Renin-angiotensin-aldosterone system inhibitors improve membrane stability and change gene-expression profiles in dystrophic skeletal muscles.

Science.gov (United States)

Chadwick, Jessica A; Bhattacharya, Sayak; Lowe, Jeovanna; Weisleder, Noah; Rafael-Fortney, Jill A

2017-02-01

Angiotensin-converting enzyme inhibitors (ACEi) and mineralocorticoid receptor (MR) antagonists are FDA-approved drugs that inhibit the renin-angiotensin-aldosterone system (RAAS) and are used to treat heart failure. Combined treatment with the ACEi lisinopril and the nonspecific MR antagonist spironolactone surprisingly improves skeletal muscle, in addition to heart function and pathology in a Duchenne muscular dystrophy (DMD) mouse model. We recently demonstrated that MR is present in all limb and respiratory muscles and functions as a steroid hormone receptor in differentiated normal human skeletal muscle fibers. The goals of the current study were to begin to define cellular and molecular mechanisms mediating the skeletal muscle efficacy of RAAS inhibitor treatment. We also compared molecular changes resulting from RAAS inhibition with those resulting from the current DMD standard-of-care glucocorticoid treatment. Direct assessment of muscle membrane integrity demonstrated improvement in dystrophic mice treated with lisinopril and spironolactone compared with untreated mice. Short-term treatments of dystrophic mice with specific and nonspecific MR antagonists combined with lisinopril led to overlapping gene-expression profiles with beneficial regulation of metabolic processes and decreased inflammatory gene expression. Glucocorticoids increased apoptotic, proteolytic, and chemokine gene expression that was not changed by RAAS inhibitors in dystrophic mice. Microarray data identified potential genes that may underlie RAAS inhibitor treatment efficacy and the side effects of glucocorticoids. Direct effects of RAAS inhibitors on membrane integrity also contribute to improved pathology of dystrophic muscles. Together, these data will inform clinical development of MR antagonists for treating skeletal muscles in DMD. Copyright © 2017 the American Physiological Society.

Radioimmunoassay for plasma renin activity

International Nuclear Information System (INIS)

1975-01-01

A radioimmunoassay for the determination of renin activity in blood plasma is described. The plasma sample is mixed with a generator buffer solution also containing an inhibitor for enzymes which convert angiotensin I into other substances. The renin in the plasma sample converts angiotensinogen into angiotensin I. The amount of angiotensin I is then measured with a competitive binding method using 125 I-labelled angiotensin I and antibodies to angiotensin I

The role of the renin-angiotensin-aldosterone system in heart failure

Directory of Open Access Journals (Sweden)

Thomas Unger

2004-03-01

Full Text Available Activity of the renin-angiotensin-aldosterone system (RAAS is increased in patients with heart failure, and its maladaptive mechanisms may lead to adverse effects such as cardiac remodelling and sympathetic activation. Elevated renin activity has been demonstrated in patients with dilated cardiomyopathy. (Third-generation synthetic non-peptide renin inhibitors, with more favourable properties than earlier renin inhibitors, lower ambulatory blood pressure and may have a role to play in other cardiovascular disease. Chymase, a protease inhibitor stored in mast cells that generates angiotensin II (Ang II (in addition to angiotensin-converting enzyme [ACE], has been linked to extracellular matrix remodelling in heart failure. Again, chymase inhibitors have been developed to investigate its functions in vitro and in vivo. Bradykinin is thought to contribute to the cardioprotective effect of ACE inhibition through modification of nitric oxide release, calcium handling and collagen accumulation. Ang II is believed to influence a number of molecular and structural changes in the heart, mostly mediated through the AT1-receptor. The importance of the RAAS in heart failure is shown by the survival benefit conferred by treