Sacubitril/valsartan was generally well tolerated, with a comparable safety profile to enalapril; symptomatic hypotension was more common with sacubitril/valsartan, whereas renal dysfunction, hyperkalemia and cough were less common compared with enalapril. In summary, sacubitril/valsartan is a superior alternative to ACEIs/ARBs in the treatment of HFrEF, a recommendation that is reflected in many HF guidelines. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Association of Circulating Renin and Aldosterone With Osteocalcin and Bone Mineral Density in African Ancestry Families.

PubMed

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

2016-05-01

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 and relative pairs: 1687). Participants underwent a clinical examination, dual-energy x-ray absorptiometry, and quantitative computed tomographic scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone/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, comorbidities, 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/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 biological mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. © 2016 American Heart Association, Inc.

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

Acute and Chronic Regulation of Aldosterone Production

PubMed Central

Hattangady, Namita; Olala, Lawrence; Bollag, Wendy B.; Rainey, William E.

2011-01-01

Aldosterone is the major mineralocorticoid synthesized by the adrenal. Secretion of aldosterone is regulated tightly by the adrenocortical glomerulosa cells due to the selective expression of CYP11B2 in the outermost zone, the zona glomerulosa. Aldosterone is largely responsible for regulation of systemic blood pressure through the absorption of electrolytes and water under the regulation of certain specific agonists. Angiotensin II (Ang II), potassium (K+) and adrenocorticotropin (ACTH) are the main physiological agonists which regulate aldosterone secretion. The mechanisms involved in this process may be regulated minutes after a stimulus (acutely) through increased expression and phosphorylation of the steroidogenic acute regulatory (StAR) protein, over hours to days (chronically) by increased expression of the enzymes involved in the synthesis of aldosterone, particularly aldosterone synthase (CYP11B2). Imbalance in any of these processes may lead to several aldosterone excess disorders. In this review we attempt to summarize the key molecular events involved in and specifically attributed to the acute and chronic phases of aldosterone secretion. PMID:21839803

The HALT Polycystic Kidney Disease Trials: Design and Implementation

PubMed Central

Torres, Vicente E.; Perrone, Ronald D.; Steinman, Theodore I.; Bae, Kyongtae T.; Miller, J. Philip; Miskulin, Dana C.; Oskoui, Frederic Rahbari; Masoumi, Amirali; Hogan, Marie C.; Winklhofer, Franz T.; Braun, William; Thompson, Paul A.; Meyers, Catherine M.; Kelleher, Cass; Schrier, Robert W.

2010-01-01

Background and objectives: Two HALT PKD trials will investigate interventions that potentially slow kidney disease progression in hypertensive autosomal dominant polycystic kidney disease (ADPKD) patients. Studies were designed in early and later stages of ADPKD to assess the impact of intensive blockade of the renin-angiotensin-aldosterone system and level of BP control on progressive renal disease. Design, settings, participants, and measurements: PKD-HALT trials are multicenter, randomized, double-blind, placebo-controlled trials studying 1018 hypertensive ADPKD patients enrolled over 3 yr with 4 to 8 yr of follow-up. In study A, 548 participants, estimated GFR (eGFR) of >60 ml/min per 1.73 m2 were randomized to one of four arms in a 2-by-2 design: combination angiotensin converting enzyme inhibitor (ACEi) and angiotensin receptor blocker (ARB) therapy versus ACEi monotherapy at two levels of BP control. In study B, 470 participants, eGFR of 25 to 60 ml/min per 1.73 m2 compared ACEi/ARB therapy versus ACEi monotherapy, with BP control of 120 to 130/70 to 80 mmHg. Primary outcomes of studies A and B are MR-based percent change kidney volume and a composite endpoint of time to 50% reduction of baseline estimated eGFR, ESRD, or death, respectively. Results: This report describes design issues related to (1) novel endpoints such as kidney volume, (2) home versus office BP measures, and (3) the impact of RAAS inhibition on kidney and patient outcomes, safety, and quality of life. Conclusions: HALT PKD will evaluate potential benefits of rigorous BP control and inhibition of the renin-angiotensin-aldosterone system on kidney disease progression in ADPKD. PMID:20089507

Exploring metabolic dysfunction in chronic kidney disease

PubMed Central

2012-01-01

Impaired kidney function and chronic kidney disease (CKD) leading to kidney failure and end-stage renal disease (ESRD) is a serious medical condition associated with increased morbidity, mortality, and in particular cardiovascular disease (CVD) risk. CKD is associated with multiple physiological and metabolic disturbances, including hypertension, dyslipidemia and the anorexia-cachexia syndrome which are linked to poor outcomes. Specific hormonal, inflammatory, and nutritional-metabolic factors may play key roles in CKD development and pathogenesis. These include raised proinflammatory cytokines, such as interleukin-1 and −6, tumor necrosis factor, altered hepatic acute phase proteins, including reduced albumin, increased C-reactive protein, and perturbations in normal anabolic hormone responses with reduced growth hormone-insulin-like growth factor-1 axis activity. Others include hyperactivation of the renin-angiotensin aldosterone system (RAAS), with angiotensin II and aldosterone implicated in hypertension and the promotion of insulin resistance, and subsequent pharmacological blockade shown to improve blood pressure, metabolic control and offer reno-protective effects. Abnormal adipocytokine levels including leptin and adiponectin may further promote the insulin resistant, and proinflammatory state in CKD. Ghrelin may be also implicated and controversial studies suggest activities may be reduced in human CKD, and may provide a rationale for administration of acyl-ghrelin. Poor vitamin D status has also been associated with patient outcome and CVD risk and may indicate a role for supplementation. Glucocorticoid activities traditionally known for their involvement in the pathogenesis of a number of disease states are increased and may be implicated in CKD-associated hypertension, insulin resistance, diabetes risk and cachexia, both directly and indirectly through effects on other systems including activation of the mineralcorticoid receptor. Insight into the multiple factors altered in CKD may provide useful information on disease pathogenesis, clinical assessment and treatment rationale such as potential pharmacological, nutritional and exercise therapies. PMID:22537670

Renin-angiotensin II-aldosterone system blockers and time to renal replacement therapy in children with CKD.

PubMed

Abraham, Alison G; Betoko, Aisha; Fadrowski, Jeffrey J; Pierce, Christopher; Furth, Susan L; Warady, Bradley A; Muñoz, Alvaro

2017-04-01

Clinical care decisions to treat chronic kidney disease (CKD) in a growing child must often be made without the benefit of evidence from clinical trials. We used observational data from the Chronic Kidney Disease in Children cohort to estimate the effectiveness of renin-angiotensin II-aldosterone system blockade (RAAS) to delay renal replacement therapy (RRT) in children with CKD. A total of 851 participants (median age: 11 years, median glomerular filtration rate [GFR]: 52 ml/min/1.73 m 2 , median urine protein to creatinine ratio: 0.35 mg/mg) were included. RAAS use was reported at annual study visits. Both Cox proportional hazards models with time-varying RAAS exposure and Cox marginal structural models (MSM) were used to evaluate the effect of RAAS use on time to RRT. Analyses were adjusted or weighted to control for age, male sex, glomerular diagnosis, GFR, nephrotic range proteinuria, anemia, elevated blood pressure, acidosis, elevated phosphate and elevated potassium. There were 217 RRT events over a 4.1-year median follow-up. At baseline, 472 children (55 %) were prevalent RAAS users, who were more likely to be older, have a glomerular etiology, have higher urine protein, be anemic, have elevated serum phosphate and potassium, take more medications, but less likely to have elevated blood pressure, compared with non-users. RAAS use was found to reduce the risk of RRT by 21 % (hazard ratio: 0.79) to 37 % (hazard ratio: 0.63) from standard regression adjustment and MSM models, respectively. These results support inferences from adult studies of a substantial benefit of RAAS use in pediatric CKD patients.

Effects of aldosterone blockade on left ventricular function and clinical status during acute myocardial infarction.

PubMed

Uzunhasan, Isil; Yildiz, Ahmet; Coskun, Ugur; Kalyoncuoglu, Muhsin; Baskurt, Murat; Cakar, Mehmet Akif; Kaya, Aysem; Pehlivanoglu, Seckin; Enar, Rasim; Okcun, Baris

2009-01-01

Heart failure is frequently a serious complication of acute myocardial infarction (AMI). ACE inhibitors, Angiotensin II receptor blockers, beta-blockers and aldosterone receptor blockers have been shown to improve outcomes in this setting. This study aimed to determine the effect of spironolactone on the frequency of clinical heart failure, mortality, rehospitalization and left ventricular functions determined by echocardiography. A total of 82 patients with STEMI hospitalized within 6-12 h of debut of symptoms were included in the study. The patients were randomly assigned into spironolactone (group A) or placebo (group B) groups after informed consent had been obtained. All patients were followed for 6 months. There were no statistically significant differences between the two groups when demographic criteria were compared. The incidence of post-MI angina pectoris, rhythm and conduction disturbance during hospitalization was significantly higher in Group B than in Group A. Although not statistically significant, the incidence of clinical heart failure was slightly lower in Group A than in Group B (5% versus 11%). Left ventricular end-diastolic volumes were slightly lower in Group A than in Group B, although statistically this was not significant. In concordance with these findings, the ejection fraction was slightly higher in Group A than in Group B, although this was not statistically significant (47% versus 44%). This trend continued during a 6-month follow-up after randomization. Our findings suggest that early administration of aldosterone blockers provides additional benefits after AMI, reducing the incidence of post-MI angina pectoris and rhythm and conduction disturbances.

The Relationship Between the Renin-Angiotensin-Aldosterone System and NMDA Receptor-Mediated Signal and the Prevention of Retinal Ganglion Cell Death.

PubMed

Kobayashi, Mamoru; Hirooka, Kazuyuki; Ono, Aoi; Nakano, Yuki; Nishiyama, Akira; Tsujikawa, Akitaka

2017-03-01

Excitotoxicity, which is due to glutamate-induced toxic effects on the retinal ganglion cell (RGC), is one of several mechanisms of RGC loss. The renin-angiotensin-aldosterone system (RAAS) has also been implicated in RGC death. Therefore, it is important to determine the exact relationship between the RAAS and N-methyl-d-aspartate (NMDA) receptor-mediated signal in order to prevent RGC death. N-methyl-d-aspartate or aldosterone was injected into the vitreous body. After intravitreal injection of NMDA or aldosterone, animals were treated with spironolactone or memantine. Retinal damage was evaluated by measuring the number of RGCs at 4 weeks after local administration of aldosterone or at 2 weeks after local administration of NMDA. Vitreous humor levels of aldosterone were measured using enzyme immunoassay kits. A significantly decreased number of RGCs were observed after intravitreal injection of NMDA. Although spironolactone did not show any neuroprotective effects, memantine significantly reduced NMDA-induced degeneration in the retina. Furthermore, a significant decrease in the number of RGCs was observed after an intravitreal injection of aldosterone. While memantine did not exhibit any neuroprotective effects, spironolactone caused a significant reduction in the aldosterone-induced degeneration in the retina. There was no change in the aldosterone concentration in the vitreous humor after an NMDA injection. Our findings indirectly show that there is no relationship between the RAAS and NMDA receptor-mediated signal with regard to RGC death.

RAAS inhibitors and cardiovascular protection in large scale trials.

PubMed

von Lueder, Thomas G; Krum, Henry

2013-04-01

Hypertension, coronary artery disease and heart failure affect over half of the adult population in most Western societies, and are prime causes of CV morbidity and mortality. With the ever-increasing worldwide prevalence of CV disease due to ageing and the "diabetes" pandemic, guideline groups have recognized the importance of achieving cardioprotection in affected individuals as well as in those at risk for future CV events. The renin-angiotensin-aldosterone system (RAAS) is the most important system controlling blood pressure (BP), cardiovascular and renal function in man. As our understanding of the crucial role of RAAS in the pathogenesis of most, if not all, CV disease has expanded over the past decades, so has the development of drugs targeting its individual components. Angiotensin-converting enzyme inhibitors (ACEi), Ang-II receptor blockers (ARB), and mineralcorticoid receptor antagonists (MRA) have been evaluated in large clinical trials for their potential to mediate cardioprotection, singly or in combination. Direct renin inhibitors are currently under scrutiny, as well as novel dual-acting RAAS-blocking agents. Herein, we review the evidence generated from large-scale clinical trials of cardioprotection achieved through RAAS-blockade.

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.

Obesity-related glomerulopathy: pathogenesis, pathologic, clinical characteristics and treatment.

PubMed

Xu, Tianhua; Sheng, Zitong; Yao, Li

2017-09-01

In light of the rapid increase in the number of obesity incidences worldwide, obesity has become an independent risk factor for chronic kidney disease. Obesity-related glomerulopathy (ORG) is characterized by glomerulomegaly in the presence or absence of focal and segmental glomerulosclerosis lesions. IgM and complement 3 (C3) nonspecifically deposit in lesions without immune-complex-type deposits during ORG immunofluorescence. ORG-associated glomerulomegaly and focal and segmental glomerulosclerosis can superimpose on other renal pathologies. The mechanisms under ORG are complex, especially hemodynamic changes, inflammation, oxidative stress, apoptosis, and reduced functioning nephrons. These mechanisms synergize with obesity to induce end-stage renal disease. A slow increase of subnephrotic proteinuria ( < 3.5 g/d) is the most common clinical manifestation of ORG. Several treatment methods for ORG have been developed. Of these methods, renin-angiotensin-aldosterone system blockade and weight loss are proven effective. Targeting mitochondria may offer a novel strategy for ORG therapy. Nevertheless, more research is needed to further understand ORG.

Renal, auricular, and ocular outcomes of Alport syndrome and their current management.

PubMed

Zhang, Yanqin; Ding, Jie

2017-09-01

Alport syndrome is a hereditary glomerular basement membrane disease caused by mutations in the COL4A3/4/5 genes encoding the type IV collagen alpha 3-5 chains. Most cases of Alport syndrome are inherited as X-linked dominant, and some as autosomal recessive or autosomal dominant. The primary manifestations are hematuria, proteinuria, and progressive renal failure, whereas some patients present with sensorineural hearing loss and ocular abnormalities. Renin-angiotensin-aldosterone system blockade is proven to delay the onset of renal failure by reducing proteinuria. Renal transplantation is a curative treatment for patients who have progressed to end-stage renal disease. However, only supportive measures can be used to improve hearing loss and visual loss. Although both stem cell therapy and gene therapy aim to repair the basement membrane defects, technical difficulties require more research in Alport mice before clinical studies. Here, we review the renal, auricular, and ocular manifestations and outcomes of Alport syndrome and their current management.

Greater efficacy of aldosterone blockade and diuretic reinforcement vs. dual renin-angiotensin blockade for left ventricular mass regression in patients with resistant hypertension.

PubMed

Azizi, Michel; Perdrix, Ludivine; Bobrie, Guillaume; Frank, Michael; Chatellier, Gilles; Ménard, Joël; Plouin, Pierre-François

2014-10-01

We report the results of an echocardiographic substudy carried out in a trial comparing the effects of two different treatment strategies - mineralocorticoid receptor blockade (MRB) and dual renin-angiotensin system blockade (RASB) - in patients with resistant hypertension. Both strategies reduce left ventricular mass index (LVMI), but they have not been compared in patients with resistant hypertension. After 4-week treatment with 300 mg irbesartan + 12.5 mg hydrochorothiazide + 5 mg amlodipine, 86 patients with resistant hypertension were randomized to the add-on 25 mg spironolactone (MRB group, n = 46) or 5 mg ramipril (RASB group, n = 40) groups for 12 weeks. Treatment intensity was increased at week 4, 8 or 10 if home blood pressure (BP) was equal to or above 135/85 mmHg, by sequentially adding 20-40 mg furosemide and 5 mg amiloride (MRB group), or 10 mg ramipril and 5-10 mg bisoprolol (RASB group). Transthoracic echography was performed at baseline and week 12. Daytime ambulatory BP decreased by 19 ± 12/11 ± 8 mmHg in the MRB group and by 8 ± 13/7 ± 7 mmHg in the RASB group (P = 0.0003/0.03). LVMI decreased by 8.2 ± 18.9 g/m in the MRB group, whereas it increased by 1.8 ± 19.1 g/m in the RASB group (P = 0.03). The decreases in posterior wall thickness, left ventricular (LV) end-systolic diameter, E/e' ratio and left atrial area were significantly greater with MRB than with RASB. The difference between groups remained significant after adjustment for the decrease in ambulatory BP. In patients with resistant hypertension, MRB-based treatment decreased both BP and LVMI more efficiently than a strategy based on dual RASB.

Human interventions to characterize novel relationships between the renin-angiotensin-aldosterone system and parathyroid hormone.

PubMed

Brown, Jenifer M; Williams, Jonathan S; Luther, James M; Garg, Rajesh; Garza, Amanda E; Pojoga, Luminita H; Ruan, Daniel T; Williams, Gordon H; Adler, Gail K; Vaidya, Anand

2014-02-01

Observational studies in primary hyperaldosteronism suggest a positive relationship between aldosterone and parathyroid hormone (PTH); however, interventions to better characterize the physiological relationship between the renin-angiotensin-aldosterone system (RAAS) and PTH are needed. We evaluated the effect of individual RAAS components on PTH using 4 interventions in humans without primary hyperaldosteronism. PTH was measured before and after study (1) low-dose angiotensin II (Ang II) infusion (1 ng/kg per minute) and captopril administration (25 mg×1); study (2) high-dose Ang II infusion (3 ng/kg per minute); study (3) blinded crossover randomization to aldosterone infusion (0.7 µg/kg per hour) and vehicle; and study (4) blinded randomization to spironolactone (50 mg/daily) or placebo for 6 weeks. Infusion of Ang II at 1 ng/kg per minute acutely increased aldosterone (+148%) and PTH (+10.3%), whereas Ang II at 3 ng/kg per minute induced larger incremental changes in aldosterone (+241%) and PTH (+36%; P<0.01). Captopril acutely decreased aldosterone (-12%) and PTH (-9.7%; P<0.01). In contrast, aldosterone infusion robustly raised serum aldosterone (+892%) without modifying PTH. However, spironolactone therapy during 6 weeks modestly lowered PTH when compared with placebo (P<0.05). In vitro studies revealed the presence of Ang II type I and mineralocorticoid receptor mRNA and protein expression in normal and adenomatous human parathyroid tissues. We observed novel pleiotropic relationships between RAAS components and the regulation of PTH in individuals without primary hyperaldosteronism: the acute modulation of PTH by the RAAS seems to be mediated by Ang II, whereas the long-term influence of the RAAS on PTH may involve aldosterone. Future studies to evaluate the impact of RAAS inhibitors in treating PTH-mediated disorders are warranted.

Aldosterone does not require angiotensin II to activate NCC through a WNK4-SPAK-dependent pathway.

PubMed

van der Lubbe, Nils; Lim, Christina H; Meima, Marcel E; van Veghel, Richard; Rosenbaek, Lena Lindtoft; Mutig, Kerim; Danser, Alexander H J; Fenton, Robert A; Zietse, Robert; Hoorn, Ewout J

2012-06-01

We and others have recently shown that angiotensin II can activate the sodium chloride cotransporter (NCC) through a WNK4-SPAK-dependent pathway. Because WNK4 was previously shown to be a negative regulator of NCC, it has been postulated that angiotensin II converts WNK4 to a positive regulator. Here, we ask whether aldosterone requires angiotensin II to activate NCC and if their effects are additive. To do so, we infused vehicle or aldosterone in adrenalectomized rats that also received the angiotensin receptor blocker losartan. In the presence of losartan, aldosterone was still capable of increasing total and phosphorylated NCC twofold to threefold. The kinases WNK4 and SPAK also increased with aldosterone and losartan. A dose-dependent relationship between aldosterone and NCC, SPAK, and WNK4 was identified, suggesting that these are aldosterone-sensitive proteins. As more functional evidence of increased NCC activity, we showed that rats receiving aldosterone and losartan had a significantly greater natriuretic response to hydrochlorothiazide than rats receiving losartan only. To study whether angiotensin II could have an additive effect, rats receiving aldosterone with losartan were compared with rats receiving aldosterone only. Rats receiving aldosterone only retained more sodium and had twofold to fourfold increase in phosphorylated NCC. Together, our results demonstrate that aldosterone does not require angiotensin II to activate NCC and that WNK4 appears to act as a positive regulator in this pathway. The additive effect of angiotensin II may favor electroneutral sodium reabsorption during hypovolemia and may contribute to hypertension in diseases with an activated renin-angiotensin-aldosterone system.

RAAS inhibition and the course of Alport syndrome.

PubMed

Savva, Isavella; Pierides, Alkis; Deltas, Constantinos

2016-05-01

Alport syndrome (AS) is a hereditary progressive glomerulonephritis with a high life-time risk for end-stage renal disease (ESRD). Most patients will reach ESRD before the age of 30 years, while a subset of them with milder mutations will do so at older ages, even after 50 years. Frequent extrarenal manifestations are hearing loss and ocular abnormalities. AS is a genetically heterogeneous collagen IV nephropathy, with 85% of the cases caused by mutations in the X-linked COL4A5 gene and the rest by homozygous or compound heterozygous mutations in either the COL4A3 or the COL4A4 gene on chromosome 2q36-37. There is no radical cure for the disease and attempts to use various stem cell therapies in animal models have been met with ambiguous success. However, effective treatment has been accomplished with pharmacological intervention at the renin-angiotensin-aldosterone system (RAAS), first in animal models of AS and more recently in humans. Angiotensin converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) have been shown to significantly delay the progression of chronic kidney disease and the onset of ESRD. Also, renin inhibitors and aldosterone blockade were used with positive results, while the combination of ACEis and ARBs was met with mixed success. An important study, the EARLY-PROTECT, aims at evaluating the efficacy of ACEis when administered very early on in children with AS. Novel therapies are also tested experimentally or are under design in animal models by several groups, including the use of amniotic fluid stem cells and synthetic chaperones. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distal Renal Tubules Are Deficient in Aggresome Formation and Autophagy upon Aldosterone Administration

PubMed Central

Cheema, Muhammad Umar; Damkier, Helle Hasager; Nielsen, Jakob; Poulsen, Ebbe Toftgaard; Enghild, Jan J.; Fenton, Robert A.; Praetorius, Jeppe

2014-01-01

Prolonged elevations of plasma aldosterone levels are associated with renal pathogenesis. We hypothesized that renal distress could be imposed by an augmented aldosterone-induced protein turnover challenging cellular protein degradation systems of the renal tubular cells. Cellular accumulation of specific protein aggregates in rat kidneys was assessed after 7 days of aldosterone administration. Aldosterone induced intracellular accumulation of 60 s ribosomal protein L22 in protein aggregates, specifically in the distal convoluted tubules. The mineralocorticoid receptor inhibitor spironolactone abolished aldosterone-induced accumulation of these aggregates. The aldosterone-induced protein aggregates also contained proteasome 20 s subunits. The partial de-ubiquitinase ataxin-3 was not localized to the distal renal tubule protein aggregates, and the aggregates only modestly colocalized with aggresome transfer proteins dynactin p62 and histone deacetylase 6. Intracellular protein aggregation in distal renal tubules did not lead to development of classical juxta-nuclear aggresomes or to autophagosome formation. Finally, aldosterone treatment induced foci in renal cortex of epithelial vimentin expression and a loss of E-cadherin expression, as signs of cellular stress. The cellular changes occurred within high, but physiological aldosterone concentrations. We conclude that aldosterone induces protein accumulation in distal renal tubules; these aggregates are not cleared by autophagy that may lead to early renal tubular damage. PMID:25000288

Aldosterone, Parathyroid Hormone, and the Use of Renin-Angiotensin-Aldosterone System Inhibitors: The Multi-Ethnic Study of Atherosclerosis

PubMed Central

Brown, Jenifer; de Boer, Ian H.; Robinson-Cohen, Cassianne; Siscovick, David S.; Kestenbaum, Bryan; Allison, Matthew

2015-01-01

Context: Aldosterone and PTH are implicated in the pathogenesis of cardiovascular and skeletal diseases. An expanding body of evidence supports a bidirectional and positive physiologic relationship between aldosterone and PTH. Large population-based studies confirming this relationship, and whether it may be targeted as a potential method to mitigate the clinical consequences associated with excess aldosterone and PTH, are needed. Objective: We hypothesized that higher aldosterone levels would associate with higher PTH, and that the use of renin-angiotensin-aldosterone system (RAAS) inhibitors would predict lower PTH in a large, multi-ethnic, community-based cohort. Design, Setting, Participants: We conducted cross-sectional analyses of participants in the Multi-Ethnic Study of Atherosclerosis without apparent primary hyperparathyroidism or chronic kidney disease (n = 5668). We evaluated associations of RAAS inhibitor use with PTH concentration among 1888 treated hypertensive participants. We also tested associations of serum aldosterone concentration with PTH concentration among 1547 participants with these measurements. Outcome: Serum PTH concentration. Results: Higher aldosterone associated with higher PTH (β = 0.19 pg/ml per 1 ng/dl of aldosterone, P < .0001), and this finding was most pronounced among those with a primary hyperaldosteronism-like phenotype. There was a stepwise increment in PTH when comparing untreated normotensives, hypertensives using RAAS inhibitors, untreated hypertensives, and treated hypertensives using non-RAAS inhibitors (40.8, 45.0, 46.2, 47.1 pg/ml, respectively). The use of any RAAS inhibitor independently associated with lower PTH (β = −2.327 pg/ml per use of RAAS inhibitor, P = .006), when compared with the use of any non-RAAS inhibitor medication. Conclusions: Higher serum aldosterone concentration is associated with higher serum PTH concentration, and the use of RAAS inhibitors is associated with lower PTH concentration. These results extend prior evidence from observational and intervention studies suggesting a potentially important and modifiable relationship between the RAAS and PTH in humans. PMID:25412416

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

Expression of Angiotensin II and Aldosterone in Radiation-induced Lung Injury.

PubMed

Cao, Shuo; Wu, Rong

2012-12-01

Radiation-induced lung injury (RILI) is the most common, dose-limiting complication in thoracic malignancy radiotherapy. Considering its negative impact on patients and restrictions to efficacy, the mechanism of RILI was studied. Wistar rats were locally irradiated with a single dose of 0, 16, and 20 Gy to the right half of the lung to establish a lung injury model. Two and six months after irradiation, the right half of the rat lung tissue was removed, and the concentrations of TGF-β1, angiotensin II, and aldosterone were determined via enzyme-linked immunosorbent assay. Statistical differences were observed in the expression levels of angiotensin II and aldosterone between the non-irradiation and irradiation groups. Moreover, the expression level of the angiotensin II-aldosterone system increased with increasing doses, and the difference was still observed as time progressed. Angiotensin II-aldosterone system has an important pathophysiological function in the progression of RILI.

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

TRAF3IP2 Mediates Aldosterone/Salt-Induced Cardiac Hypertrophy and Fibrosis

PubMed Central

Sakamuri, Siva S.V.P; Valente, Anthony J.; Siddesha, Jalahalli M.; Delafontaine, Patrice; Siebenlist, Ulrich; Gardner, Jason D.; Chandrasekar, Bysani

2016-01-01

Aberrant activation of the renin-angiotensin-aldosterone system (RAAS) contributes to adverse cardiac remodeling and eventual failure. Here we investigated whether TRAF3-interacting Protein 2 (TRAF3IP2), a redox-sensitive cytoplasmic adaptor molecule and an upstream regulator of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), mediates aldosterone-induced cardiac hypertrophy and fibrosis. Wild type (WT) and TRAF3IP2-null mice were infused with aldosterone (0.2mg/kg/day) for 4 weeks along with 1%NaCl in drinking water. Aldosterone/salt, but not salt alone, upregulated TRAF3IP2 expression in WT mouse hearts. Aldosterone elevated blood pressure to a similar extent in both WT and TRAF3IP2-null groups. Importantly, TRAF3IP2 gene deletion attenuated aldosterone/salt-induced (i) p65 and c-Jun activation, (ii) extracellular matrix (collagen Iα1 and collagen 3α1), matrix metalloproteinase (MMP2), lysyl oxidase (LOX), inflammatory cytokine (IL-6 and IL-18), chemokine (CXCL1 and CXCL2), and adhesion molecule (ICAM1) gene expression in hearts, (iii) IL-6, IL-18, and MMP2 protein levels, (iv) systemic IL-6 and IL-18 levels, and (iv) cardiac hypertrophy and fibrosis. These results indicate that TRAF3IP2 is a critical signaling intermediate in aldosterone/salt-induced myocardial hypertrophy and fibrosis, and thus a potential therapeutic target in hypertensive heart disease. PMID:27040306

TRAF3IP2 mediates aldosterone/salt-induced cardiac hypertrophy and fibrosis.

PubMed

Sakamuri, Siva S V P; Valente, Anthony J; Siddesha, Jalahalli M; Delafontaine, Patrice; Siebenlist, Ulrich; Gardner, Jason D; Bysani, Chandrasekar

2016-07-05

Aberrant activation of the renin-angiotensin-aldosterone system (RAAS) contributes to adverse cardiac remodeling and eventual failure. Here we investigated whether TRAF3 Interacting Protein 2 (TRAF3IP2), a redox-sensitive cytoplasmic adaptor molecule and an upstream regulator of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), mediates aldosterone-induced cardiac hypertrophy and fibrosis. Wild type (WT) and TRAF3IP2-null mice were infused with aldosterone (0.2 mg/kg/day) for 4 weeks along with 1%NaCl in drinking water. Aldosterone/salt, but not salt alone, upregulated TRAF3IP2 expression in WT mouse hearts. Further, aldosterone elevated blood pressure to a similar extent in both WT and TRAF3IP2-null groups. However, TRAF3IP2 gene deletion attenuated aldosterone/salt-induced (i) p65 and c-Jun activation, (ii) extracellular matrix (collagen Iα1 and collagen IIIα1), matrix metalloproteinase (MMP2), lysyl oxidase (LOX), inflammatory cytokine (IL-6 and IL-18), chemokine (CXCL1 and CXCL2), and adhesion molecule (ICAM1) mRNA expression in hearts, (iii) IL-6, IL-18, and MMP2 protein levels, (iv) systemic IL-6 and IL-18 levels, and (iv) cardiac hypertrophy and fibrosis. These results indicate that TRAF3IP2 is a critical signaling intermediate in aldosterone/salt-induced myocardial hypertrophy and fibrosis, and thus a potential therapeutic target in hypertensive heart disease. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Aldosterone is associated with left ventricular hypertrophy in hemodialysis patients.

PubMed

Feniman De Stefano, Greicy Mara Mengue; Zanati-Basan, Silméia Garcia; De Stefano, Laercio Martins; Silva, Viviana Rugolo Oliveira E; Xavier, Patrícia Santi; Barretti, Pasqual; da Silva Franco, Roberto Jorge; Caramori, Jacqueline Costa Teixeira; Martin, Luis Cuadrado

2016-10-01

Patients with chronic kidney disease present a higher degree of left ventricular hypertrophy than expected for hypertension levels. In chronic kidney disease the plot between the quotient extracellular water/total body water and aldosterone is shifted up and to the right. There are few studies that verified the role of aldosterone in cardiac remodeling in this set of patients. The aim of this study was to evaluate the relationship between serum aldosterone and left ventricular mass index in patients with chronic kidney disease on hemodialysis. The patients were submitted to clinical and laboratory evaluation, bioelectrical impedance, echocardiography and ambulatory blood pressure monitoring. The 27 patients included were divided into two groups according to aldosterone level and compared with each other. The group of patients with higher aldosterone levels had higher left ventricular mass index. These groups were heterogeneous with regard to ambulatory systolic blood pressure, body mass index, and aldosterone levels and homogeneous with regard to the quotient extracellular water/total body water, renin-angiotensin-aldosterone system blockers, beta blocker use and other clinical characteristics. The association between aldosterone levels and left ventricular mass index was adjusted to confounding variables by a multiple linear regression analysis in which aldosterone was independently associated with left ventricular mass index. The data presented are consistent with a pathogenic role of aldosterone in left ventricular hypertrophy in patients with chronic kidney dialysis in dialysis patients. ClinicalTrials.gov identifier: NCT01128101. © The Author(s), 2016.

21 CFR 862.1665 - Sodium test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic... disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone...

21 CFR 862.1665 - Sodium test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic... disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone...

[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.

21 CFR 862.1045 - Aldosterone test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Aldosterone test system. 862.1045 Section 862.1045 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 Systems § 862...

21 CFR 862.1045 - Aldosterone test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Aldosterone test system. 862.1045 Section 862.1045 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 Systems § 862...

21 CFR 862.1045 - Aldosterone test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Aldosterone test system. 862.1045 Section 862.1045 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 Systems § 862...

21 CFR 862.1045 - Aldosterone test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Aldosterone test system. 862.1045 Section 862.1045 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 Systems § 862...

21 CFR 862.1045 - Aldosterone test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Aldosterone test system. 862.1045 Section 862.1045 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 Systems § 862...

Genomic and rapid effects of aldosterone: what we know and do not know thus far.

PubMed

Hermidorff, Milla Marques; de Assis, Leonardo Vinícius Monteiro; Isoldi, Mauro César

2017-01-01

Aldosterone is the most known mineralocorticoid hormone synthesized by the adrenal cortex. The genomic pathway displayed by aldosterone is attributed to the mineralocorticoid receptor (MR) signaling. Even though the rapid effects displayed by aldosterone are long known, our knowledge regarding the receptor responsible for such event is still poor. It is intense that the debate whether the MR or another receptor-the "unknown receptor"-is the receptor responsible for the rapid effects of aldosterone. Recently, G protein-coupled estrogen receptor-1 (GPER-1) was elegantly shown to mediate some aldosterone-induced rapid effects in several tissues, a fact that strongly places GPER-1 as the unknown receptor. It has also been suggested that angiotensin receptor type 1 (AT1) also participates in the aldosterone-induced rapid effects. Despite this open question, the relevance of the beneficial effects of aldosterone is clear in the kidneys, colon, and CNS as aldosterone controls the important water reabsorption process; on the other hand, detrimental effects displayed by aldosterone have been reported in the cardiovascular system and in the kidneys. In this line, the MR antagonists are well-known drugs that display beneficial effects in patients with heart failure and hypertension; it has been proposed that MR antagonists could also play an important role in vascular disease, obesity, obesity-related hypertension, and metabolic syndrome. Taken altogether, our goal here was to (1) bring a historical perspective of both genomic and rapid effects of aldosterone in several tissues, and the receptors and signaling pathways involved in such processes; and (2) critically address the controversial points within the literature as regarding which receptor participates in the rapid pathway display by aldosterone.

Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo.

PubMed

Wang, Bin; Lin, Lilu; Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

2016-10-25

The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity.

Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo

PubMed Central

Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

2016-01-01

The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity. PMID:27732567

Interactions of NADPH oxidase, renin-angiotensin-aldosterone system and reactive oxygen species in mequindox-mediated aldosterone secretion in Wistar rats.

PubMed

Huang, Xian-Ju; Wang, Xu; Ihsan, Awais; Liu, Qin; Xue, Xi-Juan; Su, Shi-Jia; Yang, Chun-Hui; Zhou, Wen; Yuan, Zong-Hui

2010-10-05

High doses of mequindox (MEQ) are associated with oxidative stress and pathological toxicity in the kidney. In this study, we demonstrated long term effects of MEQ on intra- or extra-adrenal renin-angiotensin-aldosterone system (RAAS) in vivo. RAAS plays a major role in aldosterone secretion. High doses of MEQ in the diet for 180 days in male rats led to inhibition of intra- and extra-adrenal RAAS, concident with down-regulation of Na(+)/K(+)-ATPase (NAKA) and mineralocorticoid receptor (MR), the downstream of aldosterone action. Significant changes of malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) in kidney were also observed in the high doses (110, 275mg/kg) groups. The mRNA levels of most subunits of NADPH oxidase were significantly upregulated at low doses (25-110mg/kg) but the upregulation was diminished at higher doses in both kidney and adrenal gland, indicating a complicated and contradictory effect of MEQ on NADPH. These results highlight the complex interactions of drug metabolism, RAAS, NADPH oxidase and oxidative stress in response to MEQ-induced tissue toxicity and aldosterone secretion. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Confirmatory testing in primary aldosteronism: extensive medication switching is not needed in all patients

PubMed Central

Solar, Miroslav; Malirova, Eva; Ballon, Marek; Pelouch, Radek; Ceral, Jiri

2012-01-01

Objective Confirmatory testing of suspected primary aldosteronism (PA) requires an extensive medication switch that can be difficult for patients with severe complicated hypertension and/or refractory hypokalemia. For this reason, we investigated the effect of chronic antihypertensive medication on confirmatory testing results. To allow the results to be interpreted, the reproducibility of confirmatory testing was also evaluated. Design and methods The study enrolled 114 individuals with suspected PA who underwent two confirmatory tests. The patients were divided into two groups. In Group A, both tests were performed on the guidelines-recommended therapy, i.e. not interfering with the renin–angiotensin–aldosterone system. In Group B, the first test was performed on chronic therapy with the exclusion of thiazides, loop diuretics, and aldosterone antagonists; and the second test was performed on guidelines-recommended therapy. Saline infusion, preceded by oral sodium loading, was used to suppress aldosterone secretion. Results Agreement in the interpretation of the two confirmatory tests was observed in 84 and 66% of patients in Groups A and B respectively. For all 20 individuals in Group A who ever had end-test serum aldosterone levels ≥240 pmol/l, aldosterone was concordantly nonsuppressible during the other test. Similarly, for all 16 individuals in Group B who had end-test serum aldosterone levels ≥240 pmol/l on modified chronic therapy, aldosterone remained nonsuppressible with guidelines-recommended therapy. Conclusion Confirmatory testing performed while the patient is on chronic therapy without diuretics and aldosterone antagonists can confirm the diagnosis of PA, provided serum aldosterone remains markedly elevated at the end of saline infusion. PMID:22253400

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.

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

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.

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

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.

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

Endocrine and haemodynamic changes in resistant hypertension, and blood pressure responses to spironolactone or amiloride: the PATHWAY-2 mechanisms substudies.

PubMed

Williams, Bryan; MacDonald, Thomas M; Morant, Steve V; Webb, David J; Sever, Peter; McInnes, Gordon T; Ford, Ian; Cruickshank, J Kennedy; Caulfield, Mark J; Padmanabhan, Sandosh; Mackenzie, Isla S; Salsbury, Jackie; Brown, Morris J

2018-06-01

In the PATHWAY-2 study of resistant hypertension, spironolactone reduced blood pressure substantially more than conventional antihypertensive drugs. We did three substudies to assess the mechanisms underlying this superiority and the pathogenesis of resistant hypertension. PATHWAY-2 was a randomised, double-blind crossover trial done at 14 UK primary and secondary care sites in 314 patients with resistant hypertension. Patients were given 12 weeks of once daily treatment with each of placebo, spironolactone 25-50 mg, bisoprolol 5-10 mg, and doxazosin 4-8 mg and the change in home systolic blood pressure was assessed as the primary outcome. In our three substudies, we assessed plasma aldosterone, renin, and aldosterone-to-renin ratio (ARR) as predictors of home systolic blood pressure, and estimated prevalence of primary aldosteronism (substudy 1); assessed the effects of each drug in terms of thoracic fluid index, cardiac index, stroke index, and systemic vascular resistance at seven sites with haemodynamic monitoring facilities (substudy 2); and assessed the effect of amiloride 10-20 mg once daily on clinic systolic blood pressure during an optional 6-12 week open-label runout phase (substudy 3). The PATHWAY-2 trial is registered with EudraCT, number 2008-007149-30, and ClinicalTrials.gov, number NCT02369081. Of the 314 patients in PATHWAY-2, 269 participated in one or more of the three substudies: 126 in substudy 1, 226 in substudy 2, and 146 in substudy 3. Home systolic blood pressure reduction by spironolactone was predicted by ARR (r 2 =0·13, p<0·0001) and plasma renin (r 2 =0·11, p=0·00024). 42 patients had low renin concentrations (predefined as the lowest tertile of plasma renin), of which 31 had a plasma aldosterone concentration greater than the mean value for all 126 patients (250 pmol/L). Thus, 31 (25% [95% CI 17-33]) of 126 patients were deemed to have inappropriately high aldosterone concentrations. Thoracic fluid content was reduced by 6·8% from baseline (95% CI 4·0 to 8·8; p<0·0001) with spironolactone, but not other treatments. Amiloride (10 mg once daily) reduced clinic systolic blood pressure by 20·4 mm Hg (95% CI 18·3-22·5), compared with a reduction of 18·3 mm Hg (16·2-20·5) with spironolactone (25 mg once daily). No serious adverse events were recorded, and adverse symptoms were not systematically recorded after the end of the double-blind treatment. Mean plasma potassium concentrations increased from 4·02 mmol/L (95% CI 3·95-4·08) on placebo to 4·50 (4·44-4·57) on amiloride (p<0·0001). Our results suggest that resistant hypertension is commonly a salt-retaining state, most likely due to inappropriate aldosterone secretion. Mineralocorticoid receptor blockade by spironolactone overcomes the salt retention and resistance of hypertension to treatment. Amiloride seems to be as effective an antihypertensive as spironolactone, offering a substitute treatment for resistant hypertension. British Heart Foundation and UK National Institute for Health Research. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Aldosterone and angiotensin II synergistically induce mitogenic response in vascular smooth muscle cells.

PubMed

Min, Li-Juan; Mogi, Masaki; Li, Jian-Mei; Iwanami, Jun; Iwai, Masaru; Horiuchi, Masatsugu

2005-09-02

Interaction between aldosterone (Aldo) and angiotensin II (Ang II) in the cardiovascular system has been highlighted; however, its detailed signaling mechanism is poorly understood. Here, we examined the cross-talk of growth-promoting signaling between Aldo and Ang II in vascular smooth muscle cells (VSMC). Treatment with a lower dose of Aldo (10(-12) mol/L) and with a lower dose of Ang II (10(-10) mol/L) significantly enhanced DNA synthesis, whereas Aldo or Ang II alone at these doses did not affect VSMC proliferation. This effect of a combination of Aldo and Ang II was markedly inhibited by a selective AT1 receptor blocker, olmesartan, a mineralocorticoid receptor antagonist, spironolactone, an MEK inhibitor, PD98059, or an EGF receptor tyrosine kinase inhibitor, AG1478. Treatment with Aldo together with Ang II, even at noneffective doses, respectively, synergistically increased extracellular signal-regulated kinase (ERK) activation, reaching 2 peaks at 10 to 15 minutes and 2 to 4 hours. The early ERK peak was effectively blocked by olmesartan or an EGF receptor kinase inhibitor, AG1478, but not by spironolactone, whereas the late ERK peak was completely inhibited by not only olmesartan, but also spironolactone. Combined treatment with Aldo and Ang II attenuated mitogen-activated protein kinase phosphatase-1 (MKP-1) expression and increased Ki-ras2A expression. The late ERK peak was not observed in VSMC treated with Ki-ras2A-siRNA. Interestingly, the decrease in MKP-1 expression and the increase in Ki-ras2A expression were restored by PD98059 or AG1478. These results suggest that Aldo exerts a synergistic mitogenic effect with Ang II and support the notion that blockade of both Aldo and Ang II could be more effective to prevent vascular remodeling.

Aldosterone response to angiotensin II during hypoxemia

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

Colice, G.L.; Ramirez, G.

1986-07-01

Exercise stimulates the renin-angiotensin-aldosterone system (RAAS). However, increases in plasma aldosterone concentrations (PAC) are suppressed when exercise is performed at high altitude or under hypoxemic conditions. As the angiotensin-II response to high-altitude exercise is normal, it is speculated that an inhibitor, discharged during hypoxemia, acted to suppress angiotensin-II-mediated aldosterone release. A study was conducted to test this hypothesis, taking into account the measurement of the aldosterone response to exogenous angiotensin II during normoxemia and hypoxemia. It was found that the dose-response curve of PAC to angiotensin II was not significantly inhibited by the considered model of hypoxemia. The hypoxemia-mediated releasemore » of an angiotensin II inhibitor does, therefore, not explain the previous observations of PAC suppression during hypoxemic exercise. 28 references.« less

Success and failure of vaccines against renin-angiotensin system components.

PubMed

Brown, Morris J

2009-10-01

Therapeutic vaccination pre-dated modern drugs as a possible strategy for treating hypertension. This approach is now being rediscovered, through use of modified angiotensins as immunogens together with carriers and adjuvants. Effective blockade of the renin-angiotensin system (RAS) with treatment twice a year might suit patients who dislike taking drugs on a daily basis and would also be an attractive option for those who have blood pressures in the prehypertensive range, if it can prevent hypertension itself from developing. Proof of concept with a vaccine whose efficacy is easy to measure will encourage development of further vaccines directed against targets such as aldosterone or other pathways where alternative treatments are scarce or absent. Two angiotensin-based vaccines are currently in development: PMD3117 comprises modified angiotensin I coupled to keyhole limpet hemocyanin, and Cyt006-AngQb is a conjugate of angiotensin II linked to virus particles. Early phase II studies in patients with hypertension demonstrated some efficacy, but the vaccines are not as effective as existing inhibitors of the RAS. Large studies now in progress will establish whether further modification of the immunogen or adjuvant is required to boost antibody titers.

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.

The effect of aliskiren on urinary cytokine/chemokine responses to clamped hyperglycaemia in type 1 diabetes.

PubMed

Cherney, David Z I; Reich, Heather N; Scholey, James W; Daneman, Denis; Mahmud, Farid H; Har, Ronnie L H; Sochett, Etienne B

2013-10-01

Acute clamped hyperglycaemia activates the renin-angiotensin-aldosterone system (RAAS) and increases the urinary excretion of inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes mellitus. Our objective was to determine whether blockade of the RAAS would blunt the effect of acute hyperglycaemia on urinary cytokine/chemokine excretion, thereby giving insights into potentially protective effects of these agents prior to the onset of clinical nephropathy. Blood pressure, renal haemodynamic function (inulin and para-aminohippurate clearances) and urinary cytokines/chemokines were measured after 6 h of clamped euglycaemia (4-6 mmol/l) and hyperglycaemia (9-11 mmol/l) on two consecutive days in patients with type 1 diabetes mellitus (n = 27) without overt nephropathy. Measurements were repeated after treatment with aliskiren (300 mg daily) for 30 days. Before aliskiren, clamped hyperglycaemia increased filtration fraction (from 0.188 ± 0.007 to 0.206 ± 0.007, p = 0.003) and urinary fibroblast growth factor-2 (FGF2), IFN-α2 and macrophage-derived chemokine (MDC) (p < 0.005). After aliskiren, the filtration fraction response to hyperglycaemia was abolished, resulting in a lower filtration fraction after aliskiren under clamped hyperglycaemic conditions (p = 0.004), and none of the biomarkers increased in response to hyperglycaemia. Aliskiren therapy also reduced levels of urinary eotaxin, FGF2, IFN-α2, IL-2 and MDC during clamped hyperglycaemia (p < 0.005). The increased urinary excretion of inflammatory cytokines/chemokines in response to acute hyperglycaemia is blunted by RAAS blockade in humans with uncomplicated type 1 diabetes mellitus.

Calneuron 1 Increased Ca2+ in the Endoplasmic Reticulum and Aldosterone Production in Aldosterone-Producing Adenoma.

PubMed

Kobuke, Kazuhiro; Oki, Kenji; Gomez-Sanchez, Celso E; Gomez-Sanchez, Elise P; Ohno, Haruya; Itcho, Kiyotaka; Yoshii, Yoko; Yoneda, Masayasu; Hattori, Noboru

2018-01-01

Aldosterone production is initiated by angiotensin II stimulation and activation of intracellular Ca 2+ signaling. In aldosterone-producing adenoma (APA) cells, the activation of intracellular Ca 2+ signaling is independent of the renin-angiotensin-aldosterone systems. The purpose of our study was to clarify molecular mechanisms of aldosterone production related to Ca 2+ signaling. Transcriptome analysis revealed that the CALN1 gene encoding calneuron 1 had the strongest correlation with CYP11B2 (aldosterone synthase) among genes encoding Ca 2+ -binding proteins in APA. CALN1 modulation and synthetic or fluorescent compounds were used for functional studies in human adrenocortical carcinoma (HAC15) cells. CALN1 expression was 4.4-fold higher in APAs than nonfunctioning adrenocortical adenomas. CALN1 expression colocalized with CYP11B2 expression as investigated using immunohistochemistry in APA and zona glomerulosa of male rats fed by a low-salt diet. CALN1 expression was detected in the endoplasmic reticulum (ER) by using GFP-fused CALN1, CellLight ER-RFP, and the corresponding antibodies. CALN1 -overexpressing HAC15 cells showed increased Ca 2+ in the ER and cytosol fluorescence-based studies. Aldosterone production was potentiated in HAC15 cells by CALN1 expression, and dose-responsive inhibition with TMB-8 showed that CALN1-mediated Ca 2+ storage in ER involved sarcoendoplasmic reticulum calcium transport ATPase. The silencing of CALN1 decreased Ca 2+ in ER, and abrogated angiotensin II- or KCNJ5 T158A-mediated aldosterone production in HAC15 cells. Increased CALN1 expression in APA was associated with elevated Ca 2+ storage in ER and aldosterone overproduction. Suppression of CALN1 expression prevented angiotensin II- or KCNJ5 T158A-mediated aldosterone production in HAC15 cells, suggesting that CALN1 is a potential therapeutic target for excess aldosterone production. © 2017 American Heart Association, Inc.

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.

Pharmacodynamic and Pharmacokinetic Profiles of Sacubitril/Valsartan (LCZ696) in Patients with Heart Failure and Reduced Ejection Fraction.

PubMed

Kobalava, Zhanna; Kotovskaya, Yulia; Averkov, Oleg; Pavlikova, Elena; Moiseev, Valentine; Albrecht, Diego; Chandra, Priya; Ayalasomayajula, Surya; Prescott, Margaret F; Pal, Parasar; Langenickel, Thomas H; Jordaan, Pierre; Rajman, Iris

2016-08-01

Concomitant renin-angiotensin-aldosterone system blockade and natriuretic peptide system enhancement may provide unique therapeutic benefits to patients with heart failure and reduced ejection fraction (HFrEF). This study assessed the pharmacodynamics and pharmacokinetics of LCZ696 in patients with HFrEF. This was an open-label, noncontrolled single-sequence study. After a 24-h run-in period, patients (n = 30) with HFrEF (EF ≤ 40%; NYHA class II-IV) received LCZ696 100 mg twice daily (bid) for 7 days and 200 mg bid for 14 days, along with standard treatment for heart failure (HF) (except angiotensin-converting enzyme inhibitors [ACEIs] or angiotensin receptor blockers [ARBs]). On Day 21, significant increases were observed in the plasma biomarkers indicative of neprilysin and RAAS inhibition (ratio-to-baseline: cyclic guanosine monophosphate [cGMP], 1.38; renin concentration and activity, 3.50 and 2.27, respectively; all, P < 0.05). Plasma NT-proBNP levels significantly decreased at all the time points on Days 7 and 21; plasma aldosterone and endothelin-1 levels significantly decreased on Day 21 (all, P < 0.05). Following administration of LCZ696, the Cmax of sacubitril (neprilysin inhibitor prodrug), LBQ657 (active neprilysin inhibitor), and valsartan were reached within 0.5, 2.5, and 2 h. Between 100- and 200-mg doses, the Cmax and AUC0-12 h for sacubitril and LBQ657 were approximately dose-proportional while that of valsartan was less than dose-proportional. Treatment with LCZ696 for 21 days was well tolerated and resulted in plasma biomarker changes indicative of neprilysin and RAAS inhibition in patients with HF. The pharmacokinetic exposure of the LCZ696 analytes in patients with HF observed in this study is comparable to that observed in the pivotal Phase III study. © 2016 John Wiley & Sons Ltd.

Effects of sodium restriction and hydrochlorothiazide on RAAS blockade efficacy in diabetic nephropathy: a randomised clinical trial.

PubMed

Kwakernaak, Arjan J; Krikken, Jan A; Binnenmars, S Heleen; Visser, Folkert W; Hemmelder, Marc H; Woittiez, Arend-Jan; Groen, Henk; Laverman, Gozewijn D; Navis, Gerjan

2014-05-01

Reduction of dietary sodium intake or diuretic treatment increases renin-angiotensin-aldosterone system (RAAS) blockade efficacy in non-diabetic nephropathy. We aimed to investigate the effect of sodium restriction and the diuretic hydrochlorothiazide, separately and in combination, added to RAAS blockade on residual albuminuria in patients with type 2 diabetic nephropathy. In this multicentre, double-blind, placebo-controlled, crossover randomised trial, we included patients with type 2 diabetic nephropathy. Main entry criteria were microalbuminaria or macroalbuminuria, and creatinine clearance of 30 mL/min or higher with less than 6 mL/min decline in the previous year. We tested the separate and combined effects of sodium restriction (dietary counselling in the outpatient setting) and hydrochlorothiazide (50 mg daily), added to standardised maximal angiotensin-converting enzyme (ACE) inhibition (lisinopril 40 mg daily), on albuminuria (primary endpoint). Patients were given hydrochlorothiazide (50 mg per day) or placebo during four treatment periods of 6 weeks. Both treatments were combined with regular sodium diet or sodium restriction (target sodium intake 50 mmol Na(+) per day). The 6-week treatment periods were done consecutively in a random order. Patients were randomised in blocks of two patients. The trial was analysed by intention to treat. The trial is registered with TrialRegister.nl, number 2366. Of 89 eligible patients, 45 were included in the study. Both sodium restriction and hydrochlorothiazide significantly reduced albuminuria, irrespective of treatment sequence. Residual geometric mean albuminuria with baseline treatment was 711 mg per day (95% CI 485-1043); it was significantly reduced by sodium restriction (393 mg per day [258-599], p=0·0002), by hydrochlorothiazide (434 mg per day [306-618], p=0·0003), and to the greatest extent by their combination (306 mg per day [203-461], p<0·0001). Orthostatic complaints were present in two patients (4%) during baseline treatment, five (11%) during addition of sodium restriction, five (11%) during hydrochlorothiazide treatment, and 12 (27%) during combination treatment. No serious adverse events occurred. We conclude that sodium restriction is an effective non-pharmacological intervention to increase RAAS blockade efficacy in type 2 diabetic nephropathy. None. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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

Latest aspects of aldosterone actions on the heart muscle.

PubMed

Kritis, A A; Gouta, C P; Liaretidou, E I; Kallaras, K I

2016-02-01

The genomic action of aldosterone has already been known to the scientific community and is well-documented to a satisfactory degree. However, the existence of rapid, non-genomic aldosterone actions has repeatedly been proven. These actions are apparent to a lot of tissues, among which the cardiac tissue, with the cardiac cells being responsible for the secretion of endogenous aldosterone. In the genomic pathway, the connection between the hormone and its receptor results increased reabsorption of sodium and water and excretion of potassium. Thus, the genomic procedure reacts indirectly on cardiovascular system by altering the blood pressure. New studies have shed light on unknown aspects of the non-genomic mechanism, which is sometimes performed by means of mineralocorticoid receptor (MR), while others through an MR-independent pathway. It is believed that aldosterone exerts its non-genomic action with the help of a different receptor, probably a G protein coupled receptor. A possible target is protein kinase C (PKC), and PKCε is postulated increase the permeability of the membrane of the cardiac cells to sodium, resulting in delayed repolarization and prolongation of action potential. These findings totally agree with and account for the serendipitous finding of our laboratory, that there is a positive correlation between plasma aldosterone levels and left ventricle (LV) contraction duration. Also, aldosterone has been proven to exacerbate the oxidative stress and induce vasoconstriction by acting on the vascular resistance and the cardiac output. Finally, this article deals with the role of aldosterone in cardiac fibrosis and the latest aspects of aldosterone actions on the heart muscle as well as providing a historical overview of the landmarks pertaining aldosterone's research.

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

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 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.

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.

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.

Cardiac Hypertrophy and Fibrosis in the Metabolic Syndrome: A Role for Aldosterone and the Mineralocorticoid Receptor

PubMed Central

Essick, Eric E.; Sam, Flora

2011-01-01

Obesity and hypertension, major risk factors for the metabolic syndrome, render individuals susceptible to an increased risk of cardiovascular complications, such as adverse cardiac remodeling and heart failure. There has been much investigation into the role that an increase in the renin-angiotensin-aldosterone system (RAAS) plays in the pathogenesis of metabolic syndrome and in particular, how aldosterone mediates left ventricular hypertrophy and increased cardiac fibrosis via its interaction with the mineralocorticoid receptor (MR). Here, we review the pertinent findings that link obesity with elevated aldosterone and the development of cardiac hypertrophy and fibrosis associated with the metabolic syndrome. These studies illustrate a complex cross-talk between adipose tissue, the heart, and the adrenal cortex. Furthermore, we discuss findings from our laboratory that suggest that cardiac hypertrophy and fibrosis in the metabolic syndrome may involve cross-talk between aldosterone and adipokines (such as adiponectin). PMID:21747976

Pathophysiology and Treatment of Resistant Hypertension: The Role of Aldosterone and Amiloride-Sensitive Sodium Channels

PubMed Central

Judd, Eric K.; Calhoun, David A.; Warnock, David G.

2015-01-01

Summary Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented. PMID:25416662

Pathophysiology and treatment of resistant hypertension: the role of aldosterone and amiloride-sensitive sodium channels.

PubMed

Judd, Eric K; Calhoun, David A; Warnock, David G

2014-01-01

Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented.

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.

Beta2-adrenergic receptor genotype affects the renin-angiotensin-aldosterone system response to the Dietary Approaches to Stop Hypertension (DASH) dietary pattern.

PubMed

Sun, Bei; Williams, Jonathan S; Svetkey, Laura P; Kolatkar, Nikheel S; Conlin, Paul R

2010-08-01

Beta(2)-adrenergic receptor (beta2-AR) is a susceptibility locus for hypertension, and polymorphisms at this site relate to salt sensitivity and low plasma renin activity (PRA). The Dietary Approaches to Stop Hypertension (DASH) dietary pattern lowers blood pressure and appears to interact with the renin-angiotensin-aldosterone system (RAAS). We hypothesized that the DASH diet associates with increased RAAS activity, and genotype status at beta2-AR G46A modifies this response. We genotyped participants in the DASH-Sodium study (n = 372) at beta2-AR G46A to determine the association with blood pressure, RAAS components, and consumption of the DASH diet. We used 2-way mixed linear regression and an additive model for all primary analyses. Mean (+/-SEM) PRA was significantly higher in participants in the DASH group than in participants in the control group (0.68 +/- 0.03 compared with 0.54 +/- 0.03 ng x mL(-1) x h(-1), P = 0.002). Serum aldosterone, urinary aldosterone, and urinary potassium concentrations were also significantly higher in the DASH group (P < 0.01 for all). We observed significant gene-diet interactions for changes in systolic blood pressure (SBP) and concentrations of aldosterone and urinary potassium (P for interaction = 0.048, 0.017, and 0.001 for SBP and aldosterone and urinary potassium concentrations, respectively). There was an association between the A allele of beta2-AR G46A and greater blood pressure reduction and blunted aldosterone and PRA responses to the DASH diet. Our results indicate that the DASH diet lowers blood pressure and increases PRA and aldosterone concentrations. There is an association between the G46A polymorphism of beta2-AR and blood pressure and RAAS responses to the DASH diet, which suggests that beta2-AR may be a genetic modifier of DASH-diet responsiveness. This trial was registered at clinicaltrials.gov as NCT00000608.

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.

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.

Enzyme-linked immunosorbent assays for determination of plasma aldosterone using highly specific polyclonal antibodies.

PubMed

Schwartz, F; Hadas, E; Harnik, M; Solomon, B

1990-01-01

Two enzyme-linked immunosorbent assays were established and compared for the estimation of plasma aldosterone. In the first method immobilized aldosterone-protein complexes on the ELISA plates compete with aldosterone to be determined for the binding of certain amount of anti-aldosterone antibodies. The sensitivity of this method depends on the protein carrier used to conjugate with aldosterone. In the second method, anti-aldosterone antibodies adsorbed on ELISA plates compete for binding of known amount of the enzyme-labeled aldosterone and aldosterone to be determined. The highly specific rabbit anti-aldosterone antibodies were obtained by injection of aldosterone-oxime thyroglobulin. The detection limit of aldosterone in both methods ranged between 2-20 pg. The proposed assays are suitable for the determination of aldosterone in biological fluids compared with other reported ELISA assays, as well as with RIA.

Renal denervation attenuates aldosterone expression and associated cardiovascular pathophysiology in angiotensin II-induced hypertension.

PubMed

Hong, Mo-Na; Li, Xiao-Dong; Chen, Dong-Rui; Ruan, Cheng-Chao; Xu, Jian-Zhong; Chen, Jing; Wu, Yong-Jie; Ma, Yu; Zhu, Ding-Liang; Gao, Ping-Jin

2016-10-18

The sympathetic nervous system interacts with the renin-angiotensin-aldosterone system (RAAS) contributing to cardiovascular diseases. In this study, we sought to determine if renal denervation (RDN) inhibits aldosterone expression and associated cardiovascular pathophysiological changes in angiotensin II (Ang II)-induced hypertension. Bilateral RDN or SHAM operation was performed before chronic 14-day Ang II subcutaneous infusion (200ng/kg/min) in male Sprague-Dawley rats. Bilateral RDN blunted Ang II-induced hypertension and ameliorated the mesenteric vascular dysfunction. Cardiovascular hypertrophy in response to Ang II was significantly attenuated by RDN as shown by histopathology and transthoracic echocardiography. Moreover, Ang II-induced vascular and myocardial inflammation and fibrosis were suppressed by RDN with concurrent decrease in fibronectin and collagen deposition, macrophage infiltration, and MCP-1 expression. Interestingly, RDN also inhibited Ang II-induced aldosterone expression in the plasma, kidney and heart. This was associated with the reduction of calcitonin gene-related peptide (CGRP) in the adrenal gland. Ang II promoted aldosterone secretion which was partly attenuated by CGRP in the adrenocortical cell line, suggesting a protective role of CGRP in this model. Activation of transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinases (MAPKs) signaling pathway was both inhibited by RDN especially in the heart. These results suggest that the regulation of the renal sympathetic nerve in Ang II-induced hypertension and associated cardiovascular pathophysiological changes is likely mediated by aldosterone, with CGRP involvement.

Renal denervation attenuates aldosterone expression and associated cardiovascular pathophysiology in angiotensin II-induced hypertension

PubMed Central

Chen, Dong-Rui; Ruan, Cheng-Chao; Xu, Jian-Zhong; Chen, Jing; Wu, Yong-Jie; Ma, Yu; Zhu, Ding-Liang; Gao, Ping-Jin

2016-01-01

The sympathetic nervous system interacts with the renin-angiotensin-aldosterone system (RAAS) contributing to cardiovascular diseases. In this study, we sought to determine if renal denervation (RDN) inhibits aldosterone expression and associated cardiovascular pathophysiological changes in angiotensin II (Ang II)-induced hypertension. Bilateral RDN or SHAM operation was performed before chronic 14-day Ang II subcutaneous infusion (200ng/kg/min) in male Sprague-Dawley rats. Bilateral RDN blunted Ang II-induced hypertension and ameliorated the mesenteric vascular dysfunction. Cardiovascular hypertrophy in response to Ang II was significantly attenuated by RDN as shown by histopathology and transthoracic echocardiography. Moreover, Ang II-induced vascular and myocardial inflammation and fibrosis were suppressed by RDN with concurrent decrease in fibronectin and collagen deposition, macrophage infiltration, and MCP-1 expression. Interestingly, RDN also inhibited Ang II-induced aldosterone expression in the plasma, kidney and heart. This was associated with the reduction of calcitonin gene-related peptide (CGRP) in the adrenal gland. Ang II promoted aldosterone secretion which was partly attenuated by CGRP in the adrenocortical cell line, suggesting a protective role of CGRP in this model. Activation of transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinases (MAPKs) signaling pathway was both inhibited by RDN especially in the heart. These results suggest that the regulation of the renal sympathetic nerve in Ang II-induced hypertension and associated cardiovascular pathophysiological changes is likely mediated by aldosterone, with CGRP involvement. PMID:27661131

[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.

Leptin-Aldosterone-Neprilysin Axis: Identification of Its Distinctive Role in the Pathogenesis of the Three Phenotypes of Heart Failure in People With Obesity.

PubMed

Packer, Milton

2018-04-10

Obesity (especially visceral adiposity) can be associated with 3 different phenotypes of heart failure: heart failure with a reduced ejection fraction, heart failure with a preserved ejection fraction, and high-output heart failure. All 3 phenotypes are characterized by an excessive secretion of aldosterone and sodium retention. In addition, obesity is accompanied by increased signaling through the leptin receptor, which can promote activation of both the sympathetic nervous system and the renin-angiotensin system and can directly stimulate the secretion of aldosterone. The deleterious interaction of leptin and aldosterone is potentiated by the simultaneous action of adiposity and the renal sympathetic nerves to cause overactivity of neprilysin; the loss of the counterbalancing effects of natriuretic peptides is exacerbated by an additional effect of both obesity and heart failure to interfere with adiponectin signaling. This intricate neurohormonal interplay leads to plasma volume expansion as well as to adverse ventricular remodeling and cardiac fibrosis. Furthermore, the activity of aldosterone and neprilysin is not only enhanced by obesity, but these mechanisms can also promote adipogenesis and adipocyte dysfunction, thereby enhancing the positive feedback loop. Last, in elderly obese women, changes in quantity and biology of epicardial adipose tissue further enhances the release of leptin and other proinflammatory adipokines, thereby leading to cardiac and systemic inflammation, end-organ fibrosis, and multiple comorbidities. Regardless of the phenotypic expression, activation of the leptin-aldosterone-neprilysin axis appears to contribute importantly to the evolution and progression of heart failure in people with obesity. Efforts to interfere with the detrimental interactions of this distinctive neurohormonal ecosystem with existing or novel therapeutic agents are likely to yield unique clinical benefits. © 2018 American Heart Association, Inc.

Diabetic Kidney Disease: A Report From an ADA Consensus Conference

PubMed Central

Tuttle, Katherine R.; Bakris, George L.; Bilous, Rudolf W.; de Boer, Ian H.; Goldstein-Fuchs, Jordi; Hirsch, Irl B.; Kalantar-Zadeh, Kamyar; Narva, Andrew S.; Navaneethan, Sankar D.; Neumiller, Joshua J.; Patel, Uptal D.; Ratner, Robert E.; Whaley-Connell, Adam T.; Molitch, Mark E.

2014-01-01

The incidence and prevalence of diabetes mellitus have grown significantly throughout the world, due primarily to the increase in type 2 diabetes. This overall increase in the number of people with diabetes has had a major impact on development of diabetic kidney disease (DKD), one of the most frequent complications of both types of diabetes. DKD is the leading cause of end-stage renal disease (ESRD), accounting for approximately 50% of cases in the developed world. Although incidence rates for ESRD attributable to DKD have recently stabilized, these rates continue to rise in high-risk groups such as middle-aged African Americans, Native Americans, and Hispanics. The costs of care for people with DKD are extraordinarily high. In the Medicare population alone, DKD-related expenditures among this mostly older group were nearly $25 billion in 2011. Due to the high human and societal costs, the Consensus Conference on Chronic Kidney Disease and Diabetes was convened by the American Diabetes Association in collaboration with the American Society of Nephrology and the National Kidney Foundation to appraise issues regarding patient management, highlighting current practices and new directions. Major topic areas in DKD included 1) identification and monitoring, 2) cardiovascular disease and management of dyslipidemia, 3) hypertension and use of renin-angiotensin-aldosterone system blockade and mineralocorticoid receptor blockade, 4) glycemia measurement, hypoglycemia, and drug therapies, 5) nutrition and general care in advanced-stage chronic kidney disease, 6) children and adolescents, and 7) multidisciplinary approaches and medical home models for health care delivery. This current state summary and research recommendations are designed to guide advances in care and the generation of new knowledge that will meaningfully improve life for people with DKD. PMID:25249672

Diabetic kidney disease: a report from an ADA Consensus Conference.

PubMed

Tuttle, Katherine R; Bakris, George L; Bilous, Rudolf W; Chiang, Jane L; de Boer, Ian H; Goldstein-Fuchs, Jordi; Hirsch, Irl B; Kalantar-Zadeh, Kamyar; Narva, Andrew S; Navaneethan, Sankar D; Neumiller, Joshua J; Patel, Uptal D; Ratner, Robert E; Whaley-Connell, Adam T; Molitch, Mark E

2014-10-01

The incidence and prevalence of diabetes mellitus have grown significantly throughout the world, due primarily to the increase in type 2 diabetes. This overall increase in the number of people with diabetes has had a major impact on development of diabetic kidney disease (DKD), one of the most frequent complications of both types of diabetes. DKD is the leading cause of end-stage renal disease (ESRD), accounting for approximately 50% of cases in the developed world. Although incidence rates for ESRD attributable to DKD have recently stabilized, these rates continue to rise in high-risk groups such as middle-aged African Americans, Native Americans, and Hispanics. The costs of care for people with DKD are extraordinarily high. In the Medicare population alone, DKD-related expenditures among this mostly older group were nearly $25 billion in 2011. Due to the high human and societal costs, the Consensus Conference on Chronic Kidney Disease and Diabetes was convened by the American Diabetes Association in collaboration with the American Society of Nephrology and the National Kidney Foundation to appraise issues regarding patient management, highlighting current practices and new directions. Major topic areas in DKD included (1) identification and monitoring, (2) cardiovascular disease and management of dyslipidemia, (3) hypertension and use of renin-angiotensin-aldosterone system blockade and mineralocorticoid receptor blockade, (4) glycemia measurement, hypoglycemia, and drug therapies, (5) nutrition and general care in advanced-stage chronic kidney disease, (6) children and adolescents, and (7) multidisciplinary approaches and medical home models for health care delivery. This current state summary and research recommendations are designed to guide advances in care and the generation of new knowledge that will meaningfully improve life for people with DKD. Copyright © 2014 American Diabetes Association and the National Kidney Foundation. Published by Elsevier Inc. All rights reserved.

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

Aldosterone alters the chromatin structure of the murine endothelin-1 gene.

PubMed

Welch, Amanda K; Jeanette Lynch, I; Gumz, Michelle L; Cain, Brian D; Wingo, Charles S

2016-08-15

Aldosterone increases sodium reabsorption in the renal collecting duct and systemic blood pressure. Paradoxically, aldosterone also induces transcription of the endothelin-1 (Edn1) gene to increase protein (ET-1) levels, which inhibits sodium reabsorption. Here we investigated changes in the chromatin structure of the Edn1 gene of collecting duct cell lines in response to aldosterone treatment. The Edn1 gene has a CpG island that encompasses the transcription start site and four sites in the 5' regulatory region previously linked to transcriptional regulation. The chromatin structure of the Edn1 gene was investigated using a quantitative PCR-based DNaseI hypersensitivity assay in murine hepatocyte (AML12), renal cortical collecting duct (mpkCCDC14), outer medullary collecting duct1 (OMCD1), and inner medullary collecting duct-3 (IMCD-3) cell lines. The CpG island was uniformly accessible. One calcium-responsive NFAT element remained at low chromatin accessibility in all cell lines under all conditions tested. However, the second calcium responsive NFAT element located at -1563bp upstream became markedly more accessible in IMCD-3 cells exposed to aldosterone. Importantly, one established aldosterone hormone response element HRE at -671bp relative to the transcription start site was highly accessible, and another HRE (-551bp) became more accessible in aldosterone-treated IMCD-3 and OMCD1 cells. The evidence supports a model in which aldosterone activation of the mineralocorticoid receptor (MR) results in the MR-hormone complex binding at HRE at -671bp to open chromatin structure around other regulatory elements in the Edn1 gene. Published by Elsevier Inc.

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.

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.

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.

Association between urine aldosterone and diastolic function in patients with primary aldosteronism and essential hypertension.

PubMed

Chang, Yi-Yao; Lee, Hsiu-Hao; Hung, Chi-Sheng; Wu, Xue-Ming; Lee, Jen-Kuang; Wang, Shuo-Meng; Liao, Min-Tsun; Chen, Ying-Hsien; Wu, Vin-Cent; Wu, Kwan-Dun; Lin, Yen-Hung

2014-09-01

To investigate the association between aldosterone and cardiac diastolic dysfunction. We prospectively enrolled 20 patients with primary aldosteronism (PA) and 22 patients with essential hypertension (EH). Plasma aldosterone concentration, plasma renin activity, and 24-h urine aldosterone level were measured. Echocardiography, including tissue Doppler image recordings, was performed. PA patients had a significantly higher left ventricular (LV) mass index and worse LV diastolic function than those in EH patients. Among various measures of aldosterone, log-transformed 24-h urine aldosterone level had the most consistent correlation with diastolic function. Aldosterone is strongly associated with LV diastolic dysfunction. Twenty-four hour urine aldosterone is a good indicator to evaluate the impact of aldosterone on LV diastolic function. Copyright © 2014. Published by Elsevier Inc.

Effects of cilnidipine on sympathetic nerve activity and cardiorenal function in hypertensive patients with type 2 diabetes mellitus: association with BNP and aldosterone levels.

PubMed

Tanaka, Masami; Sekioka, Risa; Nishimura, Takeshi; Ichihara, Atsuhiro; Itoh, Hiroshi

2014-12-01

Hypertension stimulates the sympathetic nervous system and this phenomenon is exacerbated by diabetes mellitus. We investigated the effects of cilnidipine, an N/L-type calcium channel blocker, on aspects of this system in patients with type 2 diabetes mellitus. In 33 hypertensive patients with type 2 diabetes mellitus treated with a calcium channel blocker other than cilnidipine, we evaluated the influence of switching to cilnidipine on blood pressure, heart rate, catecholamine, plasma renin and aldosterone concentration, brain natriuretic peptide, urine liver-type fatty acid binding protein, and urinary albumin excretion ratio in the same patients by a cross-over design. Other biochemical parameters were also evaluated. Switching to cilnidipine did not change blood pressure but caused reduction in catecholamine concentrations in blood and urine and plasma aldosterone concentration, accompanied by significant reduction in brain natriuretic peptide, urine liver-type fatty acid binding protein, and albumin excretion ratio. These parameters other than brain natriuretic peptide were significantly increased after cilnidipine was changed to the original calcium channel blocker. In 33 hypertensive patients with type 2 diabetes mellitus, compared to other calcium channel blockers, cilnidipine suppressed sympathetic nerve activity and aldosterone, and significantly improved markers of cardiorenal disorders. Therefore, cilnidipine may be an important calcium channel blocker for use in combination with renin-angiotensin-aldosterone system inhibitors when dealing with hypertension complicated with diabetes mellitus. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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.

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

[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.

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

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.

Mineralocorticoid receptor antagonism prevents hedonic deficits induced by a chronic sodium appetite.

PubMed

Morris, Michael J; Na, Elisa S; Johnson, Alan Kim

2010-04-01

Our laboratory has reported that manipulations that provoke a robust sodium appetite (e.g., sodium depletion, deoxycorticosterone acetate) decrease lateral hypothalamic self-stimulation (LHSS) reward if rats are denied access to hypertonic saline solutions. The following studies investigated the interaction between chronic sodium appetite and the renin-angiotensin-aldosterone system on LHSS reward. In Experiment 1, animals treated with the diuretic furosemide (20 mg/kg) when denied access to saline exhibited an increase in the current required to produce 50% of the maximum LHSS response rate (ECu50) 48 hr after extracellular volume depletion. Furosemide-depleted rats that were allowed to drink 0.3 M saline after depletion, or that were treated with the selective mineralocorticoid receptor (MR) antagonist spironolactone, which significantly reduced sodium appetite, did not show ECu50 changes. In Experiment 2 chronic intracerebroventricular administration of the selective MR antagonist RU 28318 (10 microg/microl/hr) prevented decreases in the ECu50 induced by deoxycorticosterone acetate-no salt treatment. We conclude that an unresolved sodium appetite will reduce responding for rewards and that experimental manipulations that reduce sodium appetite (e.g., access to saline or blockade of MR) decrease hedonic deficits.

Blood pressure, hypertension, RAAS blockade, and drug therapy in diabetic kidney disease.

PubMed

Yamout, Hala; Lazich, Ivana; Bakris, George L

2014-05-01

Type 2 diabetes is the most common cause of CKD and ESRD in the United States and the Western world. Hypertension is prevalent in this cohort, and control of blood pressure is perhaps the most important risk factor to reduce CKD progression. The most recent blood pressure target recommended by the Kidney Disease: Improving Global Outcomes and Kidney Disease Outcomes Quality Initiative guideline committees is less than 140/90 mmHg for all patients with CKD. There is some evidence for those with 1 g or more of albuminuria, albeit weak, to support a blood pressure target of less than 130/80 mmHg. Multiple studies demonstrate that renin-angiotensin-aldosterone system (RAAS) blockers are important in reducing cardiovascular risk and progression of CKD in those with advanced proteinuric nephropathy. However, there is no evidence that they prevent nephropathy or that reduction in microalbuminuria alone is associated with slowed nephropathy progression. The purpose of this article is to review the major studies that have evaluated cardiovascular and kidney endpoints in patients with diabetes and the role of RAAS blockers in the treatment of this disease. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Abnormal aldosterone physiology and cardiometabolic risk factors.

PubMed

Vaidya, Anand; Underwood, Patricia C; Hopkins, Paul N; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H; Adler, Gail K

2013-04-01

Abnormal aldosterone physiology has been implicated in the pathogenesis of cardiometabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardiometabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the sodium-modulated aldosterone suppression-stimulation index (SASSI for serum and SAUSSI for urine), could predict cardiometabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal and restricted sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on liberal (maximally suppressed aldosterone) to the aldosterone on restricted (stimulated aldosterone) diets and associated with risk factors using adjusted regression models. Cardiometabolic risk factors associated with either impaired suppression of aldosterone on liberal diet, or impaired stimulation on restricted diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that constitute the metabolic syndrome, there was a strong positive association between the number of metabolic syndrome components (0-4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero metabolic syndrome components (86% for SASSI and 83% for SAUSSI). Assessing the physiological range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, or result from, early cardiometabolic abnormalities.

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

PubMed Central

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

2018-01-01

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

Effect of Swimming on the Production of Aldosterone in Rats

PubMed Central

Wang, Paulus S.; Jian, Cai-Yun; Yeh, Yung-Hsing; Chen, Yi-An; Wang, Kai-Lee; Lin, Yi-Chun; Chang, Ling-Ling; Wang, Guei-Jane; Wang, Shyi-Wu

2014-01-01

It has been demonstrated that exercise is one of the stresses known to increase the aldosterone secretion. Both potassium and angiotensin II (Ang II) levels are shown to be correlated with aldosterone production during exercise, but the mechanism is still unclear. In an in vivo study, male rats were catheterized via right jugular vein (RJV), and divided into four groups namely water immersion, swimming, lactate infusion (13 mg/kg/min) and pyruvate infusion (13 mg/kg/min) groups. Each group was treated for 10 min. Blood samples were collected at 0, 10, 15, 30, 60 and 120 min from RJV after administration. In an in vitro study, rat zona glomerulosa (ZG) cells were challenged by lactate (1–10 mM) in the presence or absence of Ang II (10−8 M) for 60 min. The levels of aldosterone in plasma and medium were measured by radioimmunoassay. Cell lysates were analyzed by immunoblotting assay. After exercise and lactate infusion, plasma levels of aldosterone and lactate were significantly higher than those in the control group. Swimming for 10 min significantly increased the plasma Ang II levels in male rats. Administration of lactate plus Ang II significantly increased aldosterone production and enhanced protein expression of steroidogenic acute regulatory protein (StAR) in ZG cells. These results demonstrated that acute exercise led to the increase of both aldosterone and Ang II secretion, which is associated with lactate action on ZG cells and might be dependent on the activity of renin-angiotensin system. PMID:25289701

Circulating Aldosterone and Natriuretic Peptides in the General Community: Relationship to Cardiorenal and Metabolic Disease

PubMed Central

Buglioni, Alessia; Cannone, Valentina; Cataliotti, Alessandro; Sangaralingham, S. Jeson; Heublein, Denise M.; Scott, Christopher G.; Bailey, Kent R.; Rodeheffer, Richard J.; Dessì-Fulgheri, Paolo; Sarzani, Riccardo; Burnett, John C.

2014-01-01

We sought to investigate the role of aldosterone as a mediator of disease and its relationship with the counter-regulatory natriuretic peptide (NP) system. We measured plasma aldosterone (n=1674; age ≥45 years old) in a random sample of the general population from Olmsted County, MN. In a multivariate logistic regression model, aldosterone analyzed as a continuous variable was associated with hypertension (HTN) (OR=1.75, 95%CI= 1.57,1.96; p<0.0001), obesity (OR=1.34, 95%CI= 1.21,1.48; p<0.0001), chronic kidney disease (CKD) (OR=1.39, 95%CI= 1.22,1.60; p<0.0001), central obesity (OR=1.47, 95%CI=1.32,1.63; p<0.0001), metabolic syndrome (MetS) (OR=1.41, 95%CI= 1.26,1.58; p<0.0001), high triglycerides (OR=1.23, 95%CI=1.11,1.36; p<0.0001), concentric left ventricular hypertrophy (cLVH) (OR=1.22, 95%CI= 1.09,1.38; p=0.0007) and atrial fibrillation (OR=1.24, 95%CI= 1.01,1.53; p=0.04), after adjusting for age and sex. The associations with HTN, central obesity, MetS, triglycerides and cLVH remained significant after further adjustment for BMI, NPs, and renal function. Furthermore, aldosterone in the highest tertile correlated with lower NP levels and increased mortality. Importantly, most of these associations remained significant even after excluding subjects with aldosterone levels above the normal range. In conclusion, we report that aldosterone is associated with HTN, CKD, obesity, MetS, cLVH, and lower NPs in the general community. Our data suggests that aldosterone, even within the normal range, may be a biomarker of cardiorenal and metabolic disease. Further studies are warranted to evaluate a therapeutic and preventive strategy to delay the onset and/or progression of disease, using mineralocorticoid antagonists or chronic NP administration in high risk subjects identified by plasma aldosterone. PMID:25368032

Preoperative Plasma Aldosterone Levels and Postoperative Atrial Fibrillation Occurrence Following Cardiac Surgery: A Review of Literature and Design of the ALDO-POAF Study (ALDOsterone for Prediction of Post-Operative Atrial Fibrillation).

PubMed

Chequel, Mathieu; Ollitrault, Pierre; Saloux, Eric; Parienti, Jean-Jacques; Fischer, Marc-Olivier; Desgué, Julien; Allouche, Stéphane; Milliez, Paul; Alexandre, Joachim

2016-01-01

Post-operative atrial fibrillation (POAF) is a major and frequent complication occurring after cardiac surgery, contributing to prolonged intensive care and hospital stays and is associated with several cardiovascular complications. The exact mechanisms and signaling pathways involved in the development of POAF seem to be multifactorial and remain to date incompletely understood. β-blockers and amiodarone are the first line preventive drugs but are partially effective and near 30% of POAF resist to these strategies. In this work, we review the current knowledge about pathophysiological POAF mechanisms and preventive pharmacological strategies. We also discuss the rational for the use of pre-operative plasma aldosterone and galectin-3 (Gal-3) levels as predictive biomarkers of POAF and the potential role of aldosterone antagonists in the POAF preventive strategy. POAF is a major complication occurring after cardiac surgery. In this context, there is some evidence indicating that renin-angiotensin-aldosterone system and Gal-3 could be very useful predictive biomarkers of POAF and potentially interesting therapeutic target to prevent POAF occurrence. We present the rationale and the design of the ALDO-POAF trial (ALDOsterone for prediction of Post- Operative Atrial Fibrillation, NCT 02814903).

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.

ABNORMAL ALDOSTERONE PHYSIOLOGY AND CARDIO-METABOLIC RISK FACTORS

PubMed Central

Vaidya, Anand; Underwood, Patricia C.; Hopkins, Paul N.; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H.; Adler, Gail K.

2013-01-01

Abnormal aldosterone physiology has been implicated in the pathogenesis of cardio-metabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardio-metabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI for serum and SAUSSI for urine), could predict cardio-metabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal (LIB) and restricted (RES) sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on LIB (maximally suppressed aldosterone) to aldosterone on RES (stimulated aldosterone) diets, and associated with risk factors using adjusted regression models. Cardio-metabolic risk factors associated with either impaired suppression of aldosterone on LIB diet, or impaired stimulation on RES diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that comprise the metabolic syndrome (MetS), there was a strong positive association between the number of MetS components (0–4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero MetS components (86% for SASSI and 83% for SAUSSI). Assessing the physiologic range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, and/or result from, early cardio-metabolic abnormalities. PMID:23399714

Synthesis of 19-nor-aldosterone, 18-hydroxy-19-nor-corticosterone and 18,19-dihydroxycorticosterone in the human aldosterone-producing adenoma.

PubMed

Takeda, Y; Lewicka, S; Koch, S; Bige, K; Vecsei, P; Abdelhamid, S; Cojocaru, M; Harnik, M

1990-11-30

The recently synthesized 18-C-steroid derivative, 19-nor-aldosterone(19-nor- aldo) and 18-hydroxy-19-nor-corticosterone(18-OH-19-nor-corticosterone) possess mineralocoroticoid and hypertensinogenic activity. They and an additional newly synthesized steriod, 18,19-dihydroxycorticosterone[18,19(OH)2-corticosterone], may play a role in the etiology and pathogenesis of disorders thought to be caused by steroids with mineralocorticoid and hypertensionogenic properties. In this study we provide evidence that 19-nor-aldo, 18-OH-19-nor-corticosterone and 18,19(OH)2-corticosterone are produced in vitro by aldosterone-producing adrenal adenomas and adenomas and adenoma of Cushing's syndrome. "silent" adrenal adenomas and the adjacent adrenal tissue. Measurable amounts of these steroids were found in the incubation fluids of adrenal tissues using specific RIAs performed after a sequence of HPLC systems. The rates of production of the three steroids were high in the aldosterone-producing adrenal adenomas and in adrenal hyperplasia compared with in either Cushing's adenoma or "silent" adenoma.

Therapeutic results of primary aldosteronism with special reference to renal or renovascular lesions.

PubMed

Nakada, T; Koike, H; Akiya, T; Katayama, T; Takata, M; Iida, H; Mizumura, Y

1988-01-01

A study was made of 9 patients with primary aldosteronism due to aldosterone-producing adenoma (APA) and 8 subjects with idiopathic adrenal hyperplasia (IHA) to clarify the pathogenesis of sustained hypertension after surgical or non-surgical treatment. Following each treatment, a complete improvement of hypertension was obtained in 12 patients (6 APA, 6 IHA), while 5 (3 APA, 2 IHA) showed still hypertensive status. Renal or renovascular lesions were prominent only in the hypertension-unchanged group. Under regular sodium diet, the ratio of urinary excretion of sodium to creatinine of this hypertensive group was significantly lower than that of the hypertension-improved group. However, the results of other renal function tests were similar in both groups. After respective treatments, suppressed plasma renin activity and elevated plasma aldosterone concentration were improved in all patients. In addition, patients of both groups showed normal response of the renin-aldosterone system following diuretic and dietary induced sodium and volume depletion. Based on these findings, renal or renovascular lesions appear to play an important role in the pathogenesis of maintenance of hypertension in this disorder after respective treatments.

Adrenalectomy prevents renal ischemia-reperfusion injury.

PubMed

Ramírez, Victoria; Trujillo, Joyce; Valdes, Rafael; Uribe, Norma; Cruz, Cristino; Gamba, Gerardo; Bobadilla, Norma A

2009-10-01

Spironolactone treatment prevents renal damage induced by ischemia-reperfusion (I/R), suggesting that renoprotection conferred by spironolactone is mediated by mineralocorticoid receptor (MR) blockade. It is possible, however, that this effect is due to other mechanisms. Therefore, this study evaluated whether adrenalectomy prevented renal damage induced by I/R. Three groups of Wistar rats were studied: 1) a group subjected to a sham surgery, 2) a group subjected to bilateral I/R, and 3) a group of rats in which adrenal glands were removed 3 days before induction of I/R. As expected, I/R resulted in renal dysfunction and severe tubular injury that was associated with a significant increase in tubular damage markers. In contrast, there was no renal dysfunction or tubular injury in rats that were adrenalectomized before I/R. These effects were demonstrated by normalization of glomerular filtration rate, markers of oxidative stress, and tubular injury markers in adrenalectomized rats. The renoprotection observed was associated with the reestablishment of nitric oxide metabolites, increased endothelial nitric oxide synthase expression and its activating phosphorylation, as well as normalization of Rho-kinase expression and ET(A) mRNA levels. Our results show that aldosterone plays a central role in the pathogenesis of renal damage induced by I/R and that MR blockade may be a promising strategy that opens a new therapeutic option for preventing acute renal injury.

Nebivolol and valsartan as a fixed-dose combination for the treatment of hypertension.

PubMed

Sander, Gary E; Giles, Thomas D

2015-04-01

The fixed-dose combination of nebivolol and valsartan drug has been clinically evaluated and demonstrated to represent a unique combination of nebivolol, a selective β1-adrenoceptor antagonist and a β3-adrenoceptor agonist; β3 receptor activation increases endothelial nitric oxide and produces vasodilation. Valsartan is highly selective angiotensin AT1 receptor blocker and exerts its major pharmacological effect by decreasing angiotensin II-induced vasoconstriction and production of aldosterone. The addition of nebivolol counteracts the effects of increased angiotensin II concentrations resulting from potent AT1 blockade. This review describes a recently completed trial establishing the efficacy of the nebivolol/valsartan combination. This review provides a literature search of pertinent pharmacological and clinical data that describes the mechanisms of both drugs individually and the results of a clinical trial comparing fixed-dose combinations of nebivolol with valsartan as compared with each drug as monotherapy. Fixed-dose combination drugs are intended to improve patient compliance and reduce drug costs, as well as to reduce long-term cardiovascular event rates and block counter-regulatory effects due to monotherapy. The vast majority of hypertensive patients will require at least two medications. We believe that the clinical evidence suggests that the combination of nebivolol with valsartan offers a definite clinical benefit, combining β1-adrenoceptor and angiotensin AT1 receptor blockade with β3 receptor activation and resultant increase in nitric oxide and vasodilation.

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.

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.

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.

Aldosterone and Mineralocorticoid Receptors-Physiology and Pathophysiology.

PubMed

Funder, John W

2017-05-11

Aldosterone is a uniquely terrestrial hormone, first appearing in lungfish, which have both gills and lungs. Mineralocorticoid receptors (MRs), on the other hand, evolved much earlier, and are found in cartilaginous and bony fish, presumptive ligand cortisol. MRs have equivalent high affinity for aldosterone, progesterone, and cortisol; in epithelia, despite much higher cortisol circulating levels, aldosterone selectively activates MRs by co-expression of the enzyme 11β-hydroxysteroid dehydrogenase, Type 11. In tissues in which the enzyme is not expressed, MRs are overwhelmingly occupied but not activated by cortisol, which normally thus acts as an MR antagonist; in tissue damage, however, cortisol mimics aldosterone and acts as an MR agonist. The risk profile for primary aldosteronism (PA) is much higher than that in age-, sex-, and blood pressure-matched essential hypertensives. High levels of aldosterone per se are not the problem: in chronic sodium deficiency, as seen in the monsoon season in the highlands of New Guinea, plasma aldosterone levels are extraordinarily high, but cause neither hypertension nor cardiovascular damage. Such damage occurs when aldosterone levels are out of the normal feedback control, and are inappropriately elevated for the salt status of the individual (or experimental animal). The question thus remains of how excess salt can synergize with elevated aldosterone levels to produce deleterious cardiovascular effects. One possible mechanism is through the agency of the elusive ouabain-like factors (OLFs). Such factors are secreted from the adrenal in response to ACTH (adrenalocortical tropic hormone), to angiotensin via AT2R, and-the polar opposite of aldosterone-to sodium loading. They act on blood vessels to cause vasoconstriction and thus elevate blood pressure to dump excess sodium through pressure natriuresis. Their levels are chronically elevated in PA in response to the continually elevated sodium status, and they thus act to constrict coronary and systemic arteries. In the context of the elevated blood volume and total body sodium in a PA patient, this raises blood pressure and acts as the proximate cause of cardiovascular damage. If this is the case, it would appear to offer new insights into therapy for PA. One would be the use of digibindin, or its more recent successors as antagonists of OLFs acting on Na/K ATPase at the vessel wall. A second would be to routinely combine a low dose MR antagonist, an ENaC inhibitor, and sodium restriction as first-line therapy for bilateral aldosterone overproduction. Finally, for unilateral cases post-surgery, there is good reason to include low-dose MRs in drug therapy if required, given the ability of cortisol in damaged blood vessels to mimic aldosterone vasoconstrictor action.

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.

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.

Associations between glycaemic control and activation of the renin-angiotensin-aldosterone system in participants with type 2 diabetes mellitus and hypertension.

PubMed

Griffin, T P; Wall, D; Browne, G A; Dennedy, M C; O'Shea, P M

2018-05-01

Introduction Hyperglycaemia increases succinate concentrations and succinate receptor activation in the kidney resulting in renin release. The aim of our study was to determine if there is an association between glycaemic control as evidenced by glycated haemoglobin values and activation of the renin-angiotensin-aldosterone system in patients with type 2 diabetes mellitus and hypertension. Methods A cross-sectional study was conducted at Galway University Hospitals between December 2014 and March 2015. Participants ( n = 66) were identified following interrogation of the electronic database for patients with type 2 diabetes mellitus. Baseline clinical demographics, aldosterone, plasma renin activity, direct renin concentration, urea and electrolytes, glycated haemoglobin, cholesterol, urine sodium and albumin creatinine ratio were recorded. Results There was a significant positive linear correlation between glycated haemoglobin and renin (both plasma renin activity [ P = 0.002] and direct renin concentration [ P = 0.008]) and between serum creatinine and aldosterone measured using both radioimmunoassay ( P = 0.008) and immunochemiluminometric assay ( P = 0.008). A significant negative linear correlation was demonstrated between serum sodium and plasma renin activity ( P = 0.005) and direct renin concentration ( P = 0.015) and between estimated glomerular filtration rate and aldosterone measured using radioimmunoassay ( P = 0.02) and immunochemiluminometric assay ( P = 0.016). A significant negative linear correlation existed between urine sodium and plasma renin activity ( P = 0.04) and aldosterone measured using radioimmunoassay ( P = 0.045). Conclusions There is a direct positive association between glycaemic control and renin. We advocate for renin measurement to be part of the diabetologist's armamentarium to assess, guide and optimize therapeutic strategies in patients with diabetes.

Hypokalemia and Pendrin Induction by Aldosterone.

PubMed

Xu, Ning; Hirohama, Daigoro; Ishizawa, Kenichi; Chang, Wen Xiu; Shimosawa, Tatsuo; Fujita, Toshiro; Uchida, Shunya; Shibata, Shigeru

2017-05-01

Aldosterone plays an important role in regulating Na-Cl reabsorption and blood pressure. Epithelial Na + channel, Na + -Cl - cotransporter, and Cl - /HCO 3 - exchanger pendrin are the major mediators of Na-Cl transport in the aldosterone-sensitive distal nephron. Existing evidence also suggests that plasma K + concentration affects renal Na-Cl handling. In this study, we posited that hypokalemia modulates the effects of aldosterone on pendrin in hyperaldosteronism. Chronic aldosterone infusion in mice increased pendrin levels at the plasma membrane, and correcting hypokalemia in this model almost completely blocked pendrin upregulation. However, hypokalemia induced by a low-K + diet resulted in pendrin downregulation along with reduced plasma aldosterone levels, indicating that both hypokalemia and aldosterone excess are necessary for pendrin induction. In contrast, decreased plasma K + levels were sufficient to increase Na + -Cl - cotransporter levels. We found that phosphorylation of mineralocorticoid receptor that prevents aldosterone binding in intercalated cells was suppressed by hypokalemia, which resulted in enhanced pendrin response to aldosterone, explaining the coordinated action of aldosterone and hypokalemia in pendrin regulation. Finally, to address the physiological significance of our observations, we administered aldosterone to mice lacking pendrin. Notably, plasma K + levels were significantly lower in pendrin knockout mice (2.7±0.1 mmol/L) than in wild-type mice (3.0±0.1 mmol/L) after aldosterone infusion, demonstrating that pendrin alleviates hypokalemia in a state of aldosterone excess. These data indicate that the decreased plasma K + levels promote pendrin induction by aldosterone, which, in concert with Na + -Cl - cotransporter, counteracts the progression of hypokalemia but promotes hypertension in primary aldosterone excess. © 2017 American Heart Association, Inc.

Aldosterone rapidly activates Src kinase in M-1 cells involving the mineralocorticoid receptor and HSP84.

PubMed

Braun, Sabine; Lösel, Ralf; Wehling, Martin; Boldyreff, Brigitte

2004-07-16

We investigated the effect of aldosterone on Src kinase. In the kidney cell line, M-1 aldosterone leads to a >2-fold transient activation of Src kinase seen as early as 2 min after aldosterone administration. Maximal Src kinase activation was measured at an aldosterone concentration of 1 nM. In parallel to activation, autophosphorylation at Tyr-416 of Src kinase increased. Src kinase activation was blocked by spironolactone. Aldosterone led to increased association of Src with HSP84. Furthermore, rapamycin blocked aldosterone-induced Src activation. We conclude that Src activation by aldosterone is mediated through the mineralocorticoid receptor and HSP84.

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.

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.

[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.

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.

Small-Conductance Ca2+-Activated Potassium Channels Negatively Regulate Aldosterone Secretion in Human Adrenocortical Cells.

PubMed

Yang, Tingting; Zhang, Hai-Liang; Liang, Qingnan; Shi, Yingtang; Mei, Yan-Ai; Barrett, Paula Q; Hu, Changlong

2016-09-01

Aldosterone, which plays a key role in maintaining water and electrolyte balance, is produced by zona glomerulosa cells of the adrenal cortex. Autonomous overproduction of aldosterone from zona glomerulosa cells causes primary hyperaldosteronism. Recent clinical studies have highlighted the pathological role of the KCNJ5 potassium channel in primary hyperaldosteronism. Our objective was to determine whether small-conductance Ca(2+)-activated potassium (SK) channels may also regulate aldosterone secretion in human adrenocortical cells. We found that apamin, the prototypic inhibitor of SK channels, decreased membrane voltage, raised intracellular Ca(2+) and dose dependently increased aldosterone secretion from human adrenocortical H295R cells. By contrast, 1-Ethyl-2-benzimidazolinone, an agonist of SK channels, antagonized apamin's action and decreased aldosterone secretion. Commensurate with an increase in aldosterone production, apamin increased mRNA expression of steroidogenic acute regulatory protein and aldosterone synthase that control the early and late rate-limiting steps in aldosterone biosynthesis, respectively. In addition, apamin increased angiotensin II-stimulated aldosterone secretion, whereas 1-Ethyl-2-benzimidazolinone suppressed both angiotensin II- and high K(+)-stimulated production of aldosterone in H295R cells. These findings were supported by apamin-modulation of basal and angiotensin II-stimulated aldosterone secretion from acutely prepared slices of human adrenals. We conclude that SK channel activity negatively regulates aldosterone secretion in human adrenocortical cells. Genetic association studies are necessary to determine whether mutations in SK channel subtype 2 genes may also drive aldosterone excess in primary hyperaldosteronism. © 2016 American Heart Association, Inc.

Aldosterone mediates its rapid effects in vascular endothelial cells through GPER activation.

PubMed

Gros, Robert; Ding, Qingming; Liu, Bonan; Chorazyczewski, Jozef; Feldman, Ross D

2013-03-01

The importance of the rapid vascular effects of aldosterone is increasingly appreciated. Through these rapid pathways, aldosterone has been shown to regulate vascular contractility, cell growth, and apoptosis. In our most recent studies, we demonstrated the effects of aldosterone on cell growth and contractility in vascular smooth muscle cells. We showed that these effects could occur via activation of the classic mineralocorticoid receptor, as well the recently characterized G protein-coupled estrogen receptor (GPER), initially characterized as an estrogen-specific receptor. However, the mechanisms underlying aldosterone's endothelium-dependent actions are unknown. Furthermore, the ERK regulatory and proapoptotic effects of aldosterone mediated by GPER activation in cultured vascular smooth muscle cells were only apparent when GPER was reintroduced into these cells by gene transfer. Whether GPER activation via aldosterone might be an important regulator in native vascular cells has been questioned. Therefore, to determine the role of GPER in mediating aldosterone's effects on cell growth and vascular reactivity in native cells, we examined rat aortic vascular endothelial cells, a model characterized by persistent robust expression of GPER, but without detectable mineralocorticoid receptor expression. In these endothelial cells, the GPER agonist G1 mediates a rapid increase in ERK phosphorylation that is wholly GPER-dependent, paralleling the actions of aldosterone. The effects of G1 and aldosterone to stimulate ERK phosphorylation paralleled their proapoptotic and antiproliferative effects. In previous studies, we reported that aldosterone mediates a rapid endothelium-dependent vasodilatory effect, antagonistic to its direct vasoconstrictor effect in endothelium-denuded preparations. Using a rat aortic ring/organ bath preparation to determine the GPER dependence of aldosterone's endothelium-dependent vasodilator effects, we demonstrate that aldosterone inhibits phenylephrine-mediated contraction. This vasodilator effect parallels the actions of the GPER agonist G1. Furthermore, the effects of aldosterone were completely ablated by the GPER antagonist G15. These data support an important role of GPER activation in aldosterone-mediated regulation of endothelial cell growth, as well as in aldosterone's endothelium-mediated regulation of vasoreactivity.

Evaluation of the Effects of Various Sound Pressure Levels on the Level of Serum Aldosterone Concentration in Rats

PubMed Central

Nassiri, Parvin; Zare, Sajad; Monazzam, Mohammad R.; Pourbakht, Akram; Azam, Kamal; Golmohammadi, Taghi

2017-01-01

Introduction: Noise exposure may have anatomical, nonauditory, and auditory influences. Considering nonauditory impacts, noise exposure can cause alterations in the automatic nervous system, including increased pulse rates, heightened blood pressure, and abnormal secretion of hormones. The present study aimed at examining the effect of various sound pressure levels (SPLs) on the serum aldosterone level among rats. Materials and Methods: A total of 45 adult male rats with an age range of 3 to 4 months and a weight of 200 ± 50 g were randomly divided into 15 groups of three. Three groups were considered as the control groups and the rest (i.e., 12 groups) as the case groups. Rats of the case groups were exposed to SPLs of 85, 95, and 105 dBA. White noise was used as the noise to which the rats were exposed. To measure the level of rats’ serum aldosterone, 3 mL of each rat’s sample blood was directly taken from the heart of anesthetized animals by using syringes. The taken blood samples were put in labeled test tubes that contained anticoagulant Ethylenediaminetetraacetic acid. In the laboratory, the level of aldosterone was assessed through Enzyme-linked immunosorbent assay protocol. The collected data were analyzed by the use of Statistical Package for Social Sciences (SPSS) version 18. Results: The results revealed that there was no significant change in the level of rats’ serum aldosterone as a result of exposure to SPLs of 65, 85, and 95 dBA. However, the level of serum aldosterone experienced a remarkable increase after exposure to the SPL of 105 dBA (P < 0.001). Thus, the SPL had a significant impact on the serum aldosterone level (P < 0.001). In contrast, the exposure time and the level of potassium in the used water did not have any measurable influence on the level of serum aldosterone (P = 0.25 and 0.39). Conclusion: The findings of this study demonstrated that serum aldosterone can be used as a biomarker in the face of sound exposure. PMID:28816207

Eplerenone: a selective aldosterone receptor antagonist for patients with heart failure.

PubMed

Barnes, Brian J; Howard, Patricia A

2005-01-01

To evaluate the pharmacology, pharmacokinetics, safety, and clinical use of eplerenone in heart failure (HF). English-language MEDLINE searches were performed from 1966 to May 2004. Key words included eplerenone, aldosterone receptor antagonist, heart failure, myocardial infarction, left-ventricular dysfunction, and cost-effectiveness. Additional references were identified from bibliographies of selected articles. Human trials evaluating the efficacy, safety, and cost-effectiveness of aldosterone receptor antagonists in HF were evaluated. Eplerenone is the first selective aldosterone receptor antagonist. The drug is indicated to improve the survival of stable patients with left-ventricular systolic dysfunction (ejection fraction <40%) and clinical evidence of HF following acute myocardial infarction. Efficacy and safety in this population have been demonstrated in a large, randomized clinical trial. Eplerenone is associated with severe and sometimes life-threatening hyperkalemia. Patients with reduced renal function and diabetes, as well as those on other drugs that increase potassium levels, are at highest risk. Eplerenone is metabolized by the cytochrome P450 system and may interact with drugs that interfere with this system. A major advantage of eplerenone over the nonselective aldosterone receptor antagonist spironolactone is lack of binding to progesterone and androgen receptors, which is associated with drug-induced gynecomastia, breast pain, and impotence. The addition of eplerenone to traditional HF therapy has been shown to reduce morbidity and mortality in patients who develop left-ventricular dysfunction after acute myocardial infarction. Eplerenone's selectivity reduces sex hormone-related adverse effects. Despite these benefits, the overall cost-effectiveness has yet to be determined.

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

PubMed Central

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

2011-01-01

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 AT2 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. PMID:21951628

Aldosterone and cardiovascular disease: the heart of the matter

PubMed Central

He, B. Julie; Anderson, Mark E.

2012-01-01

Aldosterone contributes to the endocrine basis of heart failure and studies on cardiac aldosterone signaling have reinforced its value as a therapeutic target. Recent focus has shifted to new roles of aldosterone that appear to depend on co-existing pathologic stimuli, cell type, and disease etiology. This review evaluates recent advances in mechanisms underlying aldosterone-induced cardiac disease and highlights the interplay between aldosterone and Ca2+ and calmodulin dependent protein kinase II, whose hyperactivity during heart failure contributes to disease progression. Increasing evidence implicates aldosterone in diastolic dysfunction, and there is need to develop more targeted therapeutics such as aldosterone synthase inhibitors and molecularly specific anti-oxidants. Despite accumulating knowledge, many questions still persist and will likely dictate areas of future research. PMID:23040074

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

Aldosterone sensitizes connecting tubule glomerular feedback via the aldosterone receptor GPR30

PubMed Central

Ren, YiLin; D'Ambrosio, Martin A.; Garvin, Jeffrey L.; Leung, Pablo; Kutskill, Kristopher; Wang, Hong; Peterson, Edward L.

2014-01-01

Increasing Na delivery to epithelial Na channels (ENaC) in the connecting tubule (CNT) dilates the afferent arteriole (Af-Art), a process we call connecting tubule glomerular feedback (CTGF). We hypothesize that aldosterone sensitizes CTGF via a nongenomic mechanism that stimulates CNT ENaC via the aldosterone receptor GPR30. Rabbit Af-Arts and their adherent CNTs were microdissected and simultaneously perfused. Two consecutive CTGF curves were elicited by increasing luminal NaCl in the CNT. During the control period, the concentration of NaCl that elicited a half-maximal response (EC50) was 37.0 ± 2.0 mmol/l; addition of aldosterone 10−8 mol/l to the CNT lumen caused a left-shift (decrease) in EC50 to 19.3 ± 1.3 mmol/l (P = 0.001 vs. control; n = 6). Neither the transcription inhibitor actinomycin D nor the translation inhibitor cycloheximide prevented the effect of aldosterone (control EC50 = 34.7 ± 1.9 mmol/l; aldosterone+actinomycin D EC50 = 22.6 ± 1.6 mmol/l; P < 0.001 and control EC50 = 32.4 ± 4.3 mmol/l; aldosterone+cycloheximide EC50 = 17.4 ± 3.3 mmol/l; P < 0.001). The aldosterone antagonist eplerenone prevented the sensitization of CTGF by aldosterone (control EC50 = 33.2 ± 1.7 mmol/l; aldosterone+eplerenone EC50 = 33.5 ± 1.3 mmol/l; n = 7). The GPR30 receptor blocker G-36 blocked the sensitization of CTGF by aldosterone (aldosterone EC50 = 16.5 ± 1.9 mmol/l; aldosterone+G-36 EC50 = 29.0 ± 2.1 mmol/l; n = 7; P < 0.001). Finally, we found that the sensitization of CTGF by aldosterone was mediated, at least in part, by the sodium/hydrogen exchanger (NHE). We conclude that aldosterone in the CNT lumen sensitizes CTGF via a nongenomic effect involving GPR30 receptors and NHE. Sensitized CTGF induced by aldosterone may contribute to renal damage by increasing Af-Art dilation and glomerular capillary pressure (glomerular barotrauma). PMID:24966088

Reversible heart rhythm complexity impairment in patients with primary aldosteronism

NASA Astrophysics Data System (ADS)

Lin, Yen-Hung; Wu, Vin-Cent; Lo, Men-Tzung; Wu, Xue-Ming; Hung, Chi-Sheng; Wu, Kwan-Dun; Lin, Chen; Ho, Yi-Lwun; Stowasser, Michael; Peng, Chung-Kang

2015-08-01

Excess aldosterone secretion in patients with primary aldosteronism (PA) impairs their cardiovascular system. Heart rhythm complexity analysis, derived from heart rate variability (HRV), is a powerful tool to quantify the complex regulatory dynamics of human physiology. We prospectively analyzed 20 patients with aldosterone producing adenoma (APA) that underwent adrenalectomy and 25 patients with essential hypertension (EH). The heart rate data were analyzed by conventional HRV and heart rhythm complexity analysis including detrended fluctuation analysis (DFA) and multiscale entropy (MSE). We found APA patients had significantly decreased DFAα2 on DFA analysis and decreased area 1-5, area 6-15, and area 6-20 on MSE analysis (all p < 0.05). Area 1-5, area 6-15, area 6-20 in the MSE study correlated significantly with log-transformed renin activity and log-transformed aldosterone-renin ratio (all p < = 0.01). The conventional HRV parameters were comparable between PA and EH patients. After adrenalectomy, all the altered DFA and MSE parameters improved significantly (all p < 0.05). The conventional HRV parameters did not change. Our result suggested that heart rhythm complexity is impaired in APA patients and this is at least partially reversed by adrenalectomy.

Circulating aldosterone induces the apical accumulation of the proton pumping V-ATPase and increases proton secretion in clear cells in the caput epididymis.

PubMed

Roy, Jeremy W; Hill, Eric; Ruan, Ye Chun; Vedovelli, Luca; Păunescu, Teodor G; Brown, Dennis; Breton, Sylvie

2013-08-15

Clear cells express the vacuolar proton-pumping H(+)-ATPase (V-ATPase) and acidify the lumen of the epididymis, a process that is essential for male fertility. The renin-angiotensin-aldosterone system (RAAS) regulates fluid and electrolyte balance in the epididymis, and a previous study showed binding of aldosterone exclusively to epididymal clear cells (Hinton BT, Keefer DA. Steroid Biochem 23: 231-233, 1985). We examined here the role of aldosterone in the regulation of V-ATPase in the epididymis. RT-PCR showed expression of the mineralocorticoid receptor [MR; nuclear receptor subfamily 3, group C member 2 (NR3C2)] and 11-β-dehydrogenase isozyme 2 (HSD11β2) mRNAs specifically in clear cells, isolated by fluorescence-activated cell sorting from B1-enhanced green fluorescent protein (EGFP) mice. Tail vein injection of adult rats with aldosterone, 1,2-dioctanoyl-sn-glycerol (DOG), or 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) induced V-ATPase apical membrane accumulation and extension of V-ATPase-labeled microvilli in clear cells in the caput epididymis but not in the cauda. V-ATPase activity was measured in EGFP-expressing clear cells using the intracellular pH (pHi)-sensing dye seminaphthorhodafluor-5F-5-(and 6)-carboxylic acid, acetoxymethyl ester acetate (SNARF-5F). Aldosterone induced a rapid increase in the rate of Na(+)- and bicarbonate-independent pHi recovery following an NH4Cl-induced acid load in clear cells isolated from the caput but not the cauda. This effect was abolished by concanamycin A, spironolactone, and chelerythrine but not myristoylated-protein kinase inhibitor (mPKI) or mifepristone. Thus aldosterone increases V-ATPase-dependent proton secretion in clear cells in the caput epididymis via MR/NR3C2 and PKC activation. This study, therefore, identifies aldosterone as an active member of the RAAS for the regulation of luminal acidification in the proximal epididymis.

NADPH Oxidase-Derived H2O2 Contributes to Angiotensin II-Induced Aldosterone Synthesis in Human and Rat Adrenal Cortical Cells

PubMed Central

Rajamohan, Senthilkumar B.; Raghuraman, Gayatri; Prabhakar, Nanduri R.

2012-01-01

Abstract Background The Renin-Angiotensin-Aldosterone-System plays a pivotal role in hypertension. Angiotensin II (Ang II) is a major regulator of aldosterone synthesis and secretion, and it is known to facilitate reactive oxygen species (ROS) generation in many cell types. Aims: Here, we assessed the role of ROS signaling in Ang II-induced aldosterone synthesis by focusing on the regulation of aldosterone synthase (CYP11B2), a cytochrome P450 oxidase that catalyzes the final step in aldosterone biosynthetic pathway. Results: Ang II increased CYP11B2 activity, mRNA and protein with a concomitant elevation of 6-Carboxy- 2′,7′-dichlorodihydrofluorescein diacetate fluorescence, malondialdehyde and protein carbonyl levels (indices of ROS), NADPH oxidase (Nox) activity, and H2O2 levels in human and rat adrenal cortical cells. The expression of nuclear receptor related 1 protein, a transcription factor known to regulate CYP11B2 expression, was also augmented by Ang II. These Ang II-evoked effects were either abolished or attenuated by pretreatment of cells with either Ang II type I receptor (AT1R) antagonist, or antioxidants or Nox inhibitor or siRNA silencing of Nox1, 2 and 4, or inhibitors of phospholipase C and protein kinase C. Exogenous H2O2 mimicked the facilitatory effects of Ang II on CYP11B2 activity, mRNA, and protein expression, and these changes were significantly reduced by PEG-catalase. Innovation: ROS, particularly H2O2, is identified as a key regulator of aldosterone production. Conclusion: Our results suggest that Ang II facilitates CYP11B2 activity and the ensuing aldosterone production via activation of AT1R-Nox-H2O2 signaling pathway. Antioxid. Redox Signal. 17, 445–459. PMID:22214405

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.

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.

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.

Diagnostic rate of primary aldosteronism in Emilia-Romagna, Northern Italy, during 16 years (2000-2015).

PubMed

Rossi, Ermanno; Perazzoli, Franco; Negro, Aurelio; Magnani, Antonia

2017-08-01

Although primary aldosteronism is considered the most common form of endocrine hypertension, the diagnostic rate of primary aldosteronism in the territory is unknown. The aims of the current study were to compare the number of patients discharged with International Classification of Diseases 9 Clinical Modification codes compatible with primary aldosteronism from all the hospitals in Emilia-Romagna during 16 years (from 2000 to 2015) with the number of expected cases of primary aldosteronism, and to compare the number of patients with primary aldosteronism who underwent adrenalectomy in the period 2000-2015 with the number of expected cases of unilateral primary aldosteronism. We accessed the Database of the Emilia-Romagna Health Service to select all patients from the age of 20 years discharged with International Classification of Diseases 9 Clinical Modification codes compatible with primary aldosteronism and, among them, those who underwent adrenalectomy in the same period. The prevalence of hypertension in Emilia-Romagna from the age of 20 years was drawn from the Health Search Database. The population from the age of 20 years in Emilia-Romagna has been drawn from the Italian National Statistical Institute. We hypothesized a prevalence of primary aldosteronism of 5% among hypertensive patients and a prevalence of unilateral subtypes of 30% among the primary aldosteronism patients. A total of 992 patients have been discharged with codes consistent with primary aldosteronism during 16 years in Emilia-Romagna, that is 1.9% of the expected cases of primary aldosteronism. A total of 160 of them underwent adrenalectomy in the same period, which corresponds to 1% of the expected cases of unilateral primary aldosteronism in Emilia-Romagna. Our results clearly indicate that primary aldosteronism is dramatically underdiagnosed and undertreated.

Long-term treatment with aldosterone slows the progression of age-related hearing loss.

PubMed

Halonen, Joshua; Hinton, Ashley S; Frisina, Robert D; Ding, Bo; Zhu, Xiaoxia; Walton, Joseph P

2016-06-01

Age-related hearing loss (ARHL), clinically referred to as presbycusis, is one of the three most prevalent chronic medical conditions of our elderly, with the majority of persons over the age of 60 suffering from some degree of ARHL. The progressive loss of auditory sensitivity and perceptual capability results in significant declines in workplace productivity, quality of life, cognition and abilities to communicate effectively. Aldosterone is a mineralocorticoid hormone produced in the adrenal glands and plays a role in the maintenance of key ion pumps, including the Na-K(+)-Cl co-transporter 1 or NKCC1, which is involved in homeostatic maintenance of the endocochlear potential. Previously we reported that aldosterone (1 μM) increases NKCC1 protein expression in vitro and that this up-regulation of NKCC1 was not dose-dependent (dosing range from 1 nM to 100 μM). In the current study we measured behavioral and electrophysiological hearing function in middle-aged mice following long-term systemic treatment with aldosterone. We also confirmed that blood pressure remained stable during treatment and that NKCC1 protein expression was upregulated. Pre-pulse inhibition of the acoustic startle response was used as a functional measure of hearing, and the auditory brainstem response was used as an objective measure of peripheral sensitivity. Long-term treatment with aldosterone improved both behavioral and physiological measures of hearing (ABR thresholds). These results are the first to demonstrate a protective effect of aldosterone on age-related hearing loss and pave the way for translational drug development, using aldosterone as a key component to prevent or slow down the progression of ARHL. Copyright © 2016 Elsevier B.V. All rights reserved.

Adrenalectomy amplifies aldosterone induced injury in cardiovascular tissue: an effect attenuated by adrenally derived steroids.

PubMed

Brem, Andrew S; Morris, David J; Li, Xiangpo; Ge, Yan; Shaw, Sunil; Gong, Rujun

2013-03-01

Aldosterone induces fibrotic changes in cardiovascular tissues but its effects have usually been demonstrated in models of pre-existing renal injury and/or hypertension. This study tests the hypothesis that aldosterone can directly induce vascular fibrotic changes in the absence of prior renal injury or hypertension. Experiments were conducted in intact or adrenalectomized (ADX) mice. Mice were divided into groups and treated for 1 week with vehicle or aldosterone (8 μg/kg/day)± inhibitor (800 μg/kg/day): CONTROLS, mice treated with aldosterone, ADX-CONTROLS, ADX+corticosterone (CORT 8 μg/kg/day), ADX with aldosterone, ADX with aldosterone plus the mineralocorticoid receptor (MR) antagonist RU-318, ADX with aldosterone+CORT (CORT inhibitor dose), and ADX with aldosterone+11-dehydro-CORT. Aortic smooth muscle to collagen ratio, aorta intimal thickness (μm), heart weight/body weight ratio (mg/gm), and left ventricular collagen (%) were measured. Prior to sacrifice, blood pressures were normal in all animals. Lower dose CORT alone had no effect on any of the variables examined. Aldosterone exposure was associated with extra-cellular matrix accumulation in cardiovascular tissues in intact mice and adrenalectomy exacerbated these effects. RU-318, CORT (inhibitor dose), and 11-deydro-CORT each attenuated the early fibrotic changes induced by aldosterone. In the heart, aldosterone exposure affected all the parameters measured and caused intimal hypercellularity with monocytes adhering to endothelial cells lining coronary vessels. Cultured endothelial cells exposed to aldosterone (10nM) released E-selectin, produced collagen, and promoted monocyte adhesion. These effects were inhibited by RU-318 and 11-deydro-CORT but not by CORT. Thus, adrenalectomy enhances aldosterone induced early fibrotic changes in heart and aorta. Aldosterone initially targets vascular endothelial cells. MR antagonists and 11-dehydro-CORT, an 11β-HSD dehydrogenase end-product, directly attenuate these effects. Copyright © 2012 Elsevier Inc. All rights reserved.

Aldosterone Induced Galectin-3 Secretion In Vitro and In Vivo: From Cells to Humans

PubMed Central

Lin, Yen-Hung; Chou, Chia-Hung; Wu, Xue-Ming; Chang, Yi-Yao; Hung, Chi-Sheng; Chen, Ying-Hsien; Tzeng, Yu-Lin; Wu, Vin-Cent; Ho, Yi-Lwun; Hsieh, Fon-Jou; Wu, Kwan-Dun

2014-01-01

Context Patients with primary aldosteronism are associated with increased myocardial fibrosis. Galectin-3 is one of the most important mediators between macrophage activation and myocardial fibrosis. Objective To investigate whether aldosterone induces galectin-3 secretion in vitro and in vivo. Methods and Results We investigated the possible molecular mechanism of aldosterone-induced galectin-3 secretion in macrophage cell lines (THP-1 and RAW 264.7 cells). Aldosterone induced galectin-3 secretion through mineralocorticoid receptors via the PI3K/Akt and NF-κB transcription signaling pathways. In addition, aldosterone-induced galectin-3 expression enhanced fibrosis-related factor expression in fibroblasts. We observed that galectin-3 mRNA from peripheral blood mononuclear cells and serum galectin-3 levels were both significantly increased in mice implanted with aldosterone pellets on days 7 and 14. We then conducted a prospective preliminary clinical study to investigate the association between aldosterone and galectin-3. Patients with aldosterone-producing adenoma had a significantly higher plasma galectin-3 level than patients with essential hypertension. One year after adrenalectomy, the plasma galectin-3 level had decreased significantly in the patients with aldosterone-producing adenoma. Conclusion This study demonstrated that aldosterone could induce galectin-3 secretion in vitro and in vivo. PMID:25180794

24-hour urinary aldosterone excretion test

MedlinePlus

Aldosterone - urine; Addison disease - urine aldosterone; Cirrhosis - serum aldosterone ... A 24-hour urine sample is needed. You will need to collect your urine over 24 hours . Your health care provider will tell ...

Overview of aldosterone-related genetic syndromes and recent advances.

PubMed

Zennaro, Maria-Christina; Fernandes-Rosa, Fabio L; Boulkroun, Sheerazed

2018-06-01

Primary aldosteronism is the most common form of secondary hypertension. Early diagnosis and treatment are key to cure of hypertension and prevention of cardiovascular complications. Recent genetic discoveries have improved our understanding on the pathophysiology of aldosterone production and triggered the development of new diagnostic procedures and targeted treatments for primary aldosteronism. Different inherited genetic abnormalities distinguish specific forms of familial hyperaldosteronism. Somatic mutations are found not only in aldosterone-producing adenoma (APA), leading to primary aldosteronism, but also in aldosterone producing cell clusters of normal and micronodules from image-negative adrenal glands. Genetic knowledge has allowed the discovery of surrogate biomarkers and specific pharmacological inhibitors. Ageing appears to be associated with dysregulated and relatively autonomous aldosterone production. New biochemical markers and pharmacological approaches may allow preoperative identification of somatic mutation carriers and use of targeted treatments.

[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.

Endocrine system dynamics and MS epidemiology.

PubMed

Moynihan, James; Moore, Helena

2010-05-01

In the kidney there is a co-transport relationship in the nephron between the reabsorption of positive Na(+) ions and the reabsorption of negative ions such as uric acid anions. Uric acid acts as an anti-oxidant and it has been shown to have a sealing effect on the blood-brain barrier. The theory developed here is that chronic neurological vasoconstriction in cool environmental conditions injects an offset into the rennin-angiotensin-aldosterone system (RAAS) blood pressure control loop and reduces demand for angiotensin and aldosterone. (Aldosterone is produced in the adrenal gland and has a direct effect on renal reabsorption of Na(+) ions.) Via co-transport these conditions will reduce the body's ability to reabsorb uric acid and this in turn will weaken the integrity of the blood-brain barrier. Also, in cool environments, where levels of vasopressin (ADH) and aldosterone are lower, the gain of the hypothalamus-pituitary-adrenal gland (HPA) axis is reduced so that the production average levels of ACTH, cortisone and aldosterone will be biased at a lower level and the kidney-local levels of aldosterone in particular will remain lower. This paper develops these ideas and suggests that they can help explain the traditionally-recognized latitudinal gradient in MS epidemiology. Also, acclimatization to heat encourages sweating, which should create a greater demand for the renal reabsorption of Na(+) ions which enables greater reabsorption of uric acid. Therefore people living at low latitudes should have a lower chance of hypouricemia and a lower chance of developing MS. In fact people who spend their first fifteen years in the tropics almost never go onto develop MS. And MS patients in relapse are consistently hypouricemic. This hypothesis can explain both of these facts. The paper goes onto show how the MS condition will tend to progress because of a number of self-sustaining effects: over time the immune system becomes more targeted to myelin, MS patients are unlikely to become acclimatized to heat because they tend to avoid heat since demyelinated nerve function is worsened by elevated temperature, and the normal circadian excitation of the HPA axis gets weaker under the benign environmental conditions typically adopted by MS patients as the disease develops.

[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.

Fenofibrate inhibits aldosterone-induced apoptosis in adult rat ventricular myocytes via stress-activated kinase-dependent mechanisms

PubMed Central

De Silva, Deepa S.; Wilson, Richard M.; Hutchinson, Christoph; Ip, Peter C.; Garcia, Anthony G.; Lancel, Steve; Ito, Masa; Pimentel, David R.; Sam, Flora

2009-01-01

Aldosterone induces extracellular signal-regulated kinase (ERK)-dependent cardiac remodeling. Fenofibrate improves cardiac remodeling in adult rat ventricular myocytes (ARVM) partly via inhibition of aldosterone-induced ERK1/2 phosphorylation and inhibition of matrix metalloproteinases. We sought to determine whether aldosterone caused apoptosis in cultured ARVM and whether fenofibrate ameliorated the apoptosis. Aldosterone (1 μM) induced apoptosis by increasing terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive nuclei in ARVM. Spironolactone (100 nM), an aldosterone receptor antagonist, but not RU-486, a glucocorticoid receptor, inhibited aldosterone-mediated apoptosis, indicating that the mineralocorticoid receptor (MR) plays a role. SP-600125 (3 μM)—a selective inhibitor of c-Jun NH2-terminal kinase (JNK)—inhibited aldosterone-induced apoptosis in ARVM. Although aldosterone increased the expression of both stress-activated protein kinases, pretreatment with fenofibrate (10 μM) decreased aldosterone-mediated apoptosis by inhibiting only JNK phosphorylation and the aldosterone-induced increases in Bax, p53, and cleaved caspase-3 and decreases in Bcl-2 protein expression in ARVM. In vivo studies demonstrated that chronic fenofibrate (100 mg·kg body wt−1·day−1) inhibited myocardial Bax and increased Bcl-2 expression in aldosterone-induced cardiac hypertrophy. Similarly, eplerenone, a selective MR inhibitor, used in chronic pressure-overload ascending aortic constriction inhibited myocardial Bax expression but had no effect on Bcl-2 expression. Therefore, involvement of JNK MAPK-dependent mitochondrial death pathway mediates ARVM aldosterone-induced apoptosis and is inhibited by fenofibrate, a peroxisome proliferator-activated receptor (PPAR)α ligand. Fenofibrate mediates beneficial effects in cardiac remodeling by inhibiting programmed cell death and the stress-activated kinases. PMID:19395558

Aldosterone-Signaling Defect Exacerbates Sodium Wasting in Very Preterm Neonates: The Premaldo Study.

PubMed

Martinerie, Laetitia; Pussard, Eric; Yousef, Nadya; Cosson, Claudine; Lema, Ingrid; Husseini, Khaled; Mur, Sébastien; Lombès, Marc; Boileau, Pascal

2015-11-01

The neonatal period, notably in preterm infants, is characterized by high sodium wasting, implying that aldosterone, the main hormone regulating sodium reabsorption, is unable to maintain sodium homeostasis. This study sought to assess aldosterone secretion and action in neonates according to gestational age (GA). This was a multicenter prospective study (NCT01176162) conducted between 2011 and 2014 at five neonatology departments in France. Infants were followed during their first 3 months. The 155 newborns included were classified into three groups: Group 1 (n = 46 patients), <33 gestational weeks (GW); Group 2 (n = 67 patients), 33-36 GW; and Group 3 (n = 42 patients), ≥37 GW. Plasma aldosterone was measured in umbilical cord blood. Urinary aldosterone (UAldo) was assessed at day 0, day 3, month 1, and month 3 postnatal. The correlation between UAldo and the urinary Na/K ratio was determined as an index of renal aldosterone sensitivity. UAldo significantly increased with GA: from 8.8 ± 7.5 μg/mmol of creatinine (Group 1) to 21.1 ± 21.0 (Group 3) in correlation with plasma aldosterone levels in all groups (P < .001), demonstrating its reliability. The aldosterone/renin ratio significantly increased with GA, suggesting an aldosterone secretion defect in preterm infants. UAldo and urinary Na/K were correlated in very preterm but not in term neonates, consistent with very preterm neonates being renal-aldosterone sensitive and term neonates being aldosterone resistant. Very preterm infants have a previously unrecognized defective aldosterone secretion but conserved renal aldosterone sensitivity in the neonatal period, which modifies the current view of sodium balance in these infants and suggests alternative management approaches.

Transcriptome Pathway Analysis of Pathological and Physiological Aldosterone-Producing Human Tissues.

PubMed

Zhou, Junhua; Lam, Brian; Neogi, Sudeshna G; Yeo, Giles S H; Azizan, Elena A B; Brown, Morris J

2016-12-01

Primary aldosteronism is present in ≈10% of hypertensives. We previously performed a microarray assay on aldosterone-producing adenomas and their paired zona glomerulosa and fasciculata. Confirmation of top genes validated the study design and functional experiments of zona glomerulosa selective genes established the role of the encoded proteins in aldosterone regulation. In this study, we further analyzed our microarray data using AmiGO 2 for gene ontology enrichment and Ingenuity Pathway Analysis to identify potential biological processes and canonical pathways involved in pathological and physiological aldosterone regulation. Genes differentially regulated in aldosterone-producing adenoma and zona glomerulosa were associated with steroid metabolic processes gene ontology terms. Terms related to the Wnt signaling pathway were enriched in zona glomerulosa only. Ingenuity Pathway Analysis showed "NRF2-mediated oxidative stress response pathway" and "LPS (lipopolysaccharide)/IL-1 (interleukin-1)-mediated inhibition of RXR (retinoid X receptor) function" were affected in both aldosterone-producing adenoma and zona glomerulosa with associated genes having up to 21- and 8-fold differences, respectively. Comparing KCNJ5-mutant aldosterone-producing adenoma, zona glomerulosa, and zona fasciculata samples with wild-type samples, 138, 56, and 59 genes were differentially expressed, respectively (fold-change >2; P<0.05). ACSS3, encoding the enzyme that synthesizes acetyl-CoA, was the top gene upregulated in KCNJ5-mutant aldosterone-producing adenoma compared with wild-type. NEFM, a gene highly upregulated in zona glomerulosa, was upregulated in KCNJ5 wild-type aldosterone-producing adenomas. NR4A2, the transcription factor for aldosterone synthase, was highly expressed in zona fasciculata adjacent to a KCNJ5-mutant aldosterone-producing adenoma. Further interrogation of these genes and pathways could potentially provide further insights into the pathology of primary aldosteronism. © 2016 The Authors.

NLRP3 Inflammasome Mediates Aldosterone-Induced Vascular Damage.

PubMed

Bruder-Nascimento, Thiago; Ferreira, Nathanne S; Zanotto, Camila Z; Ramalho, Fernanda; Pequeno, Isabela O; Olivon, Vania C; Neves, Karla B; Alves-Lopes, Rheure; Campos, Eduardo; Silva, Carlos Alberto A; Fazan, Rubens; Carlos, Daniela; Mestriner, Fabiola L; Prado, Douglas; Pereira, Felipe V; Braga, Tarcio; Luiz, Joao Paulo M; Cau, Stefany B; Elias, Paula C; Moreira, Ayrton C; Câmara, Niels O; Zamboni, Dario S; Alves-Filho, Jose Carlos; Tostes, Rita C

2016-12-06

Inflammation is a key feature of aldosterone-induced vascular damage and dysfunction, but molecular mechanisms by which aldosterone triggers inflammation remain unclear. The NLRP3 inflammasome is a pivotal immune sensor that recognizes endogenous danger signals triggering sterile inflammation. We analyzed vascular function and inflammatory profile of wild-type (WT), NLRP3 knockout (NLRP3 -/- ), caspase-1 knockout (Casp-1 -/- ), and interleukin-1 receptor knockout (IL-1R -/- ) mice treated with vehicle or aldosterone (600 µg·kg -1 ·d -1 for 14 days through osmotic mini-pump) while receiving 1% saline to drink. Here, we show that NLRP3 inflammasome plays a central role in aldosterone-induced vascular dysfunction. Long-term infusion of aldosterone in mice resulted in elevation of plasma interleukin-1β levels and vascular abnormalities. Mice lacking the IL-1R or the inflammasome components NLRP3 and caspase-1 were protected from aldosterone-induced vascular damage. In vitro, aldosterone stimulated NLRP3-dependent interleukin-1β secretion by bone marrow-derived macrophages by activating nuclear factor-κB signaling and reactive oxygen species generation. Moreover, chimeric mice reconstituted with NLRP3-deficient hematopoietic cells showed that NLRP3 in immune cells mediates aldosterone-induced vascular damage. In addition, aldosterone increased the expression of NLRP3, active caspase-1, and mature interleukin-1β in human peripheral blood mononuclear cells. Hypertensive patients with hyperaldosteronism or normal levels of aldosterone exhibited increased activity of NLRP3 inflammasome, suggesting that the effect of hyperaldosteronism on the inflammasome may be mediated through high blood pressure. Together, these data demonstrate that NLRP3 inflammasome, through activation of IL-1R, is critically involved in the deleterious vascular effects of aldosterone, placing NLRP3 as a potential target for therapeutic interventions in conditions with high aldosterone levels. © 2016 American Heart Association, Inc.

Photon blockade in optomechanical systems with a position-modulated Kerr-type nonlinear coupling

NASA Astrophysics Data System (ADS)

Zhang, X. Y.; Zhou, Y. H.; Guo, Y. Q.; Yi, X. X.

2018-03-01

We explore the photon blockade in optomechanical systems with a position-modulated Kerr-type nonlinear coupling, i.e. H_int˜\\hat{a}\\dagger2\\hat{a}^2(\\hat{b}_1^\\dagger+\\hat{b}_1) . We find that the Kerr-type nonlinear coupling can enhance the photon blockade greatly. We evaluate the equal-time second-order correlation function of the cavity photons and find that the optimal photon blockade does not happen at the single photon resonance. By working within the few-photon subspace, we get an approximate analytical expression for the correlation function and the condition for the optimal photon blockade. We also find that the photon blockade effect is not always enhanced as the Kerr-type nonlinear coupling strength g 2 increases. At some values of g 2, the photon blockade is even weakened. For the system we considered here, the second-order correlation function can be smaller than 1 even in the unresolved sideband regime. By numerically simulating the master equation of the system, we also find that the thermal noise of the mechanical environment can enhance the photon blockade. We give out an explanation for this counter-intuitive phenomenon qualitatively.

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.

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

Neuroendocrine and Inflammatory Responses to Losartan and Continuous Positive Airway Pressure in Patients with Hypertension and Obstructive Sleep Apnea. A Randomized Controlled Trial.

PubMed

Thunström, Erik; Manhem, Karin; Yucel-Lindberg, Tülay; Rosengren, Annika; Lindberg, Caroline; Peker, Yüksel

2016-11-01

Blood pressure reduction in response to antihypertensive agents is less for patients with obstructive sleep apnea (OSA). Increased sympathetic and inflammatory activity, as well as alterations in the renin-angiotensin-aldosterone system, may play a role in this context. To address the cardiovascular mechanisms involved in response to an angiotensin II receptor antagonist, losartan, and continuous positive airway pressure (CPAP) as add-on treatment for hypertension and OSA. Newly diagnosed hypertensive patients with or without OSA (allocated in a 2:1 ratio for OSA vs. no OSA) were treated with losartan 50 mg daily during a 6-week two-center, open-label, prospective, case-control, parallel-design study. In the second 6-week, sex-stratified, open-label, randomized, parallel-design study, all subjects with OSA continued to receive losartan and were randomly assigned to either CPAP as add-on therapy or to no CPAP (1:1 ratio for CPAP vs. no CPAP). Study subjects without OSA were followed in parallel while they continued to take losartan. Blood samples were collected at baseline, after 6 weeks, and after 12 weeks for analysis of renin, aldosterone, noradrenaline, adrenaline, and inflammatory markers. Fifty-four patients with OSA and 35 without OSA were included in the first 6-week study. Losartan significantly increased renin levels and reduced aldosterone levels in the group without OSA. There was no significant decrease in aldosterone levels among patients with OSA. Add-on CPAP treatment tended to lower aldosterone levels, but reductions were more pronounced in measures of sympathetic activity. No significant changes in inflammatory markers were observed following treatment with losartan and CPAP. Hypertensive patients with OSA responded to losartan treatment with smaller reductions in aldosterone compared with hypertensive patients without OSA. Sympathetic system activity seemed to respond primarily to add-on CPAP treatment in patients with newly discovered hypertension and OSA. Clinical trial registered with www.clinicaltrials.gov (NCT00701428).

Obesity-stimulated aldosterone release is not related to an S1P-dependent mechanism.

PubMed

Werth, Stephan; Müller-Fielitz, Helge; Raasch, Walter

2017-12-01

Aldosterone has been identified as an important factor in obesity-associated hypertension. Here, we investigated whether sphingosine-1-phosphate (S1P), which has previously been linked to obesity, increases aldosterone release. S1P-induced aldosterone release was determined in NCI H295R cells in the presence of S1P receptor (S1PR) antagonists. In vivo release of S1P (100-300 µg/kg bw ) was investigated in pithed, lean Sprague Dawley (SD) rats, diet-obese spontaneous hypertensive rats (SHRs), as well as in lean or obese Zucker rats. Aldosterone secretion was increased in NCI H295R cells by S1P, the selective S1PR1 agonist SEW2871 and the selective S1PR2 antagonist JTE013. Treatment with the S1PR1 antagonist W146 or fingolimod and the S1PR1/3 antagonist VPbib2319 decreased baseline and/or S1P-stimulated aldosterone release. Compared to saline-treated SD rats, plasma aldosterone increased by ~50 pg/mL after infusing S1P. Baseline levels of S1P and aldosterone were higher in obese than in lean SHRs. Adrenal S1PR expression did not differ between chow- or CD-fed rats that had the highest S1PR1 and lowest S1PR4 levels. S1P induced a short-lasting increase in plasma aldosterone in obese, but not in lean SHRs. However, 2-ANOVA did not demonstrate any difference between lean and obese rats. S1P-induced aldosterone release was also similar between obese and lean Zucker rats. We conclude that S1P is a local regulator of aldosterone production. S1PR1 agonism induces an increase in aldosterone secretion, while stimulating adrenal S1PR2 receptor suppresses aldosterone production. A significant role of S1P in influencing aldosterone secretion in states of obesity seems unlikely. © 2017 Society for Endocrinology.

Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor?

PubMed

Araujo, Carolina Morais; Hermidorff, Milla Marques; Amancio, Gabriela de Cassia Sousa; Lemos, Denise da Silveira; Silva, Marcelo Estáquio; de Assis, Leonardo Vinícius Monteiro; Isoldi, Mauro César

2016-10-01

Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.

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.

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

Aldosterone affects blood flow and vascular tone regulated by endothelium-derived NO: therapeutic implications

PubMed Central

Toda, Noboru; Nakanishi, Sadanobu; Tanabe, Shinichi

2013-01-01

Aldosterone, in doses inappropriate to the salt status, plays an important role in the development of cardiovascular injury, including endothelial dysfunction, independent of its hypertensive effects. Acute non-genomic effects of aldosterone acting on mineralocorticoid receptors are inconsistent in healthy humans: vasoconstriction or forearm blood flow decrease via endothelial dysfunction, vasodilatation mediated by increased NO actions, or no effects. However, in studies with experimental animals, aldosterone mostly enhances vasodilatation mediated by endothelium-derived NO. Chronic exposure to aldosterone, which induces genomic responses, results in impairments of endothelial function through decreased NO synthesis and action in healthy individuals, experimental animals and isolated endothelial cells. Chronic aldosterone reduces NO release from isolated human endothelial cells only when extracellular sodium is raised. Oxidative stress is involved in the impairment of endothelial function by promoting NO degradation. Aldosterone liberates endothelin-1 (ET-1) from endothelial cells, which elicits ETA receptor–mediated vasoconstriction by inhibiting endothelial NO synthesis and action and through its own direct vasoconstrictor action. Ca2+ flux through T-type Ca2+ channels activates aldosterone synthesis and thus enhances unwanted effects of aldosterone on the endothelium. Mineralocorticoid receptor inhibitors, ETA receptor antagonists and T-type Ca2+ channel blockers appear to diminish the pathophysiological participation of aldosterone in cardiovascular disease and exert beneficial actions on bioavailability of endothelium-derived NO, particularly in resistant hypertension and aldosteronism. PMID:23190073

Metoclopramide unmasks potentially misleading contralateral suppression in patients undergoing adrenal vein sampling for primary aldosteronism.

PubMed

Rossitto, Giacomo; Miotto, Diego; Battistel, Michele; Barbiero, Giulio; Maiolino, Giuseppe; Bisogni, Valeria; Sanga, Viola; Rossi, Gian Paolo

2016-11-01

As metoclopramide stimulates aldosterone secretion, we tested its usefulness in the assessment of lateralization of primary aldosteronism by adrenal vein sampling (AVS). Prospective within-patient study in consecutive patients undergoing AVS for primary aldosteronism subtyping. We compared the diagnostic accuracy of baseline and postmetoclopramide lateralization index and relative (to cortisol) aldosterone secretion indices (RASI) for each adrenal gland with aldosterone-producing adenoma (APA) determined by the four corners criteria as the reference diagnosis. We recruited 93 consecutive patients (mean age: 52 years; women 31%). Metoclopramide increased plasma aldosterone in the inferior vena cava and in both adrenal veins. The postmetoclopramide lateralization index was accurate in identifying APA, but did not increase diagnostic accuracy over baseline lateralization index, because the RASI increased similarly in both sides. Conversely, metoclopramide raised RASI to values more than 0.90 bilaterally in non-APA patients allowing accurate identification of factitious aldosterone suppression. In contrast, RASI was 0.90 or less in 48% contralateral to the tumor in APA patients. Regression analysis showed the APA patients with persistent suppression of RASI contralaterally showed a more florid primary aldosteronism phenotype. Metoclopramide does not enhance lateralization of aldosterone excess in APA, but consistently increased the value of RASI in non-APA cases, thus unmasking potentially misleading suppression of aldosterone. Postmetoclopramide RASI may therefore allow a more precise diagnosis when AVS can be achieved only unilaterally.

Molecular genetic studies in a case series of isolated hypoaldosteronism due to biosynthesis defects or aldosterone resistance.

PubMed

Turan, Ihsan; Kotan, Leman Damla; Tastan, Mehmet; Gurbuz, Fatih; Topaloglu, Ali Kemal; Yuksel, Bilgin

2018-06-01

Hypoaldosteronism is associated with either insufficient aldosterone production or aldosterone resistance (pseudohypoaldosteronism). Patients with aldosterone defects typically present with similar symptoms and findings, which include failure to thrive, vomiting, hyponatremia, hyperkalemia and metabolic acidosis. Accurate diagnosis of these clinical conditions therefore can be challenging. Molecular genetic analyses can help to greatly clarify this complexity. The aim of this study was to obtain an overview of the clinical and genetic characteristics of patients with aldosterone defects due to biosynthesis defects or aldosterone resistance. We investigated the clinical and molecular genetic features of 8 consecutive patients with a clinical picture of aldosterone defects seen in our clinics during the period of May 2015 through October 2017. We screened CYP11B2 for aldosterone synthesis defects and NR3C2 and the three EnaC subunits (SCNN1A, SCNN1B and SCNN1G) for aldosterone resistance. We found 4 novel and 2 previously reported mutations in the genes CYP11B2, NR3C2, SCNN1A and SCNN1G in 9 affected individuals from 7 unrelated families. Molecular genetic investigations can help confidently diagnose these conditions and clarify the pathogenicity of aldosterone defects. This study may expand the clinical and genetic correlations of defects in aldosterone synthesis or resistance. © 2018 John Wiley & Sons Ltd.

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.

Activity of [des-Aspartyl1]-Angiotensin II in Primary Aldosteronism

PubMed Central

Carey, Robert M.; Ayers, Carlos R.; Vaughan, E. Darracott; Peach, Michael J.; Herf, Steven M.

1979-01-01

This study describes the effects of [des-Aspartyl1]-angiotensin II ([des-Asp]-AII) on blood pressure and aldosterone production in patients with primary aldosteronism due to aldosterone-producing adrenal adenoma (APA) and idiopathic adrenal hyperplasia (IHA), and in normotensive control subjects. 10 patients with primary aldosteronism, 7 with APA and 3 with IHA, and 6 normotensive control subjects were placed on a constant 150-meq sodium diet for 4 days. [des-Asp]-AII was infused for 30 min at 6, 12, and 18 pmol/kg per min. Three groups of patients were identified on the basis of aldosterone response to [des-Asp]-AII. Group I, composed of normotensive control subjects, showed incremental increases in plasma aldosterone concentration from 6±1 to 14±3 ng/100 ml (P < 0.01) with [des-Asp]-AII infusion. Group II, composed of patients with primary aldosteronism, showed incremental increases in plasma aldosterone concentration from 33±8 to 65±13 ng/100 ml (P < 0.05) with 12 pmol/kg per min of [des-Asp]-AII. Group III, also composed of patients with primary aldosteronism, showed no increase of plasma aldosterone concentration with [des-Asp]-AII. Groups I and II showed similar percentage increases in plasma aldosterone concentration (P = NS). Group III showed significantly lower aldosterone responses than group I (P < 0.01). Group II included all patients with IHA and two patients with APA. Group III included only patients with APA. The blood pressure responses to [des-Asp]-AII of subjects in group I did not differ significantly from those of groups II or III. Thus, patients with IHA and a subgroup of patients with APA showed responsiveness to [des-Asp]-AII which was limited to adrenal cortical stimulation of aldosterone biosynthesis. This suggests that adrenal responsiveness to angiotensin is a major control mechanism in some forms of primary aldosteronism. The differential adrenal responsiveness to [des-Asp]-AII in patients with APA indicates either that there are two distinct subpopulations of APA, or that alteration in tumor response to angiotensin occurs during the natural progression of the disease history. PMID:438332

Body mass index predicts aldosterone production in normotensive adults on a high-salt diet.

PubMed

Bentley-Lewis, Rhonda; Adler, Gail K; Perlstein, Todd; Seely, Ellen W; Hopkins, Paul N; Williams, Gordon H; Garg, Rajesh

2007-11-01

The mechanisms underlying obesity-mediated cardiovascular disease are not fully understood. Aldosterone and insulin resistance both are associated with obesity and cardiovascular disease. The objectives of this study were to test the hypotheses that aldosterone production is elevated and associated with insulin resistance in overweight adults on a high-sodium diet. Healthy normotensive adults were categorized as lean body mass index (BMI) less than 25 kg/m(2) (n = 63) or overweight BMI 25 kg/m(2) or greater (n = 57). After 7 d of a high-sodium diet, participants fasted overnight and remained supine throughout hemodynamic and laboratory assessments and angiotensin II (AngII) stimulation. The overweight group, compared with the lean group, had higher 24-h urinary aldosterone (9.0 +/- 0.8 vs. 6.6 +/- 0.5 microg per 24 h; P = 0.003) and higher AngII-stimulated serum aldosterone (11.4 +/- 1.0 vs. 9.0 +/- 0.6 ng/dl; P = 0.04). There were no differences in 24-h urinary cortisol or sodium or supine measurements of plasma renin activity, serum aldosterone, or serum potassium. The homeostasis model assessment of insulin resistance was predicted by urinary aldosterone excretion (r = 0.32, P = 0.03) and serum aldosterone response to AngII stimulation (r = 0.28, P = 0.02) independent of age and BMI. Urinary aldosterone excretion and AngII-stimulated aldosterone are increased in overweight, compared with lean, normotensive adults. The correlation of these measures of aldosterone production with insulin resistance suggests a potential role for aldosterone in the pathophysiology of obesity-mediated insulin resistance.

Local Control of Aldosterone Production and Primary Aldosteronism.

PubMed

Lalli, Enzo; Barhanin, Jacques; Zennaro, Maria-Christina; Warth, Richard

2016-03-01

Primary aldosteronism (PA) is caused by excessive production of aldosterone by the adrenal cortex and is determined by a benign aldosterone-producing adenoma (APA) in a significant proportion of cases. Local mechanisms, as opposed to circulatory ones, that control aldosterone production in the adrenal cortex are particularly relevant in the physiopathological setting and in the pathogenesis of PA. A breakthrough in our understanding of the pathogenetic mechanisms in APA has been the identification of somatic mutations in genes controlling membrane potential and intracellular calcium concentrations. However, recent data show that the processes of nodule formation and aldosterone hypersecretion can be dissociated in pathological adrenals and suggest a model envisaging different molecular events for the pathogenesis of APA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relationships of Hardiness to Physical and Mental Health Status in Military Men: A Test of Mediated Effects

DTIC Science & Technology

2013-01-01

physiological changes. Acute autonomic nervous system changes, for example, include innervation of the heart, blood vessels, and adrenal glands by...Fardella, C. E., & Kalergis, A. M. (2011). Aldosterone as a modulator of immunity: Implications in the organ damage. Journal of Hypertension... aldosterone on cardiometabolic syndrome. International Journal of Hyperten- sion, 685238, 1–8. Stuart-Hamilton, I. (2007). Dictionary of psychological

Copernicus Revisited: Overturning Ptolemy's View of the GPER Universe.

PubMed

Feldman, Ross D; Limbird, Lee E

2015-11-01

Whether aldosterone activates the G-protein-coupled estrogen receptor (GPER) has been questioned, recently, in the name of Copernicus. However, for G-protein-coupled receptors (GPCRs) multiple hormone activators are common. Further, studies in mineralocorticoid receptor (MR)-deficient systems, with pharmacological GPER-selective antagonists or regulation of GPER expression, consistently show that some aldosterone effects can be GPER mediated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alport Syndrome in Women and Girls.

PubMed

Savige, Judy; Colville, Deb; Rheault, Michelle; Gear, Susie; Lennon, Rachel; Lagas, Sharon; Finlay, Moira; Flinter, Frances

2016-09-07

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Inheritance is X-linked (85%) or autosomal recessive (15%). Many renal physicians think of Alport syndrome as primarily affecting men. However, twice as many women are affected by the X-linked diseases. Affected women are commonly undiagnosed, but 15%-30% develop renal failure by 60 years and often hearing loss by middle age. Half of their sons and daughters are also affected. Autosomal recessive Alport syndrome is less common, but is often mistaken for X-linked disease. Recessive inheritance is suspected where women develop early-onset renal failure or lenticonus. Their family may be consanguineous. The prognosis for other family members is very different from X-linked disease. Other generations, including parents and offspring, are not affected, and on average only one in four of their siblings inherit the disease. All women with Alport syndrome should have their diagnosis confirmed with genetic testing, even if their renal function is normal, because of their own risk of renal failure and the risk to their offspring. Their mutations indicate the mode of inheritance and the likelihood of disease transmission to their children, and the mutation type suggests the renal prognosis for both X-linked and recessive disease. Women with X-linked Alport syndrome should be tested at least annually for albuminuria and hypertension. The "Expert guidelines for the diagnosis and management of Alport syndrome" recommend treating those with albuminuria with renin-angiotensin-aldosterone system (RAAS) blockade (and adequate birth control because of the teratogenic risks of angiotensin converting enzyme inhibitors), believing that this will delay renal failure. Current recommendations are that women with autosomal recessive Alport syndrome should be treated with RAAS blockade from the time of diagnosis. In addition, women should be offered genetic counseling, informed of their reproductive options, and monitored closely during pregnancy for the development of hypertension. Copyright © 2016 by the American Society of Nephrology.

Worsening renal function and outcome in heart failure patients with preserved ejection fraction and the impact of angiotensin receptor blocker treatment.

PubMed

Damman, Kevin; Perez, Ana C; Anand, Inder S; Komajda, Michel; McKelvie, Robert S; Zile, Michael R; Massie, Barrie; Carson, Peter E; McMurray, John J V

2014-09-16

Worsening renal function (WRF) associated with renin-angiotensin-aldosterone system (RAAS) inhibition does not confer excess risk in heart failure patients with reduced ejection fraction (HFrEF). The goal of this study was to investigate the relationship between WRF and outcomes in heart failure patients with preserved ejection fraction (HFpEF) and the interaction with RAAS blockade. In 3,595 patients included in the I-PRESERVE (Irbesartan in Heart Failure With Preserved Ejection Fraction) trial, change in estimated glomerular filtration rate (eGFR) and development of WRF after initiation of irbesartan or placebo were examined. We examined the association between WRF and the first occurrence of cardiovascular death or heart failure hospitalization (primary outcome in this analysis) and the interaction with randomized treatment. Estimated GFR decreased early with irbesartan treatment and remained significantly lower than in the placebo group. WRF developed in 229 (6.4%) patients and occurred more frequently with irbesartan treatment (8% vs. 4%). Overall, WRF was associated with an increased risk of the primary outcome (adjusted hazard ratio [HR]: 1.43; 95% confidence interval [CI]: 1.10 to 1.85; p = 0.008). Although the risk related to WRF was greater in the irbesartan group (HR: 1.66; 95% CI: 1.21 to 2.28; p = 0.002) than with placebo (HR: 1.09; 95% CI: 0.66 to 1.79; p = 0.73), the interaction between treatment and WRF on outcome was not significant in an adjusted analysis. The incidence of WRF in HFpEF was similar to that previously reported in HFrEF but more frequent with irbesartan than with placebo. WRF after initiation of irbesartan treatment in HFpEF was associated with excess risk, in contrast to WRF occurring with RAAS blockade in HFrEF. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Alport Syndrome in Women and Girls

PubMed Central

Colville, Deb; Rheault, Michelle; Gear, Susie; Lennon, Rachel; Lagas, Sharon; Finlay, Moira; Flinter, Frances

2016-01-01

Alport syndrome is an inherited disease characterized by progressive renal failure, hearing loss, and ocular abnormalities. Inheritance is X-linked (85%) or autosomal recessive (15%). Many renal physicians think of Alport syndrome as primarily affecting men. However, twice as many women are affected by the X-linked diseases. Affected women are commonly undiagnosed, but 15%–30% develop renal failure by 60 years and often hearing loss by middle age. Half of their sons and daughters are also affected. Autosomal recessive Alport syndrome is less common, but is often mistaken for X-linked disease. Recessive inheritance is suspected where women develop early-onset renal failure or lenticonus. Their family may be consanguineous. The prognosis for other family members is very different from X-linked disease. Other generations, including parents and offspring, are not affected, and on average only one in four of their siblings inherit the disease. All women with Alport syndrome should have their diagnosis confirmed with genetic testing, even if their renal function is normal, because of their own risk of renal failure and the risk to their offspring. Their mutations indicate the mode of inheritance and the likelihood of disease transmission to their children, and the mutation type suggests the renal prognosis for both X-linked and recessive disease. Women with X-linked Alport syndrome should be tested at least annually for albuminuria and hypertension. The “Expert guidelines for the diagnosis and management of Alport syndrome” recommend treating those with albuminuria with renin-angiotensin-aldosterone system (RAAS) blockade (and adequate birth control because of the teratogenic risks of angiotensin converting enzyme inhibitors), believing that this will delay renal failure. Current recommendations are that women with autosomal recessive Alport syndrome should be treated with RAAS blockade from the time of diagnosis. In addition, women should be offered genetic counseling, informed of their reproductive options, and monitored closely during pregnancy for the development of hypertension. PMID:27287265

Measurement of salivary aldosterone: validation by low-dose ACTH test and gender differences.

PubMed

Hlavacova, N; Kerlik, J; Radikova, Z; Izakova, L; Jezova, D

2013-10-01

The aim of the present study was to validate the feasibility of measurement of the salivary aldosterone concentrations by performing a low-dose adrenocorticotropic hormone (ACTH) test. Moreover, the presence of gender differences in salivary aldosterone, considering the phase of the menstrual cycle in women, was verified. The sample consisted of 107 volunteers (60 men, 21 women in the follicular phase and 26 women in the luteal phase of the menstrual cycle). Saliva samples were taken by the subjects themselves around 08:00 AM, at least 60 min after awaking. A separate group of female subjects in the follicular phase underwent low-dose ACTH test (1µg synthetic ACTH i.v.) performed at 08:30 AM with blood and saliva sampling every 30 min for 120 min. Modification of the commercial aldosterone radioimmunoassay methodology for the salivary aldosterone measurement was performed. Salivary aldosterone concentrations rose in response to low-dose ACTH test and positive significant correlation in aldosterone concentrations between plasma and saliva was found. The results showed that women in the luteal phase of the menstrual cycle exhibited significantly higher morning concentrations in salivary aldosterone than men and women in the follicular phase. This study clearly demonstrates suitability of measurement of salivary aldosterone concentrations in the low-dose ACTH test and reveals gender differences in salivary aldosterone levels. The results show high validity of the presented method and its usefulness for assessment of the aldosterone concentrations in saliva.

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.

Regulation of aldosterone production by ion channels: From basal secretion to primary aldosteronism.

PubMed

Yang, Tingting; He, Min; Hu, Changlong

2018-03-01

Aldosterone is produced by zona glomerulosa (ZG) cells of the adrenal cortex and plays a key role in balancing water and electrolytes levels. Autonomous overproduction of aldosterone leads to primary aldosteronism (PA), which is the most common form of secondary endocrine hypertension. Recently, significant progress has been made towards understanding the genetic basis of PA, where increasing clinical evidence suggests that mutations in ion channels appear to be the major cause of aldosterone-producing adenomas. In this review, we focused on potassium and calcium channels that regulate aldosterone secretion, and their roles in the pathology of PA. Because potassium and calcium channels are differentially expressed in ZG cells in different species of mammals, the limitations of published studies are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

The Aldosterone Synthase Inhibitor FAD286 is Suitable for Lowering Aldosterone Levels in ZDF Rats but not in db/db Mice.

PubMed

Hofmann, Anja; Brunssen, Coy; Peitzsch, Mirko; Balyura, Mariya; Mittag, Jennifer; Frenzel, Annika; Jannasch, Anett; Brown, Nicholas F; Weldon, Steven M; Gueneva-Boucheva, Kristina K; Eisenhofer, Graeme; Bornstein, Stefan R; Morawietz, Henning

2017-06-01

Inhibition of aldosterone synthase is an alternative treatment option to mineralocorticoid receptor antagonism to prevent harmful aldosterone actions. FAD286 is one of the best characterized aldosterone synthase inhibitors to date. FAD286 improves glucose tolerance and increases glucose-stimulated insulin secretion in obese and diabetic ZDF rats. However, there is limited knowledge about the dose-dependent effects of FAD286 on plasma aldosterone, corticosterone, and 11-deoxycorticosterone in ZDF rats and in db / db mice, a second important rodent model of obesity and type 2 diabetes. In addition, effects of FAD286 on plasma steroids in mice and rats are controversial. Therefore, obese Zucker diabetic fatty (ZDF) rats and db / db mice were treated with FAD286 for up to 15 weeks and plasma steroids were evaluated using highly sensitive liquid chromatography-tandem mass spectrometry. In ZDF rats, FAD286 (10 mg/kg/d) treatment resulted in nearly complete disappearance of plasma aldosterone while corticosterone levels remained unaffected and those of 11-deoxycorticosterone were increased ~4-fold compared to vehicle control. A lower dose of FAD286 (3 mg/kg / d) showed no effect on plasma aldosterone or corticosterone, but 11-deoxycorticosterone was again increased ~4-fold compared to control. In contrast to ZDF rats, a high dose of FAD286 (40 mg/kg/d) did not affect plasma aldosterone levels in db / db mice although 11-deoxycorticosterone increased ~2.5-fold. A low dose of FAD286 (10 mg/kg/d) increased plasma aldosterone without affecting corticosterone or 11-deoxycorticosterone. In conclusion, the aldosterone synthase inhibitor, FAD286, lowers plasma aldosterone in obese ZDF rats, but not in obese db / db mice. © Georg Thieme Verlag KG Stuttgart · New York.

Excess aldosterone-induced changes in insulin signaling molecules and glucose oxidation in gastrocnemius muscle of adult male rat.

PubMed

Selvaraj, Jayaraman; Sathish, Sampath; Mayilvanan, Chinnaiyan; Balasubramanian, Karundevi

2013-01-01

Emerging evidences demonstrate that excess aldosterone and insulin interact at target tissues. It has been shown that increased levels of aldosterone contribute to the development of insulin resistance and thus act as a risk factor for the development of type-2 diabetes mellitus. However, the molecular mechanisms involved in this scenario are yet to be identified. This study was designed to assess the dose-dependent effects of aldosterone on insulin signal transduction and glucose oxidation in the skeletal muscle (gastrocnemius) of adult male rat. Healthy adult male albino rats of Wistar strain (Rattus norvegicus) weighing 180-200 g were used in this study. Rats were divided into four groups. Group I: control (treated with 1 % ethanol only), group II: aldosterone treated (10 μg /kg body weight, twice daily for 15 days), group III: aldosterone treated (20 μg /kg body weight, twice daily for 15 days), and group IV: aldosterone treated (40 μg/kg body weight, twice daily for 15 days). Excess aldosterone caused glucose intolerance in a dose-dependent manner. Serum insulin and aldosterone were significantly increased, whereas serum testosterone was decreased. Aldosterone treatment impaired the rate of glucose uptake, oxidation, and insulin signal transduction in the gastrocnemius muscle through defective expression of IR, IRS-1, Akt, AS160, and GLUT4 genes. Phosphorylation of IRS-1, β-arrestin-2, and Akt was also reduced in a dose-dependent manner. Excess aldosterone results in glucose intolerance as a result of impaired insulin signal transduction leading to decreased glucose uptake and oxidation in skeletal muscle. In addition to this, it is inferred that excess aldosterone may act as one of the causative factors for the onset of insulin resistance and thus increased incidence of type-2 diabetes.

Severity of Obstructive Sleep Apnea is Related to Aldosterone Status in Subjects with Resistant Hypertension

PubMed Central

Gonzaga, Carolina C.; Gaddam, Krishna K.; Ahmed, Mustafa I.; Pimenta, Eduardo; Thomas, S. Justin; Harding, Susan M.; Oparil, Suzanne; Cofield, Stacey S.; Calhoun, David A.

2010-01-01

Background: We previously described a significant correlation between plasma aldosterone concentration (PAC) and severity of obstructive sleep apnea (OSA) in patients with resistant hypertension. This investigation examines the relationship between aldosterone status and OSA in patients with resistant hypertensive—with and without hyperaldosteronism. Methods and Results: One hundred and nine consecutive patients with resistant hypertension were prospectively evaluated with plasma renin activity (PRA), PAC, 24-hour urinary aldosterone excretion (UAldo), and polysomnography. Hyperaldosteronism (PRA < 1 ng·mL-1·h-1 and UAldo ≥ 12 μg/24-h) prevalence was 28% and OSA prevalence was 77%. In patients with hyperaldosteronism, OSA prevalence was 84%, compared with 74% in hypertensive patients with normal aldosterone levels. There were no significant differences in body mass index or neck circumference between aldosterone groups. PAC and UAldo were both significantly correlated with apnea-hypopnea index (AHI) in the high-aldosterone group (ρ = 0.568, p = 0.0009; ρ = 0.533, p = 0.002, respectively). UAldo correlated weakly with apnea-hypopnea index in the normal-aldosterone group, but there was no significant correlation between PAC and AHI in the normal-aldosterone group (ρ = 0.224, p = 0.049; ρ = 0.015, p = 0.898, respectively). Conclusions: Our analysis of patients with resistant hypertension confirms a markedly high prevalence of OSA in this group. Furthermore, severity of OSA was greater in those patients with hyperaldosteronism and related to the degree of aldosterone excess. The correlation between OSA severity and aldosterone supports the hypothesis that aldosterone excess contributes to greater severity of OSA. Citation: Gonzaga CC; Gaddam KK; Ahmed MI; Pimenta E; Thomas SJ; Harding SM; Oparil S; Cofield SS; Calhoun DA. Severity of obstructive sleep apnea is related to aldosterone status in subjects with resistant hypertension. J Clin Sleep Med 2010;6(4):363-368. PMID:20726285

Early nongenomic events in aldosterone action in renal collecting duct cells: PKCalpha activation, mineralocorticoid receptor phosphorylation, and cross-talk with the genomic response.

PubMed

Le Moëllic, Cathy; Ouvrard-Pascaud, Antoine; Capurro, Claudia; Cluzeaud, Francoise; Fay, Michel; Jaisser, Frederic; Farman, Nicolette; Blot-Chabaud, Marcel

2004-05-01

Effects of aldosterone on its target cells have long been considered to be mediated exclusively through the genomic pathway; however, evidence has been provided for rapid effects of the hormone that may involve nongenomic mechanisms. Whether an interaction exists between these two signaling pathways is not yet established. In this study, the authors show that aldosterone triggers both early nongenomic and late genomic increase in sodium transport in the RCCD(2) rat cortical collecting duct cell line. In these cells, the early (up to 2.5 h) aldosterone-induced increase in short-circuit current (Isc) is not blocked by the mineralocorticoid receptor (MR) antagonist RU26752, it does not require mRNA or protein synthesis, and it involves the PKCalpha signaling pathway. In addition, this early response is reproduced by aldosterone-BSA, which acts at the cell surface and presumably does not enter the cells (aldo-BSA is unable to trigger the late response). The authors also show that MR is rapidly phosphorylated on serine and threonine residues by aldosterone or aldosterone-BSA. In contrast, the late (4 to 24 h) aldosterone-induced increase in ion transport occurs through activation of the MR and requires mRNA and protein synthesis. Interestingly, nongenomic and genomic aldosterone actions appear to be interdependent. Blocking the PKCalpha pathway results in the inhibition of the late genomic response to aldosterone, as demonstrated by the suppression of aldosterone-induced increase in MR transactivation activity, alpha1 Na(+)/K(+)/ATPase mRNA, and Isc. These data suggest cross-talk between the nongenomic and genomic responses to aldosterone in renal cells and suggest that the aldosterone-MR mediated increase in mRNA/protein synthesis and ion transport depends, at least in part, upon PKCalpha activation. E-mail: marcel.blot-chabaud@pharmacie.univ-mrs.fr

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

Of channels and pumps: different ways to boost the aldosterone?

PubMed

Bandulik, S

2017-07-01

The mineralocorticoid aldosterone is a major factor controlling the salt and water balance and thereby also the arterial blood pressure. Accordingly, primary aldosteronism (PA) characterized by an inappropriately high aldosterone secretion is the most common form of secondary hypertension. The physiological stimulation of aldosterone synthesis in adrenocortical glomerulosa cells by angiotensin II and an increased plasma K + concentration depends on a membrane depolarization and an increase in the cytosolic Ca 2+ activity. Recurrent gain-of-function mutations of ion channels and transporters have been identified in a majority of cases of aldosterone-producing adenomas and in familial forms of PA. In this review, the physiological role of these genes in the regulation of aldosterone synthesis and the altered function of the mutant proteins as well are described. The specific changes of the membrane potential and the cellular ion homoeostasis in adrenal cells expressing the different mutants are compared, and their impact on autonomous aldosterone production and proliferation is discussed. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

The Role of Aldosteronism in Causing Obesity-Related Cardiovascular Risk

PubMed Central

Calhoun, David A.; Sharma, Kumar

2010-01-01

Synopsis A large body of evidence strongly links aldosterone to development and progression of cardiovacscular disease, including vascular stiffness, left ventricular hypertrophy, congestive heart failure, chronic kidney disease, and especially, hypertension. Emerging data suggests that adipocytes may serve as a source of aldosterone, either directly, or indirectly, through release of aldosterone-stimulating factors. If adipocytes are confirmed to contribute importantly to hyperaldosteronism, it would have significant clinical implications in linking aldosterone to obesity-related increases in cardiovascular risk. Such a cause-and-effect would then provide the opportunity to reverse that risk with preferential use of aldosterone antagonists in obese patients. PMID:20621254

Aldosterone acutely stimulates NCC activity via a SPAK-mediated pathway

PubMed Central

Mistry, Abinash C.; Hanson, Lauren; Mallick, Rickta; Wynne, Brandi M.; Thai, Tiffany L.; Bailey, James L.; Klein, Janet D.; Hoover, Robert S.

2013-01-01

Hypertension is a leading cause of morbidity and mortality worldwide, and disordered sodium balance has long been implicated in its pathogenesis. Aldosterone is perhaps the key regulator of sodium balance and thus blood pressure. The sodium chloride cotransporter (NCC) in the distal convoluted tubule of the kidney is a major site of sodium reabsorption and plays a key role in blood pressure regulation. Chronic exposure to aldosterone increases NCC protein expression and function. However, more acute effects of aldosterone on NCC are unknown. In our salt-abundant modern society where chronic salt deprivation is rare, understanding the acute effects of aldosterone is critical. Here, we examined the acute effects (12–36 h) of aldosterone on NCC in the rodent kidney and in a mouse distal convoluted tubule cell line. Studies demonstrated that aldosterone acutely stimulated NCC activity and phosphorylation without affecting total NCC abundance or surface expression. This effect was dependent upon the presence of the mineralocorticoid receptor and serum- and glucocorticoid-regulated kinase 1 (SGK1). Furthermore, STE20/SPS-1-related proline/alanine-rich kinase (SPAK) phosphorylation also increased, and gene silencing of SPAK eliminated the effect of aldosterone on NCC activity. Aldosterone administration via a minipump in adrenalectomized rodents confirmed an increase in NCC phosphorylation without a change in NCC total protein. These data indicate that acute aldosterone-induced SPAK-dependent phosphorylation of NCC increases individual transporter activity. PMID:23739593

Aldosterone induces clonal β-cell failure through glucocorticoid receptor

PubMed Central

Chen, Fang; Liu, Jia; Wang, Yanyang; Wu, Tijun; Shan, Wei; Zhu, Yunxia; Han, Xiao

2015-01-01

Aldosterone excess causes insulin resistance in peripheral tissues and directly impairs the function of clonal β-cell. The aim of this study was to investigate the molecular mechanisms involved in the aldosterone-induced impairment of clonal β-cells. As expected, aldosterone induced apoptosis and β-cell dysfunction, including impairment of insulin synthesis and secretion, which were reversed by Glucocorticoid receptor (GR) antagonists or GR-specific siRNA. However, mineralocorticoid receptor (MR) antagonists or MR-specific siRNA had no effect on impairment of clonal β-cells induced by aldosterone. Besides, aldosterone significantly decreased expression and activity of MafA, while activated JNK and p38 MAPK in a GR-dependent manner. In addition, JNK inhibitors (SP600125) and/or p38 inhibitors (SB203580) could abolish the effect of aldosterone on MafA expression and activity. Importantly, overexpression of JNK1 or p38 reversed the protective effect of a GR antagonist on the decrease of MafA expression and activity. Furthermore, aldosterone inhibits MafA expression at the transcriptional and post-transcriptional level through activation of JNK and p38, respectively. Consequently, overexpression of MafA increased synthesis and secretion of insulin, and decreased apoptosis in clonal β-cells exposed to aldosterone. These findings identified aldosterone as an inducer of clonal β-cell failure that operates through the GR-MAPK-MafA signaling pathway. PMID:26287126

Aldosterone acutely stimulates NCC activity via a SPAK-mediated pathway.

PubMed

Ko, Benjamin; Mistry, Abinash C; Hanson, Lauren; Mallick, Rickta; Wynne, Brandi M; Thai, Tiffany L; Bailey, James L; Klein, Janet D; Hoover, Robert S

2013-09-01

Hypertension is a leading cause of morbidity and mortality worldwide, and disordered sodium balance has long been implicated in its pathogenesis. Aldosterone is perhaps the key regulator of sodium balance and thus blood pressure. The sodium chloride cotransporter (NCC) in the distal convoluted tubule of the kidney is a major site of sodium reabsorption and plays a key role in blood pressure regulation. Chronic exposure to aldosterone increases NCC protein expression and function. However, more acute effects of aldosterone on NCC are unknown. In our salt-abundant modern society where chronic salt deprivation is rare, understanding the acute effects of aldosterone is critical. Here, we examined the acute effects (12-36 h) of aldosterone on NCC in the rodent kidney and in a mouse distal convoluted tubule cell line. Studies demonstrated that aldosterone acutely stimulated NCC activity and phosphorylation without affecting total NCC abundance or surface expression. This effect was dependent upon the presence of the mineralocorticoid receptor and serum- and glucocorticoid-regulated kinase 1 (SGK1). Furthermore, STE20/SPS-1-related proline/alanine-rich kinase (SPAK) phosphorylation also increased, and gene silencing of SPAK eliminated the effect of aldosterone on NCC activity. Aldosterone administration via a minipump in adrenalectomized rodents confirmed an increase in NCC phosphorylation without a change in NCC total protein. These data indicate that acute aldosterone-induced SPAK-dependent phosphorylation of NCC increases individual transporter activity.

A marked proportional rise in IVC aldosterone following cosyntropin administration during AVS is a signal to the presence of adrenal hyperplasia in primary aldosteronism.

PubMed

Kline, G A; Pasieka, J L; Harvey, A; So, B; Dias, V C

2014-05-01

We hypothesized aldosteronoma responsiveness to cosyntropin may be a characterizing feature that could be determined in addition to standard adrenal vein sampling (AVS) data. We reviewed an AVS database from June 2005 to October 2011 including 65 patients with confirmed primary aldosteronism (PA) who underwent AVS and, if applicable, unilateral adrenalectomy. Patients were divided into confirmed lateralized and non-lateralized groups and subgrouped by histology. Plasma aldosterone in inferior vena cava (IVC) pre- and post-cosyntropin infusion during AVS was measured. Peak aldosterone and proportional change was compared between groups. Baseline and peak IVC aldosterone was higher in lateralized patients but incremental aldosterone rise was much greater in subjects with bilateral hyperplasia. From receiver operator characteristics (ROC) analysis, the optimized diagnostic cut point of peak IVC aldosterone of >649 pmol l(-1) would have a sensitivity of 94% for surgical disease although specificity of just 59%. A 250% increase in IVC aldosterone following cosyntropin would be specific enough to exclude 87% of surgical/lateralized disease. These diagnostic capabilities are similar to other results with non-AVS tests performed for diagnosis of lateralization. Although not specific enough to replace standard AVS interpretation, a marked IVC aldosterone increase after cosyntropin during AVS is a useful additional test to diagnose non-lateralizing forms of PA. Such a calculation requires no additional expense or tests.

Aldosterone-Induced Vascular Remodeling and Endothelial Dysfunction Require Functional Angiotensin Type 1a Receptors.

PubMed

Briet, Marie; Barhoumi, Tlili; Mian, Muhammad Oneeb Rehman; Coelho, Suellen C; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M; Paradis, Pierre; Schiffrin, Ernesto L

2016-05-01

We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors in Agtr1a(-/-) and wild-type (WT) mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure (BP) by ≈30 mm Hg in WT mice and ≈50 mm Hg in Agtr1a(-/-) mice. Aldosterone induced aortic and small artery remodeling, impaired endothelium-dependent relaxation in WT mice, and enhanced fibronectin and collagen deposition and vascular inflammation. None of these vascular effects were observed in Agtr1a(-/-) mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in WT mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in WT and Agtr1a(-/-) mice. Agtr1a(-/-) mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting that sodium retention could contribute to the exaggerated BP rise induced by aldosterone. Agtr1a(-/-) mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention, exacerbate BP responses to aldosterone/salt in Agtr1a(-/-) mice. We conclude that although aldosterone activation of mineralocorticoid receptors raises BP more in Agtr1a(-/-) mice, AGTR1a is required for mineralocorticoid receptor stimulation to induce vascular remodeling and inflammation and endothelial dysfunction. © 2016 American Heart Association, Inc.

ALDOSTERONE-INDUCED VASCULAR REMODELING AND ENDOTHELIAL DYSFUNCTION REQUIRE FUNCTIONAL ANGIOTENSIN TYPE 1a RECEPTORS

PubMed Central

Coelho, Suellen C.; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M.; Paradis, Pierre; Schiffrin, Ernesto L.

2016-01-01

We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors (MR) in Agtr1a−/− and wild-type mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure by ~30 mmHg in wild-type mice, and ~50 mmHg in Agtr1a−/− mice. Aldosterone induced aortic and small artery remodeling and impaired endothelium-dependent relaxation in wild-type mice, and enhanced fibronectin and collagen deposition, and vascular inflammation. None of these vascular effects were observed in Agtr1a−/− mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in wild-type mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in wild-type and Agtr1a−/− mice. Agtr1a−/− mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting sodium retention that could contribute to the exaggerated blood pressure rise induced by aldosterone. Agtr1a−/− mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention exacerbate BP responses to aldosterone/salt in Agtr1a−/− mice. We conclude that although aldosterone activation of MR raises BP more in Agtr1a−/− mice, AGTR1a is required for MR stimulation to induce vascular remodeling and inflammation, and endothelial dysfunction. PMID:27045029

Angiotensin II type 1 receptor autoantibody as a novel regulator of aldosterone independent of preeclampsia.

PubMed

Yang, Jie; Li, Li; Shang, Jian-Yu; Cai, Lin; Song, Li; Zhang, Su-Li; Li, Hao; Li, Xiao; Lau, Wayne Bond; Ma, Xin-Liang; Liu, Hui-Rong

2015-05-01

Preeclamptic women and their infants have significant morbidity and mortality worldwide. Abnormal aldosterone signaling is involved in the pathogenesis of preeclampsia, and the presence of agonistic autoantibodies against the angiotensin II type 1 receptor (AT1-AA) during disease has been observed. The role of AT1-AA in aldosterone generation with or without disease and the long-term impact of AT1-AA circulation in blood remain unclear. We therefore assessed circulating AT1-AA and aldosterone levels in 76 patients with preeclampsia (35 severe and 41 mild), 26 patients with gestational hypertension, and 50 normotensive healthy pregnant women. First, the correlation of AT1-AA levels was confirmed for preeclamptic patients. We report here that all AT1-AA-positive hypertensive pregnant women exhibited decreased aldosterone levels, and early-onset preeclampsia patients with high proteinuria showed an inverse correlation of aldosterone levels with AT1-AA. To study this effect in more detail, we confirmed that AT1-AA decreased aldosterone levels in pregnant rats and then demonstrated that aldosterone levels decreased in response to the chronic administration of AT1-AA into nonpregnant rats. These results suggested that AT1-AA regulates levels of aldosterone, which was tested with cell culture studies, revealing that activation of AT1 receptors by AT1-AA directly led to abnormal aldosterone generation in a time and dose-dependent manner. We present here a mechanism for regulation of aldosterone production: AT1-AA activates AT1 receptors on adrenocortical cells independent of pregnancy, in a time and dose-dependent manner.

[The influence of single moderate exercise on the sympathetic nervous system activity in patients with essential hypertension].

PubMed

Gajek, Jacek; Zyśko, Dorota

2002-12-01

Sympathetic nervous system may play an important role in development and maintenance of hypertension. Its activity can be assessed by plasma levels of catecholamines, neuropeptide Y (NPY) and adrenergic receptor density. Hypertensive subjects may be more prone to reveal overactivity of sympathetic nervous system, for instance as a result of physical stress. The aim of the study was to determine the activity of sympathetic nervous system in young patients with newly recognized, untreated mild hypertension. The study was carried out in 22 patients (age 38.5 +/- 10.3 years) and 20 normotensive volunteers (age 38.5 +/- 8.6 years) as a control group, matched for sex. Density of alpha 2- and beta-adrenergic receptors using 3H-yohimbine and 125I-cyanopindolol respectively, total catecholamines and plasma renin activity using radioenzymatic assay, neuropeptide Y and aldosterone using radioimmunoassay were assessed in the blood taken in the supine position and after moderate bicycle ergometer exercise. Plasma concentration of NPY at rest did not differ between the groups, but increased significantly after exercise and was greater in hypertensive patients (p < 0.05). The density of alpha 2- and beta-adrenergic receptors at rest and after exercise in hypertensive subjects was unchanged when comparing to healthy individuals. The plasma concentrations of endogenous catecholamines, plasma renin activity and aldosterone level increase during exercise in both studied groups (p < 0.05). Aldosterone level was higher in hypertensive patients at rest (p < 0.05). There was a negative correlation between baseline aldosterone and NPY levels in hypertensive patients (r = -0.44, p < 0.05). Moderate exercise in hypertensive subjects causes the hyperactivity of sympathetic nervous system expressed as increase of NPY plasma level.

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.

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.

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

ACTH and Polymorphisms at Steroidogenic Loci as Determinants of Aldosterone Secretion and Blood Pressure.

PubMed

MacKenzie, Scott M; Freel, E Marie; Connell, John M; Fraser, Robert; Davies, Eleanor

2017-03-07

The majority of genes contributing to the heritable component of blood pressure remain unidentified, but there is substantial evidence to suggest that common polymorphisms at loci involved in the biosynthesis of the corticosteroids aldosterone and cortisol are important. This view is supported by data from genome-wide association studies that consistently link the CYP17A1 locus to blood pressure. In this review article, we describe common polymorphisms at three steroidogenic loci (CYP11B2, CYP11B1 and CYP17A1) that alter gene transcription efficiency and levels of key steroids, including aldosterone. However, the mechanism by which this occurs remains unclear. While the renin angiotensin system is rightly regarded as the major driver of aldosterone secretion, there is increasing evidence that the contribution of corticotropin (ACTH) is also significant. In light of this, we propose that the differential response of variant CYP11B2, CYP11B1 and CYP17A1 genes to ACTH is an important determinant of blood pressure, tending to predispose individuals with an unfavourable genotype to hypertension.

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.

Clock genes and salt-sensitive hypertension: a new type of aldosterone-synthesizing enzyme controlled by the circadian clock and angiotensin II.

PubMed

Okamura, Hitoshi; Doi, Masao; Goto, Kaoru; Kojima, Rika

2016-10-01

With the current societal norm of shiftwork and long working hours, maintaining a stable daily life is becoming very difficult. An irregular lifestyle disrupts circadian rhythms, resulting in the malfunction of body physiology and ultimately leading to lifestyle-related diseases, including hypertension. By analyzing completely arrhythmic Cry1/Cry2 double-knockout (Cry-null) mice, we found salt-sensitive hypertension accompanied by hyperaldosteronism. On the basis of a DNA microarray analysis of the adrenal gland and subsequent biochemical analyses, we discovered that Hsd3b6/HSD3B1, a subtype of 3β-HSD, is markedly overexpressed in aldosterone-producing cells in the Cry-null adrenal cortex. In addition, we found that Hsd3b6/HSD3B1, which converts pregnenolone to progesterone, is a clock-controlled gene and might also be a key enzyme for the regulation of aldosterone biosynthesis, in addition to the previously established CYP11B2, which synthesizes aldosterone from deoxycorticosterone. Importantly, angiotensin II induces HSD3B1 via the transcription factor NGFIB in human adrenocortical H295R cells, similarly to CYP11B2. As HSD3B1 levels are abnormally high in the adrenal aldosterone-producing cells of idiopathic hyperaldosteronism (IHA), the temporal component of this system in the pathophysiology of IHA is a promising area for future research.

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.

Primary aldosteronism: diagnosis and treatment.

PubMed

Pimenta, Eduardo; Calhoun, David A

2006-12-01

Recent studies have indicated a higher prevalence of primary aldosteronism (PA) than reported historically. Aldosterone excess induces sodium and fluid retention with consequential increases in blood pressure. Patients with PA are at an increased risk of developing left ventricular hypertrophy, chronic kidney disease, and endothelial dysfunction. Measurement of the plasma aldosterone/plasma renin activity ratio is an effective screening test for PA. The majority of patients with PA do not have a discernable aldosterone-producing adenoma (APA), and the aldosterone excess is considered idiopathic in etiology and/or attributed to adrenal hyperplasia. Treatment of PA includes medical therapy with mineralocorticoid receptor antagonists and adrenalectomy for patients with a unilateral APA. A reasonable treatment strategy is to attempt medical therapy in all patients with a high plasma aldosterone/PRA ratio and reserve the extensive workup needed to identify an APA for those patients whose hypertension or hypokalemia cannot be controlled medically.

Plasma adrenocorticotropic hormone but not aldosterone is correlated with blood pressure in patients with aldosterone-producing adenomas.

PubMed

Kobayashi, Hiroki; Haketa, Akira; Takahiro, Ueno; Otsuka, Hiromasa; Tanaka, Sho; Hatanaka, Yoshinari; Ikeda, Yukihiro; Abe, Masanori; Fukuda, Noboru; Soma, Masayoshi

2017-03-01

Although plasma aldosterone concentration (PAC) varies depending on primary aldosteronism (PA) subtypes, patients with different subtypes may have similar blood pressure (BP). The authors hypothesized that hormones other than aldosterone might influence BP in PA patients. A total of 73 PA cases, including 30 cases of aldosterone-producing adenomas (APAs), 29 cases of bilateral hyperaldosteronism, and 24 control cases of essential hypertension were enrolled retrospectively. The authors examined the levels of aldosterone, cortisol, renin, and adrenocorticotropic hormone (ACTH) measured at 12 am, 6 am, 12 pm, and 6 pm and BP in the early morning (6 am to 7 am), late morning (9 am to 11 am), and early evening (5 pm to 7 pm). Results showed no statistically significant correlation between PAC and BP in the patients with PA; however, early and late morning systolic BP strongly correlated with ACTH at 6 am in patients with APA. These results suggest that hormones other than aldosterone, such as ACTH, may affect BP in patients with APA. ©2016 Wiley Periodicals, Inc.

Dual Endothelin-A/Endothelin-B Receptor Blockade and Cardiac Remodeling in Heart Failure With Preserved Ejection Fraction

PubMed Central

Valero-Munoz, Maria; Li, Shanpeng; Wilson, Richard M.; Boldbaatar, Batbold; Iglarz, Marc; Sam, Flora

2017-01-01

Background Despite the increasing prevalence of heart failure with preserved ejection fraction (HFpEF) in humans, there remains no evidence-based therapies for HFpEF. Endothelin-1 (ET-1) antagonists are a possibility because elevated ET-1 levels are associated with adverse cardiovascular effects, such as arterial and pulmonary vasoconstriction, impaired left ventricular (LV) relaxation, and stimulation of LV hypertrophy. LV hypertrophy is a common phenotype in HFpEF, particularly when associated with hypertension. Methods and Results In the present study, we found that ET-1 levels were significantly elevated in patients with chronic stable HFpEF. We then sought to investigate the effects of chronic macitentan, a dual ET-A/ET-B receptor antagonist, on cardiac structure and function in a murine model of HFpEF induced by chronic aldosterone infusion. Macitentan caused LV hypertrophy regression independent of blood pressure changes in HFpEF. Although macitentan did not modulate diastolic dysfunction in HFpEF, it significantly reduced wall thickness and relative wall thickness after 2 weeks of therapy. In vitro studies showed that macitentan decreased the aldosterone-induced cardiomyocyte hypertrophy. These changes were mediated by a reduction in the expression of cardiac myocyte enhancer factor 2a. Moreover, macitentan improved adverse cardiac remodeling, by reducing the stiffer cardiac collagen I and titin n2b expression in the left ventricle of mice with HFpEF. Conclusions These findings indicate that dual ET-A/ET-B receptor inhibition improves HFpEF by abrogating adverse cardiac remodeling via antihypertrophic mechanisms and by reducing stiffness. Additional studies are needed to explore the role of dual ET-1 receptor antagonists in patients with HFpEF. PMID:27810862

Cost-effectiveness analysis of aldosterone blockade with eplerenone in patients with heart failure after acute myocardial infarction in the French context: the EPHESUS study.

PubMed

de Pouvourville, Gérard; Solesse, Anne; Beillat, Maud

2008-09-01

The Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) randomized clinical trial demonstrated the efficacy of eplerenone, a new aldosterone antagonist diuretic, with standard treatment versus standard treatment alone in the reduction of cardiovascular mortality and cardiovascular-related hospital readmissions for patients with heart failure after an acute myocardial infarction. We assessed the incremental cost per life-year saved of eplerenone in the French context versus standard treatment. A within-trial study was designed. A piecewise regression model yielded death rates and survival gains adjusted for patients' characteristics, based on the extraction of comparable patients from the Saskatchewan Health database. Resource use was collected alongside the clinical trial data. Only direct medical costs were considered. All costs were in 2003 euros. Costs and outcomes were discounted at 5%. The overall mortality rate was 14.4% in the treatment group versus 16.7% in the placebo group (p=0.008). Combined cardiovascular deaths and hospitalization rates were 26.7% in the treatment group versus 30.3% in the placebo group (p=0.002). The discounted survival gain was 3.2 weeks. The incremental cost per life-year saved was euro15,382 (95% confidence interval 8274-42,723). Seventy-four per cent of the values of the incremental cost-effectiveness ratio fell under a euro15,000 per life-year saved threshold. The cost of eplerenone leads to an acceptable level of incremental cost per life-year saved when compared with existing treatments in the cardiovascular domain for the prevention of cardiovascular death and morbidity in patients with heart failure after an acute myocardial infarction.

Dual Endothelin-A/Endothelin-B Receptor Blockade and Cardiac Remodeling in Heart Failure With Preserved Ejection Fraction.

PubMed

Valero-Munoz, Maria; Li, Shanpeng; Wilson, Richard M; Boldbaatar, Batbold; Iglarz, Marc; Sam, Flora

2016-11-01

Despite the increasing prevalence of heart failure with preserved ejection fraction (HFpEF) in humans, there remains no evidence-based therapies for HFpEF. Endothelin-1 (ET-1) antagonists are a possibility because elevated ET-1 levels are associated with adverse cardiovascular effects, such as arterial and pulmonary vasoconstriction, impaired left ventricular (LV) relaxation, and stimulation of LV hypertrophy. LV hypertrophy is a common phenotype in HFpEF, particularly when associated with hypertension. In the present study, we found that ET-1 levels were significantly elevated in patients with chronic stable HFpEF. We then sought to investigate the effects of chronic macitentan, a dual ET-A/ET-B receptor antagonist, on cardiac structure and function in a murine model of HFpEF induced by chronic aldosterone infusion. Macitentan caused LV hypertrophy regression independent of blood pressure changes in HFpEF. Although macitentan did not modulate diastolic dysfunction in HFpEF, it significantly reduced wall thickness and relative wall thickness after 2 weeks of therapy. In vitro studies showed that macitentan decreased the aldosterone-induced cardiomyocyte hypertrophy. These changes were mediated by a reduction in the expression of cardiac myocyte enhancer factor 2a. Moreover, macitentan improved adverse cardiac remodeling, by reducing the stiffer cardiac collagen I and titin n2b expression in the left ventricle of mice with HFpEF. These findings indicate that dual ET-A/ET-B receptor inhibition improves HFpEF by abrogating adverse cardiac remodeling via antihypertrophic mechanisms and by reducing stiffness. Additional studies are needed to explore the role of dual ET-1 receptor antagonists in patients with HFpEF. © 2016 American Heart Association, Inc.

CNS neuroplasticity and salt-sensitive hypertension induced by prior treatment with subpressor doses of ANG II or aldosterone.

PubMed

Clayton, Sarah C; Zhang, Zhongming; Beltz, Terry; Xue, Baojian; Johnson, Alan Kim

2014-06-15

Although sensitivity to high dietary NaCl is regarded to be a risk factor for cardiovascular disease, the causes of salt-sensitive hypertension remain elusive. Previously, we have shown that rats pretreated with subpressor doses of either ANG II or aldosterone (Aldo) show sensitized hypertensive responses to a mild pressor dose of ANG II when tested after an intervening delay. The current studies investigated whether such treatments will induce salt sensitivity. In studies employing an induction-delay-expression experimental design, male rats were instrumented for chronic mean arterial pressure (MAP) recording. In separate experiments, ANG II, Aldo, or vehicle was delivered either subcutaneously or intracerebroventricularly during the induction. There were no sustained differences in BP during the delay prior to being given 2% saline. While consuming 2% saline during the expression, both ANG II- and Aldo-pretreated rats showed significantly greater hypertension. When hexamethonium was used to assess autonomic control of MAP, no differences in the decrease of MAP in response to ganglionic blockade were detected during the induction. However, during the expression, the fall was greater in sensitized rats. In separate experiments, brain tissue that was collected at the end of delay showed increases in message or activation of putative markers of neuroplasticity (i.e., brain-derived neurotrophic factor, p38 mitogen-activated protein kinase, and cAMP response element-binding protein). These experiments demonstrate that prior administration of nonpressor doses of either ANG II or Aldo will induce salt sensitivity. Collectively, our findings indicate that treatment with subpressor doses of ANG II and Aldo initiate central neuroplastic changes that are involved in hypertension of different etiologies. Copyright © 2014 the American Physiological Society.

Aldosterone signaling regulates the over-expression of claudin-4 and -8 at the distal nephron from type 1 diabetic rats.

PubMed

Molina-Jijón, Eduardo; Rodríguez-Muñoz, Rafael; González-Ramírez, Ricardo; Namorado-Tónix, Carmen; Pedraza-Chaverri, José; Reyes, Jose L

2017-01-01

Hyperglycemia in diabetes alters tight junction (TJ) proteins in the kidney. We evaluated the participation of aldosterone (ALD), and the effect of spironolactone (SPL), a mineralocorticoid receptor antagonist, on the expressions of claudin-2, -4, -5 and -8, and occludin in glomeruli, proximal and distal tubules isolated from diabetic rats. Type 1 diabetes was induced in female Wistar rats by a single tail vein injection of streptozotocin (STZ), and SPL was administrated daily by gavage, from days 3-21. Twenty-one days after STZ injection the rats were sacrificed. In diabetic rats, the serum ALD levels were increased, and SPL-treatment did not have effect on these levels or in hyperglycemia, however, proteinuria decreased in SPL-treated diabetic rats. Glomerular damage, evaluated by nephrin and Wilm's tumor 1 (WT1) protein expressions, and proximal tubular damage, evaluated by kidney injury molecule 1 (Kim-1) and heat shock protein 72 kDa (Hsp72) expressions, were ameliorated by SPL. Also, SPL prevented decrement in claudin-5 in glomeruli, and claudin-2 and occludin in proximal tubules by decreasing oxidative stress, evaluated by superoxide anion (O2●-) production, and oxidative stress markers. In distal tubules, SPL ameliorated increase in mRNA, protein expression, and phosphorylation in threonine residues of claudin-4 and -8, through a serum and glucocorticoid-induced kinase 1 (SGK1), and with-no-lysine kinase 4 (WNK4) signaling pathway. In conclusion, this is the first study that demonstrates that ALD modulates the expression of renal TJ proteins in diabetes, and that the blockade of its actions with SPL, may be a promising therapeutic strategy to prevent alterations of TJ proteins in diabetic nephropathy.

Contribution of aldosterone to cardiovascular and renal inflammation and fibrosis

PubMed Central

Brown, Nancy J.

2014-01-01

The steroid hormone aldosterone regulates sodium and potassium homeostasis. Aldosterone and activation of the mineralocorticoid receptor also causes inflammation and fibrosis of the heart, fibrosis and remodelling of blood vessels and tubulointerstitial fibrosis and glomerular injury in the kidney. Aldosterone and mineralocorticoid-receptor activation initiate an inflammatory response by increasing the generation of reactive oxygen species by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondria. High salt intake potentiates these effects, in part by activating the Rho family member Rac1, a regulatory subunit of reduced NADPH oxidase that activates the mineralocorticoid receptor. Studies in mice in which the mineralocorticoid receptor has been deleted from specific cell types suggest a key role for macrophages in promoting inflammation and fibrosis. Aldosterone can exert mineralocorticoid-receptor-independent effects via the angiotensin II receptor and via G-protein-coupled receptor 30. Mineralocorticoid-receptor antagonists are associated with decreased mortality in patients with heart disease and show promise in patients with kidney injury, but can elevate serum potassium concentration. Studies in rodents genetically deficient in aldosterone synthase or treated with a pharmacological aldosterone-synthase inhibitor are providing insight into the relative contribution of aldosterone compared with the contribution of mineralocorticoid-receptor activation in inflammation, fibrosis, and injury. Aldosterone-synthase inhibitors are under development in humans. PMID:23774812

The effects of 19-nor-aldosterone on blood pressure of adrenalectomized spontaneously hypertensive rats.

PubMed

Morris, D J; Gorsline, J; Tresco, P A; Harnik, M

1985-12-01

The relative hypertensinogenic potencies of recently synthesized 19-nor-aldosterone and its precursor 19-OH-aldosterone were assessed in comparison to that of aldosterone (Aldo) in young (6-week-old) adrenalectomized (ADX) spontaneously hypertensive rats (SHR). Infusion of 19-nor-aldosterone for 2 weeks by Alza mini-osmotic pumps caused significant, dose-dependent increases in the systolic blood pressure (BP) of young ADX SHR; dosages of 0.1 and 0.5 microgram/day raised the BP from 127 +/- 2 mmHg to 164 +/- 9 and 180 +/- 11 mmHg, respectively. During this period, control ADX SHR receiving vehicle only remained normotensive. Similar increases in BP were seen only with infusion of slightly higher dosages of Aldo (0.5 and 1.0 micrograms/day). In contrast, 19-OH-aldosterone infused at higher dosages (10 or 25 micrograms/day) caused little change in BP of ADX SHR. Full suppression of plasma renin activity (PRA) was observed with 0.1 and 0.5 microgram/day 19-nor-aldosterone, whereas Aldo caused similar decreases in PRA only at dosages of 0.5 microgram/day and higher. Interestingly, although infusions of 19-OH-aldosterone did not cause a significant change in BP, these dosages (10 and 25 micrograms/day) significantly suppressed PRA. These studies which show that 19-nor-aldosterone is equipotent to Aldo, and perhaps slightly more active in ADX SHR, indicate that 19-nor-aldosterone is a potentially important hypertensinogenic steroid.

Stimulatory Effect of Food Restriction on the Steroidogenesis of Aldosterone in Ovariectomized Rats.

PubMed

Kau, Mei-Mei; Yu, Ching-Han; Tsai, Shiow-Chwen; Wang, Jiing-Rong; Wang, Paulus S.

2017-04-30

Food or calorie restriction (FR or CR) induces several physiological changes including weight loss, metabolic adaptations, mineral and hormonal changes. However, the effects of FR on aldosterone steroidogenesis in zona glomerulosa (ZG) cells have not been elucidated. Therefore, the present study was designed to investigate the effects of FR on aldosterone secretion and the involved mechanisms in ovariectomized (Ovx) rats. Ovx rats were divided into ad libitum fed (control) and FR groups. The FR rats exhibited decreased body weight, water intake, urine flow, sodium excretion and increased plasma aldosterone in comparison with control rats. FR elevated the basal and angiotensin II-stimulated aldosterone secretion from ZG cells. The conversions of 25-hydroxy-cholesterol to pregnenolone or corticosterone to aldosterone in ZG cells of FR group were greater than that in control group. FR group had a higher protein expression of steroidogenic acute regulatory (StAR) protein in ZG cells. However, there was no different protein expression of cytochrome P450 sidechain cleavage enzyme (P450scc) in ZG cells between control and FR groups. In summary, the increased activities of P450scc and aldosterone synthase as well as the protein expression of StAR protein in ZG cells are involved in the effects of FR on aldosterone steroidogenesis in Ovx rats. We also suggest that the increase of aldosterone might be associated with anti-diuresis and antinatriuresis in FR group. These results are helpful for understanding the role of aldosterone in physiological adaptation and renal sodium conservation during FR.

Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

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

Sheng, Lili; Yang, Min; Ding, Wei

Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangialmore » cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.« less

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.

Intracellular calcium: a prerequisite for aldosterone action.

PubMed

Schäfer, C; Shahin, V; Albermann, L; Schillers, H; Hug, M J; Oberleithner, H

2003-12-01

Transport of salt and water in various tissues is under control of the mineralocorticoid hormone aldosterone. As a liphophilic hormone, aldosterone diffuses through the plasma membrane and, then, binds to cytosolic mineralocorticoid receptors in the target cells. After binding to nuclear pore complexes, the activated receptor is translocated to the nucleus where transcription processes are initiated. After a lag period of about 20 minutes hormone-specific early mRNA transcripts leave the nucleus through nuclear pores. Some of the steps in this cascade can be followed by electrophysiology in Xenopus laevis oocyte nuclei. In addition to the genomic pathway, aldosterone exerts a rapid pre-genomic response that involves an increase in intracellular calcium. In this study, we tested for the potential role of Ca(2+) in the genomic response of the hormone. We measured the electrical resistance across the nuclear envelope in response to aldosterone, in presence and absence of intracellular Ca(2+). Nuclear envelope electrical resistance reflects receptor binding to the nuclear pore complexes ("early" resistance peak, 2 minutes after aldosterone), ongoing transcription ("transient" resistance drop, 5-15 minutes after aldosterone) and mRNA export ("late" resistance peak, 20 minutes after aldosterone). Pre-injection of the Ca(2+) chelator EGTA eliminated all electrical responses evoked by aldosterone. The transient resistance drop and the late resistance peak, induced by the hormone, were prevented by the transcription inhibitor actinomycin D, coinjected with aldosterone, while the early resistance peak remained unaffected. We conclude that (i). the presence of intracellular Ca(2+) is a prerequisite for the genomic action of aldosterone. (ii). Intracellular calcium plays a role early in the signaling cascade, either in agonist-receptor interaction, or receptor transport/docking to the nuclear pore complexes.

Caveolin 1-related autophagy initiated by aldosterone-induced oxidation promotes liver sinusoidal endothelial cells defenestration.

PubMed

Luo, Xiaoying; Dan Wang; Luo, Xuan; Zhu, Xintao; Wang, Guozhen; Ning, Zuowei; Li, Yang; Ma, Xiaoxin; Yang, Renqiang; Jin, Siyi; Huang, Yun; Meng, Ying; Li, Xu

2017-10-01

Aldosterone, with pro-oxidation and pro-autophagy capabilities, plays a key role in liver fibrosis. However, the mechanisms underlying aldosterone-promoted liver sinusoidal endothelial cells (LSECs) defenestration remain unknown. Caveolin 1 (Cav1) displays close links with autophagy and fenestration. Hence, we aim to investigate the role of Cav1-related autophagy in LSECs defenestration. We found the increase of aldosterone/MR (mineralocorticoid receptor) level, oxidation, autophagy, and defenestration in LSECs in the human fibrotic liver, BDL or hyperaldosteronism models; while antagonizing aldosterone or inhibiting autophagy relieved LSECs defenestration in BDL-induced fibrosis or hyperaldosteronism models. In vitro, fenestrae of primary LSECs gradually shrank, along with the down-regulation of the NO-dependent pathway and the augment of the AMPK-dependent autophagy; these effects were aggravated by rapamycin (an autophagy activator) or aldosterone treatment. Additionally, aldosterone increased oxidation mediated by Cav1, reduced ATP generation, and subsequently induced the AMPK-dependent autophagy, leading to the down-regulation of the NO-dependent pathway and LSECs defenestration. These effects were reversed by MR antagonist spironolactone, antioxidants or autophagy inhibitors. Besides, aldosterone enhanced the co-immunoprecipitation of Cav1 with p62 and ubiquitin, and induced Cav1 co-immunofluorescence staining with LC3, ubiquitin, and F-actin in the perinuclear area of LSECs. Furthermore, aldosterone treatment increased the membrane protein level of Cav1, whereas decrease the cytoplasmic protein level of Cav1, indicating that aldosterone induced Cav1-related selective autophagy and F-actin remodeling to promote defenestration. Consequently, Cav1-related selective autophagy initiated by aldosterone-induced oxidation promotes LSECs defenestration via activating the AMPK-ULK1 pathway and inhibiting the NO-dependent pathway. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Calpain-10 Activity Underlies Angiotensin II-Induced Aldosterone Production in an Adrenal Glomerulosa Cell Model

PubMed Central

Seremwe, Mutsa; Schnellmann, Rick G.

2015-01-01

Aldosterone is a steroid hormone important in the regulation of blood pressure. Aberrant production of aldosterone results in the development and progression of diseases including hypertension and congestive heart failure; therefore, a complete understanding of aldosterone production is important for developing more effective treatments. Angiotensin II (AngII) regulates steroidogenesis, in part through its ability to increase intracellular calcium levels. Calcium can activate calpains, proteases classified as typical or atypical based on the presence or absence of penta-EF-hands, which are involved in various cellular responses. We hypothesized that calpain, in particular calpain-10, is activated by AngII in adrenal glomerulosa cells and underlies aldosterone production. Our studies showed that pan-calpain inhibitors reduced AngII-induced aldosterone production in 2 adrenal glomerulosa cell models, primary bovine zona glomerulosa and human adrenocortical carcinoma (HAC15) cells, as well as CYP11B2 expression in the HAC15 cells. Although AngII induced calpain activation in these cells, typical calpain inhibitors had no effect on AngII-elicited aldosterone production, suggesting a lack of involvement of classical calpains in this process. However, an inhibitor of the atypical calpain, calpain-10, decreased AngII-induced aldosterone production. Consistent with this result, small interfering RNA (siRNA)-mediated knockdown of calpain-10 inhibited aldosterone production and CYP11B2 expression, whereas adenovirus-mediated overexpression of calpain-10 resulted in increased AngII-induced aldosterone production. Our results indicate that AngII-induced activation of calpain-10 in glomerulosa cells underlies aldosterone production and identify calpain-10 or its downstream pathways as potential targets for the development of drug therapies for the treatment of hypertension. PMID:25836666

GPER is involved in the stimulatory effects of aldosterone in breast cancer cells and breast tumor-derived endothelial cells

PubMed Central

Rigiracciolo, Damiano Cosimo; Scarpelli, Andrea; Lappano, Rosamaria; Pisano, Assunta; Santolla, Maria Francesca; Avino, Silvia; De Marco, Paola; Bussolati, Benedetta; Maggiolini, Marcello; De Francesco, Ernestina Marianna

2016-01-01

Aldosterone induces relevant effects binding to the mineralcorticoid receptor (MR), which acts as a ligand-gated transcription factor. Alternate mechanisms can mediate the action of aldosterone such as the activation of epidermal growth factor receptor (EGFR), MAPK/ERK, transcription factors and ion channels. The G-protein estrogen receptor (GPER) has been involved in the stimulatory effects of estrogenic signalling in breast cancer. GPER has been also shown to contribute to certain responses to aldosterone, however the role played by GPER and the molecular mechanisms implicated remain to be fully understood. Here, we evaluated the involvement of GPER in the stimulatory action exerted by aldosterone in breast cancer cells and breast tumor derived endothelial cells (B-TEC). Competition assays, gene expression and silencing studies, immunoblotting and immunofluorescence experiments, cell proliferation and migration were performed in order to provide novel insights into the role of GPER in the aldosterone-activated signalling. Our results demonstrate that aldosterone triggers the EGFR/ERK transduction pathway in a MR- and GPER-dependent manner. Aldosterone does not bind to GPER, it however induces the direct interaction between MR and GPER as well as between GPER and EGFR. Next, we ascertain that the up-regulation of the Na+/H+ exchanger-1 (NHE-1) induced by aldosterone involves MR and GPER. Biologically, both MR and GPER contribute to the proliferation and migration of breast and endothelial cancer cells mediated by NHE-1 upon aldosterone exposure. Our data further extend the current knowledge on the molecular mechanisms through which GPER may contribute to the stimulatory action elicited by aldosterone in breast cancer. PMID:26646587

GPER is involved in the stimulatory effects of aldosterone in breast cancer cells and breast tumor-derived endothelial cells.

PubMed

Rigiracciolo, Damiano Cosimo; Scarpelli, Andrea; Lappano, Rosamaria; Pisano, Assunta; Santolla, Maria Francesca; Avino, Silvia; De Marco, Paola; Bussolati, Benedetta; Maggiolini, Marcello; De Francesco, Ernestina Marianna

2016-01-05

Aldosterone induces relevant effects binding to the mineralcorticoid receptor (MR), which acts as a ligand-gated transcription factor. Alternate mechanisms can mediate the action of aldosterone such as the activation of epidermal growth factor receptor (EGFR), MAPK/ERK, transcription factors and ion channels. The G-protein estrogen receptor (GPER) has been involved in the stimulatory effects of estrogenic signalling in breast cancer. GPER has been also shown to contribute to certain responses to aldosterone, however the role played by GPER and the molecular mechanisms implicated remain to be fully understood. Here, we evaluated the involvement of GPER in the stimulatory action exerted by aldosterone in breast cancer cells and breast tumor derived endothelial cells (B-TEC). Competition assays, gene expression and silencing studies, immunoblotting and immunofluorescence experiments, cell proliferation and migration were performed in order to provide novel insights into the role of GPER in the aldosterone-activated signalling. Our results demonstrate that aldosterone triggers the EGFR/ERK transduction pathway in a MR- and GPER-dependent manner. Aldosterone does not bind to GPER, it however induces the direct interaction between MR and GPER as well as between GPER and EGFR. Next, we ascertain that the up-regulation of the Na+/H+ exchanger-1 (NHE-1) induced by aldosterone involves MR and GPER. Biologically, both MR and GPER contribute to the proliferation and migration of breast and endothelial cancer cells mediated by NHE-1 upon aldosterone exposure. Our data further extend the current knowledge on the molecular mechanisms through which GPER may contribute to the stimulatory action elicited by aldosterone in breast cancer.

Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands

PubMed Central

Nishimoto, Koshiro; Tomlins, Scott A.; Kuick, Rork; Cani, Andi K.; Giordano, Thomas J.; Hovelson, Daniel H.; Liu, Chia-Jen; Sanjanwala, Aalok R.; Edwards, Michael A.; Gomez-Sanchez, Celso E.; Nanba, Kazutaka; Rainey, William E.

2015-01-01

Primary aldosteronism (PA) represents the most common cause of secondary hypertension, but little is known regarding its adrenal cellular origins. Recently, aldosterone-producing cell clusters (APCCs) with high expression of aldosterone synthase (CYP11B2) were found in both normal and PA adrenal tissue. PA-causing aldosterone-producing adenomas (APAs) harbor mutations in genes encoding ion channels/pumps that alter intracellular calcium homeostasis and cause renin-independent aldosterone production through increased CYP11B2 expression. Herein, we hypothesized that APCCs have APA-related aldosterone-stimulating somatic gene mutations. APCCs were studied in 42 normal adrenals from kidney donors. To clarify APCC molecular characteristics, we used microarrays to compare the APCC transcriptome with conventional adrenocortical zones [zona glomerulosa (ZG), zona fasciculata, and zona reticularis]. The APCC transcriptome was most similar to ZG but with an enhanced capacity to produce aldosterone. To determine if APCCs harbored APA-related mutations, we performed targeted next generation sequencing of DNA from 23 APCCs and adjacent normal adrenal tissue isolated from both formalin-fixed, paraffin-embedded, and frozen tissues. Known aldosterone driver mutations were identified in 8 of 23 (35%) APCCs, including mutations in calcium channel, voltage-dependent, L-type, α1D-subunit (CACNA1D; 6 of 23 APCCs) and ATPase, Na+/K+ transporting, α1-polypeptide (ATP1A1; 2 of 23 APCCs), which were not observed in the adjacent normal adrenal tissue. Overall, we show three major findings: (i) APCCs are common in normal adrenals, (ii) APCCs harbor somatic mutations known to cause excess aldosterone production, and (iii) the mutation spectrum of aldosterone-driving mutations is different in APCCs from that seen in APA. These results provide molecular support for APCC as a precursor of PA. PMID:26240369

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

Prevalence of and risk factors for primary aldosteronism among patients with resistant hypertension in China.

PubMed

Sang, Xiaojing; Jiang, Yiran; Wang, Weiqing; Yan, Li; Zhao, Jiasheng; Peng, Yongde; Gu, Wei; Chen, Gang; Liu, Wei; Ning, Guang

2013-07-01

It is estimated that there are more than 16 million adults with drug-resistant hypertension in China. Nevertheless, the prevalence of and risk factors for primary aldosteronism, a highly curable condition among adults with drug-resistant hypertension, has not been fully investigated. Between January 2010 and October 2011, a multicenter epidemiologic study was conducted among 1656 patients with resistant hypertension in 11 provinces of China. Serum aldosterone and plasma renin activity were measured in every participant and aldosterone-to-renin ratio (ARR) was calculated. Patients with ARR more than 20 underwent an intravenous (i.v.) sodium infusion test, and diagnosis of primary aldosteronism was established by the presence of unsuppressed postinfusion aldosterone (>8 ng/dl). Patients with biochemically proved primary aldosteronism then underwent adrenal computed tomography (CT) scanning and adrenal vein sampling (AVS) for subtype classification. Among the 1656 patients, 494 (29.8%) had ARR greater than 20 and underwent i.v. sodium infusion. Of these 494, 118 were diagnosed as primary aldosteronism, yielding a prevalence of 7.1% (95% confidential interval 5.9-8.3%). Seventy of the 118 patients were categorized into unilateral (39) and bilateral (31) by AVS. Generalized additive regression analysis revealed that among all the factors investigated (age of hypertension onset, BMI, family history of hypertension, cigarette smoking, alcohol consumption, diabetes, serum potassium, hyperlipidemia, and creatinine), only age of hypertension onset and serum potassium were independently associated with the presence of primary aldosteronism. The prevalence of primary aldosteronism among Chinese patients with resistant hypertension is relatively lower than that reported previously for other ethnic populations. The screening for primary aldosteronism should be focused on those with early onset hypertension and/or hypokalemia.

Aldosterone induces fibrosis, oxidative stress and DNA damage in livers of male rats independent of blood pressure changes

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

Queisser, Nina; Happ, Kathrin; Link, Samuel

Mineralocorticoid receptor blockers show antifibrotic potential in hepatic fibrosis. The mechanism of this protective effect is not known yet, although reactive oxygen species seem to play an important role. Here, we investigated the effects of elevated levels of aldosterone (Ald), the primary ligand of the mineralocorticoid receptor, on livers of rats in a hyperaldosteronism model: aldosterone-induced hypertension. Male Sprague–Dawley rats were treated for 4 weeks with aldosterone. To distinguish if damage caused in the liver depended on increased blood pressure or on increased Ald levels, the mineralocorticoid receptor antagonist spironolactone was given in a subtherapeutic dose, not normalizing blood pressure.more » To investigate the impact of oxidative stress, the antioxidant tempol was administered. Aldosterone induced fibrosis, detected histopathologically, and by expression analysis of the fibrosis marker, α-smooth muscle actin. Further, the mRNA amount of the profibrotic cytokine TGF-β was increased significantly. Fibrosis could be reduced by scavenging reactive oxygen species, and also by blocking the mineralocorticoid receptor. Furthermore, aldosterone treatment caused oxidative stress and DNA double strand breaks in livers, as well as the elevation of DNA repair activity. An increase of the transcription factor Nrf2, the main regulator of the antioxidative response could be observed, and of its target genes heme oxygenase-1 and γ-glutamylcysteine synthetase. All these effects of aldosterone were prevented by spironolactone and tempol. Already after 4 weeks of treatment, aldosteroneinfusion induced fibrosis in the liver. This effect was independent of elevated blood pressure. DNA damage caused by aldosterone might contribute to fibrosis progression when aldosterone is chronically increased. - Highlights: • Aldosterone has direct profibrotic effects on the liver independent of blood pressure. • Fibrosis is mediated by the mineralocorticoid receptor and oxidative stress. • Aldosterone induces transcription factor Nrf2 and Nrf2-regulated genes in the liver. • DNA damage caused by aldosterone might contribute to fibrosis progression.« less

GSTA1 Expression Is Correlated With Aldosterone Level in KCNJ5-Mutated Adrenal Aldosterone-Producing Adenoma.

PubMed

Li, Xintao; Wang, Baojun; Tang, Lu; Zhang, Yu; Chen, Luyao; Gu, Liangyou; Zhang, Fan; Ouyang, Jinzhi; Zhang, Xu

2018-03-01

KCNJ5 mutation is a major cause of aldosterone-producing adenomas (APAs). The development of APA apart from KCNJ5 mutation is less investigated. To investigate other mechanisms affecting aldosterone secretion apart from KCNJ5. Six pairs of KCNJ5-mutated, high and low aldosterone-secreting APAs, five non-KCNJ5-mutated APAs, and four normal adrenal glands were assayed by Affymetrix GeneChip Human Transcriptome Array 2.0. A total of 113 APA samples were investigated to explore the expression of glutathione-S-transferase A1 (GSTA1). H295R cells were used to verify the function of GSTA1. GSTA1 was the top gene downregulated in high-aldosterone KCNJ5-mutated APAs. GSTA1 was also downregulated in KCNJ5-mutated APAs compared with wild-type KCNJ5 APAs. Accordingly, mutant KCNJ5 decreased GSTA1 messenger RNA and protein expression levels. GSTA1 overexpression suppressed aldosterone secretion whether in wild-type or mutant KCNJ5 H295R cells. Adding ethacrynic acid or silencing of GSTA1 increased aldosterone secretion by increasing reactive oxygen species (ROS), superoxide, H2O2 levels, and Ca2+ influx. The expression of the transcription factors NR4A1, NR4A2, and CAMK1 and intracellular Ca2+ were significantly upregulated by GSTA1 inhibition. The reduced form of NAD phosphate oxidase inhibitor or H2O2 scavenger or blocking calmodulin or calcium channels could significantly reduce aldosterone secretion in GSTA1-inhibited cells. (1) GSTA1 expression is reversely correlated with aldosterone level in KCNJ5-mutated APAs, (2) GSTA1 regulates aldosterone secretion by ROS and Ca2+ signaling, and (3) KCNJ5 mutation downregulates GSTA1 expression, and overexpression of GSTA1 reverses increased aldosterone in KCNJ5-mutated adrenal cells.

Association of Renin and Aldosterone With Ethnicity and Blood Pressure: The Multi-Ethnic Study of Atherosclerosis

PubMed Central

2014-01-01

BACKGROUND Although variations in plasma renin activity (PRA) and aldosterone have been examined in whites and blacks, the association of these hormones with blood pressure in multiethnic populations has not been described. METHODS We measured PRA and aldosterone in 1,021 participants in the Multi-Ethnic Study of Atherosclerosis not taking antihypertensives and examined the association between ethnicity and PRA/aldosterone and the association between PRA/aldosterone with systolic blood pressure (SBP). RESULTS Average age was 62 (SD = 9) years, and 49% of participants were women. Median PRA was 0.51 (interquartile range (IQR) = 0.29–0.87) ng/ml/hour, and median aldosterone was 12.6 (IQR = 9.1–17.1) ng/dl. After age and sex adjustment, compared with whites, blacks had 28% lower PRA and 17.4% lower aldosterone, and Hispanics had 20.1% higher PRA but similar aldosterone levels. After multivariable adjustment, compared with whites, only Hispanic ethnicity independently associated with higher PRA (0.18ng/ml/hour; 95% confidence interval (CI) = 0.06–0.31). Blacks had lower aldosterone (−1.7ng/dl; 95% CI = −3.2 to −0.2) compared with whites. After multivariable adjustment, PRA was associated with lower SBP in whites (−3.2mm Hg; 95% CI = −5.2 to −1.2 per standardized unit PRA), Chinese (−3.5mm Hg; 95% CI = −6.2 to −0.80 per standardized unit), and Hispanics (−2.3mm Hg; 95% CI = −4.1 to −0.6 per standardized unit) but not blacks. Aldosterone was associated with higher SBP only in Hispanics (2.5mm Hg; 95% CI = 0.4–4.5 per SD). CONCLUSIONS Compared with whites, blacks have lower aldosterone and Hispanics have higher PRA. Aldosterone had significant associations with higher SBP in Hispanics compared with other groups, a finding that may suggest a different mechanism of hypertension. PMID:24436325

Proteomic prediction and Renin angiotensin aldosterone system Inhibition prevention Of early diabetic nephRopathy in TYpe 2 diabetic patients with normoalbuminuria (PRIORITY): essential study design and rationale of a randomised clinical multicentre trial.

PubMed

Lindhardt, Morten; Persson, Frederik; Currie, Gemma; Pontillo, Claudia; Beige, Joachim; Delles, Christian; von der Leyen, Heiko; Mischak, Harald; Navis, Gerjan; Noutsou, Marina; Ortiz, Alberto; Ruggenenti, Piero Luigi; Rychlik, Ivan; Spasovski, Goce; Rossing, Peter

2016-03-02

Diabetes mellitus affects 9% of the European population and accounts for 15% of healthcare expenditure, in particular, due to excess costs related to complications. Clinical trials aiming for earlier prevention of diabetic nephropathy by renin angiotensin system blocking treatment in normoalbumuric patients have given mixed results. This might reflect that the large fraction of normoalbuminuric patients are not at risk of progression, thereby reducing power in previous studies. A specific risk classifier based on urinary proteomics (chronic kidney disease (CKD)273) has been shown to identify normoalbuminuric diabetic patients who later progressed to overt kidney disease, and may hold the potential for selection of high-risk patients for early intervention. Combining the ability of CKD273 to identify patients at highest risk of progression with prescription of preventive aldosterone blockade only to this high-risk population will increase power. We aim to confirm performance of CKD273 in a prospective multicentre clinical trial and test the ability of spironolactone to delay progression of early diabetic nephropathy. Investigator-initiated, prospective multicentre clinical trial, with randomised double-masked placebo-controlled intervention and a prospective observational study. We aim to include 3280 type 2 diabetic participants with normoalbuminuria. The CKD273 classifier will be assessed in all participants. Participants with high-risk pattern are randomised to treatment with spironolactone 25 mg once daily, or placebo, whereas, those with low-risk pattern will be observed without intervention other than standard of care. Treatment or observational period is 3 years.The primary endpoint is development of confirmed microalbuminuria in 2 of 3 first morning voids urine samples. The study will be conducted under International Conference on Harmonisation - Good clinical practice (ICH-GCP) requirements, ethical principles of Declaration of Helsinki and national laws. This first new biomarker-directed intervention trial aiming at primary prevention of diabetic nephropathy may pave the way for personalised medicine approaches in treatment of diabetes complications. NCT02040441; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effect of renin-angiotensin-aldosterone system blockade in adults with diabetes mellitus and advanced chronic kidney disease not on dialysis: a systematic review and meta-analysis.

PubMed

Nistor, Ionut; De Sutter, Johan; Drechsler, Christiane; Goldsmith, David; Soler, Maria Jose; Tomson, Charles; Wiecek, Andrzej; Donciu, Mihaela-Dora; Bolignano, Davide; Van Biesen, Wim; Covic, Adrian

2018-01-01

The presumed superiority of renin-angiotensin-aldosterone system (RAAS)-blocking agents over other antihypertensive agents in patients with diabetes to delay development of end-stage kidney disease (ESKD) has recently been challenged. In addition, there is ongoing uncertainty whether RAAS-blocking agents reduce mortality and/or delay ESKD in patients with diabetes and chronic kidney disease (CKD) stages 3-5. In this subgroup, there might be an expedited need for renal replacement therapy (RRT) when RAAS-blocking agents are used. We conducted a meta-analysis of randomized controlled trials (RCTs) of at least 6-months duration in adult patients with diabetes who also have non-dialysis CKD stages 3-5. RCTs comparing single RAAS-blocking agents to placebo or alternative antihypertensive agents were included. Outcomes of interest were all-cause mortality, cardiovascular morbidity, progression of renal function, ESKD and adverse events. A total of nine trials (n = 9797 participants with CKD stages 3-5) fit our inclusion criteria. There was no difference between the RAAS group and control group regarding all-cause mortality {relative risk [RR] = 0.97 [95% confidence interval (CI) 0.85-1.10]}, cardiovascular mortality [RR = 1.03 (95% CI 0.75-1.41)] and adverse events [RR = 1.05 (95% CI 0.89-1.25)]. There was a trend for a favourable effect for non-fatal cardiovascular events [RR = 0.90 (95% CI 0.81-1.00)] and a lower risk of the composite endpoint need for RRT/doubling of serum creatinine [RR = 0.81 (95% CI 0.70-0.92)] in the RAAS-blocking agents group versus the control group. We found evidence that in patients with diabetes mellitus and CKD stages 3-5, treatment with RAAS-blocking agents did not result in a clear survival advantage. The effect on renal outcomes did depend on the selected outcome measure. However, we did not find evidence that the use of RAAS-blocking agents expedited the need for RRT in patients with CKD stages 3-5. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

PubMed

Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

2013-12-01

Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

Prenatal Testosterone Exposure Decreases Aldosterone Production but Maintains Normal Plasma Volume and Increases Blood Pressure in Adult Female Rats.

PubMed

More, Amar S; Mishra, Jay S; Hankins, Gary D; Kumar, Sathish

2016-08-01

Plasma testosterone levels are elevated in pregnant women with preeclampsia and polycystic ovaries; their offspring are at increased risk for hypertension during adult life. We tested the hypothesis that prenatal testosterone exposure induces dysregulation of the renin-angiotensin-aldosterone system, which is known to play an important role in water and electrolyte balance and blood pressure regulation. Female rats (6 mo old) prenatally exposed to testosterone were examined for adrenal expression of steroidogenic genes, telemetric blood pressure, blood volume and Na(+) and K(+) levels, plasma aldosterone, angiotensin II and vasopressin levels, and vascular responses to angiotensin II and arg(8)-vasopressin. The levels of Cyp11b2 (aldosterone synthase), but not the other adrenal steroidogenic genes, were decreased in testosterone females. Accordingly, plasma aldosterone levels were lower in testosterone females. Plasma volume and serum and urine Na(+) and K(+) levels were not significantly different between control and testosterone females; however, prenatal testosterone exposure significantly increased plasma vasopressin and angiotensin II levels and arterial pressure in adult females. In testosterone females, mesenteric artery contractile responses to angiotensin II were significantly greater, while contractile responses to vasopressin were unaffected. Angiotensin II type-1 receptor expression was increased, while angiotensin II type-2 receptor was decreased in testosterone arteries. These results suggest that prenatal testosterone exposure downregulates adrenal Cyp11b2 expression, leading to decreased plasma aldosterone levels. Elevated angiotensin II and vasopressin levels along with enhanced vascular responsiveness to angiotensin II may serve as an underlying mechanism to maintain plasma volume and Na(+) and K(+) levels and mediate hypertension in adult testosterone females. © 2016 by the Society for the Study of Reproduction, Inc.

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

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.

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.

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.

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.

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.

Obesity, hypertension and aldosterone: is leptin the link?

PubMed

Xie, Ding; Bollag, Wendy B

2016-07-01

Obesity is a serious health hazard with rapidly increasing prevalence in the United States. In 2014, the World Health Organization estimated that nearly 2 billion people worldwide were overweight with an estimated 600 million of these obese. Obesity is associated with many chronic diseases, including cardiovascular disease and hypertension. Data from the Framingham Heart study suggest that approximately 78% of the risk for hypertension in men and 65% in women is related to excess body weight, a relationship that is further supported by studies showing increases in blood pressure with weight gain and decreases with weight loss. However, the exact mechanism by which excess body fat induces hypertension remains poorly understood. Several clinical studies have demonstrated elevated plasma aldosterone levels in obese individuals, especially those with visceral adiposity, with decreased aldosterone levels measured in concert with reduced blood pressure following weight loss. Since aldosterone is a mineralocorticoid hormone that regulates blood volume and pressure, serum aldosterone levels may link obesity and hypertension. Nevertheless, the mechanism by which obesity induces aldosterone production is unclear. A recent study by Belin de Chantemele and coworkers suggests that one adipose-released factor, leptin, is a direct agonist for aldosterone secretion; other adipose-related factors may also contribute to elevated aldosterone levels in obesity, such as very low-density lipoprotein (VLDL), the levels of which are elevated in obesity and which also directly stimulates aldosterone biosynthesis. This focused review explores the possible roles of leptin and VLDL in modulating aldosterone secretion to underlie obesity-associated hypertension. © 2016 Society for Endocrinology.

Subchronic treatment with aldosterone induces depression-like behaviours and gene expression changes relevant to major depressive disorder.

PubMed

Hlavacova, Natasa; Wes, Paul D; Ondrejcakova, Maria; Flynn, Marianne E; Poundstone, Patricia K; Babic, Stanislav; Murck, Harald; Jezova, Daniela

2012-03-01

The potential role of aldosterone in the pathophysiology of depression is unclear. The aim of this study was to test the hypothesis that prolonged elevation of circulating aldosterone induces depression-like behaviour accompanied by disease-relevant changes in gene expression in the hippocampus. Subchronic (2-wk) treatment with aldosterone (2 μg/100 g body weight per day) or vehicle via subcutaneous osmotic minipumps was used to induce hyperaldosteronism in male rats. All rats (n = 20/treatment group) underwent a modified sucrose preference test. Half of the animals from each treatment group were exposed to the forced swim test (FST), which served both as a tool to assess depression-like behaviour and as a stress stimulus. Affymetrix microarray analysis was used to screen the entire rat genome for gene expression changes in the hippocampus. Aldosterone treatment induced an anhedonic state manifested by decreased sucrose preference. In the FST, depressogenic action of aldosterone was manifested by decreased latency to immobility and increased time spent immobile. Aldosterone treatment resulted in transcriptional changes of genes in the hippocampus involved in inflammation, glutamatergic activity, and synaptic and neuritic remodelling. Furthermore, aldosterone-regulated genes substantially overlapped with genes affected by stress in the FST. This study demonstrates the existence of a causal relationship between the hyperaldosteronism and depressive behaviour. In addition, aldosterone treatment induced changes in gene expression that may be relevant to the aetiology of major depressive disorder. Subchronic treatment with aldosterone represents a new animal model of depression, which may contribute to the development of novel targets for the treatment of depression.

Aldosterone down-regulates the slowly activated delayed rectifier potassium current in adult guinea pig cardiomyocytes.

PubMed

Lv, Yankun; Bai, Song; Zhang, Hua; Zhang, Hongxue; Meng, Jing; Li, Li; Xu, Yanfang

2015-12-01

There is emerging evidence that the mineralocorticoid hormone aldosterone is associated with arrhythmias in cardiovascular disease. However, the effect of aldosterone on the slowly activated delayed rectifier potassium current (IK s ) remains poorly understood. The present study was designed to investigate the modulation of IK s by aldosterone. Adult guinea pigs were treated with aldosterone for 28 days via osmotic pumps. Standard glass microelectrode recordings and whole-cell patch-clamp techniques were used to record action potentials in papillary muscles and IK s in ventricular cardiomyocytes. The aldosterone-treated animals exhibited a prolongation of the QT interval and action potential duration with a higher incidence of early afterdepolarizations. Patch-clamp recordings showed a significant down-regulation of IK s density in the ventricular myocytes of these treated animals. These aldosterone-induced electrophysiological changes were fully prevented by a combined treatment with spironolactone, a mineralocorticoid receptor (MR) antagonist. In addition, in in vitro cultured ventricular cardiomyocytes, treatment with aldosterone (sustained exposure for 24 h) decreased the IK s density in a concentration-dependent manner. Furthermore, a significant corresponding reduction in the mRNA/protein expression of IKs channel pore and auxiliary subunits, KCNQ1 and KCNE1 was detected in ventricular tissue from the aldosterone-treated animals. Aldosterone down-regulates IK s by inhibiting the expression of KCNQ1 and KCNE1, thus delaying the ventricular repolarization. These results provide new insights into the mechanism underlying K(+) channel remodelling in heart disease and may explain the highly beneficial effects of MR antagonists in HF. © 2015 The British Pharmacological Society.

Aldosterone concentrations in saliva reflect the duration and severity of depressive episode in a sex dependent manner.

PubMed

Segeda, V; Izakova, L; Hlavacova, N; Bednarova, A; Jezova, D

2017-08-01

Evidence is accumulating that aldosterone may exert central actions and influence mental functions. The aim of the present study was to test the hypothesis that major depressive disorder affects the diurnal variation of salivary aldosterone and that aldosterone concentrations reflect the duration and severity of the depressive episode in a sex dependent manner. The sample consisted of 60 patients (37 postmenopausal women, 23 men) with major depressive disorder. Patients were examined two times, in acute depressive episode (admission to the hospital) and after reaching clinical remission (discharge). The samples of saliva were taken by the patients themselves twice a day (8.00-9.00 h in the morning and in the evening). Aldosterone concentrations were significantly higher in women compared to men and were significantly higher at the time of admission to the hospital compared to those at the discharge. Morning but not evening salivary aldosterone concentrations reflected the length of the depressive episode in women as well as the severity of the disorder in both sexes. Moreover, the patients with depression failed to exert known daily rhythmicity of aldosterone release. The present study brings several pieces of evidence suggesting the association of aldosterone with the pathophysiology of depression. Salivary aldosterone concentrations appear to reflect the outcome, the duration and the severity of the depressive episode in a sex dependent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dysregulation of Aldosterone Secretion in Mast Cell-Deficient Mice.

PubMed

Boyer, Hadrien-Gaël; Wils, Julien; Renouf, Sylvie; Arabo, Arnaud; Duparc, Céline; Boutelet, Isabelle; Lefebvre, Hervé; Louiset, Estelle

2017-12-01

Resident adrenal mast cells have been shown to activate aldosterone secretion in rat and man. Especially, mast cell proliferation has been observed in adrenal tissues from patients with aldosterone-producing adrenocortical adenoma. In the present study, we show that the activity of adrenal mast cells is stimulated by low-sodium diet and correlates with aldosterone synthesis in C57BL/6 and BALB/c mice. We have also investigated the regulation of aldosterone secretion in mast cell-deficient C57BL/6 Kit W-sh/W-sh mice in comparison with wild-type C57BL/6 mice. Kit W-sh/W-sh mice submitted to normal sodium diet had basal plasma aldosterone levels similar to those observed in wild-type animals. Conversely, low-sodium diet unexpectedly induced an exaggerated aldosterone response, which seemed to result from an increase in adrenal renin and angiotensin type 1 receptor expression. Severe hyperaldosteronism was associated with an increase in systolic blood pressure and marked hypokalemia, which favored polyuria. Adrenal renin and angiotensin type 1 receptor overexpression may represent a compensatory mechanism aimed at activating aldosterone production in the absence of mast cells. Finally, C57BL/6 Kit W-sh/W-sh mice represent an unexpected animal model of primary aldosteronism, which has the particularity to be triggered by sodium restriction. © 2017 American Heart Association, Inc.

Aldosterone induces a vascular inflammatory phenotype in the rat heart.

PubMed

Rocha, Ricardo; Rudolph, Amy E; Frierdich, Gregory E; Nachowiak, Denise A; Kekec, Beverly K; Blomme, Eric A G; McMahon, Ellen G; Delyani, John A

2002-11-01

Vascular inflammation was examined as a potential mechanism of aldosterone-mediated myocardial injury in uninephrectomized rats receiving 1% NaCl-0.3% KCl to drink for 1, 2, or 4 wk and 1) vehicle, 2) aldosterone infusion (0.75 microg/h), or 3) aldosterone infusion (0.75 microg/h) plus the selective aldosterone blocker eplerenone (100 mg. kg(-1). day(-1)). Aldosterone induced severe hypertension at 4 wk [systolic blood pressure (SBP), 210 +/- 3 mmHg vs. vehicle, 131 +/- 2 mmHg, P < 0.001], which was partially attenuated by eplerenone (SBP, 180 +/- 7 mmHg; P < 0.001 vs. aldosterone alone and vehicle). No significant increases in myocardial interstitial collagen fraction or hydroxyproline concentration were detected throughout the study. However, histopathological analysis of the heart revealed severe coronary inflammatory lesions, which were characterized by monocyte/macrophage infiltration and resulted in focal ischemic and necrotic changes. The histological evidence of coronary lesions was preceded by and associated with the elevation of cyclooxygenase-2 (up to approximately 4-fold), macrophage chemoattractant protein-1 (up to approximately 4-fold), and osteopontin (up to approximately 13-fold) mRNA expression. Eplerenone attenuated proinflammatory molecule expression in the rat heart and subsequent vascular and myocardial damage. Thus aldosterone and salt treatment in uninephrectomized rats led to severe hypertension and the development of a vascular inflammatory phenotype in the heart, which may represent one mechanism by which aldosterone contributes to myocardial disease.

Aldosterone hypersecretion in “non-salt-losing” congenital adrenal hyperplasia

PubMed Central

Bartter, Frederic C.; Henkin, Robert I.; Bryan, George T.

1968-01-01

Patients with the “non-salt-losing” form of the adrenogenital syndrome were studied before and after suppression of adrenal cortical activity with carbohydrate-active steroids. The response of aldosterone secretion to sodium deprivation was measured; in some patients response to adrenocorticotropic hormone (ACTH) was measured as well. The aldosterone secretion was normal and responded normally to sodium deprivation in all patients studied during suppression with carbohydrate-active steroids. This finding suggests that 21-hydroxylation of progesterone is normal in this syndrome. The sole abnormality in the production of aldosterone in these patients was found to be excessive secretion of aldosterone while they were not receiving suppressive doses of carbohydrate-active steroids. This finding strongly supports the view that the biogenetic pathways through which aldosterone is produced from progesterone are intact in this syndrome. No patient showed hypertension or hypokalemic alkalosis despite very high aldosterone secretion rates. This observation suggests that the hyper-aldosteronism is secondary to a tendency to sodium loss in the patient whose ACTH production is not suppressed. These studies provide additional evidence in support of the hypothesis that the salt-losing and “non-salt-losing” forms of adrenogenital syndrome are genetically and biochemically distinct. PMID:4299011

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.

VLDL-activated cell signaling pathways that stimulate adrenal cell aldosterone production

PubMed Central

Tsai, Ying-Ying; Rainey, William E.; Johnson, Maribeth H.; Bollag, Wendy B.

2016-01-01

Aldosterone plays an important role in regulating ion and fluid homeostasis and thus blood pressure, and hyperaldosteronism results in hypertension. Hypertension is also observed with obesity, which is associated with additional health risks, including cardiovascular disease. Obese individuals have high serum levels of very low-density lipoprotein (VLDL), which has been shown to stimulate aldosterone production; however, the mechanisms underlying VLDL-induced aldosterone production are still unclear. Here we demonstrate in human adrenocortical carcinoma (HAC15) cells that submaximal concentrations of angiotensin II and VLDL stimulate aldosterone production in an additive fashion, suggesting the possibility of common mechanisms of action. We show using inhibitors that VLDL-induced aldosterone production is mediated by the PLC/IP3/PKC signaling pathway. Our results suggest that PKC is upstream of the extracellular signal-regulated kinase (ERK) activation previously observed with VLDL. An understanding of the mechanisms mediating VLDL-induced aldosterone production may provide insights into therapies to treat obesity-associated hypertension. PMID:27222295

VLDL-activated cell signaling pathways that stimulate adrenal cell aldosterone production.

PubMed

Tsai, Ying-Ying; Rainey, William E; Johnson, Maribeth H; Bollag, Wendy B

2016-09-15

Aldosterone plays an important role in regulating ion and fluid homeostasis and thus blood pressure, and hyperaldosteronism results in hypertension. Hypertension is also observed with obesity, which is associated with additional health risks, including cardiovascular disease. Obese individuals have high serum levels of very low-density lipoprotein (VLDL), which has been shown to stimulate aldosterone production; however, the mechanisms underlying VLDL-induced aldosterone production are still unclear. Here we demonstrate in human adrenocortical carcinoma (HAC15) cells that submaximal concentrations of angiotensin II and VLDL stimulate aldosterone production in an additive fashion, suggesting the possibility of common mechanisms of action. We show using inhibitors that VLDL-induced aldosterone production is mediated by the PLC/IP3/PKC signaling pathway. Our results suggest that PKC is upstream of the extracellular signal-regulated kinase (ERK) activation previously observed with VLDL. An understanding of the mechanisms mediating VLDL-induced aldosterone production may provide insights into therapies to treat obesity-associated hypertension. Published by Elsevier Ireland Ltd.

Vascular effects of aldosterone: sorting out the receptors and the ligands.

PubMed

Feldman, Ross D; Gros, Robert

2013-12-01

Aldosterone has actions far beyond its role as a renal regulator of sodium reabsorption, and broader mechanisms of action than simply a transcriptional regulator. Aldosterone has a number of vascular effects, including regulation of vascular reactivity and vascular growth and/or development. Aldosterone-mediated effects on vascular reactivity reflect a balance between its endothelial-dependent vasodilator effects and its direct smooth muscle vasoconstrictor effects. The endothelial vasodilator effects of aldosterone are mediated by phosphatidylinositol 3-kinase-dependent activation of nitric oxide synthase. G-Protein oestrogen receptor (GPER) is a recently recognized G-protein coupled receptor (GPCR) that is activated by steroid hormones. It was first recognized as the GPCR mediating the rapid effects of oestrogens. Activation of GPER also mediates at least some of the vascular effects of aldosterone in smooth muscle and endothelial cells. In vascular endothelial cells, aldosterone activation of GPER mediates vasodilation. In contrast, activation of endothelial mineralocorticoid receptors has been linked to enhanced vasoconstrictor and/or impaired vasodilator responses. © 2013 Wiley Publishing Asia Pty Ltd.

Expression and biochemical characteristics of two different aldosterone receptors in both healthy and dilated cardiomyopathy dog heart tissue.

PubMed

Reynoso Palomar, Alejandro R; Rodriguez Bravo, Moncerrat; Villa Mancera, Abel E; Mucha, Carlos J

2017-03-01

Recently, replicates of the aldosterone receptor expression have been done in healthy heart dog tissues through immunohistochemistry, showing an apparent heterogeneous distribution in the four chambers. Recent studies have also identified immediate effects of aldosterone, suggesting aldosterone also produces non-genomic effects caused by an unidentified receptor. In order to study the molecular and quantitative expression characteristics of aldosterone binding receptors in the canine heart, we conducted studies, using Western Blot, in the heart from both healthy animals and animals with dilated cardiomyopathy. The results show the presence and distribution of two aldosterone receptors; one of 110/120 kDa molecular weight, suggested as cytosolic/nuclear and the other of undetermined location with a 250 kDa molecular weight.

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.

ACE insertion/deletion polymorphism (rs1799752) modifies the renoprotective effect of renin-angiotensin system blockade in patients with IgA nephropathy.

PubMed

Teranishi, Junya; Yamamoto, Ryohei; Nagasawa, Yasuyuki; Shoji, Tatsuya; Iwatani, Hirotsugu; Okada, Noriyuki; Moriyama, Toshiki; Yamauchi, Atsushi; Tsubakihara, Yoshiharu; Imai, Enyu; Rakugi, Hiromi; Isaka, Yoshitaka

2015-09-01

Little is known about genetic predictors that modify the renoprotective effect of renin-angiotensin system (RAS) blockade in IgA nephropathy (IgAN). The present multicenter retrospective observational study examined effect modification between RAS blockade and three RAS-related gene polymorphisms in 237 IgAN patients, including ACE I/D (rs1799752), AT1R A1166C (rs5186) and AGT T704C (rs699). During 9.9 ± 4.2 years of observation, 63 patients progressed to a 50% increase in serum creatinine level. Only ACE I/D predicted the outcome (ACE DD vs ID/II, hazard ratio 1.86 (95% confidence interval 1.03, 3.33)) and modified the renoprotective effect of RAS blockade (p for interaction between ACE DD and RAS blockade = 0.087). RAS blockade suppressed progression in ACE DD patients but not in ID/II patients (ACE ID/II with RAS blockade as a reference; ID/II without RAS blockade 1.45 (0.72, 2.92); DD without RAS blockade 3.06 (1.39, 6.73); DD with RAS blockade 1.51 (0.54, 4.19)), which was ascertained in a model with the outcome of slope of estimated glomerular filtration rate (p = 0.045 for interaction). ACE I/D predicted the IgAN progression and the renoprotective effect of RAS blockade in IgAN patients whereas neither AT1R A1166C nor AGT T704C did. © The Author(s) 2014.

The past, present and future of renin–angiotensin aldosterone system inhibition☆

PubMed Central

Mentz, Robert J.; Bakris, George L.; Waeber, Bernard; McMurray, John J.V.; Gheorghiade, Mihai; Ruilope, Luis M.; Maggioni, Aldo P.; Swedberg, Karl; Piña, Ileana L.; Fiuzat, Mona; O’Connor, Christopher M.; Zannad, Faiez; Pitt, Bertram

2014-01-01

The renin–angiotensin aldosterone system (RAAS) is central to the pathogenesis of cardiovascular disease. RAAS inhibition can reduce blood pressure, prevent target organ damage in hypertension and diabetes, and improve outcomes in patients with heart failure and/or myocardial infarction. This review presents the history of RAAS inhibition including a summary of key heart failure, myocardial infarction, hypertension and atrial fibrillation trials. Recent developments in RAAS inhibition are discussed including implementation and optimization of current drug therapies. Finally, ongoing clinical trials, opportunities for future trials and issues related to the barriers and approvability of novel RAAS inhibitors are highlighted. PMID:23121914

Aldosterone and the conquest of land.

PubMed

Colombo, L; Dalla Valle, L; Fiore, C; Armanini, D; Belvedere, P

2006-04-01

The sequence of the phylogenetic events that preceded the appearance of aldosterone in vertebrates is described, starting from the ancestral conversion of cytochrome P450s from oxygen detoxification to xenobiotic detoxification and synthesis of oxygenated endobiotics with useful functions in intercellular signalling, such as steroid hormones. At the end of the Silurian period [438-408 million yr ago, (Mya)], a complete set of cytochrome P450s for corticoid synthesis was presumably already available, except for mitochondrial cytochrome P450c18 or aldosterone synthase encoded by CYP11B2. This gene arose by duplication of the CYP11B gene in the sarcopterygian or lobe-finned fish/tetrapod line after its divergence from the actinopterygian or ray-finned fish line 420 Mya, but before the beginning of the colonization of land by tetrapods in the late Devonian period, around 370 Mya. The fact that aldosterone is already present in Dipnoi, which occupy an evolutionary transition between water- and air-breathing but are fully aquatic, suggests that the role of this steroid was to potentiate the corticoid response to hypoxia, rather than to prevent dehydration out of the water. In terrestrial amphibians, there is no differentiation between the secretion rates and gluco- and mineralocorticoid effects of aldosterone and corticosterone. In sauropsids, plasma aldosterone concentrations are much lower than in amphibians, but regulation of salt/water balance is dependent upon both aldosterone and corticosterone, though sometimes with opposed actions. In terrestrial mammals, aldosterone acquires a specific mineralocorticoid function, because its interaction with the mineralocorticoid receptor is protected by the coexpression of the enzyme 11beta-hydroxysteroid dehydrogenase type 2, which inactivates both cortisol and corticosterone. There is evidence that aldosterone can be also synthesized extra-adrenally in brain neurons and cardiac myocytes, which lack this protection and where the effects of aldosterone oppose those of glucocorticoids. In conclusion, the phylogenetic history of aldosterone documents the erratic progression of evolutionary changes in the course of the strenuous struggle for environmental resources and survival.

Use of plasma metanephrine to aid adrenal venous sampling in combined aldosterone and cortisol over-secretion.

PubMed

Goupil, Rémi; Wolley, Martin; Ungerer, Jacobus; McWhinney, Brett; Mukai, Kuniaki; Naruse, Mitsuhide; Gordon, Richard D; Stowasser, Michael

2015-01-01

In patients with primary aldosteronism (PA) undergoing adrenal venous sampling (AVS), cortisol levels are measured to assess lateralization of aldosterone overproduction. Concomitant adrenal autonomous cortisol and aldosterone secretion therefore have the potential to confound AVS results. We describe a case where metanephrine was measured during AVS to successfully circumvent this problem. A 55-year-old hypertensive male had raised plasma aldosterone/renin ratios and PA confirmed by fludrocortisone suppression testing. Failure of plasma cortisol to suppress overnight following dexamethasone and persistently suppressed corticotrophin were consistent with adrenal hypercortisolism. On AVS, comparison of adrenal and peripheral A/F ratios (left 5.7 vs peripheral 1.0; right 1.7 vs peripheral 1.1) suggested bilateral aldosterone production, with the left gland dominant but without contralateral suppression. However, using aldosterone/metanephrine ratios (left 9.7 vs peripheral 2.4; right 1.3 vs peripheral 2.5), aldosterone production lateralized to the left with good contralateral suppression. The patient underwent left laparoscopic adrenalectomy with peri-operative glucocorticoid supplementation to prevent adrenal insufficiency. Pathological examination revealed adrenal cortical adenomas producing both cortisol and aldosterone within a background of aldosterone-producing cell clusters. Hypertension improved and cured of PA and hypercortisolism were confirmed by negative post-operative fludrocortisone suppression and overnight 1 mg dexamethasone suppression testing. Routine dexamethasone suppression testing in patients with PA permits detection of concurrent hypercortisolism which can confound AVS results and cause unilateral PA to be misdiagnosed as bilateral with patients thereby denied potentially curative surgical treatment. In such patients, measurement of plasma metanephrine during AVS may overcome this issue. Simultaneous autonomous overproduction of cortisol and aldosterone is increasingly recognised although still apparently uncommon.Because cortisol levels are used during AVS to correct for differences in dilution of adrenal with non-adrenal venous blood when assessing for lateralisation, unilateral cortisol overproduction with contralateral suppression could confound the interpretation of AVS resultsMeasuring plasma metanephrine during AVS to calculate lateralisation ratios may circumvent this problem.

The impact of galectin-3 inhibition on aldosterone-induced cardiac and renal injuries.

PubMed

Calvier, Laurent; Martinez-Martinez, Ernesto; Miana, Maria; Cachofeiro, Victoria; Rousseau, Elodie; Sádaba, J Rafael; Zannad, Faiez; Rossignol, Patrick; López-Andrés, Natalia

2015-01-01

This study investigated whether galectin (Gal)-3 inhibition could block aldosterone-induced cardiac and renal fibrosis and improve cardiorenal dysfunction. Aldosterone is involved in cardiac and renal fibrosis that is associated with the development of cardiorenal injury. However, the mechanisms of these interactions remain unclear. Gal-3, a β-galactoside-binding lectin, is increased in heart failure and kidney injury. Rats were treated with aldosterone-salt combined with spironolactone (a mineralocorticoid receptor antagonist) or modified citrus pectin (a Gal-3 inhibitor), for 3 weeks. Wild-type and Gal-3 knockout mice were treated with aldosterone for 3 weeks. Hemodynamic, cardiac, and renal parameters were analyzed. Hypertensive aldosterone-salt-treated rats presented cardiac and renal hypertrophy (at morphometric, cellular, and molecular levels) and dysfunction. Cardiac and renal expressions of Gal-3 as well as levels of molecular markers attesting fibrosis were also augmented by aldosterone-salt treatment. Spironolactone or modified citrus pectin treatment reversed all of these effects. In wild-type mice, aldosterone did not alter blood pressure levels but increased cardiac and renal Gal-3 expression, fibrosis, and renal epithelial-mesenchymal transition. Gal-3 knockout mice were resistant to aldosterone effects. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac and renal fibrosis and dysfunction but was prevented by pharmacological inhibition (modified citrus pectin) or genetic disruption of Gal-3. These data suggest a key role for Gal-3 in cardiorenal remodeling and dysfunction induced by aldosterone. Gal-3 could be used as a new biotarget for specific pharmacological interventions. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Aldosterone Activates Transcription Factor Nrf2 in Kidney Cells Both In Vitro and In Vivo

PubMed Central

Oteiza, Patricia I.; Link, Samuel; Hey, Valentin; Stopper, Helga; Schupp, Nicole

2014-01-01

Abstract Aims: An increased kidney cancer risk was found in hypertensive patients, who frequently exhibit hyperaldosteronism, known to contribute to kidney injury, with oxidative stress playing an important role. The capacity of kidney cells to up-regulate transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2), a key regulator of the cellular antioxidative defense, as a prevention of aldosterone-induced oxidative damage was investigated both in vitro and in vivo. Results: Aldosterone activated Nrf2 and increased the expression of enzymes involved in glutathione (GSH) synthesis and detoxification. This activation depended on the mineralocorticoid receptor (MR) and oxidative stress. In vitro, Nrf2 activation, GSH amounts, and target gene levels decreased after 24 h, while oxidant levels remained high. Nrf2 activation could not protect cells against oxidative DNA damage, as aldosterone-induced double-strand breaks and 7,8-dihydro-8-oxo-guanine (8-oxodG) lesions steadily rose. The Nrf2 activator sulforaphane enhanced the Nrf2 response both in vitro and in vivo, thereby preventing aldosterone-induced DNA damage. In vivo, Nrf2 activation further had beneficial effects on the aldosterone-caused blood pressure increase and loss of kidney function. Innovation: This is the first study showing the activation of Nrf2 by aldosterone. Moreover, the results identify sulforaphane as a substance that is capable of preventing aldosterone-induced damage both in vivo and in vitro. Conclusion: Aldosterone-induced Nrf2 adaptive response cannot neutralize oxidative actions of chronically increased aldosterone, which, therefore could be causally involved in the increased cancer incidence of hypertensive individuals. Enhancing the cellular antioxidative defense with sulforaphane might exhibit beneficial effects. Antioxid. Redox Signal. 21, 2126–2142. PMID:24512358

Inflammation and Fibrosis in Perirenal Adipose Tissue of Patients With Aldosterone-Producing Adenoma.

PubMed

Wu, Chunyan; Zhang, Huijian; Zhang, Jiajun; Xie, Cuihua; Fan, Cunxia; Zhang, Hongbin; Wu, Peng; Wei, Qiang; Tan, Wanlong; Xu, Lingling; Wang, Ling; Xue, Yaoming; Guan, Meiping

2018-01-01

The prevalence of primary aldosteronism is much higher than previously thought. Recent studies have shown that primary aldosteronism is related to a higher risk of cardiovascular events. However, the underlying mechanism is not yet clear. Here we investigate the characteristics, including inflammation, fibrosis, and adipokine expression, of adipose tissues from different deposits in patients with aldosterone-producing adenoma (APA). Inflammation and fibrosis changes were evaluated in perirenal and subcutaneous adipose tissues obtained from patients with APA (n = 16), normotension (NT; n = 10), and essential hypertension (EH; n = 5) undergoing laparoscopic surgery. We also evaluated the effect of aldosterone in isolated human perirenal adipose tissue stromal vascular fraction (SVF) cells and investigated the effect of aldosterone in mouse 3T3-L1 and brown preadipocytes. Compared with the EH group, significantly higher levels of interleukin-6 (IL-6) and tumor necrosis factor-α messenger RNA (mRNA) and protein were observed in perirenal adipose tissue of patients with APA. Expression of genes related to fibrosis and adipogenesis in perirenal adipose tissue was notably higher in patients with APA than in patients with NT and EH. Aldosterone significantly induced IL-6 and fibrosis gene mRNA expression in differentiated SVF cells. Aldosterone treatment enhanced mRNA expression of genes associated with inflammation and fibrosis and stimulated differentiation of 3T3-L1 and brown preadipocytes. In conclusion, these data indicate that high aldosterone in patients with APA may induce perirenal adipose tissue dysfunction and lead to inflammation and fibrosis, which may be involved in the high risk of cardiovascular events observed in patients with primary aldosteronism. Copyright © 2018 Endocrine Society.

Aldosterone Is Not Associated With Metabolic and Microvascular Insulin Sensitivity in Abdominally Obese Men.

PubMed

Schütten, Monica T J; Kusters, Yvo H A M; Houben, Alfons J H M; Scheijen, Jean L J M; van de Waarenburg, Marjo P H; Schalkwijk, Casper G; Joris, Peter J; Plat, Jogchum; Mensink, Ronald P; de Leeuw, Peter W; Stehouwer, Coen D A

2018-02-01

Impaired insulin-mediated muscle microvascular recruitment (IMMR) may add to the development of insulin resistance and hypertension. Increased aldosterone levels have been linked to these obesity-related complications in severely to morbidly obese individuals and to impaired microvascular function in experimental studies. To investigate whether aldosterone levels are associated with IMMR, insulin sensitivity, and blood pressure in lean and moderately abdominally obese men, and to study the effect of weight loss. In 25 lean and 53 abdominally obese men, 24-hour blood pressure measurement was performed, and aldosterone levels were measured using ultra-performance liquid chromatography tandem mass spectrometry. Insulin sensitivity was assessed by determining whole-body glucose disposal during a hyperinsulinemic clamp. IMMR in forearm skeletal muscle was measured with contrast-enhanced ultrasonography. These assessments were repeated in the abdominally obese men following an 8-week weight loss or weight stable period. Sodium excretion and aldosterone levels were similar in lean and abdominally obese participants, but sodium excretion was inversely associated with aldosterone concentration only in the lean individuals [lean, β/100 mmol sodium excretion (adjusted for age and urinary potassium excretion) = -0.481 (95% confidence interval, -0.949 to -0.013); abdominally obese, β/100 mmol sodium excretion = -0.081 (95% confidence interval, -0.433 to 0.271); P for interaction = 0.02]. Aldosterone was not associated with IMMR, insulin sensitivity, or blood pressure and was unaffected by weight loss. In moderately abdominally obese men, the inverse relationship between sodium excretion and aldosterone concentration is less than that in lean men but does not translate into higher aldosterone levels. The absolute aldosterone level does not explain differences in microvascular and metabolic insulin sensitivity and blood pressure between lean and moderately abdominally obese men. Copyright © 2017 Endocrine Society

Interleukin-18 deficiency protects against renal interstitial fibrosis in aldosterone/salt-treated mice.

PubMed

Tanino, Akiko; Okura, Takafumi; Nagao, Tomoaki; Kukida, Masayoshi; Pei, Zuowei; Enomoto, Daijiro; Miyoshi, Ken-Ichi; Okamura, Haruki; Higaki, Jitsuo

2016-10-01

Interleukin (IL)-18 is a member of the IL-1 family of cytokines and was described originally as an interferon γ-inducing factor. Aldosterone plays a central role in the regulation of sodium and potassium homoeostasis by binding to the mineralocorticoid receptor and contributes to kidney and cardiovascular damage. Aldosterone has been reported to induce IL-18, resulting in cardiac fibrosis with induced IL-18-mediated osteopontin (OPN). We therefore hypothesized that aldosterone-induced renal fibrosis via OPN may be mediated by IL-18. To verify this hypothesis, we compared mice deficient in IL-18 and wild-type (WT) mice in a model of aldosterone/salt-induced hypertension. IL-18(-/-) and C57BL/6 WT mice were used for the uninephrectomized aldosterone/salt hypertensive model, whereas NRK-52E cells (rat kidney epithelial cells) were used in an in vitro model. In the present in vivo study, IL-18 protein expression was localized in medullary tubules in the WT mice, whereas in aldosterone-infused WT mice this expression was up-regulated markedly in the proximal tubules, especially in injured and dilated tubules. This renal damage caused by aldosterone was attenuated significantly by IL-18 knockout with down-regulation of OPN expression. In the present in vitro study, aldosterone directly induced IL-18 gene expression in renal tubular epithelial cells in a concentration- and time-dependent manner. These effects were inhibited completely by spironolactone. IL-18 may be a key mediator of aldosterone-induced renal fibrosis by inducing OPN, thereby exacerbating renal interstitial fibrosis. Inhibition of IL-18 may therefore provide a potential target for therapeutic intervention aimed at preventing the progression of renal injury. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

ALDOSTERONE DYSREGULATION WITH AGING PREDICTS RENAL-VASCULAR FUNCTION AND CARDIO-VASCULAR RISK

PubMed Central

Brown, Jenifer M.; Underwood, Patricia C.; Ferri, Claudio; Hopkins, Paul N.; Williams, Gordon H.; Adler, Gail K.; Vaidya, Anand

2014-01-01

Aging and abnormal aldosterone regulation are both associated with vascular disease. We hypothesized that aldosterone dysregulation influences the age-related risk of renal- and cardio-vascular disease. We conducted an analysis of 562 subjects who underwent detailed investigations under conditions of liberal and restricted dietary sodium intake (1,124 visits) in a Clinical Research Center. Aldosterone regulation was characterized by the ratio of maximal suppression-to-stimulation (supine serum aldosterone on a liberal sodium diet divided by the same measure on a restricted sodium diet). We previously demonstrated that higher levels of this Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI) indicate greater aldosterone dysregulation. Renal plasma flow (RPF) was determined via p-aminohippurate clearance to assess basal renal hemodynamics, and the renal-vascular responses to dietary sodium manipulation and angiotensin II (AngII) infusion. Cardiovascular risk was calculated using the Framingham Risk Score. In univariate linear regression, older age (β= -4.60, p<0.0001) and higher SASSI (β= -58.63, p=0.001) predicted lower RPF and a blunted RPF response to sodium loading and AngII infusion. We observed a continuous, independent, multivariate-adjusted interaction between age and SASSI, where the inverse relationship between SASSI and RPF was most apparent with older age (p<0.05). Higher SASSI and lower RPF independently predicted higher Framingham Risk Score (p<0.0001) and together displayed an additive effect. Aldosterone regulation and age may interact to mediate renal-vascular disease. Our findings suggest that the combination of aldosterone dysregulation and renal-vascular dysfunction could additively increase the risk of future cardiovascular outcomes; therefore, aldosterone dysregulation may represent a modifiable mechanism of age-related vascular disease. PMID:24664291

Re-evaluation of the fludrocortisone test: duration, NaCl supplementation and cut-off limits for aldosterone.

PubMed

Westerdahl, Christina; Bergenfelz, Anders; Larsson, Johanna; Nerbrand, Christina; Valdemarsson, Stig; Wihl, Anders; Isaksson, Anders

2009-01-01

Primary aldosteronism (PA) is the most common form of secondary hypertension. Thus, the aims of this study were: (1) to clarify whether the fludrocortisone suppression test (FST), which confirms autonomous aldosterone secretion, is reliable when carried out during a shorter period of time and (2) to confirm the importance of NaCl supplementation. The cut-off limits already obtained for aldosterone in healthy subjects during the FST were applied in hypertensive patients with a high aldosterone to renin ratio (ARR). The healthy subjects were allocated to three groups. Fludrocortisone was administered 4 times daily over 4 days and sodium chloride was supplemented in 3 different doses. The result was applied in 24 hypertensive patients, in 24 healthy subjects (10 women (23-38 years old) and 14 men (23-58 years old)) and in 24 patients with hypertension and high ARR (16 women (45-74 years old) and 8 men (56-73 years old)). Blood pressure, aldosterone, renin, potassium and sodium were measured. After three days of FST, there was a significant decrease in the serum level of aldosterone in the healthy subjects, regardless of high or low sodium chloride supplementation (p<0.001). The decrease in serum aldosterone was significantly less pronounced in patients with PA than in healthy subjects and hypertensive patients without PA (p<0.001). The 95th percentile of plasma aldosterone at the end of the test was 225 pmol/L. The FST can be shortened to 3 days and a daily 500 mg NaCl supplementation is sufficient. A cut-off value for aldosterone of 225 pmol/L after 4 days with FST is appropriate.

Aldosterone dysregulation with aging predicts renal vascular function and cardiovascular risk.

PubMed

Brown, Jenifer M; Underwood, Patricia C; Ferri, Claudio; Hopkins, Paul N; Williams, Gordon H; Adler, Gail K; Vaidya, Anand

2014-06-01

Aging and abnormal aldosterone regulation are both associated with vascular disease. We hypothesized that aldosterone dysregulation influences the age-related risk of renal vascular and cardiovascular disease. We conducted an analysis of 562 subjects who underwent detailed investigations under conditions of liberal and restricted dietary sodium intake (1124 visits) in the General Clinical Research Center. Aldosterone regulation was characterized by the ratio of maximal suppression to stimulation (supine serum aldosterone on a liberal sodium diet divided by the same measure on a restricted sodium diet). We previously demonstrated that higher levels of this Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI) indicate greater aldosterone dysregulation. Renal plasma flow (RPF) was determined via p-aminohippurate clearance to assess basal renal hemodynamics and the renal vascular responses to dietary sodium manipulation and angiotensin II infusion. Cardiovascular risk was calculated using the Framingham Risk Score. In univariate linear regression, older age (β=-4.60; P<0.0001) and higher SASSI (β=-58.63; P=0.001) predicted lower RPF and a blunted RPF response to sodium loading and angiotensin II infusion. We observed a continuous, independent, multivariate-adjusted interaction between age and SASSI, where the inverse relationship between SASSI and RPF was most apparent with older age (P<0.05). Higher SASSI and lower RPF independently predicted higher Framingham Risk Score (P<0.0001) and together displayed an additive effect. Aldosterone regulation and age may interact to mediate renal vascular disease. Our findings suggest that the combination of aldosterone dysregulation and renal vascular dysfunction could additively increase the risk of future cardiovascular outcomes; therefore, aldosterone dysregulation may represent a modifiable mechanism of age-related vascular disease.

Intra-adrenal Aldosterone Secretion: Segmental Adrenal Venous Sampling for Localization.

PubMed

Satani, Nozomi; Ota, Hideki; Seiji, Kazumasa; Morimoto, Ryo; Kudo, Masataka; Iwakura, Yoshitsugu; Ono, Yoshikiyo; Nezu, Masahiro; Omata, Kei; Ito, Sadayoshi; Satoh, Fumitoshi; Takase, Kei

2016-01-01

To use segmental adrenal venous sampling (AVS) (S-AVS) of effluent tributaries (a version of AVS that, in addition to helping identify aldosterone hypersecretion, also enables the evaluation of intra-adrenal hormone distribution) to detect and localize intra-adrenal aldosterone secretion. The institutional review board approved this study, and all patients provided informed consent. S-AVS was performed in 65 patients with primary aldosteronism (34 men; mean age, 50.9 years ± 11 [standard deviation]). A microcatheter was inserted in first-degree tributary veins. Unilateral aldosterone hypersecretion at the adrenal central vein was determined according to the lateralization index after cosyntropin stimulation. Excess aldosterone secretion at the adrenal tributary vein was considered to be present when the aldosterone/cortisol ratio from this vein exceeded that from the external iliac vein; suppressed secretion was indicated by the opposite pattern. Categoric variables were expressed as numbers and percentages; continuous variables were expressed as means ± standard errors of the mean. The AVS success rate, indicated by a selectivity index of 5 or greater, was 98% (64 of 65). The mean numbers of sampled tributaries on the left and right sides were 2.11 and 1.02, respectively. The following diagnoses were made on the basis of S-AVS results: unilateral aldosterone hypersecretion in 30 patients, bilateral hypersecretion without suppressed segments in 22 patients, and bilateral hypersecretion with at least one suppressed segment in 12 patients. None of the patients experienced severe complications. S-AVS could be used to identify heterogeneous intra-adrenal aldosterone secretion. Patients who have bilateral aldosterone-producing adenomas can be treated with adrenal-sparing surgery or other minimally invasive local therapies if any suppressed segment is identified at S-AVS. © RSNA, 2015.

Aldosterone and mortality in hemodialysis patients: role of volume overload.

PubMed

Hung, Szu-Chun; Lin, Yao-Ping; Huang, Hsin-Lei; Pu, Hsiao-Fung; Tarng, Der-Cherng

2013-01-01

Elevated aldosterone is associated with increased mortality in the general population. In patients on dialysis, however, the association is reversed. This paradox may be explained by volume overload, which is associated with lower aldosterone and higher mortality. We evaluated the relationship between aldosterone and outcomes in a prospective cohort of 328 hemodialysis patients stratified by the presence or absence of volume overload (defined as extracellular water/total body water >48%, as measured with bioimpedance). Baseline plasma aldosterone was measured before dialysis and categorized as low (<140 pg/mL), middle (140 to 280 pg/mL) and high (>280 pg/mL). Overall, 36% (n = 119) of the hemodialysis patients had evidence of volume overload. Baseline aldosterone was significantly lower in the presence of volume overload than in its absence. During a median follow-up of 54 months, 83 deaths and 70 cardiovascular events occurred. Cox multivariate analysis showed that by using the low aldosterone as the reference, high aldosterone was inversely associated with decreased hazard ratios for mortality (0.49; 95% confidence interval, 0.25-0.76) and first cardiovascular event (0.70; 95% confidence interval, 0.33-0.78) in the presence of volume overload. In contrast, high aldosterone was associated with an increased risk for mortality (1.97; 95% confidence interval, 1.69-3.75) and first cardiovascular event (2.01; 95% confidence interval, 1.28-4.15) in the absence of volume overload. The inverse association of aldosterone with adverse outcomes in hemodialysis patients is due to the confounding effect of volume overload. These findings support treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control.

Molecular identity and gene expression of aldosterone synthase cytochrome P450

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

Okamoto, Mitsuhiro; Nonaka, Yasuki; Takemori, Hiroshi

11{beta}-Hydroxylase (CYP11B1) of bovine adrenal cortex produced corticosterone as well as aldosterone from 11-deoxycorticosterone in the presence of the mitochondrial P450 electron transport system. CYP11B1s of pig, sheep, and bullfrog, when expressed in COS-7 cells, also performed corticosterone and aldosterone production. Since these CYP11B1s are present in the zonae fasciculata and reticularis as well as in the zona glomerulosa, the zonal differentiation of steroid production may occur by the action of still-unidentified factor(s) on the enzyme-catalyzed successive oxygenations at C11- and C18-positions of steroid. In contrast, two cDNAs, one encoding 11{beta}-hydroxylase and the other encoding aldosterone synthase (CYP11B2), were isolatedmore » from rat, mouse, hamster, guinea pig, and human adrenals. The expression of CYP11B1 gene was regulated by cyclic AMP (cAMP)-dependent signaling, whereas that of CYP11B2 gene by calcium ion-signaling as well as cAMP-signaling. Salt-inducible protein kinase, a cAMP-induced novel protein kinase, was one of the regulators of CYP11B2 gene expression.« less

Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension.

PubMed

Reinold, Annemarie; Schneider, Andreas; Kalizki, Tatjana; Raff, Ulrike; Schneider, Markus P; Schmieder, Roland E; Schmidt, Bernhard M W

2017-05-01

Hyperaldosteronism is well known cause of secondary hypertension. However, the importance of aldosterone for the much larger group of patients with primary hypertension is less clear. We hypothesized that in young subjects with primary hypertension, the rise of plasma aldosterone levels in response to head-up tilt testing as a stress stimulus is exaggerated. Hemodynamics (blood pressure (BP), heart rate (HR), cardiac index (CI), and total peripheral vascular resistance index (TPRI), all by TaskForce monitor) and hormones (plasma renin activity (PRA), angiotensin II (Ang II), aldosterone) were measured before and during 30 minutes of head-up tilt in 45 young hypertensive and 45 normotensive subjects. BP, HR, CI, and TPRI all increased in response to head-up tilt, with no difference between groups. There was no difference in baseline PRA, Ang II, and aldosterone between groups. During head-up tilt, PRA, and Ang II levels increased similarly. However, aldosterone levels increased to a greater extent in the hypertensive vs. normotensive subjects (P = 0.0021). Our data suggest that an increased release of aldosterone in response to orthostatic stress is a feature of early primary hypertension. The similar increase in PRA and Ang II suggests a potential role for secretagogues of aldosterone other than Ang II in this response. In addition to its established role in secondary hypertension, dysregulation of aldosterone release might contribute to the development of primary arterial hypertension. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Aldosterone Inhibits the Fetal Program and Increases Hypertrophy in the Heart of Hypertensive Mice

PubMed Central

Azibani, Feriel; Devaux, Yvan; Coutance, Guillaume; Schlossarek, Saskia; Polidano, Evelyne; Fazal, Loubina; Merval, Regine; Carrier, Lucie; Solal, Alain Cohen; Chatziantoniou, Christos; Launay, Jean-Marie; Samuel, Jane-Lise; Delcayre, Claude

2012-01-01

Background Arterial hypertension (AH) induces cardiac hypertrophy and reactivation of “fetal” gene expression. In rodent heart, alpha-Myosin Heavy Chain (MyHC) and its micro-RNA miR-208a regulate the expression of beta-MyHC and of its intronic miR-208b. However, the role of aldosterone in these processes remains unclear. Methodology/Principal Findings RT-PCR and western-blot were used to investigate the genes modulated by arterial hypertension and cardiac hyperaldosteronism. We developed a model of double-transgenic mice (AS-Ren) with cardiac hyperaldosteronism (AS mice) and systemic hypertension (Ren). AS-Ren mice had increased (x2) angiotensin II in plasma and increased (x2) aldosterone in heart. Ren and AS-Ren mice had a robust and similar hypertension (+70%) versus their controls. Anatomical data and echocardiography showed a worsening of cardiac hypertrophy (+41%) in AS-Ren mice (P<0.05 vs Ren). The increase of ANP (x 2.5; P<0.01) mRNA observed in Ren mice was blunted in AS-Ren mice. This non-induction of antitrophic natriuretic peptides may be involved in the higher trophic cardiac response in AS-Ren mice, as indicated by the markedly reduced cardiac hypertrophy in ANP-infused AS-Ren mice for one month. Besides, the AH-induced increase of ßMyHC and its intronic miRNA-208b was prevented in AS-Ren. The inhibition of miR 208a (−75%, p<0.001) in AS-Ren mice compared to AS was associated with increased Sox 6 mRNA (x 1.34; p<0.05), an inhibitor of ßMyHC transcription. Eplerenone prevented all aldosterone-dependent effects. Conclusions/Significance Our results indicate that increased aldosterone in heart inhibits the induction of atrial natriuretic peptide expression, via the mineralocorticoid receptor. This worsens cardiac hypertrophy without changing blood pressure. Moreover, this work reveals an original aldosterone-dependent inhibition of miR-208a in hypertension, resulting in the inhibition of β-myosin heavy chain expression through the induction of its transcriptional repressor Sox6. Thus, aldosterone inhibits the fetal program and increases cardiac hypertrophy in hypertensive mice. PMID:22666483

Diabetic kidney disease.

PubMed

Thomas, Merlin C; Brownlee, Michael; Susztak, Katalin; Sharma, Kumar; Jandeleit-Dahm, Karin A M; Zoungas, Sophia; Rossing, Peter; Groop, Per-Henrik; Cooper, Mark E

2015-07-30

The kidney is arguably the most important target of microvascular damage in diabetes. A substantial proportion of individuals with diabetes will develop kidney disease owing to their disease and/or other co-morbidity, including hypertension and ageing-related nephron loss. The presence and severity of chronic kidney disease (CKD) identify individuals who are at increased risk of adverse health outcomes and premature mortality. Consequently, preventing and managing CKD in patients with diabetes is now a key aim of their overall management. Intensive management of patients with diabetes includes controlling blood glucose levels and blood pressure as well as blockade of the renin-angiotensin-aldosterone system; these approaches will reduce the incidence of diabetic kidney disease and slow its progression. Indeed, the major decline in the incidence of diabetic kidney disease (DKD) over the past 30 years and improved patient prognosis are largely attributable to improved diabetes care. However, there remains an unmet need for innovative treatment strategies to prevent, arrest, treat and reverse DKD. In this Primer, we summarize what is now known about the molecular pathogenesis of CKD in patients with diabetes and the key pathways and targets implicated in its progression. In addition, we discuss the current evidence for the prevention and management of DKD as well as the many controversies. Finally, we explore the opportunities to develop new interventions through urgently needed investment in dedicated and focused research. For an illustrated summary of this Primer, visit: http://go.nature.com/NKHDzg.

Coronary care medicine: it's not your father's CCU anymore.

PubMed

Antman, Elliott M

2004-01-01

The management of ST-elevation MI (STEMI) has gone through four phases: 1. The "clinical observation phase"; 2. the "coronary care unit phase"; 3. the "high-technology phase"; and 4. the "evidence-based coronary care phase". A significant advance in the care of patients with acute myocardial infarction that arose as an outgrowth of the evidence-based era was introduction of a lexicon that more accurately reflected contemporary concepts of the pathophysiology underlying myocardial ischemia and infarction. Although considerable improvement has occurred in the process of care for patient with STEMI, room for improvement exists. Despite strong evidence in the literature that prompt use of reperfusion therapy improves survival of STEMI patients such treatment is underutilized and often not administered in an expeditious timeframe relative to the onset of symptom. Even in the reperfusion era, left ventricular dysfunction remains the single most important predictor of mortality following STEMI. After administration of aspirin, initiating reperfusion strategies and, where appropriate, beta blockade all STEMI patients should be considered for inhibition of the renin-angiotensin-aldosterone system. Several adjunctive pharmacotherapies have been investigated to prevent inflammatory damage in the infarct zone. Contrary to earlier beliefs that the heart is a terminally differentiated organ without the capacity to regenerate, evidence now exists that human cardiac myocytes divide after STEMI and stem cells can promote regeneration of cardiac tissue. These observations open up the possibility of myocardial replacement therapy after STEMI.

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.

Recent advances in distal tubular potassium handling

PubMed Central

Rodan, Aylin R.; Cheng, Chih-Jen

2011-01-01

It is well known that sodium reabsorption and aldosterone play important roles in potassium secretion by the aldosterone-sensitive distal nephron. Sodium- and aldosterone-independent mechanisms also exist. This review focuses on some recent studies that provide novel insights into the sodium- and aldosterone-independent potassium secretion by the aldosterone-sensitive distal nephron. In addition, we discuss a study reporting on the regulation of the mammalian potassium kidney channel ROMK by intracellular and extracellular magnesium, which may be important in the pathogenesis of persistent hypokalemia in patients with concomitant potassium and magnesium deficiency. We also discuss outstanding questions and propose working models for future investigation. PMID:21270092

Aldosterone antagonists: effective add-on therapy for the treatment of resistant hypertension.

PubMed

Gaddam, Krishna K; Pratt-Ubunama, Monique N; Calhoun, David A

2006-05-01

Resistant hypertension is defined as blood pressure that remains above target levels despite treatment with three different antihypertensive agents. Cross-sectional analyses and hypertension outcome studies indicate that it is a common clinical problem, which will undoubtedly become increasingly prevalent with an aging and increasingly overweight population. Secondary causes of hypertension are common in patients with resistant hypertension, particularly hyperaldosteronism, with a prevalence of approximately 15-20%. This, however, is likely to be an underestimation of the role excess aldosterone plays in causing resistance to treatment. In subjects with resistant hypertension, suppressed renin levels are common, exceeding 60% in studies conducted by the authors and from centers elsewhere in the world, suggesting occurrence of excess aldosterone beyond cases of true primary aldosteronism. Recent clinical studies indicate that aldosterone antagonists provide significant additional blood pressure reduction when added to treatment regimens of patients with resistant hypertension independent of aldosterone levels. These agents are generally well tolerated. Hyperkalemia is an uncommon complication of aldosterone antagonists, but it can occur. Therefore, biochemical monitoring is necessary, particularly in high-risk patients.

Renin-angiotensin system blockade alone or combined with ETA receptor blockade: effects on the course of chronic kidney disease in 5/6 nephrectomized Ren-2 transgenic hypertensive rats.

PubMed

Sedláková, Lenka; Čertíková Chábová, Věra; Doleželová, Šárka; Škaroupková, Petra; Kopkan, Libor; Husková, Zuzana; Červenková, Lenka; Kikerlová, Soňa; Vaněčková, Ivana; Sadowski, Janusz; Kompanowska-Jezierska, Elzbieta; Kujal, Petr; Kramer, Herbert J; Červenka, Luděk

2017-01-01

Early addition of endothelin (ET) type A (ET A ) receptor blockade to complex renin-angiotensin system (RAS) blockade has previously been shown to provide better renoprotection against progression of chronic kidney disease (CKD) in Ren-2 transgenic hypertensive rats (TGR) after 5/6 renal ablation (5/6 NX). In this study, we examined if additional protection is provided when ET A blockade is applied in rats with already developed CKD. For complex RAS inhibition, an angiotensin-converting enzyme inhibitor along with angiotensin II type 1 receptor blocker was used. Alternatively, ET A receptor blocker was added to the RAS blockade. The treatments were initiated 6 weeks after 5/6 NX and the follow-up period was 50 weeks. When applied in established CKD, addition of ET A receptor blockade to the complex RAS blockade brought no further improvement of the survival rate (30% in both groups); surprisingly, aggravated albuminuria (588 ± 47 vs. 245 ± 38 mg/24 h, p < 0.05) did not reduce renal glomerular injury index (1.25 ± 0.29 vs. 1.44 ± 0.26), did not prevent the decrease in creatinine clearance (203 ± 21 vs. 253 ± 17 µl/min/100 g body weight), and did not attenuate cardiac hypertrophy to a greater extent than observed in 5/6 NX TGR treated with complex RAS blockade alone. When applied in the advanced phase of CKD, addition of ET A receptor blockade to the complex RAS blockade brings no further beneficial renoprotective effects on the CKD progression in 5/6 NX TGR, in addition to those seen with RAS blockade alone.

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 effects of infusions of ring-A-reduced derivatives of aldosterone on the antinatriuretic and kaliuretic actions of aldosterone.

PubMed

Morris, D J; Souness, G W; Saccoccio, N A; Harnik, M

1989-01-01

Infusion of Ring-A-reduced metabolites of aldosterone in adrenalectomized male rats for 4 days revealed that 5 alpha-Ring-A-reduced derivatives, 5 alpha-dihydroaldosterone (5 alpha-DHAldo; 2.5-5.0 micrograms/day), 3 alpha,5 alpha-tetrahydroaldosterone (3 alpha,5 alpha-THAldo; 5-25 micrograms/day), and 3 beta,5 alpha-THAldo (50-175 micrograms/day) possessed intrinsic Na+-retaining activity. The same infusions of 5 alpha-DHAldo, 3 alpha,5 alpha-THAldo, and 3 beta,5 alpha-THAldo, also lowered the urinary excretion of potassium. The 5 beta-Ring-A-reduced derivative 3 alpha,5 beta-THAldo did not demonstrate either of these biological properties. In another set of experiments, on the fourth day of infusion, aldosterone (0.1 microgram/rat) was administered acutely subcutaneously; none of the Ring-A-reduced derivatives altered the Na+-retaining activity of aldosterone. However, in a dose-dependent manner, both 3 alpha,5 alpha-THAldo and 3 beta,5 alpha-THAldo blunted the urinary K+-secretory effect of aldosterone; low dosages of 5 alpha-DHAldo and larger dosages of 3 alpha,5 beta-THAldo did not. Thus, the 5 alpha-reduced derivatives of aldosterone not only lowered urinary Na+ and K+ excretion in their own right, but two of them blunted the kaliuretic response of the parent mineralocorticoid, aldosterone. Further experiments will be required to determine whether these aldosterone metabolites are further metabolized or interconverted during the expression of the regulatory properties described here and whether these properties are physiologically relevant.

Microalbuminuria and plasma aldosterone levels in nondiabetic treatment-naïve patients with hypertension.

PubMed

Catena, Cristiana; Colussi, GianLuca; Martinis, Flavia; Novello, Marileda; Sechi, Leonardo A

2017-12-01

Identification of factors that contribute to urinary albumin losses in hypertensive nephropathy is crucial for prevention of renal deterioration. The aim of this study was to investigate the relationship of low-grade albuminuria with plasma aldosterone levels in treatment-naïve hypertensive patients free of additional comorbidities that might affect renal function. In 242 newly diagnosed patients with uncomplicated primary hypertension, we obtained duplicate 24-h urine collections for measurement of urinary albumin/creatinine ratio (UACR) and measured plasma aldosterone levels. Patients with diabetes, overt proteinuria (>300 mg/day), glomerular filtration rate less than 30 ml/min per 1.73 m, and previous renal diseases were excluded. Increasing UACR was associated with significantly and progressively higher blood pressure (BP), HDL-cholesterol, and plasma aldosterone levels, and with lower glomerular filtration. Microalbuminuria (30-300 mg/day) was detected in 41 (17%) of 242 hypertensive patients, and these patients had significantly higher BP and plasma aldosterone levels (178 ± 113 vs. 128 ± 84 pg/ml; P = 0.001), and lower glomerular filtration than patients without microalbuminuria. UACR was directly and independently correlated with BP and plasma aldosterone levels. In a logistic regression model, presence of microalbuminuria was associated with plasma aldosterone levels independently of glomerular filtration and demographic, anthropometric, and metabolic variables. In nondiabetic, treatment-naïve patients with hypertension, low-grade albuminuria is independently associated with elevated plasma aldosterone. These findings suggest a contribution of aldosterone to the early glomerular changes occurring in hypertensive nephropathy.

A MicroRNA Cluster miR-23-24-27 Is Upregulated by Aldosterone in the Distal Kidney Nephron Where it Alters Sodium Transport.

PubMed

Liu, Xiaoning; Edinger, Robert S; Klemens, Christine A; Phua, Yu L; Bodnar, Andrew J; LaFramboise, William A; Ho, Jacqueline; Butterworth, Michael B

2017-06-01

The epithelial sodium channel (ENaC) is expressed in the epithelial cells of the distal convoluted tubules, connecting tubules, and cortical collecting duct (CCD) in the kidney nephron. Under the regulation of the steroid hormone aldosterone, ENaC is a major determinant of sodium (Na + ) and water balance. The ability of aldosterone to regulate microRNAs (miRs) in the kidney has recently been realized, but the role of miRs in Na + regulation has not been well established. Here we demonstrate that expression of a miR cluster mmu-miR-23-24-27, is upregulated in the CCD by aldosterone stimulation both in vitro and in vivo. Increasing the expression of these miRs increased Na + transport in the absence of aldosterone stimulation. Potential miR targets were evaluated and miR-27a/b was verified to bind to the 3'-untranslated region of intersectin-2, a multi-domain protein expressed in the distal kidney nephron and involved in the regulation of membrane trafficking. Expression of Itsn2 mRNA and protein was decreased after aldosterone stimulation. Depletion of Itsn2 expression, mimicking aldosterone regulation, increased ENaC-mediated Na + transport, while Itsn2 overexpression reduced ENaC's function. These findings reinforce a role for miRs in aldosterone regulation of Na + transport, and implicate miR-27 in aldosterone's action via a novel target. J. Cell. Physiol. 232: 1306-1317, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Regulation of aldosterone secretion by mineralocorticoid receptor-mediated signaling.

PubMed

Chong, Cherish; Hamid, Anis; Yao, Tham; Garza, Amanda E; Pojoga, Luminita H; Adler, Gail K; Romero, Jose R; Williams, Gordon H

2017-03-01

We posit the existence of a paracrine/autocrine negative feedback loop, mediated by the mineralocorticoid receptor (MR), regulating aldosterone secretion. To assess this hypothesis, we asked whether altering MR activity in zona glomerulosa (ZG) cells affects aldosterone production. To this end, we studied ex vivo ZG cells isolated from male Wistar rats fed chow containing either high (1.6% Na + (HS)) or low (0.03% Na + (LS)) amount of sodium. Western blot analyses demonstrated that MR was present in both the ZG and zona fasciculata/zona reticularis (ZF/ZR/ZR). In ZG cells isolated from rats on LS chow, MR activation by fludrocortisone produced a 20% and 60% reduction in aldosterone secretion basally and in response to angiotensin II (ANGII) stimulation, respectively. Corticosterone secretion was increased in these cells suggesting that aldosterone synthase activity was being reduced by fludrocortisone. In contrast, canrenoic acid, an MR antagonist, enhanced aldosterone production by up to 30% both basally and in response to ANGII. Similar responses were observed in ZG cells from rats fed HS. Modulating glucocorticoid receptor (GR) activity did not alter aldosterone production by ZG cells; however, altering GR activity did modify corticosterone production from ZF/ZR/ZR cells both basally and in response to adrenocorticotropic hormone (ACTH). Additionally, activating the MR in ZF/ZR/ZR cells strikingly reduced corticosterone secretion. In summary, these data support the hypothesis that negative ultra-short feedback loops regulate adrenal steroidogenesis. In the ZG, aldosterone secretion is regulated by the MR, but not the GR, an effect that appears to be secondary to a change in aldosterone synthase activity. © 2017 Society for Endocrinology.

Prolonged oral administration of potassium upon aldosterone biosynthesis by rat glomerulosa tissue in vitro.

PubMed

Regöly-Mérei, J; Sólyom, J

1975-01-01

Steroid production rate of adrenals derived from rats drinking a 0.3 M KC1 + 5% glucose solution for 7 days was compared to that of control rats drinking a 5% glucose solution in order to investigate the effect of potassium loading upon the early and late step of aldosterone biosynthesis. Following potassium loading the quartered adrenals produced more aldosterone but less corticosterone as compared to the control. Potassium loading resulted in an increased aldosterone production rate by capsular adrenals (z. glomerulosa) provided that the corticosterone concentration in the incubation medium was elevated either by incubating it together with the decapsulated adrenal or adding exogenous corticosterone (4--16 mug/ml) to the medium. The corticosterone to aldosterone converting capacity of capsular adrenals is markedly higher in the potassium-loaded rats than in the controls. In the first 15 minutes of incubation the corticosterone production rate of the two groups was equal, aldosterone production rate by capsular adrenals of potassium-loaded rats, being higher than that of control animals. Corticosterone output of capsular adrenals from potassium-loaded rats decreased more rapidly in course of the incubation than it did in control tissue. These results suggest that the increase in aldosterone secretion in vivo following potassium loading is due to the stimulation of conversion of corticosterone to aldosterone in the glomerulosa cells. However, the endogenous corticosterone production during the incubation of glomerulosa cells from pottasium-loaded rats decreases so rapidly that the cells are not capable of producing more aldosterone than the control ones in spite of activated 18-hydroxylase.

Physiological Aldosterone Concentrations Are Associated with Alterations of Lipid Metabolism: Observations from the General Population.

PubMed

Hannich, M; Wallaschofski, H; Nauck, M; Reincke, M; Adolf, C; Völzke, H; Rettig, R; Hannemann, A

2018-01-01

Aldosterone and high-density lipoprotein cholesterol (HDL-C) are involved in many pathophysiological processes that contribute to the development of cardiovascular diseases. Previously, associations between the concentrations of aldosterone and certain components of the lipid metabolism in the peripheral circulation were suggested, but data from the general population is sparse. We therefore aimed to assess the associations between aldosterone and HDL-C, low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, or non-HDL-C in the general adult population. Data from 793 men and 938 women aged 25-85 years who participated in the first follow-up of the Study of Health in Pomerania were obtained. The associations of aldosterone with serum lipid concentrations were assessed in multivariable linear regression models adjusted for sex, age, body mass index (BMI), estimated glomerular filtration rate (eGFR), and HbA1c. The linear regression models showed statistically significant positive associations of aldosterone with LDL-C ( β -coefficient = 0.022, standard error = 0.010, p = 0.03) and non-HDL-C ( β -coefficient = 0.023, standard error = 0.009, p = 0.01) as well as an inverse association of aldosterone with HDL-C ( β -coefficient = -0.022, standard error = 0.011, p = 0.04). The present data show that plasma aldosterone is positively associated with LDL-C and non-HDL-C and inversely associated with HDL-C in the general population. Our data thus suggests that aldosterone concentrations within the physiological range may be related to alterations of lipid metabolism.

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.

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.

Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

DTIC Science & Technology

2014-09-30

hormones and function in elephant seals; 3) determine the impact of baseline variation in aldosterone on electrolyte balance in elephant seals; 4...may have broad implications for marine mammal species. Task 3 – Impact of aldosterone variability on osmolality Work on the Parent Project and...a parallel project on bottlenose dolphins has shown the importance of aldosterone as a stress hormone in marine mammals. Aldosterone covaries with

Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

DTIC Science & Technology

2015-09-30

hormones and function in elephant seals; 3) determine the impact of baseline variation in aldosterone on electrolyte balance in elephant seals; 4...3 – Impact of aldosterone variability on osmolality Work on the Parent Project and a parallel project on bottlenose dolphins has shown the...importance of aldosterone as a stress hormone in marine mammals. Aldosterone covaries with cortisol in many groups (Figure 4) and ACTH challenges in the

SFE/SFHTA/AFCE consensus on primary aldosteronism, part 4: Subtype diagnosis.

PubMed

Bardet, Stéphane; Chamontin, Bernard; Douillard, Claire; Pagny, Jean-Yves; Hernigou, Anne; Joffre, Francis; Plouin, Pierre-François; Steichen, Olivier

2016-07-01

To establish the cause of primary aldosteronism (PA), it is essential to distinguish unilateral from bilateral adrenal aldosterone secretion, as adrenalectomy improves aldosterone secretion and controls hypertension and hypokalemia only in the former. Except in the rare cases of type 1 or 3 familial hyperaldosteronism, which can be diagnosed genetically and are not candidates for surgery, lateralized aldosterone secretion is diagnosed on adrenal CT or MRI and adrenal venous sampling. Postural stimulation tests and (131)I-norcholesterol scintigraphy have poor diagnostic value and (11)C-metomidate PET is not yet available. We recommend that adrenal CT or MRI be performed in all cases of PA. Imaging may exceptionally identify adrenocortical carcinoma, for which the surgical objectives are carcinologic, and otherwise shows either normal or hyperplastic adrenals or unilateral adenoma. Imaging alone carries a risk of false positives in patients over 35 years of age (non-aldosterone-secreting adenoma) and false negatives in all patients (unilateral hyperplasia). We suggest that all candidates for surgery over 35 years of age undergo adrenal venous sampling, simultaneously in both adrenal veins, without ACTH stimulation, to confirm the unilateral form of the hypersecretion. Sampling results should be confirmed on adrenal vein cortisol assay showing a concentration at least double that found in peripheral veins. Aldosterone secretion should be considered lateralized when aldosterone/cortisol ratio on the dominant side is at least 4-fold higher than contralaterally. Published by Elsevier Masson SAS.

Influence of aldosterone and salt or ouabain in a10 rat aorta smooth muscle cells.

PubMed

Schwerdt, Gerald; Frisch, Annett; Mildenberger, Sigrid; Hilgenfeld, Tim; Grossmann, Claudia; Gekle, Michael

2012-01-01

It is currently under debate whether aldosterone is able to induce fibrosis or whether it acts only as a cofactor under pathological conditions, e.g. as an elevated salt (NaCl) load. We tested the interaction of 10 nM aldosterone, 15 mM NaCl and 1 μM ouabain using rat aorta smooth muscle cells (A10) with respect to the following parameters: necrosis, apoptosis, glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase activity, glutathione (GSH) content, collagen and fibronectin homeostasis and intracellular calcium distribution. Necrosis rates were increased after 48 h of incubation with aldosterone, salt or ouabain and in the combination of aldosterone and salt or ouabain. Apoptosis rates were decreased. A reduced defense capacity against oxidative stress was mirrored in the decreased G6PD activity and GSH content. Collagen III or fibronectin synthesis rates were unchanged, but gelatinase activity was increased resulting in a decreased media collagen III and fibronectin content. Calcium stores were increased by aldosterone in combination with ouabain. Aldosterone and salt per se can lead to cell injury that is aggravated in combination or with cardiotonic steroids. In cooperation with other vascular cells, this can generate a permissive milieu enabling aldosterone or salt to promote more extensive vascular injury. Copyright © 2012 S. Karger AG, Basel.

Vascular Consequences of Aldosterone Excess and Mineralocorticoid Receptor Antagonism.

PubMed

Chrissobolis, Sophocles

2017-01-01

Aldosterone binds to mineralocorticoid receptors (MRs) on renal epithelial cells to regulate sodium and water reabsorption, and therefore blood pressure. Recently, the actions of aldosterone outside the kidney have been extensively investigated, with numerous reports of aldosterone having detrimental actions, including in the vasculature. Notably, elevated aldosterone levels are an independent cardiovascular risk factor, and in addition to causing an increase in blood pressure, aldosterone can have blood pressure-dependent and -independent effects commonly manifested in the vasculature in cardiovascular diseases, including oxidative stress, endothelial dysfunction, inflammation, remodeling, stiffening, and plaque formation. Receptor-dependent mechanisms mediating these actions include the MR expressed on vascular endothelial and smooth muscle cells, but also include the angiotensin II type 1 receptor, epidermal growth factor receptor and vascular endothelial growth factor receptor 1, with downstream mechanisms including NADPH oxidase, cyclooxygenase, glucose-6-phosphate dehydrogenase, poly-(ADP ribose) polymerase and placental growth factor. The beneficial actions of MR antagonism in experimental hypertension include improved endothelial function, reduced hypertrophy and remodeling, and in atherosclerosis beneficial actions include reduced plaque area, inflammation, oxidative stress and endothelial dysfunction. Aldosterone excess is detrimental and MR antagonism is beneficial in humans also. The emerging concept of the contribution of aldosterone/MR-induced immunity to vascular pathology will also be discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aldosterone Induces Renal Fibrosis and Inflammatory M1-Macrophage Subtype via Mineralocorticoid Receptor in Rats

PubMed Central

Martín-Fernández, Beatriz; Rubio-Navarro, Alfonso; Cortegano, Isabel; Ballesteros, Sandra; Alía, Mario; Cannata-Ortiz, Pablo; Olivares-Álvaro, Elena; Egido, Jesús; de Andrés, Belén; Gaspar, María Luisa; de las Heras, Natalia; Lahera, Vicente; Moreno, Juan Antonio

2016-01-01

We aimed to evaluate macrophages heterogeneity and structural, functional and inflammatory alterations in rat kidney by aldosterone + salt administration. The effects of treatment with spironolactone on above parameters were also analyzed. Male Wistar rats received aldosterone (1 mgkg-1d-1) + 1% NaCl for 3 weeks. Half of the animals were treated with spironolactone (200 mg kg-1d-1). Systolic and diastolic blood pressures were elevated (p<0.05) in aldosterone + salt–treated rats. Relative kidney weight, collagen content, fibronectin, macrophage infiltrate, CTGF, Col I, MMP2, TNF-α, CD68, Arg2, and SGK-1 were increased (p<0.05) in aldosterone + salt–treated rats, being reduced by spironolactone (p<0.05). Increased iNOS and IFN-γ mRNA gene expression (M1 macrophage markers) was observed in aldosterone + salt rats, whereas no significant differences were observed in IL-10 and gene ArgI mRNA expression or ED2 protein content (M2 macrophage markers). All the observed changes were blocked with spironolactone treatment. Macrophage depletion with liposomal clodronate reduced macrophage influx and inflammatory M1 markers (INF-γ or iNOS), whereas interstitial fibrosis was only partially reduced after this intervention, in aldosterone plus salt-treated rats. In conclusion, aldosterone + salt administration mediates inflammatory M1 macrophage phenotype and increased fibrosis throughout mineralocorticoid receptors activation. PMID:26730742

Role of radiology in the management of primary aldosteronism.

PubMed

Patel, Shilpan M; Lingam, Ravi K; Beaconsfield, Tina I; Tran, Tan L; Brown, Beata

2007-01-01

The diagnosis of primary aldosteronism, the most common form of secondary hypertension, is based on clinical and biochemical features. Although radiology plays no role in the initial diagnosis, it has an important role in differentiating between the two main causes of primary aldosteronism: aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). This distinction is important because APAs are generally managed surgically and BAH medically. Adrenal venous sampling is considered the standard of reference for determining the cause of primary aldosteronism but is technically demanding, operator dependent, costly, and time consuming, with a low but significant complication rate. Other imaging modalities, including computed tomography, magnetic resonance imaging, and adrenal scintigraphy, have also been used to determine the cause of primary aldosteronism. Cross-sectional imaging has traditionally focused on establishing the diagnosis of an APA, with that of BAH being one of exclusion. A high specificity for detecting an APA is desirable, since it will avert unnecessary surgery in patients with BAH. However, an overreliance on cross-sectional imaging can lead to the incorrect treatment of affected patients, mainly due to the wide variation in the reported diagnostic performance of these modalities. A combination of modalities is usually required to confidently determine the cause of primary aldosteronism. The quest for optimal radiologic management of primary aldosteronism continues just over a half century since this disease entity was first described. RSNA, 2007

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.

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.

Aldosterone does not alter endothelin B receptor signaling in the inner medullary collecting duct.

PubMed

Ramkumar, Nirupama; Stuart, Deborah; Yang, Tianxin; Kohan, Donald E

2017-03-01

Recent studies suggest that aldosterone-mediated sulfenic acid modification of the endothelin B receptor (ETB) promotes renal injury in an ischemia/reperfusion model through reduced ETB-stimulated nitric oxide production. Similarly, aldosterone inactivation of ETB signaling promotes pulmonary artery hypertension. Consequently, we asked whether aldosterone inhibits collecting duct ETB signaling; this could promote fluid retention since CD ETB exerts natriuretic and diuretic effects. A mouse inner medullary collecting duct cell line (IMCD3) was treated with aldosterone for 48 h followed by sarafotoxin-6c, an ETB-selective agonist, and extracellular signal-related kinase 1/2 (ERK) phosphorylation assessed. S6c increased the phospho/total-ERK ratio similarly in control and aldosterone-treated cells (aldosterone alone increased phospho/total-ERK). Since cultured IMCD cell lines lack ETB inhibited AVP signaling, the effect of S6c on AVP-stimulated cAMP in acutely isolated IMCD was assessed. Rats (have much higher CD ETB expression than mice) were exposed to 3 days of a normal or low Na + diet, or low Na + diet + desoxycorticosterone acetate. S6c inhibited AVP-stimulated cAMP in rat IMCD by the same degree in the high mineralocorticoid groups compared to controls. Finally, S6c-stimulated cGMP accumulation in cultured IMCD, or S6c-stimulated nitric oxide or cGMP in acutely isolated IMCD, was not affected by prior aldosterone exposure. These findings provide evidence that aldosterone does not modify ETB effects on ERK phosphorylation, AVP-dependent cAMP inhibition, or NO/cGMP accumulation in the IMCD Thus, while aldosterone can inhibit endothelial cell ETB activity to promote hypertension and injury, this response does not appear to occur in the IMCD. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Long-term aldosterone administration increases renal Na+-Cl- cotransporter abundance in late distal convoluted tubule.

PubMed

Poulsen, Søren Brandt; Christensen, Birgitte Mønster

2017-09-01

Renal Na + -Cl - cotransporter (NCC) is expressed in early distal convoluted tubule (DCT) 1 and late DCT (DCT2). NCC activity can be stimulated by aldosterone administration, and the mechanism is assumed to depend on the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which inactivates glucocorticoids that would otherwise occupy aldosterone receptors. Because 11β-HSD2 in rat may only be abundantly expressed in DCT2 cells and not in DCT1 cells, it has been speculated that aldosterone specifically stimulates NCC activity in DCT2 cells. In mice, however, it is debated if 11β-HSD2 is expressed in DCT2 cells. The present study examined whether aldosterone administration in mice stimulates NCC abundance and phosphorylation in DCT2 cells but not in DCT1 cells. B6/C57 male mice were administered 100 µg aldosterone·kg body weight -1 ·24 h -1 for 6 days and euthanized during isoflurane inhalation. Western blotting of whole kidney homogenate showed that aldosterone administration stimulated NCC and pT58-NCC abundances ( P < 0.001). In DCT1 cells, confocal microscopy detected no effect of the aldosterone administration on NCC and pT58-NCC abundances. By contrast, NCC and pT58-NCC abundances were stimulated by aldosterone administration in the middle of DCT2 ( P < 0.001 and <0.01, respectively) and at the junction between DCT2 and CNT ( P < 0.001 and <0.05, respectively). In contrast to rat, immunohistochemistry in mouse showed no/very weak 11β-HSD2 expression in DCT2 cells. Collectively, long-term aldosterone administration stimulates mouse NCC and pT58-NCC abundances in DCT2 cells and presumably not in DCT1 cells. Copyright © 2017 the American Physiological Society.

Aldosterone stimulates superoxide production in macula densa cells.

PubMed

Zhu, Xiaolong; Manning, R Davis; Lu, Deyin; Gomez-Sanchez, Celso E; Fu, Yiling; Juncos, Luis A; Liu, Ruisheng

2011-09-01

Two major factors which regulate tubuloglomerular feedback (TGF)-mediated constriction of the afferent arteriole are release of superoxide (O(2)(-)) and nitric oxide (NO) by macula densa (MD) cells. MD O(2)(-) inactivates NO; however, among the factors that increase MD O(2)(-) release, the role of aldosterone is unclear. We hypothesize that aldosterone activates the mineralocorticoid receptor (MR) on MD cells, resulting in increased O(2)(-) production due to upregulation of cyclooxygenase-1 (COX-2) and NOX-2, and NOX-4, isoforms of NAD(P)H oxidase. Studies were performed on MMDD1 cells, a renal epithelial cell line with properties of MD cells. RT-PCR and Western blotting confirmed the expression of MR. Aldosterone (10(-8) mol/l for 30 min) doubled MMDD1 cell O(2)(-) production, and this was completely blocked by MR inhibition with 10(-5) mol/l eplerenone. RT-PCR, real-time PCR, and Western blotting demonstrated aldosterone-induced increases in COX-2, NOX-2, and NOX-4 expression. Inhibition of COX-2 (NS398), NADPH oxidase (apocynin), or a combination blocked aldosterone-induced O(2)(-) production to the same degree. These data suggest that aldosterone-stimulated MD O(2)(-) production is mediated by COX-2 and NADPH oxidase. Next, COX-2 small-interfering RNA (siRNA) specifically decreased COX-2 mRNA without affecting NOX-2 or NOX-4 mRNAs. In the presence of the COX-2 siRNA, the aldosterone-induced increases in COX-2, NOX-2, and NOX-4 mRNAs and O(2)(-) production were completely blocked, suggesting that COX-2 causes increased expression of NOX-2 and NOX-4. In conclusion 1) MD cells express MR; 2) aldosterone increases O(2)(-) production by activating MR; and 3) aldosterone stimulates COX-2, which further activates NOX-2 and NOX-4 and generates O(2)(-). The resulting balance between O(2)(-) and NO in the MD is important in modulating TGF.

Adrenal venous sampling in primary aldosteronism: multinomial regression modeling to detect aldosterone secretion lateralization when right adrenal sampling is missing.

PubMed

Durivage, Camille; Blanchette, Rémi; Soulez, Gilles; Chagnon, Miguel; Gilbert, Patrick; Giroux, Marie-France; Bourdeau, Isabelle; Oliva, Vincent L; Lacroix, André; Therasse, Eric

2017-02-01

Difficulty to recognize or canulate the right adrenal vein is the most frequent cause of adrenal venous sampling (AVS) failure. We aimed to assess multinomial regression modeling (MRM) of peripheral and left adrenal vein samplings to detect lateralization of aldosterone secretion when the right AVS is missing. Simultaneous bilateral AVS samplings were performed before (basal) and after intravenous cosyntropin injection in 188 consecutive patients between December 1989 and September 2015. Different reference standards for lateralization of aldosterone secretion were defined for basal and for postcosyntropin AVS and according to lateralization index cutoffs at least 2 and at least 4. MRMs were built to detect lateralization of aldosterone secretion according to these reference standards using only peripheral and left adrenal veins samplings (without the right AVS). Detection accuracy was assessed by the area under the receiver operating characteristic (AUROC) curves and detection sensitivities were reported for specificity at least 95%. For basal AVS with lateralization index at least 2, AUROC were respectively 0.931 [95% confidence interval (CI) 0.894-0.968] and 0.922 (95% CI 0.882-0.962) for right and left lateralization of aldosterone secretion detection and MRM could detect respectively 65.5 and 62.7% of the right and left lateralization of aldosterone secretion. For AVS after cosyntropin with lateralization index at least 4, AUROC were respectively 0.964 (95% CI: 0.940-0.987) and 0.955 (95% CI: 0.927-0.983) for right and left lateralization of aldosterone secretion, and MRM could detect respectively 77.2 and 72.9% of the right and left lateralization of aldosterone secretion. MRM can detect lateralization of aldosterone secretion without the right AVS in most patients and could eliminate the need for repeat AVS when right adrenal vein canulation is nonselective or impossible.

Does continuous positive airway pressure reduce aldosterone levels in patients with obstructive sleep apnea?

PubMed

Yang, Si-Jiu; Jiang, Xing-Tang; Zhang, Xiao-Bin; Yin, Xiao-Wen; Deng, Wei-Xian

2016-09-01

Aldosterone is associated with the development of obstructive sleep apnea (OSA) and cardiovascular diseases. Continuous positive airway pressure (CPAP) is an effective treatment for OSA, but the impact of CPAP therapy on aldosterone levels in patients with OSA remains unclear. To address this issue, a meta-analysis was conducted to evaluate the effects of CPAP therapy on serum aldosterone levels in OSA. Two reviewers independently searched PubMed, Cochrane library, Embase, and Web of Science before March 2015. Information on characteristics of subjects, study design, and pre- and post-CPAP treatment of serum aldosterone was extracted for analysis. Standardized mean difference (SMD) was calculated to estimate the treatment effects of CPAP therapy. A total of 5 studies involving 329 patients were pooled into this meta-analysis, including 3 observational studies and 2 randomized controlled studies. Results indicated significantly decreased aldosterone levels after CPAP therapy (SMD = -0.236, 95 % confidence interval (CI) = -0.45 to -0.02, z = 2.12, p = 0.034). This meta-analysis suggested that CPAP therapy was associated with a decrease in serum aldosterone in patients with OSA. Further large-scale, well-designed interventional investigations are needed to clarify this issue.

Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes.

PubMed

Knechtle, B; Morales, N P Hernández; González, E Ruvalcaba; Gutierrez, A A Aguirre; Sevilla, J Noriega; Gómez, R Amézquita; Robledo, A R Estrada; Rodríguez, A L Marroquín; Fraire, O Salas; Andonie, J L; Lopez, L C; Kohler, G; Rosemann, T

2012-02-01

Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P < 0.0001). Aldosterone increased from 70.8 (104.5) pg/mL to 102.6 (104.6) pg/mL (P = 0.033); vasopressin remained unchanged. The increase in ECW was related neither to postrace aldosterone nor to postrace vasopressin. In conclusion, ECW and aldosterone increased after this multistage ultraendurance triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.

Plasma aldosterone and sweat sodium concentrations after exercise and heat acclimation

NASA Technical Reports Server (NTRS)

Kirby, C. R.; Convertino, V. A.

1986-01-01

The relationship between plasma aldosterone levels and sweat sodium excretion after chronic exercise and heat acclimation was investigated, using subjects exercised, at 40 C and 45 percent humidity, for 2 h/day on ten consecutive days at 45 percent of their maximal oxygen uptake. The data indicate that, following heat acclimation, plasma aldosterone concentrations decrease, and that the eccrine gland responsiveness to aldosterone, as represented by sweat sodium reabsorption, may be augmented through exercise and heat acclimation.

LGR5 Activates Noncanonical Wnt Signaling and Inhibits Aldosterone Production in the Human Adrenal.

PubMed

Shaikh, Lalarukh Haris; Zhou, Junhua; Teo, Ada E D; Garg, Sumedha; Neogi, Sudeshna Guha; Figg, Nichola; Yeo, Giles S; Yu, Haixiang; Maguire, Janet J; Zhao, Wanfeng; Bennett, Martin R; Azizan, Elena A B; Davenport, Anthony P; McKenzie, Grahame; Brown, Morris J

2015-06-01

Aldosterone synthesis and cellularity in the human adrenal zona glomerulosa (ZG) is sparse and patchy, presumably due to salt excess. The frequency of somatic mutations causing aldosterone-producing adenomas (APAs) may be a consequence of protection from cell loss by constitutive aldosterone production. The objective of the study was to delineate a process in human ZG, which may regulate both aldosterone production and cell turnover. This study included a comparison of 20 pairs of ZG and zona fasciculata transcriptomes from adrenals adjacent to an APA (n = 13) or a pheochromocytoma (n = 7). Interventions included an overexpression of the top ZG gene (LGR5) or stimulation by its ligand (R-spondin-3). A transcriptome profile of ZG and zona fasciculata and aldosterone production, cell kinetic measurements, and Wnt signaling activity of LGR5 transfected or R-spondin-3-stimulated cells were measured. LGR5 was the top gene up-regulated in ZG (25-fold). The gene for its cognate ligand R-spondin-3, RSPO3, was 5-fold up-regulated. In total, 18 genes associated with the Wnt pathway were greater than 2-fold up-regulated. ZG selectivity of LGR5, and its absence in most APAs, were confirmed by quantitative PCR and immunohistochemistry. Both R-spondin-3 stimulation and LGR5 transfection of human adrenal cells suppressed aldosterone production. There was reduced proliferation and increased apoptosis of transfected cells, and the noncanonical activator protein-1/Jun pathway was stimulated more than the canonical Wnt pathway (3-fold vs 1.3-fold). ZG of adrenal sections stained positive for apoptosis markers. LGR5 is the most selectively expressed gene in human ZG and reduces aldosterone production and cell number. Such conditions may favor cells whose somatic mutation reverses aldosterone inhibition and cell loss.

Seated saline suppression testing for the diagnosis of primary aldosteronism: a preliminary study.

PubMed

Ahmed, Ashraf H; Cowley, Diane; Wolley, Martin; Gordon, Richard D; Xu, Shengxin; Taylor, Paul J; Stowasser, Michael

2014-08-01

Failure of aldosterone suppression by sodium loading during fludrocortisone suppression testing (FST) or saline suppression testing (SST) confirms primary aldosteronism (PA). We previously found recumbent SST (RSST) to lack sensitivity. Aldosterone levels can be higher upright (e.g. seated) than recumbent in patients with PA and upright levels are used during FST. We therefore hypothesized that seated SST (SSST) is more sensitive than RSST, especially for posture-responsive PA. Of 66 patients who underwent FST (upright plasma aldosterone levels measured at 10am basally and after 4 days fludrocortisone 0.1 mg 6-hourly and oral salt loading), 31 underwent SST (aldosterone levels measured basally at 8am and after infusion of 2 L normal saline over 4h) both recumbent and seated in randomized order and at least 2 weeks apart. FST confirmed PA in 23 of 31 patients (day 4 upright aldosterone level >165 pmol/L), excluded PA in three and was originally "inconclusive" in five. However, one with "inconclusive" FST had PA confirmed by lateralizing AVS and was reclassified "unilateral PA". Of 24 with confirmed PA (eight unilateral, 11 bilateral, and five undetermined subtype), 23 (96%) tested positive by SSST (4-h aldosterone level >165 pmol/L) compared with 8 (33%) by RSST (4-h plasma aldosterone level >140 pmol/L) (P < .001). RSST missed one unilateral, all bilateral, and four with as-yet undetermined subtype. RSST was positive in 7 of 10 (70%) posture-unresponsive vs one of 14 (7.1%) posture-responsive patients (P < .005). These preliminary results suggest that seated SST may be superior to recumbent SST in terms of sensitivity for detecting PA, especially posture-responsive forms, and may represent a reliable alternative to FST.

Interaction between nitric oxide and superoxide in the macula densa in aldosterone-induced alterations of tubuloglomerular feedback

PubMed Central

Zhang, Qian; Lin, Lin; Lu, Yan; Liu, Haifeng; Duan, Yanhua; Zhu, Xiaolong; Zou, Chengwei; Manning, R. Davis

2013-01-01

Tubuloglomerular feedback (TGF)-mediated constriction of the afferent arteriole is modulated by a balance between release of superoxide (O2−) and nitric oxide (NO) in macula densa (MD) cells. Aldosterone activates mineralocorticoid receptors that are expressed in the MD and induces both NO and O2− generation. We hypothesize that aldosterone enhances O2− production in the MD mediated by protein kinase C (PKC), which buffers the effect of NO in control of TGF response. Studies were performed in microdissected and perfused MD and in a MD cell line, MMDD1 cells. Aldosterone significantly enhanced O2− generation both in perfused MD and in MMDD1 cells. When aldosterone (10−7 mol/l) was added in the tubular perfusate, TGF response was reduced from 2.4 ± 0.3 μm to 1.4 ± 0.2 μm in isolated perfused MD. In the presence of tempol, a O2− scavenger, TGF response was 1.5 ± 0.2 μm. In the presence of both tempol and aldosterone in the tubular perfusate, TGF response was further reduced to 0.4 ± 0.2 μm. To determine if PKC is involved in aldosterone-induced O2− production, we exposed the O2− cells to a nonselective PKC inhibitor chelerythrine chloride, a specific PKCα inhibitor Go6976, or a PKCα siRNA, and the aldosterone-induced increase in O2− production was blocked. These data indicate that aldosterone-stimulated O2− production in the MD buffers the effect of NO in control of TGF response, an effect that was mediated by PKCα. PMID:23220724

Therapeutic targeting of aldosterone: a novel approach to the treatment of glomerular disease

PubMed Central

Brem, Andrew S.; Gong, Rujun

2015-01-01

Numerous studies have established a role for mineralocorticoids in the development of renal fibrosis. Originally, the research focus for mineralocorticoid-induced fibrosis was on the collecting duct, where “classical” mineralocorticoid receptors (MR) involved with electrolyte transport are present. Epithelial cells in this segment can, under selected circumstances, also respond to MR activation by initiating pro-fibrotic pathways. More recently, “non-classical” MR have been described in kidney cells not associated with electrolyte transport including mesangial cells and podocytes within the glomerulus. Activation of MR in these cells appears to lead to glomerular sclerosis. Mechanistically, aldosterone induces excess production of reactive oxygen species (ROS) and oxidative stress in glomerular cells through activation of NADPH oxidase. In mesangial cells, aldosterone also has pro-apoptotic, mitogenic, and pro-fibrogenic effects, all of which potentially promote active remodeling and expansion of the mesangium. While mitochondrial dysfunction seems to mediate the aldosterone-induced mesangial apoptosis, the ROS dependent EGFR transactivation is likely responsible for aldosterone-induced mesangial mitosis and proliferation. In podocytes, mitochondrial dysfunction elicited by oxidative stress is an early event associated with aldosterone-induced podocyte injury. Both the p38MAPK signaling and the redox sensitive glycogen synthase kinase (GSK) 3β pathways are centrally implicated in aldosterone-induced podocyte death. Aldosterone-induced GSK3β over-activity could potentially cause hyperphosphorylation and over-activation of putative GSK3β substrates, including structural components of the mitochondrial permeability transition (MPT) pore, all of which lead to cell injury and death. Clinically, proteinuria significantly decreases when aldosterone inhibitors are included in the treatment of many glomerular diseases further supporting the view that mineralocorticoids are important players in glomerular pathology. PMID:25671776

Global- and renal-specific sympathoinhibition in aldosterone hypertension.

PubMed

Lohmeier, Thomas E; Liu, Boshen; Hildebrandt, Drew A; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

2015-06-01

Recent technology for chronic electric activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12 μg/kg per day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ≈40% and arterial pressure by 16±2 mm Hg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mm Hg) was diminished (≈55%) during aldosterone hypertension when compared with control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. © 2015 American Heart Association, Inc.

Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway.

PubMed

Feng, Xiuyan; Zhang, Yiqian; Shao, Ningjun; Wang, Yanhui; Zhuang, Zhizhi; Wu, Ping; Lee, Matthew J; Liu, Yingli; Wang, Xiaonan; Zhuang, Jieqiu; Delpire, Eric; Gu, Dingying; Cai, Hui

2015-05-15

Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs.

Global and Renal-Specific Sympathoinhibition in Aldosterone Hypertension

PubMed Central

Lohmeier, Thomas E.; Liu, Boshen; Hildebrandt, Drew A.; Cates, Adam W.; Georgakopoulos, Dimitrios; Irwin, Eric D.

2015-01-01

Recent technology for chronic electrical activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12µg/kg/day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ~ 40% and arterial pressure by 16±2 mmHg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mmHg) was diminished (~ 55%) during aldosterone hypertension as compared to control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. PMID:25895584

Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway

PubMed Central

Feng, Xiuyan; Zhang, Yiqian; Shao, Ningjun; Wang, Yanhui; Zhuang, Zhizhi; Wu, Ping; Lee, Matthew J.; Liu, Yingli; Wang, Xiaonan; Zhuang, Jieqiu; Delpire, Eric; Gu, Dingying

2015-01-01

Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs. PMID:25761881

Association of Post-Saline Load Plasma Aldosterone Levels With Left Ventricular Hypertrophy in Primary Hypertension.

PubMed

Catena, Cristiana; Verheyen, Nicolas D; Url-Michitsch, Marion; Kraigher-Krainer, Elisabeth; Colussi, GianLuca; Pilz, Stefan; Tomaschitz, Andreas; Pieske, Burkert; Sechi, Leonardo A

2016-03-01

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular morbidity in hypertension. Current evidence suggests a contribution to LVH of plasma aldosterone levels that are inappropriately elevated for the salt status. The aim of this study was to investigate whether inappropriate modulation of aldosterone production by a saline load is associated with left ventricular (LV) mass in hypertensive patients. In 90 hypertensive patients free of clinically relevant cardiovascular complications in whom secondary forms of hypertension were ruled out, we performed a standard intravenous saline load (0.9% NaCl, 2 l in 4 hours) with measurement of plasma aldosterone and active renin at baseline and end of infusion. Bi-dimensional echocardiography was performed for the assessment of cardiac morphology and function. LVH was present in 19% of patients who had significantly worse renal function and higher body mass, blood pressure, and plasma aldosterone levels measured both at baseline and after the saline load than patients without LVH. LV mass was directly related to age, body mass, systolic blood pressure, duration of hypertension, baseline, and post-saline load plasma aldosterone levels and inversely to glomerular filtration. Multivariate regression analysis showed independent correlation of LV mass with body mass, systolic blood pressure, and plasma aldosterone levels measured after intravenous saline load, but not at baseline. In patients with hypertension, aldosterone levels measured after intravenous saline load are related to LV mass independent of age, body mass, and blood pressure, suggesting that limited ability of salt to modulate aldosterone production could contribute to LVH. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Normotensive blood pressure in pregnancy: the role of salt and aldosterone.

PubMed

Gennari-Moser, Carine; Escher, Geneviève; Kramer, Simea; Dick, Bernhard; Eisele, Nicole; Baumann, Marc; Raio, Luigi; Frey, Felix J; Surbek, Daniel; Mohaupt, Markus G

2014-02-01

A successful pregnancy requires an accommodating environment. Salt and water availability are critical for plasma volume expansion. Any changes in sodium intake would alter aldosterone, a hormone previously described beneficial in pregnancy. To date, it remains ambiguous whether high aldosterone or high salt intake is preferable. We hypothesized that increased aldosterone is a rescue mechanism and appropriate salt availability is equally effective in maintaining a normotensive blood pressure (BP) phenotype in pregnancy. We compared normotensive pregnant women (n=31) throughout pregnancy with young healthy female individuals (n=31-62) and performed salt sensitivity testing within the first trimester. Suppression of urinary tetrahydro-aldosterone levels by salt intake as measured by gas chromatography-mass spectrometry and urinary sodium excretion corrected for creatinine, respectively, was shifted toward a higher salt intake in pregnancy (P<0.0001). In pregnancy, neither high urinary tetrahydro-aldosterone nor sodium excretion was correlated with higher BP. In contrast, in nonpregnant women, systolic BP rose with aldosterone (P<0.05). Testing the impact of salt on BP, we performed salt sensitivity testing in a final cohort of 19 pregnant and 24 nonpregnant women. On salt loading, 24-hour mean arterial pressure rose by 3.6±1.5 and dropped by -2.8±1.5 mm Hg favoring pregnant women (P<0.01; χ(2)=6.04; P<0.02). Our data suggest first that salt responsiveness of aldosterone is alleviated in conditions of pregnancy without causing aldosterone-induced hypertension. Second, salt seems to aid in BP lowering in pregnancy for reasons incompletely elucidated, yet involving renin suppression and potentially placental sensing mechanisms. Further research should identify susceptible individuals and clarify effector mechanisms.

Application of strict criteria in adrenal venous sampling increases the proportion of missed patients with unilateral disease who benefit from surgery for primary aldosteronism.

PubMed

Kline, Gregory; Leung, Alexander; So, Benny; Chin, Alex; Harvey, Adrian; Pasieka, Janice L

2018-06-01

Adrenal vein sampling (AVS) is intended to confirm unilateral forms of primary aldosteronism, which are amenable to surgical cure. Excessively strict AVS criteria to define lateralization may result in many patients incorrectly categorized as bilateral primary aldosteronism and opportunity for surgical cure missed. Retrospective review of an AVS-primary aldosteronism database in which surgical cases are verified by standardized outcomes. Having used 'less strict' AVS criteria for lateralization, we examined the distribution of AVS lateralization indices in our confirmed unilateral primary aldosteronism cases both with and without cosyntropin stimulation. The proportion of proven unilateral cases that would have been missed with stricter AVS interpretation criteria was calculated. Particular focus was given to the proportion of missed cases according to use of international guidelines. False-positive lateralization with 'less strict' interpretation was also calculated. Of 80 surgical primary aldosteronism cases, 10-23% would have been missed with AVS lateralization indices of 3 : 1 to 5 : 1, with or without cosyntropin. If strict selectivity indices (for confirmation of catheterization) were combined with strict lateralization indices, up to 70% of unilateral primary aldosteronism cases could have been missed. Use of Endocrine Society AVS guidelines would have missed 21-43% of proven unilateral cases. 'Less strict' AVS interpretation yielded one case (1.2%) of false lateralization. Excessively strict AVS interpretation criteria will result in a high rate of missed unilateral primary aldosteronism with subsequent loss of opportunity for intervention. Use of more lenient lateralization criteria will improve the detection rate of unilateral primary aldosteronism with very low false-positive rate.

Combination therapy strategies for improving PD-1 blockade efficacy: a new era in cancer immunotherapy.

PubMed

Chowdhury, P S; Chamoto, K; Honjo, T

2018-02-01

Programmed death 1 (PD-1) is an immune checkpoint molecule that negatively regulates T-cell immune function through the interaction with its ligand PD-L1. Blockage of this interaction unleashes the immune system to fight cancer. Immunotherapy using PD-1 blockade has led to a paradigm shift in the field of cancer drug discovery, owing to its durable effect against a wide variety of cancers with limited adverse effects. A brief history and development of PD-1 blockade, from the initial discovery of PD-1 to the recent clinical output of this therapy, have been summarized here. Despite its tremendous clinical success rate over other cancer treatments, PD-1 blockade has its own pitfall; a significant fraction of patients remains unresponsive to this therapy. The key to improve the PD-1 blockade therapy is the development of combination therapies. As this approach has garnered worldwide interest, here, we have summarized the recent trends in the development of PD-1 blockade-based combination therapies and the ongoing clinical trials. These include combinations with checkpoint inhibitors, radiation therapy, chemotherapy and several other existing cancer treatments. Importantly, FDA has approved PD-1 blockade agent to be used in combination with either CTLA-4 blockade or chemotherapy. Responsiveness to the PD-1 blockade therapy is affected by tumour and immune system-related factors. The role of the immune system, especially T cells, in determining the responsiveness has been poorly studied compared with those factors related to the tumour side. Energy metabolism has emerged as one of the important regulatory mechanisms for the function and differentiation of T cells. We have documented here the recent results regarding the augmentation of PD-1 blockade efficacy by augmenting mitochondrial energy metabolism of T cell. © 2017 The Association for the Publication of the Journal of Internal Medicine.

Thapsigargin-induced increase in cytoplasmic Ca2+ concentration and aldosterone production in rat adrenal glomerulosa cells: interaction with potassium and angiotensin-II.

PubMed

Hajnóczky, G; Várnai, P; Holló, Z; Christensen, S B; Balla, T; Enyedi, P; Spät, A

1991-05-01

Thapsigargin (Tg), a microsomal Ca2+ pump inhibitor, dose-dependently increases the cytoplasmic Ca2+ concentration and aldosterone production without having any striking effect on the formation of inositol phosphates in isolated rat adrenal glomerulosa cells. The interaction of Tg with the major Ca2(+)-mediated stimuli of glomerulosa cells on aldosterone production was also examined. The effects of Tg and the Ca2(+)-mobilizing angiotensin-II (AII) were additive. The aldosterone production stimulatory effect of potassium, which induces Ca2+ influx via voltage-operated Ca2+ channels, was potentiated by Tg. The positive interaction between Tg and potassium on aldosterone production raises the possibility that stimuli generating Ca2+ signal by depleting intracellular Ca2+ stores, such as Tg or AII, enhance the response of the cell to depolarization. Such an interaction between AII and potassium may have an important role in the physiological control of aldosterone production.

Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

PubMed

Rachid, Myriam; Dreux, Sophie; Pean de Ponfilly, Gauthier; Vargas-Poussou, Rosa; Czerkiewicz, Isabelle; Chevenne, Didier; Oury, Jean-François; Deschênes, Georges; Muller, Françoise

2017-04-01

Bartter syndrome is a severe inherited tubulopathy characterized at birth by salt wasting, severe polyuria, dehydration, growth retardation and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following onset of severe polyhydramnios. We studied amniotic fluid aldosterone concentration in cases of Bartter syndrome and in control groups. Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of postnatally diagnosed Bartter syndrome and 144 controls matched for gestational age. Two controls groups were defined: controls with polyhydramnios (n=72) and control without polyhydramnios (n=72). Amniotic fluid aldosterone was compared between the three groups. The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) did not differ significantly from that in the controls with polyhydramnios (90 pg/mL, p=0.33) or the controls without polyhydramnios (87 pg/mL, p=0.41). In conclusion, amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome.

Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

PubMed

Rachid, Myriam L; Dreux, Sophie; Pean de Ponfilly, Gauthier; Vargas-Poussou, Rosa; Czerkiewicz, Isabelle; Chevenne, Didier; Oury, Jean-François; Deschênes, Georges; Muller, Françoise

2016-01-01

Bartter syndrome is a severe inherited tubulopathy characterized by postnatal salt wasting, severe polyuria, dehydration, failure to thrive and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following the onset of severe polyhydramnios in the second trimester. We studied amniotic fluid aldosterone concentration in Bartter syndrome and in controls. Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of prenatally suspected and postnatally confirmed Bartter syndrome (22 with identified mutations): and 72 gestational age matched controls presenting with polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was compared between the three groups. The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) was not different from that in the controls with polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, P = 0.41). Amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome. © 2015 John Wiley & Sons, Ltd. © 2015 John Wiley & Sons, Ltd.

Plasma potassium concentrations in neonatal diarrhoeic calves are correlated with serum aldosterone concentrations but not with insulin concentrations.

PubMed

Trefz, Florian M; Lorenz, Ingrid

2017-12-01

Hyperkalaemia is a clinically relevant electrolyte imbalance in neonatal diarrhoeic calves which was previously associated with severe dehydration and acidaemia. The present study assessed the association of plasma potassium (cK) with serum aldosterone and insulin concentrations, since these hormones are involved in the regulation of potassium homeostasis. Serum aldosterone (r s =0.62), but not insulin concentrations (r s =0.22) were closely correlated to cK in 123 hospitalised neonatal diarrhoeic calves. Median values for serum aldosterone concentrations in 38 hyperkalaemic calves (cK>5.8mmol/L) were 3.2 and 15.3 times higher (P<0.001) than in 85 non-hyperkalaemic diarrhoeic calves and nine healthy control calves, respectively. Aldosterone, but not insulin secretion, appears to be highly stimulated in dehydrated diarrhoeic calves with hyperkalaemia, but hypovolaemia and a concomitant decrease in renal perfusion and urinary flow rate are likely to limit the efficacy of aldosterone-induced control mechanisms in these animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of phonon reservoir on photon blockade in a driven quantum dot-cavity system

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

Gao, Bo; Li, Gao-xiang, E-mail: gaox@phy.ccnu.edu.cn; Zhu, Jia-pei, E-mail: fengxue0506@163.com

2016-03-14

We theoretically investigate the influence of the phonon bath on photon blockade in a simultaneously driven dot-cavity system. An optimal condition for avoiding two-photon excitation of a cavity field is put forward which can be achieved by modulating the phase difference and the strengths of the driving fields. The second-order correlation function and the mean photon number of the cavity field are discussed. In the absence of phonon effect, the strong photon blockade in a moderate quantum dot (QD)-cavity coupling regime occurs, which can be attributed to the destructive quantum interference arisen from different transition paths induced by simultaneously drivingmore » the dressed QD-cavity system. The participation of acoustic-phonon reservoir produces new transition channels for the QD-cavity system, which leads to the damage of destructive interference. As a result, the photon blockade effect is hindered when taking the electron-phonon interaction into account. It is also found that the temperature of the phonon reservoir is disadvantageous for the generation of photon blockade.« less

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.

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.

[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.

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.

Interactions Between Adrenal and Calcium-Regulatory Hormones in Human Health

PubMed Central

Brown, Jenifer M.; Vaidya, Anand

2014-01-01

Purpose of Review To summarize evidence characterizing the interactions between adrenal- and calcium-regulating hormones, and the relevance of these interactions to human cardiovascular and skeletal health. Recent Findings Human studies support the regulation of parathyroid hormone (PTH) by the renin-angiotensin-aldosterone system (RAAS): angiotensin II may stimulate PTH secretion via an acute and direct mechanism, whereas aldosterone may exert a chronic stimulation of PTH secretion. Studies in primary aldosteronism, congestive heart failure, and chronic kidney disease have identified associations between hyperaldosteronism, hyperparathyroidism, and bone loss, which appear to improve when inhibiting the RAAS. Conversely, elevated PTH and insufficient vitamin D status have been associated with adverse cardiovascular outcomes, which may be mediated by the RAAS. Studies of primary hyperparathyroidism implicate PTH-mediated stimulation of the RAAS, and recent evidence shows that the vitamin D-vitamin D receptor (VDR) complex may negatively regulate renin expression and RAAS activity. Ongoing human interventional studies are evaluating the influence of RAAS inhibition on PTH and the influence of VDR agonists on RAAS activity. Summary While previously considered independent endocrine systems, emerging evidence supports a complex web of interactions between adrenal and calcium-regulating hormones, with implications for human cardiovascular and skeletal health. PMID:24694551

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.

Reversed association between aldosterone and mortality in hemodialysis patients: Role of volume overload.

PubMed

Hung, Szu-Chun; Tarng, Der-Cherng

2016-07-01

The role of aldosterone has expanded from its genomic effects that involve renal sodium transport to nongenomic effects such as cardiac and renal fibrosis. Elevated aldosterone levels are associated with increased mortality in the general population. However, the association is reversed in patients with end-stage renal disease on maintenance hemodialysis. We have shown that the inverse association between aldosterone and mortality in hemodialysis patients is due to the confounding effect of volume overload. Volume overload, which is prevalent in patients with chronic kidney disease, is associated with both lower aldosterone concentrations and higher mortality. Our findings support salt and water restriction and treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control. Copyright © 2016 Elsevier Inc. All rights reserved.

Aldosterone interaction with epidermal growth factor receptor signaling in MDCK cells.

PubMed

Gekle, Michael; Freudinger, Ruth; Mildenberger, Sigrid; Silbernagl, Stefan

2002-04-01

Epidermal growth factor (EGF) regulates cell proliferation, differentiation, and ion transport by using extracellular signal-regulated kinase (ERK)1/2 as a downstream signal. Furthermore, the EGF-receptor (EGF-R) is involved in signaling by G protein-coupled receptors, growth hormone, and cytokines by means of transactivation. It has been suggested that steroids interact with peptide hormones, in part, by rapid, potentially nongenomic, mechanisms. Previously, we have shown that aldosterone modulates Na(+)/H(+) exchange in Madin-Darby canine kidney (MDCK) cells by means of ERK1/2 in a way similar to growth factors. Here, we tested the hypothesis that aldosterone uses the EGF-R as a heterologous signal transducer in MDCK cells. Nanomolar concentrations of aldosterone induce a rapid increase in ERK1/2 phosphorylation, cellular Ca(2+) concentration, and Na(+)/H(+) exchange activity similar to increases induced by EGF. Furthermore, aldosterone induced a rapid increase in EGF-R-Tyr phosphorylation, and inhibition of EGF-R kinase abolished aldosterone-induced signaling. Inhibition of ERK1/2 phosphorylation reduced the Ca(2+) response, whereas prevention of Ca(2+) influx did not abolish ERK1/2 phosphorylation. Our data show that aldosterone uses the EGF-R-ERK1/2 signaling cascade to elicit its rapid effects in MDCK cells.

Sodium interference in the determination of urinary aldosterone.

PubMed

Aldea, Marta Lucía; Barallat, Jaume; Martín, María Amparo; Rosas, Irene; Pastor, María Cruz; Granada, María Luisa

2016-02-01

Primary hyperaldosteronism (PHA) is one of the most common endocrine forms of secondary hypertension. Among the most used confirmatory tests for PHA is urinary aldosterone determination after oral sodium loading test. The primary aim of our study was to investigate if sodium concentrations interfere with urinary aldosterone in an automated competitive immunoassay (Liaison®) as well as to verify the manufacturer's specifications. 24-hr urine samples were collected and stored frozen until assayed. Two pools at low and high aldosterone concentrations were prepared. Verification of performance for precision was tested according to Clinical and Laboratory Standards Institute (CLSI) document EP15-A2 and interference with increasing concentrations of NaCl according to CLSI EP7-A2. The assay met the quality specifications according to optimal biological variation. Our results show that sodium concentrations up to 200mmol/L do not interfere on urinary aldosterone quantification, but sodium concentrations above 486mmol/L negatively interfere with the test. The Liaison® automated method is useful for aldosterone determination in the PHA confirmatory test, but interferences with NaCl may occur. It is therefore recommended to determine urinary NaCl before measuring urinary aldosterone to avoid falsely low results. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

GENETICS IN ENDOCRINOLOGY: The expanding genetic horizon of primary aldosteronism.

PubMed

Monticone, Silvia; Buffolo, Fabrizio; Tetti, Martina; Veglio, Franco; Pasini, Barbara; Mulatero, Paolo

2018-03-01

Aldosterone is the main mineralocorticoid hormone in humans and plays a key role in maintaining water and electrolyte homeostasis. Primary aldosteronism (PA), characterized by autonomous aldosterone overproduction by the adrenal glands, affects 6% of the general hypertensive population and can be either sporadic or familial. Aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH) are the two most frequent subtypes of sporadic PA and 4 forms of familial hyperaldosteronism (FH-I to FH-IV) have been identified. Over the last six years, the introduction of next-generation sequencing has significantly improved our understanding of the molecular mechanisms responsible for autonomous aldosterone overproduction in both sporadic and familial PA. Somatic mutations in four genes ( KCNJ5, ATP1A1, ATP2B3 and CACNA1D ), differently implicated in intracellular ion homeostasis, have been identified in nearly 60% of the sporadic APAs. Germline mutations in KCNJ5 and CACNA1H cause FH-III and FH-IV, respectively, while germline mutations in CACNA1D cause the rare PASNA syndrome, featuring primary aldosteronism seizures and neurological abnormalities. Further studies are warranted to identify the molecular mechanisms underlying BAH and FH-II, the most common forms of sporadic and familial PA whose molecular basis is yet to be uncovered. © 2018 European Society of Endocrinology.

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 Association Between Renin-Angiotensin System Blockade and Long-term Outcomes in Renal Transplant Recipients: The Wisconsin Allograft Recipient Database (WisARD).

PubMed

Shin, Jung-Im; Palta, Mari; Djamali, Arjang; Kaufman, Dixon B; Astor, Brad C

2016-07-01

Renin-angiotensin system (RAS) blockade reduces mortality in the general population and among non-dialysis-dependent patients with chronic kidney disease. The RAS blockade also decreases proteinuria and protects renal function in non-transplant patients with chronic kidney disease. It remains controversial, however, whether this translates to improved patient or graft survival among transplant recipients. We analyzed 2684 primary kidney transplant recipients at the University of Wisconsin in 1994 to 2010 who had a functioning graft at 6 months after transplantation. We assessed the association of RAS blockade with patient and graft survival using time-dependent Cox and marginal structural models. Three hundred seventy-seven deaths and 329 graft failures before death (638 total graft losses) occurred during a median of 5.4 years of follow-up. The RAS blockade was associated with an adjusted-hazard ratio of 0.63 (95% confidence interval, 0.53-0.75) for total graft loss, 0.69 (0.55-0.86) for death, and 0.62 (0.49-0.78) for death-censored graft failure. The associations of RAS blockade with a lower risk of total graft loss and mortality were stronger with more severe proteinuria. The RAS blockade was associated with a 2-fold higher risk of hyperkalemia. Our findings suggest RAS blockade is associated with better patient and graft survival in renal transplant recipients.

Serum potassium is a predictor of incident diabetes in African Americans with normal aldosterone: the Jackson Heart Study12

PubMed Central

Chatterjee, Ranee; Davenport, Clemontina A; Svetkey, Laura P; Batch, Bryan C; Lin, Pao-Hwa; Ramachandran, Vasan S; Fox, Ervin R; Harman, Jane; Yeh, Hsin-Chieh; Selvin, Elizabeth; Correa, Adolfo; Butler, Kenneth; Edelman, David

2017-01-01

Background: Low-normal potassium is a risk factor for diabetes and may account for some of the racial disparity in diabetes risk. Aldosterone affects serum potassium and is associated with insulin resistance. Objectives: We sought to confirm the association between potassium and incident diabetes in an African-American cohort, and to determine the effect of aldosterone on this association. Design: We studied participants from the Jackson Heart Study, an African-American adult cohort, who were without diabetes at baseline. With the use of logistic regression, we characterized the associations of serum, dietary, and urinary potassium with incident diabetes. In addition, we evaluated aldosterone as a potential effect modifier of these associations. Results: Of 2157 participants, 398 developed diabetes over 8 y. In a minimally adjusted model, serum potassium was a significant predictor of incident diabetes (OR: 0.83; 95% CI: 0.74, 0.92 per SD increment in serum potassium). In multivariable models, we found a significant interaction between serum potassium and aldosterone (P = 0.046). In stratified multivariable models, in those with normal aldosterone (<9 ng/dL, n = 1163), participants in the highest 2 potassium quartiles had significantly lower odds of incident diabetes than did those in the lowest potassium quartile [OR (95% CI): 0.61 (0.39, 0.97) and 0.54 (0.33, 0.90), respectively]. Among those with high-normal aldosterone (≥9 ng/dL, n = 202), we found no significant association between serum potassium and incident diabetes. In these stratified models, serum aldosterone was not a significant predictor of incident diabetes. We found no statistically significant associations between dietary or urinary potassium and incident diabetes. Conclusions: In this African-American cohort, we found that aldosterone may modify the association between serum potassium and incident diabetes. In participants with normal aldosterone, high-normal serum potassium was associated with a lower risk of diabetes than was low-normal serum potassium. Additional studies are warranted to determine whether serum potassium is a modifiable risk factor that could be a target for diabetes prevention. This trial was registered at clinicaltrials.gov as NCT00415415. PMID:27974310

Role of Nongenomic Signaling Pathways Activated by Aldosterone During Cardiac Reperfusion Injury.

PubMed

Ashton, Anthony W; Le, Thi Y L; Gomez-Sanchez, Celso E; Morel-Kopp, Marie-Christine; McWhinney, Brett; Hudson, Amanda; Mihailidou, Anastasia S

2015-08-01

Aldosterone (Aldo) activates both genomic and nongenomic signaling pathways in the cardiovascular system. Activation of genomic signaling pathways contributes to the adverse cardiac actions of Aldo during reperfusion injury; however, the extent nongenomic signaling pathways contribute has been difficult to identify due to lack of a specific ligand that activates only nongenomic signaling pathways. Using a pegylated aldosterone analog, aldosterone-3-carboxymethoxylamine-TFP ester conjugated to methoxypegylated amine (Aldo-PEG), we are able for the first time to distinguish between nongenomic and genomic cardiac actions of Aldo. We confirm Aldo-PEG activates phosphorylation of ERK1/2 in rat cardiomyocyte H9c2 cells similar to Aldo and G protein-coupled receptor 30 (GPR30 or GPER) agonist G1. GPER antagonist, G36, but not mineralocorticoid receptor (MR) antagonist spironolactone, prevented ERK1/2 phosphorylation by Aldo, Aldo-PEG, and G1. The selective nongenomic actions of Aldo-PEG are confirmed, with Aldo-PEG increasing superoxide production in H9c2 cells to similar levels as Aldo but having no effect on subcellular localization of MR. Striatin serves as a scaffold for GPER and MR, with GPER antagonist G36, but not spironolactone, restoring MR-striatin complexes. Aldo-PEG had no effect on MR-dependent transcriptional activation, whereas Aldo increased transcript levels of serum-regulated kinase 1 and plasminogen activator inhibitor-1. Using our ex vivo experimental rat model of myocardial infarction, we found aggravated infarct size and apoptosis by Aldo but not Aldo-PEG. Our studies confirm that in the heart, activation of nongenomic signaling pathways alone are not sufficient to trigger the deleterious effects of aldosterone during myocardial reperfusion injury.

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.

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.

Macrolides Blunt Aldosterone Biosynthesis: A Proof-of-Concept Study in KCNJ5 Mutated Adenoma Cells Ex Vivo.

PubMed

Caroccia, Brasilina; Prisco, Selene; Seccia, Teresa Maria; Piazza, Maria; Maiolino, Giuseppe; Rossi, Gian Paolo

2017-12-01

Aldosterone-producing adenoma (APA), a major subtype of primary hyperaldosteronism, the main curable cause of human endocrine hypertension, involves somatic mutations in the potassium channel Kir3.4 ( KCNJ5 ) in 30% to 70% of cases, typically the more florid phenotypes. Because KCNJ5 mutated channels were reported to be specifically sensitive to inhibition by macrolide antibiotics, which concentration dependently blunts aldosterone production in HAC15 transfected with the G151R and L168R mutated channel, we herein tested the effect of clarithromycin on aldosterone synthesis and secretion in a pure population of aldosterone-secreting cells obtained by immunoseparation (CD56 + cells) from APA tissues with/without the 2 most common KCNJ5 mutations. From a large cohort of patients with an unambiguous APA diagnosis, we recruited those who were wild type (n=3) or had G151R (n=2) and L168R (n=2) mutations. We found that clarithromycin concentration dependently lowered CYP11B2 gene expression (by 60%) and aldosterone secretion (by 70%; P <0.001 for both) in CD56 + cells isolated ex vivo from KCNJ5 mutated APAs, although it was ineffective in CD56 + cells from wild-type APAs. By proving the principle that the oversecretion of aldosterone can be specifically blunted in APA cells ex vivo with G151R and L168R mutations, these results provide compelling evidence of the possibility of specifically correcting aldosterone excess in patients with APA carrying the 2 most common KCNJ5 somatic mutations. © 2017 American Heart Association, Inc.

Very low-density lipoprotein (VLDL)-induced signals mediating aldosterone production.

PubMed

Tsai, Ying-Ying; Rainey, William E; Bollag, Wendy B

2017-02-01

Aldosterone, secreted by the adrenal zona glomerulosa, enhances sodium retention, thus increasing blood volume and pressure. Excessive production of aldosterone results in high blood pressure and contributes to cardiovascular and renal disease, stroke and visual loss. Hypertension is also associated with obesity, which is correlated with other serious health risks as well. Although weight gain is associated with increased blood pressure, the mechanism by which excess fat deposits increase blood pressure remains unclear. Several studies have suggested that aldosterone levels are elevated with obesity and may represent a link between obesity and hypertension. In addition to hypertension, obese patients typically have dyslipidemia, including elevated serum levels of very low-density lipoprotein (VLDL). VLDL, which functions to transport triglycerides from the liver to peripheral tissues, has been demonstrated to stimulate aldosterone production. Recent studies suggest that the signaling pathways activated by VLDL are similar to those utilized by AngII. Thus, VLDL increases cytosolic calcium levels and stimulates phospholipase D (PLD) activity to result in the induction of steroidogenic acute regulatory (StAR) protein and aldosterone synthase (CYP11B2) expression. These effects seem to be mediated by the ability of VLDL to increase the phosphorylation (activation) of their regulatory transcription factors, such as the cAMP response element-binding (CREB) protein family of transcription factors. Thus, research into the pathways by which VLDL stimulates aldosterone production may identify novel targets for the development of therapies for the treatment of hypertension, particularly those associated with obesity, and other aldosterone-modulated pathologies. © 2017 Society for Endocrinology.

Nonsteroidal mineralocorticoid antagonists in diabetic kidney disease.

PubMed

Dojki, Farheen K; Bakris, George

2017-09-01

Current data highlight the pathological aspects of excess aldosterone in promoting glomerular hypertrophy, glomerulosclerosis, and proteinuria in diabetic kidney disease (DKD). The role of nonsteroidal mineralocorticoid receptor antagonists (MRAs) in DKD is being evaluated in ongoing clinical trials. Recent studies demonstrate beneficial effects of adding MRAs to the treatment regimen of patients with type 2 diabetes with nephropathy. The MRAs spironolactone and eplerenone can protect against organ damage caused by elevated levels of serum aldosterone in patients with heart failure and DKD but are limited by their side effects, for example, hyperkalemia. Finerenone is more selective for the mineralocorticoid receptor than spironolactone and has greater affinity for the mineralocorticoid receptor than eplerenone. It reduces the concentration of aldosterone without causing significant elevation in serum potassium. MRAs have a clear role in reducing albuminuria when used with other renin-angiotensin system blockers in DKD; however, hyperkalemia limits their use. This article provides an overview of clinical studies with a novel MRA, finerenone, and several nonsteroidal MRAs being studied for treatment in DKD.

Decoding resistant hypertension signalling pathways.

PubMed

Parreira, Ricardo Cambraia; Lacerda, Leandro Heleno Guimarães; Vasconcellos, Rebecca; Lima, Swiany Silveira; Santos, Anderson Kenedy; Fontana, Vanessa; Sandrim, Valéria Cristina; Resende, Rodrigo Ribeiro

2017-12-01

Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signalling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction and variations in the renin-angiotensin-aldosterone system (RAAS). miRNAs comprise a family of small non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. miRNAs are involved in the development of both cardiovascular damage and hypertension. Little is known of the molecular mechanisms that lead to development and progression of this condition. This review aims to cover the potential roles of miRNAs in the mechanisms associated with the development and consequences of RH, and explore the current state of the art of diagnostic and therapeutic tools based on miRNA approaches. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

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.

Myocardial pathology induced by aldosterone is dependent on non-canonical activities of G protein-coupled receptor kinases

PubMed Central

Cannavo, Alessandro; Liccardo, Daniela; Eguchi, Akito; Elliott, Katherine J.; Traynham, Christopher J.; Ibetti, Jessica; Eguchi, Satoru; Leosco, Dario; Ferrara, Nicola; Rengo, Giuseppe; Koch, Walter J.

2016-01-01

Hyper-aldosteronism is associated with myocardial dysfunction including induction of cardiac fibrosis and maladaptive hypertrophy. Mechanisms of these cardiotoxicities are not fully understood. Here we show that mineralocorticoid receptor (MR) activation by aldosterone leads to pathological myocardial signalling mediated by mitochondrial G protein-coupled receptor kinase 2 (GRK2) pro-death activity and GRK5 pro-hypertrophic action. Moreover, these MR-dependent GRK2 and GRK5 non-canonical activities appear to involve cross-talk with the angiotensin II type-1 receptor (AT1R). Most importantly, we show that ventricular dysfunction caused by chronic hyper-aldosteronism in vivo is completely prevented in cardiac Grk2 knockout mice (KO) and to a lesser extent in Grk5 KO mice. However, aldosterone-induced cardiac hypertrophy is totally prevented in Grk5 KO mice. We also show human data consistent with MR activation status in heart failure influencing GRK2 levels. Therefore, our study uncovers GRKs as targets for ameliorating pathological cardiac effects associated with high-aldosterone levels. PMID:26932512

Mineralocorticoids in the heart and vasculature: new insights for old hormones.

PubMed

Lother, Achim; Moser, Martin; Bode, Christoph; Feldman, Ross D; Hein, Lutz

2015-01-01

The mineralocorticoid aldosterone is a key regulator of water and electrolyte homeostasis. Numerous recent developments have advanced the field of mineralocorticoid pharmacology—namely, clinical trials have shown the beneficial effects of aldosterone antagonists in chronic heart failure and post-myocardial infarction treatment. Experimental studies using cell type-specific gene targeting of the mineralocorticoid receptor (MR) gene in mice have revealed the importance of extrarenal aldosterone signaling in cardiac myocytes, endothelial cells, vascular smooth cells, and macrophages. In addition, several molecular pathways involving signal transduction via the classical MR as well as the G protein-coupled receptor GPER mediate the diverse spectrum of effects of aldosterone on cells. This knowledge has initiated the development of new pharmacological ligands to specifically interfere with targets on different levels of aldosterone signaling. For example, aldosterone synthase inhibitors such as LCI699 and the novel nonsteroidal MR antagonist BAY 94-8862 have been tested in clinical trials. Interference with the interaction between MR and its coregulators seems to be a promising strategy toward the development of selective MR modulators.

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.

Renoprotective RAAS inhibition does not affect the association between worse renal function and higher plasma aldosterone levels.

PubMed

Gant, Christina M; Laverman, Gozewijn D; Vogt, Liffert; Slagman, Maartje C J; Heerspink, Hiddo J L; Waanders, Femke; Hemmelder, Marc H; Navis, Gerjan

2017-12-20

Aldosterone is elevated in chronic kidney disease (CKD) and may be involved in hypertension. Surprisingly, the determinants of the plasma aldosterone concentration (PAC) and its role in hypertension are not well studied in CKD. Therefore, we studied the determinants of aldosterone and its association with blood pressure in CKD patients. We also studied this during renin-angiotensin-aldosterone system inhibition (RAASi) to establish clinical relevance, as RAASi is the treatment of choice in CKD with albuminuria. We performed a post-hoc analysis on data from a randomized controlled double blind cross-over trial in non-diabetic CKD patients (n = 33, creatinine clearance (CrCl) 85 (75-95) ml/min, proteinuria 3.2 (2.5-4.0) g/day). Patients were treated with losartan 100 mg (ARB), and ARB + hydrochlorothiazide 25 mg (HCT), during both a regular (200 ± 10 mmol Na + /day) and low (89 ± 8 mmol Na + /day) dietary sodium intake, in 6-week study periods. PAC data at the end of each study period were analyzed. The association between PAC and blood pressure was analyzed continuously, and according to PAC above or below the median. Lower CrCl was correlated with higher PAC during placebo as well as during ARB (β = -1.213, P = 0.008 and β = -1.090, P = 0.010). Higher PAC was not explained by high renin, illustrated by a comparable association between CrCl and the aldosterone-to-renin ratio. The association between lower CrCl and higher PAC was also found in a second study with single RAASi with ACE inhibition (ACEi; lisinopril 40 mg/day), and dual RAASi (lisinopril 40 mg/day + valsartan 320 mg/day). Higher PAC was associated with a higher systolic blood pressure (P = 0.010) during different study periods. Only during maximal treatment with ARB + HCT + dietary sodium restriction, blood pressure was no longer different in subjects with a PAC above and below the median. In CKD patients with a standardized regular sodium intake, worse renal function is associated with a higher aldosterone, untreated and during RAASi with either ARB, ACEi, or both. Furthermore, higher aldosterone is associated with higher blood pressure, which can be treated with the combination of RAASi, HCT and dietary sodium restriction. The first study was performed before it was standard to register trials and the study was not retrospectively registered. The second study was registered in the Netherlands Trial Register on the 5th of May 2006 (NTR675).

Association of Aldosterone Synthase Polymorphism (CYP11B2 -344T>C) and Genetic Ancestry with Atrial Fibrillation and Serum Aldosterone in African Americans with Heart Failure

PubMed Central

Bress, Adam; Han, Jin; Patel, Shitalben R.; Desai, Ankit A.; Mansour, Ibrahim; Groo, Vicki; Progar, Kristin; Shah, Ebony; Stamos, Thomas D.; Wing, Coady; Garcia, Joe G. N.; Kittles, Rick; Cavallari, Larisa H.

2013-01-01

The objective of this study was to examine the extent to which aldosterone synthase genotype (CYP11B2) and genetic ancestry correlate with atrial fibrillation (AF) and serum aldosterone in African Americans with heart failure. Clinical data, echocardiographic measurements, and a genetic sample for determination of CYP11B2 -344T>C (rs1799998) genotype and genetic ancestry were collected from 194 self-reported African Americans with chronic, ambulatory heart failure. Genetic ancestry was determined using 105 autosomal ancestry informative markers. In a sub-set of patients (n = 126), serum was also collected for determination of circulating aldosterone. The CYP11B2 −344C allele frequency was 18% among the study population, and 19% of patients had AF. Multiple logistic regression revealed that the CYP11B2 −344CC genotype was a significant independent predictor of AF (OR 12.7, 95% CI 1.60–98.4, p = 0.0150, empirical p = 0.011) while holding multiple clinical factors, left atrial size, and percent European ancestry constant. Serum aldosterone was significantly higher among patients with AF (p = 0.036), whereas increased West African ancestry was inversely correlated with serum aldosterone (r = −0.19, p = 0.037). The CYP11B2 −344CC genotype was also overrepresented among patients with extreme aldosterone elevation (≥90th percentile, p = 0.0145). In this cohort of African Americans with chronic ambulatory heart failure, the CYP11B2 −344T>C genotype was a significant independent predictor of AF while holding clinical, echocardiographic predictors, and genetic ancestry constant. In addition, increased West African ancestry was associated with decreased serum aldosterone levels, potentially providing an explanation for the lower risk for AF observed among African Americans. PMID:23936266

Mechanisms of connecting tubule glomerular feedback enhancement by aldosterone

PubMed Central

Ren, YiLin; Janic, Branislava; Kutskill, Kristopher; Peterson, Edward L.

2016-01-01

Connecting tubule glomerular feedback (CTGF) is a mechanism where an increase in sodium (Na) concentration in the connecting tubule (CNT) causes the afferent arteriole (Af-Art) to dilate. We recently reported that aldosterone within the CNT lumen enhances CTGF via a nongenomic effect involving GPR30 receptors and sodium/hydrogen exchanger (NHE), but the signaling pathways of this mechanism are unknown. We hypothesize that aldosterone enhances CTGF via cAMP/protein kinase A (PKA) pathway that activates protein kinase C (PKC) and stimulates superoxide (O2−) production. Rabbit Af-Arts and their adherent CNTs were microdissected and simultaneously perfused. Two consecutive CTGF curves were elicited by increasing the CNT luminal NaCl. We found that the main effect of aldosterone was to sensitize CTGF and we analyzed data by comparing NaCl concentration in the CNT perfusate needed to achieve half of the maximal response (EC50). During the control period, the NaCl concentration that elicited a half-maximal response (EC50) was 37.0 ± 2.0 mmol/l; addition of aldosterone (10−8 mol/l) to the CNT lumen decreased EC50 to 19.3 ± 1.3 mmol/l (P ≤ 0.001 vs. Control). The specific adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (ddA; 2 × 10−4 mol/l) and the PKA inhibitor H-89 dihydrochloride hydrate (H-89; 2 × 10−6 mol/l) prevented the aldosterone effect. The selective PKC inhibitor GF109203X (10−8 mol/l) also prevented EC50 reduction caused by aldosterone. CNT intraluminal addition of O2− scavenger tempol (10−4 mol/l) blocked the aldosterone effect. We conclude that aldosterone inside the CNT lumen enhances CTGF via a cAMP/PKA/PKC pathway and stimulates O2− generation and this process may contribute to renal damage by increasing glomerular capillary pressure. PMID:27413197

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.

Combination use of medicines from two classes of renin-angiotensin system blocking agents: risk of hyperkalemia, hypotension, and impaired renal function.

PubMed

Esteras, Raquel; Perez-Gomez, Maria Vanessa; Rodriguez-Osorio, Laura; Ortiz, Alberto; Fernandez-Fernandez, Beatriz

2015-08-01

European and United States regulatory agencies recently issued warnings against the use of dual renin-angiotensin system (RAS) blockade therapy through the combined use of angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs) or aliskiren in any patient, based on absence of benefit for most patients and increased risk of hyperkalemia, hypotension, and renal failure. Special emphasis was made not to use these combinations in patients with diabetic nephropathy. The door was left open to therapy individualization, especially for patients with heart failure, when the combined use of an ARB and ACEI is considered absolutely essential, although renal function, electrolytes and blood pressure should be closely monitored. Mineralocorticoid receptor antagonists were not affected by this warning despite increased risk of hyperkalemia. We now critically review the risks associated with dual RAS blockade and answer the following questions: What safety issues are associated with dual RAS blockade? Can the safety record of dual RAS blockade be improved? Is it worth trying to improve the safety record of dual RAS blockade based on the potential benefits of the combination? Is dual RAS blockade dead? What is the role of mineralocorticoid antagonists in combination with other RAS blocking agents: RAAS blockade?

Aldosterone induces rapid sodium intake by a nongenomic mechanism in the nucleus tractus solitarius.

PubMed

Qiao, Hu; Hu, Bo; Zhou, Hong; Yan, Jianqun; Jia, Ru; Lu, Bo; Sun, Bo; Luo, Xiao; Fan, Yuanyuan; Wang, Nan

2016-12-09

The purpose of this study was to determine whether aldosterone has a rapid action in the nucleus tractus solitarius (NTS) that increases sodium intake, and to examine whether this effect of aldosterone, if present, is mediated by G protein-coupled estrogen receptor (GPER). Adult male Sprague-Dawley rats with a stainless-steel cannula in the NTS were used. Aldosterone was injected into the NTS at the doses of 1, 5, 10 and 20 ng 0.1 μl -1 . A rapid dose-related increase of 0.3 M NaCl intake was induced within 30 min and this increase was not suppressed by the mineralocorticoid receptor (MR) antagonist spironolactone (10 ng 0.1 μl -1 ). Water intake was not affected by aldosterone. The GPER agonist G-1 produced a parallel and significant increase in sodium intake, while pre-treatment with GPER antagonist G15 (10 ng 0.1 μl -1 ) blocked the G-1 or aldosterone-induced rapid sodium intake. In addition, sodium intake induced by sodium depletion or low-sodium diet fell within 30 min after injection into the NTS of the MR antagonist spironolactone, while G15 had no effect. Our results confirm previous reports, and support the hypothesis that aldosterone evokes rapid sodium intake through a non-genomic mechanism involving GPER in NTS.

A serine protease inhibitor attenuates aldosterone-induced kidney injuries via the suppression of plasmin activity.

PubMed

Kakizoe, Yutaka; Miyasato, Yoshikazu; Onoue, Tomoaki; Nakagawa, Terumasa; Hayata, Manabu; Uchimura, Kohei; Morinaga, Jun; Mizumoto, Teruhiko; Adachi, Masataka; Miyoshi, Taku; Sakai, Yoshiki; Tomita, Kimio; Mukoyama, Masashi; Kitamura, Kenichiro

2016-10-01

Emerging evidence has suggested that aldosterone has direct deleterious effects on the kidney independently of its hemodynamic effects. However, the detailed mechanisms of these direct effects remain to be elucidated. We have previously reported that camostat mesilate (CM), a synthetic serine protease inhibitor, attenuated kidney injuries in Dahl salt-sensitive rats, remnant kidney rats, and unilateral ureteral obstruction rats, suggesting that some serine proteases would be involved in the pathogenesis of kidney injuries. The current study was conducted to investigate the roles of serine proteases and the beneficial effects of CM in aldosterone-related kidney injuries. We observed a serine protease that was activated by aldosterone/salt in rat kidney lysate, and identified it as plasmin with liquid chromatography-tandem mass spectrometry. Plasmin increased pro-fibrotic and inflammatory gene expressions in rat renal fibroblast cells. CM inhibited the protease activity of plasmin and suppressed cell injury markers induced by plasmin in the fibroblast cells. Furthermore, CM ameliorated glomerulosclerosis and interstitial fibrosis in the kidney of aldosterone/salt-treated rats. Our findings indicate that plasmin has important roles in kidney injuries that are induced by aldosterone/salt, and that serine protease inhibitor could provide a new strategy for the treatment of aldosterone-associated kidney diseases in humans. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Investigation of aldosterone-synthase inhibition in rats.

PubMed

Ménard, Joël; Gonzalez, Marie-Françoise; Guyene, Thanh-Tam; Bissery, Alvine

2006-06-01

In-vivo investigation of aldosterone-synthase inhibitors requires experimental models to characterize the biological effects of these compounds. Seven successive experiments were performed in groups of 2-month-old male spontaneously hypertensive rats. Urinary free aldosterone was the main end-point measured during two contrasted diets: low sodium-high potassium (LS), inducing high urinary aldosterone (839 pmol/24 h, 95% confidence interval 654-1077), and high sodium-normal potassium (HS), inducing low urinary aldosterone (38.1 pmol/24 h; 95% confidence interval, 32.4-44.9). FAD 286 A (10 and 30 mg/kg) decreased urinary free aldosterone by 53 and 87% on the LS diet, and 50 and 75% on the HS. Plasma renin concentration increased three-fold after a 4-week treatment of 30 mg/kg FAD 286 A on the LS diet and did not change on the HS. The combination of FAD 286 A (30 mg/kg) and spironolactone (30 mg/kg) on the LS diet induced a biological picture of severe hypoaldosteronism and was not tolerated, whereas the HS diet prevented these abnormalities. The combination of FAD 286 A (30 mg/kg) and furosemide (30 mg/kg) on the HS diet corrected the diuretic-induced hypokalemia (4.1 +/- 0.2 versus 3.7 +/- 2.2 mEq/l, P < 0.033). This experimental model will be useful to screen future aldosterone-synthase inhibitors and study their biological effects in various experimental conditions.

The Potassium Channel, Kir3.4 Participates in Angiotensin II-Stimulated Aldosterone Production by a Human Adrenocortical Cell Line

PubMed Central

Oki, Kenji; Plonczynski, Maria W.; Lam, Milay Luis; Gomez-Sanchez, Elise P.

2012-01-01

Angiotensin II (A-II) regulation of aldosterone secretion is initiated by inducing cell membrane depolarization, thereby increasing intracellular calcium and activating the calcium calmodulin/calmodulin kinase cascade. Mutations in the selectivity filter of the KCNJ5 gene coding for inward rectifying potassium channel (Kir)3.4 has been found in about one third of aldosterone-producing adenomas. These mutations result in loss of selectivity of the inward rectifying current for potassium, which causes membrane depolarization and opening of calcium channels and activation of the calcium calmodulin/calmodulin kinase cascade and results in an increase in aldosterone secretion. In this study we show that A-II and a calcium ionophore down-regulate the expression of KCNJ5 mRNA and protein. Activation of Kir3.4 by naringin inhibits A-II-stimulated membrane voltage and aldosterone secretion. Overexpression of KCNJ5 in the HAC15 cells using a lentivirus resulted in a decrease in membrane voltage, intracellular calcium, expression of steroidogenic acute regulatory protein, 3-β-hydroxysteroid dehydrogenase 3B2, cytochrome P450 11B1 and cytochrome P450 11B2 mRNA, and aldosterone synthesis. In conclusion, A-II appears to stimulate aldosterone secretion by depolarizing the membrane acting in part through the regulation of the expression and activity of Kir3.4. PMID:22798349

The Renin-Angiotensin-Aldosterone System in Greyhounds and Non-Greyhound Dogs.

PubMed

Martinez, J; Kellogg, C; Iazbik, M C; Couto, C G; Pressler, B M; Hoepf, T M; Radin, M J

2017-07-01

The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure, electrolyte homeostasis, and renal function. Blood pressure, serum sodium concentrations, and urinary albumin excretion are higher in Greyhounds than other purebred and mixed-breed dogs. Alterations in the RAAS in Greyhounds are associated with hemodynamic and clinicopathologic differences observed in the breed. Clinically healthy Greyhound and non-Greyhound dogs consecutively enrolled as blood donors (n = 20/group). Prospective study. Standard chemical analysis was performed on serum and urine. Serum angiotensin-converting enzyme (ACE) activity was determined by fluorometric assay. All other RAAS hormones were determined by radioimmunoassay. Symmetric dimethylarginine (SDMA) was measured by immunoassay. Measurements were compared to blood pressure and urine albumin concentration. Data are presented as mean ± SD or median, range. Serum creatinine (1.5 ± 0.2 vs 1.0 ± 0.1 mg/dL, P < .001), sodium (149, 147-152 vs 148, 146-150 mEq/L, P = .017), and SDMA (16.1 ± 2.9 vs 12.2 ± 1.8 μg/dL, P < .001) were significantly higher in Greyhounds versus non-Greyhounds, respectively. Plasma renin activity (0.69, 0.10-1.93 vs 0.65, 0.27-2.93 ng/mL/h, P = .60) and ACE activity (4.5, 2.1-8.5 vs 4.6, 2.1-11.4 activity/mL; P = .77) were similar between groups and did not correlate with higher systolic pressures and albuminuria in Greyhounds. Plasma aldosterone concentration was significantly lower in Greyhounds versus non-Greyhounds (11, 11-52 vs 15, 11-56 pg/mL, respectively, P = .002). Basal RAAS activation did not differ between healthy Greyhounds and non-Greyhounds. Lower aldosterone concentration in Greyhounds is an appropriate physiologic response to higher serum sodium concentration and blood pressure, suggesting that angiotensin II effects in the renal tubule predominate over those of aldosterone. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

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%.

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.

Amplification of mineralocorticoid activity of aldosterone by 18-hydroxy-corticosterone and 18-hydroxy-19-nor-corticosterone in adrenalectomized rats.

PubMed

Rosenthal, T; Shani, M; Peleg, E; Harnik, M

1990-01-01

A combination of aldosterone (1 micrograms) with either 18-OH-corticosterone (1 micrograms) or 18-OH-19-norcorticosterone (1 micrograms) injected to adrenalectomized rats indicated an amplification of mineralocorticoid activity as expressed by Na/K ratio in urine. Without aldosterone their mineralocorticoid potency was negligible.

Determining Baseline Stress-Related Hormone Values in Large Cetaceans

DTIC Science & Technology

2014-09-30

reconstructed chemical profiles provided a unique window into stress-related hormone (cortisol, aldosterone , T3 and T4) concentrations and...Stress-related hormone radioimmunoassay technique Cortisol, aldosterone , hormones thyroxine (T4) and triiodothyronine (T3) levels in each identified...contaminant concentrations will be calculated using Pearson correlation coefficients. These measurements will include all hormones ( aldosterone , T3

Endothelin ETA Receptor Blockade, by Activating ETB Receptors, Increases Vascular Permeability and Induces Exaggerated Fluid Retention.

PubMed

Vercauteren, Magali; Trensz, Frederic; Pasquali, Anne; Cattaneo, Christophe; Strasser, Daniel S; Hess, Patrick; Iglarz, Marc; Clozel, Martine

2017-05-01

Endothelin (ET) receptor antagonists have been associated with fluid retention. It has been suggested that, of the two endothelin receptor subtypes, ET B receptors should not be blocked, because of their involvement in natriuresis and diuresis. Surprisingly, clinical data suggest that ET A -selective antagonists pose a greater risk of fluid overload than dual antagonists. The purpose of this study was to evaluate the contribution of each endothelin receptor to fluid retention and vascular permeability in rats. Sitaxentan and ambrisentan as ET A -selective antagonists and bosentan and macitentan as dual antagonists were used as representatives of each class, respectively. ET A -selective antagonism caused a dose-dependent hematocrit/hemoglobin decrease that was prevented by ET B -selective receptor antagonism. ET A -selective antagonism led to a significant blood pressure reduction, plasma volume expansion, and a greater increase in vascular permeability than dual antagonism. Isolated vessel experiments showed that ET A -selective antagonism increased vascular permeability via ET B receptor overstimulation. Acutely, ET A -selective but not dual antagonism activated sympathetic activity and increased plasma arginine vasopressin and aldosterone concentrations. The hematocrit/hemoglobin decrease induced by ET A -selective antagonism was reduced in Brattleboro rats and in Wistar rats treated with an arginine vasopressin receptor antagonist. Finally, the decrease in hematocrit/hemoglobin was larger in the venous than in the arterial side, suggesting fluid redistribution. In conclusion, by activating ET B receptors, endothelin receptor antagonists (particularly ET A -selective antagonists) favor edema formation by causing: 1) fluid retention resulting from arginine vasopressin and aldosterone activation secondary to vasodilation, and 2) increased vascular permeability. Plasma volume redistribution may explain the clinical observation of a hematocrit/hemoglobin decrease even in the absence of signs of fluid retention. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Selective aldosterone blockade prevents angiotensin II/salt-induced vascular inflammation in the rat heart.

PubMed

Rocha, Ricardo; Martin-Berger, Cynthia L; Yang, Pochang; Scherrer, Rachel; Delyani, John; McMahon, Ellen

2002-12-01

We studied the role of aldosterone (aldo) in myocardial injury in a model of angiotensin (Ang) II-hypertension. Wistar rats were given 1% NaCl (salt) to drink and randomized into one of the following groups (n = 10; treatment, 21 d): 1) vehicle control (VEH); 2) Ang II infusion (25 ng/min, sc); 3) Ang II infusion plus the selective aldo blocker, eplerenone (epl, 100 mg/kg.d, orally); 4) Ang II infusion in adrenalectomized (ADX) rats; and 5) Ang II infusion in ADX rats with aldo treatment (20 micro g/kg.d, sc). ADX rats received also dexamethasone (12 micro g/kg.d, sc). Systolic blood pressure increased with time in all treatment groups except the VEH group (VEH, 136 +/- 6; Ang II/NaCl, 203 +/- 12; Ang II/NaCl/epl, 196 +/- 10; Ang II/NaCl/ADX, 181 +/- 7; Ang II/NaCl/ADX/aldo, 236 +/- 8 mm Hg). Despite similar levels of hypertension, epl and ADX attenuated the increase in heart weight/body weight induced by Ang II. Histological examination of the hearts evidenced myocardial and vascular injury in the Ang II/salt (7 of 10 hearts with damage, P < 0.05 vs. VEH) and Ang II/salt/ADX/aldo groups (10 of 10 hearts with damage, P < 0.05). Injury included arterial fibrinoid necrosis, perivascular inflammation (primarily macrophages), and focal infarctions. Vascular lesions were associated with expression of the inflammatory mediators cyclooxygenase 2 (COX-2) and osteopontin in the media of coronary arteries. Myocardial injury, COX-2, and osteopontin expression were markedly attenuated by epl treatment (1 of 10 hearts with damage, P < 0.05 vs. Ang II/salt) and adrenalectomy (2 of 10 hearts with damage, P < 0.05 vs. Ang II/salt). Our data indicate that aldo plays a major role in Ang II-induced vascular inflammation in the heart and implicate COX-2 and osteopontin as potential mediators of the damage.

Coronary Care Medicine: It's Not Your Father's CCU Anymore.

PubMed Central

Antman, Elliott M.

2004-01-01

The management of ST-elevation MI (STEMI) has gone through four phases: 1. The "clinical observation phase"; 2. the "coronary care unit phase"; 3. the "high-technology phase"; and 4. the "evidence-based coronary care phase". A significant advance in the care of patients with acute myocardial infarction that arose as an outgrowth of the evidence-based era was introduction of a lexicon that more accurately reflected contemporary concepts of the pathophysiology underlying myocardial ischemia and infarction. Although considerable improvement has occurred in the process of care for patient with STEMI, room for improvement exists. Despite strong evidence in the literature that prompt use of reperfusion therapy improves survival of STEMI patients such treatment is underutilized and often not administered in an expeditious timeframe relative to the onset of symptom. Even in the reperfusion era, left ventricular dysfunction remains the single most important predictor of mortality following STEMI. After administration of aspirin, initiating reperfusion strategies and, where appropriate, beta blockade all STEMI patients should be considered for inhibition of the renin-angiotensin-aldosterone system. Several adjunctive pharmacotherapies have been investigated to prevent inflammatory damage in the infarct zone. Contrary to earlier beliefs that the heart is a terminally differentiated organ without the capacity to regenerate, evidence now exists that human cardiac myocytes divide after STEMI and stem cells can promote regeneration of cardiac tissue. These observations open up the possibility of myocardial replacement therapy after STEMI. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:17060962

Prognosis and treatment of diabetic nephropathy: Recent advances and perspectives.

PubMed

Rossing, Peter; Persson, Frederik; Frimodt-Møller, Marie

2018-04-01

Approximately 20 to 40% of patients with type 1 or type 2 diabetes develop diabetic kidney disease. It is a clinical syndrome characterized by persistent albuminuria (>300mg/24h, or 300mg/g creatinine), a relentless decline in glomerular filtration rate, raised arterial blood pressure and enhanced cardiovascular morbidity and mortality. The natural course of classical diabetic nephropathy is initially microalbuminuria or moderately increased urine albumin excretion (30-300mg/g creatinine). Untreated microalbuminuria may then rise gradually, reaching severely increased albuminuric (macroalbuminuria) over 5 to 15 years. Glomerular filtration rate then begins to decline and end-stage renal failure is reached without treatment in 5 to 7 years. Regular, systematic screening for diabetic kidney disease is needed to identify patients at risk for, or with presymptomatic stages of diabetic kidney disease. Multifactorial intervention targeting glucose, lipids and blood pressure including blockade of renin angiotensin system and lifestyle, has improved renal and cardiovascular prognosis and reduced mortality with 50%. Recent data suggest beneficial pleiotropic effects on renal endpoint with new glucose lowering agents. It is also being investigated if blocking aldosterone could be an option as a potential new treatment. Thus, although diabetic nephropathy remains a major burden, prognosis has improved and new options for further improvements are currently tested in phase 3 clinical renal outcome studies. Copyright © 2018 Association Société de néphrologie. Published by Elsevier Masson SAS. All rights reserved.

The angiotensin receptor blocker losartan reduces coronary arteriole remodeling in type 2 diabetic mice

PubMed Central

Husarek, Kathryn E.; Katz, Paige S.; Trask, Aaron J.; Galantowicz, Maarten L.; Cismowski, Mary J.; Lucchesi, Pamela A.

2017-01-01

Cardiovascular complications are a leading cause of morbidity and mortality in type 2 diabetes mellitus (T2DM) and are associated with alterations of blood vessel structure and function. Although endothelial dysfunction and aortic stiffness have been documented, little is known about the effects of T2DM on coronary microvascular structural remodeling. The renin–angiotensin–aldosterone system plays an important role in large artery stiffness and mesenteric vessel remodeling in hypertension and T2DM. The goal of this study was to determine whether the blockade of AT1R signaling dictates vascular smooth muscle growth that partially underlies coronary arteriole remodeling in T2DM. Control and db/db mice were given AT1R blocker losartan via drinking water for 4 weeks. Using pressure myography, we found that coronary arterioles from 16-week db/db mice undergo inward hypertrophic remodeling due to increased wall thickness and wall-to-lumen ratio with a decreased lumen diameter. This remodeling was accompanied by decreased elastic modulus (decreased stiffness). Losartan treatment decreased wall thickness, wall-to-lumen ratio, and coronary arteriole cell number in db/db mice. Losartan treatment did not affect incremental elastic modulus. However, losartan improved coronary flow reserve. Our data suggest that Ang II–AT1R signaling mediates, at least in part, coronary arteriole inward hypertrophic remodeling in T2DM without affecting vascular mechanics, further suggesting that targeting the coronary microvasculature in T2DM may help reduce cardiac ischemic events. PMID:26133668

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.

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.

Aldosterone-to-Renin Ratio Is Associated With Reduced 24-Hour Heart Rate Variability and QTc Prolongation in Hypertensive Patients

PubMed Central

Grübler, Martin R.; Kienreich, Katharina; Gaksch, Martin; Verheyen, Nicolas; Hartaigh, Bríain Ó.; Fahrleitner-Pammer, Astrid; März, Winfried; Schmid, Johannes; Oberreither, Eva-Maria; Wetzel, Julia; Catena, Cristiana; Sechi, Leonardo A.; Pieske, Burkert; Tomaschitz, Andreas; Pilz, Stefan

2016-01-01

Abstract Aldosterone is considered to exert direct effects on the myocardium and the sympathetic nervous system. Both QT time and heart rate (HR) variability (HRV) are considered to be markers of arrhythmic risk and autonomous dysregulation. In this study, we investigated the associations between aldosterone, QT time, and HRV in patients with arterial hypertension. We recruited 477 hypertensive patients (age: 60.2 ± 10.2 years; 52.3% females) with a mean systolic/diastolic 24-hour ambulatory blood pressure monitoring (ABPM) value of 128 ± 12.8/77.1 ± 9.2 mmHg and with a median of 2 (IQR: 1–3) antihypertensive agents. Patients were recruited from the outpatient clinic at the Department of Internal Medicine of the Medical University of Graz, Austria. Blood samples, 24-hour HRV derived from 24-hour blood pressure monitoring (ABPM) and ECG's were obtained. Plasma aldosterone and plasma renin concentrations were measured by means of a radioimmunoassay. Twenty-four-hour urine specimens were collected in parallel with ABPM. Mean QTc was 423.3 ± 42.0 milliseconds for males and 434.7 ± 38.3 milliseconds for females. Mean 24H-HR and 24H-HRV was 71.9 ± 9.8 and 10.0 ± 3.6 bpm, respectively. In linear regression analyses adjusted for age, sex, body mass index, ABPM, and current medication, aldosterone to active renin ratio (AARR) was significantly associated with the QTc interval, a marker for cardiac repolarization abnormalities (mean = 426 ± 42.4 milliseconds; β-coefficient = 0.121; P = 0.03) as well as with the 24-hour heart rate variability a surrogate for autonomic dysfunction (median = 9.67 [IQR = 7.38–12.22 bpm]; β-coefficient = −0.133; P = 0.01). In hypertensive patients, AARR is significantly related to QTc prolongation as well as HRV. Further studies investigating the effects of mineralocorticoid receptor blocker and aldosterone synthase inhibitors on QTc and HRV are warranted. PMID:26937909

Antiapolipoprotein A-1 IgG chronotropic effects require nongenomic action of aldosterone on L-type calcium channels.

PubMed

Rossier, Michel F; Pagano, Sabrina; Python, Magaly; Maturana, Andres D; James, Richard W; Mach, François; Roux-Lombard, Pascale; Vuilleumier, Nicolas

2012-03-01

Autoantibodies to apolipoprotein A-1 (antiapoA-1 IgG) have been shown to be associated with higher resting heart rate and morbidity in myocardial infarction patients and to behave as a chronotropic agent in the presence of aldosterone on isolated neonatal rat ventricular cardiomyocytes (NRVC). We aimed at identifying the pathways accounting for this aldosterone-dependent antiapoA-1 IgG-positive chronotropic effect on NRVC. The rate of regular spontaneous contractions was determined on NRVC in the presence of different steroid hormones and antagonists. AntiapoA-1 IgG chronotropic response was maximal within 20 min and observed only in aldosterone-pretreated cells but not in those exposed to other steroids. The positive antiapoA-1 IgG chronotropic effect was already significant after 5 min aldosterone preincubation, was dependent on 3-kinase and protein kinase A activities, was not inhibited by actinomycin D, and was fully abrogated by eplerenone (but not by spironolactone), demonstrating the dependence on a nongenomic action of aldosterone elicited through the mineralocorticoid receptor (MR). Under oxidative conditions (but not under normal redox state), corticosterone mimicked the permissive action of aldosterone on the antiapoA-1 IgG chronotropic response. Pharmacological and patch-clamp studies identified L-type calcium channels as crucial effectors of antiapoA-1 IgG chronotropic action, involving two converging pathways that increase the channel activity. The first one involves the rapid, nongenomic activation of the phosphatidylinositol 3-kinase enzyme by MR, and the second one requires a constitutive basal protein kinase A activity. In conclusion, our results indicate that, on NRVC, the aldosterone-dependent chronotropic effects of antiapoA-1 IgG involve the nongenomic activation of L-type calcium channels.

MicroRNA-34b/c inhibits aldosterone-induced vascular smooth muscle cell calcification via a SATB2/Runx2 pathway.

PubMed

Hao, Jianbing; Zhang, Lei; Cong, Guangting; Ren, Liansheng; Hao, Lirong

2016-12-01

Increasing evidence shows that aldosterone and specific microRNAs (miRs) contribute to vascular smooth muscle cell (VSMC) calcification. In this study, we aim to explore the mechanistic links between miR-34b/c and aldosterone in VSMC calcification. VSMC calcification models were established both in vitro and in vivo. First, the levels of aldosterone, miR-34b/c and special AT-rich sequence-binding protein 2 (SATB2) were measured. Then, miR-34b/c mimics or inhibitors were transfected into VSMCs to evaluate the function of miR-34b/c. Luciferase reporter assays were used to demonstrate whether SATB2 was a direct target of miR-34b/c. Aldosterone and SATB2 were found to be markedly upregulated during VSMC calcification, whereas miR-34b/c expression was downregulated. Treatment with the mineralocorticoid receptor (MR) antagonist eplerenone inhibited VSMC calcification. In aldosterone-induced VSMC calcification, miR-34b/c levels were downregulated and SATB2 protein was upregulated. Furthermore, miR-34b/c overexpression alleviated aldosterone-induced VSMC calcification as well as inhibited the expression of SATB2 protein, whereas miR-34b/c inhibition markedly enhanced VSMC calcification and upregulated SATB2 protein. In addition, luciferase reporter assays showed that SATB2 is a direct target of miR-34b/c in VSMCs. Overexpression of SATB2 induced Runx2 overproduction and VSMC calcification. Therefore, miR-34b/c participates in aldosterone-induced VSMC calcification via a SATB2/Runx2 pathway. As miR-34b/c appears to be a negative regulator, it has potential as a therapeutic target of VSMC calcification.

Aldosterone Does Not Predict Cardiovascular Events Following Acute Coronary Syndrome in Patients Initially Without Heart Failure.

PubMed

Pitts, Reynaria; Gunzburger, Elise; Ballantyne, Christie M; Barter, Philip J; Kallend, David; Leiter, Lawrence A; Leitersdorf, Eran; Nicholls, Stephen J; Shah, Prediman K; Tardif, Jean-Claude; Olsson, Anders G; McMurray, John J V; Kittelson, John; Schwartz, Gregory G

2017-01-10

Aldosterone may have adverse effects in the myocardium and vasculature. Treatment with an aldosterone antagonist reduces cardiovascular risk in patients with acute myocardial infarction complicated by heart failure (HF) and left ventricular systolic dysfunction. However, most patients with acute coronary syndrome do not have advanced HF. Among such patients, it is unknown whether aldosterone predicts cardiovascular risk. To address this question, we examined data from the dal-OUTCOMES trial that compared the cholesteryl ester transfer protein inhibitor dalcetrapib with placebo, beginning 4 to 12 weeks after an index acute coronary syndrome. Patients with New York Heart Association class II (with LVEF <40%), III, or IV HF were excluded. Aldosterone was measured at randomization in 4073 patients. The primary outcome was a composite of coronary heart disease death, nonfatal myocardial infarction, stroke, hospitalization for unstable angina, or resuscitated cardiac arrest. Hospitalization for HF was a secondary endpoint. Over a median follow-up of 37 months, the primary outcome occurred in 366 patients (9.0%), and hospitalization for HF occurred in 72 patients (1.8%). There was no association between aldosterone and either the time to first occurrence of a primary outcome (hazard ratio for doubling of aldosterone 0.92, 95% confidence interval 0.78-1.09, P=0.34) or hospitalization for HF (hazard ratio 1.38, 95% CI 0.96-1.99, P=0.08) in Cox regression models adjusted for covariates. In patients with recent acute coronary syndrome but without advanced HF, aldosterone does not predict major cardiovascular events. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00658515. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Effects of acrolein on aldosterone release from zona glomerulosa cells in male rats.

PubMed

Wang, Kai-Lee; Huang, Wen-Ching; Chou, Jou-Chun; Weng, Ting-Chun; Hu, Sindy; Lieu, Fu-Kong; Lai, Wei-Ho; Idova, Galina; Wang, Paulus S; Wang, Shyi-Wu

2016-07-01

A positive correlation between smoking and hypertension has been well established. Acrolein is a major toxic volatile compound found in cigarette smoke. Human exposure to low levels of acrolein is unavoidable due to its production in daily activities, such as smoke from industrial, hot oil cooking vapors, and exhaust fumes from vehicles. The toxicity and the action mechanism of acrolein to induce apoptosis have been extensively studied, but the effects of acrolein on hypertension are still unknown. The present study aimed to examine the effects of acrolein on aldosterone release both in vivo and in vitro. Male rats were divided into three groups, and intraperitoneally injected with normal saline, or acrolein (2mg/kg) for 1 (group A-1) or 3 (group A-3) days, respectively. After sacrificing, rat blood samples were obtained to measure plasma aldosterone and angiotensin II (Ang II) levels. Zona glomerulosa (ZG) cells were prepared from rat adrenal cortex, and were incubated with or without stimulants. We found that the serum aldosterone was increased by 1.2-fold (p<0.05) in A-3 group as compared to control group. Basal aldosterone release from ZG cells in A-3 group was also increased significantly. Moreover, acrolein enhanced the stimulatory effects of Ang II and 8-bromo-cyclic AMP on aldosterone secretion from ZG cells prepared in both A-1 and A-3 groups. Furthermore, the enzyme activity of P450scc, the rate-limiting step of aldosterone synthesis, was elevated after acrolein injection. Plasma level of Ang II was increased in both A-1 and A-3 groups. These results suggested that acrolein exposure increased aldosterone production, at least in part, through elevating the level of plasma Ang II and stimulating steroidogenesis pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

Albuminuria is associated with an increased prostasin in urine while aldosterone has no direct effect on urine and kidney tissue abundance of prostasin.

PubMed

Oxlund, Christina; Kurt, Birgül; Schwarzensteiner, Ilona; Hansen, Mie R; Stæhr, Mette; Svenningsen, Per; Jacobsen, Ib A; Hansen, Pernille B; Thuesen, Anne D; Toft, Anja; Hinrichs, Gitte R; Bistrup, Claus; Jensen, Boye L

2017-06-01

The proteinase prostasin is a candidate mediator for aldosterone-driven proteolytic activation of the epithelial sodium channel (ENaC). It was hypothesized that the aldosterone-mineralocorticoid receptor (MR) pathway stimulates prostasin abundance in kidney and urine. Prostasin was measured in plasma and urine from type 2 diabetic patients with resistant hypertension (n = 112) randomized to spironolactone/placebo in a clinical trial. Prostasin protein level was assessed by immunoblotting in (1) human and rat urines with/without nephrotic syndrome, (2) human nephrectomy tissue, (3) urine and kidney from aldosterone synthase-deficient (AS -/- ) mice and ANGII- and aldosterone-infused mice, and in (4) kidney from adrenalectomized rats. Serum aldosterone concentration related to prostasin concentration in urine but not in plasma. Plasma prostasin concentration increased significantly after spironolactone compared to control. Urinary prostasin and albumin related directly and were reduced by spironolactone. In patients with nephrotic syndrome, urinary prostasin protein was elevated compared to controls. In rat nephrosis, proteinuria coincided with increased urinary prostasin, unchanged kidney tissue prostasin, and decreased plasma prostasin while plasma aldosterone was suppressed. Prostasin protein abundance in human nephrectomy tissue was similar across gender and ANGII inhibition regimens. Prostasin urine abundance was not different in AS -/- and aldosterone-infused mice. Prostasin kidney level was not different from control in adrenalectomized rats and AS -/- mice. We found no evidence for a direct relationship between mineralocorticoid receptor signaling and kidney and urine prostasin abundance. The reduction of urinary prostasin in spironolactone-treated patients is most likely the result of an improved glomerular filtration barrier function and generally reduced proteinuria.

Diagnostic value of ACTH stimulation test in determining the subtypes of primary aldosteronism.

PubMed

Jiang, Yiran; Zhang, Cui; Wang, Weiqing; Su, Tingwei; Zhou, Weiwei; Jiang, Lei; Zhu, Wei; Xie, Jing; Ning, Guang

2015-05-01

Adrenal venous sampling is recommended as the golden standard for subtyping primary aldosteronism (PA). However, it is invasive and inconvenient, and seeking a better way to make differential diagnosis of PA is necessary. The objective of the study was to evaluate the diagnostic value of ACTH stimulation test under 1 mg dexamethasone suppression test (DST) in determining the subtypes of PA. Ninety-five patients with PA confirmed by saline infusion test were included in this study. According to adrenal venous sampling and histopathology, 39 patients were diagnosed as bilateral adrenal hyperplasia (BAH), 37 as aldosterone-producing adenoma (APA), and 19 as unilateral adrenal hyperplasia (UAH). An ACTH stimulation test under 1 mg DST was performed in all patients. Plasma aldosterone and cortisol levels were measured every 30 minutes until 120 minutes after the iv injection of 50 IU ACTH. During the ACTH stimulation test, aldosterone levels in APA and UAH were similar (P > .05) but higher than those in BAH (P < .001). Furthermore, stimulated aldosterone levels of unilateral PA (APA and UAH) were significantly higher than bilateral PA (BAH) (P < .001). Receiver-operated characteristics curve analyses showed the aldosterone after ACTH stimulation was effective for distinguishing between unilateral PA and bilateral PA. The diagnostic accuracy was highest at 120 minutes after ACTH stimulation, and the optimal cutoff value of the aldosterone was 77.90 ng/dL, with a sensitivity of 76.8%, a specificity of 87.2%, a positive predictive value of 89.6%, and a negative predictive value of 72.3%. The ACTH stimulation test under 1 mg DST is useful to determine the subtypes of PA, especially in unilateral and bilateral PA, and may guide further treatment in PA patients.

Mineralocorticoid and apparent mineralocorticoid syndromes of secondary hypertension.

PubMed

Ardhanari, Sivakumar; Kannuswamy, Rohini; Chaudhary, Kunal; Lockette, Warren; Whaley-Connell, Adam

2015-05-01

The mineralocorticoid aldosterone is a key hormone in the regulation of plasma volume and blood pressure in man. Excessive levels of this mineralocorticoid have been shown to mediate metabolic disorders and end-organ damage more than what can be attributed to its effects on blood pressure alone. Inappropriate excess levels of aldosterone contribute significantly to the cardiorenal metabolic syndrome and target organ injury that include atherosclerosis, myocardial hypertrophy, fibrosis, heart failure, and kidney disease. The importance of understanding the role of excess mineralocorticoid hormones such as aldosterone in resistant hypertension and in those with secondary hypertension should be visited. Primary aldosteronism is one of the commonly identified causes of hypertension and is treatable and/or potentially curable. We intend to review the management of mineralocorticoid-induced hypertension in the adult population along with other disease entities that mimic primary aldosteronism. Copyright © 2015 National Kidney Foundation, Inc. All rights reserved.

[How to screen for pheochromocytoma, primary aldosteronism and Cushing's syndrome].

PubMed

Meyer, Patrick

2009-01-07

Pheochromocytoma, primary aldosteronism and Cushing's syndrome are uncommon disorders and are difficult to diagnose because laboratory tests lack validation and specificity. Despite these limitations, practice guidelines are proposed to standardize the screening procedure. The most reliable method to diagnose pheochromocytoma is the measurement of plasmatic and/or urinary metanephrines and normetanephrines depending on the pre-test probability of the disease. The approach for detection of primary aldosteronism is based on the aldosterone-renin ratio under standard conditions. Finally, three tests are available to establish the diagnosis of Cushing's syndrome: 24-h urinary free cortisol excretion, low-dose dexamethasone suppression test and the recent and promising late evening salivary cortisol.

Fano effect dominance over Coulomb blockade in transport properties of parallel coupled quantum dot system

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

Brogi, Bharat Bhushan, E-mail: brogi-221179@yahoo.in; Ahluwalia, P. K.; Chand, Shyam

2015-06-24

Theoretical study of the Coulomb blockade effect on transport properties (Transmission Probability and I-V characteristics) for varied configuration of coupled quantum dot system has been studied by using Non Equilibrium Green Function(NEGF) formalism and Equation of Motion(EOM) method in the presence of magnetic flux. The self consistent approach and intra-dot Coulomb interaction is being taken into account. As the key parameters of the coupled quantum dot system such as dot-lead coupling, inter-dot tunneling and magnetic flux threading through the system can be tuned, the effect of asymmetry parameter and magnetic flux on this tuning is being explored in Coulomb blockademore » regime. The presence of the Coulomb blockade due to on-dot Coulomb interaction decreases the width of transmission peak at energy level ε + U and by adjusting the magnetic flux the swapping effect in the Fano peaks in asymmetric and symmetric parallel configuration sustains despite strong Coulomb blockade effect.« less

Macrolides selectively inhibit mutant KCNJ5 potassium channels that cause aldosterone-producing adenoma

PubMed Central

Scholl, Ute I.; Abriola, Laura; Zhang, Chengbiao; Reimer, Esther N.; Plummer, Mark; Zhang, Junhui; Hoyer, Denton; Merkel, Jane S.; Wang, Wenhui; Lifton, Richard P.

2017-01-01

Aldosterone-producing adenomas (APAs) are benign tumors of the adrenal gland that constitutively produce the salt-retaining steroid hormone aldosterone and cause millions of cases of severe hypertension worldwide. Either of 2 somatic mutations in the potassium channel KCNJ5 (G151R and L168R, hereafter referred to as KCNJ5MUT) in adrenocortical cells account for half of APAs worldwide. These mutations alter channel selectivity to allow abnormal Na+ conductance, resulting in membrane depolarization, calcium influx, aldosterone production, and cell proliferation. Because APA diagnosis requires a difficult invasive procedure, patients often remain undiagnosed and inadequately treated. Inhibitors of KCNJ5MUT could allow noninvasive diagnosis and therapy of APAs carrying KCNJ5 mutations. Here, we developed a high-throughput screen for rescue of KCNJ5MUT-induced lethality and identified a series of macrolide antibiotics, including roxithromycin, that potently inhibit KCNJ5MUT, but not KCNJ5WT. Electrophysiology demonstrated direct KCNJ5MUT inhibition. In human aldosterone-producing adrenocortical cancer cell lines, roxithromycin inhibited KCNJ5MUT-induced induction of CYP11B2 (encoding aldosterone synthase) expression and aldosterone production. Further exploration of macrolides showed that KCNJ5MUT was similarly selectively inhibited by idremcinal, a macrolide motilin receptor agonist, and by synthesized macrolide derivatives lacking antibiotic or motilide activity. Macrolide-derived selective KCNJ5MUT inhibitors thus have the potential to advance the diagnosis and treatment of APAs harboring KCNJ5MUT. PMID:28604387

Adrenal Venous Sampling: Where Is the Aldosterone Disappearing to?

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

Solar, Miroslav; Ceral, Jiri, E-mail: ceral.jiri@fnhk.c; Krajina, Antonin

Adrenal venous sampling (AVS) is generally considered to be the gold standard in distinguishing unilateral and bilateral aldosterone hypersecretion in primary hyperaldosteronism. However, during AVS, we noticed a considerable variability in aldosterone concentrations among samples thought to have come from the right adrenal glands. Some aldosterone concentrations in these samples were even lower than in samples from the inferior vena cava. We hypothesized that the samples with low aldosterone levels were unintentionally taken not from the right adrenal gland, but from hepatic veins. Therefore, we sought to analyze the impact of unintentional cannulation of hepatic veins on AVS. Thirty consecutivemore » patients referred for AVS were enrolled. Hepatic vein sampling was implemented in our standardized AVS protocol. The data were collected and analyzed prospectively. AVS was successful in 27 patients (90%), and hepatic vein cannulation was successful in all procedures performed. Cortisol concentrations were not significantly different between the hepatic vein and inferior vena cava samples, but aldosterone concentrations from hepatic venous blood (median, 17 pmol/l; range, 40-860 pmol/l) were markedly lower than in samples from the inferior vena cava (median, 860 pmol/l; range, 460-4510 pmol/l). The observed difference was statistically significant (P < 0.001). Aldosterone concentrations in the hepatic veins are significantly lower than in venous blood taken from the inferior vena cava. This finding is important for AVS because hepatic veins can easily be mistaken for adrenal veins as a result of their close anatomic proximity.« less

Mineralocorticoid receptor antagonism protects the aorta from vascular smooth muscle cell proliferation and collagen deposition in a rat model of adrenal aldosterone-producing adenoma.

PubMed

Yan, Yongji; Wang, Chao; Lu, Yiqin; Gong, Huijie; Wu, Zhun; Ma, Xin; Li, Hongzhao; Wang, Baojun; Zhang, Xu

2018-02-01

The number of patients with adrenal aldosterone-producing adenomas (APAs) has gradually increased. However, even after adenoma resection, some patients still suffer from high systolic blood pressure (SBP), which is possibly due to great arterial remodeling. Moreover, mineralocorticoid receptors (MRs) were found to be expressed in vascular smooth muscle cells (VSMCs). This study aims to determine whether MR antagonism protects the aorta from aldosterone-induced aortic remolding. Male rats were subcutaneously implanted with an osmotic minipumps and randomly divided into four groups: control; aldosterone (1 μg/h); aldosterone plus a specific MR antagonist, eplerenone (100 mg/kg/day); and aldosterone plus a vasodilator, hydralazine (25 mg/kg/day). After 8 weeks of infusion, aortic smooth muscle cell proliferation and collagen deposition, as well as the MDM2 and TGF-β1 expression levels in the aorta, were examined. Model rats with APAs were successfully constructed. Compared with the control rats, the model rats exhibited (1) marked SBP elevation, (2) no significant alteration in aortic morphology, (3) increased VSMC proliferation and MDM2 expression in the aorta, and (4) enhanced total collagen and collagen III depositions in the aorta, accompanied with up-regulated expression of TGF-β1. These effects were significantly inhibited by co-administration with eplerenone but not with hydralazine. These findings suggested that specific MR antagonism protects the aorta from aldosterone-induced VSMC proliferation and collagen deposition.

Macrolides selectively inhibit mutant KCNJ5 potassium channels that cause aldosterone-producing adenoma.

PubMed

Scholl, Ute I; Abriola, Laura; Zhang, Chengbiao; Reimer, Esther N; Plummer, Mark; Kazmierczak, Barbara I; Zhang, Junhui; Hoyer, Denton; Merkel, Jane S; Wang, Wenhui; Lifton, Richard P

2017-06-30

Aldosterone-producing adenomas (APAs) are benign tumors of the adrenal gland that constitutively produce the salt-retaining steroid hormone aldosterone and cause millions of cases of severe hypertension worldwide. Either of 2 somatic mutations in the potassium channel KCNJ5 (G151R and L168R, hereafter referred to as KCNJ5MUT) in adrenocortical cells account for half of APAs worldwide. These mutations alter channel selectivity to allow abnormal Na+ conductance, resulting in membrane depolarization, calcium influx, aldosterone production, and cell proliferation. Because APA diagnosis requires a difficult invasive procedure, patients often remain undiagnosed and inadequately treated. Inhibitors of KCNJ5MUT could allow noninvasive diagnosis and therapy of APAs carrying KCNJ5 mutations. Here, we developed a high-throughput screen for rescue of KCNJ5MUT-induced lethality and identified a series of macrolide antibiotics, including roxithromycin, that potently inhibit KCNJ5MUT, but not KCNJ5WT. Electrophysiology demonstrated direct KCNJ5MUT inhibition. In human aldosterone-producing adrenocortical cancer cell lines, roxithromycin inhibited KCNJ5MUT-induced induction of CYP11B2 (encoding aldosterone synthase) expression and aldosterone production. Further exploration of macrolides showed that KCNJ5MUT was similarly selectively inhibited by idremcinal, a macrolide motilin receptor agonist, and by synthesized macrolide derivatives lacking antibiotic or motilide activity. Macrolide-derived selective KCNJ5MUT inhibitors thus have the potential to advance the diagnosis and treatment of APAs harboring KCNJ5MUT.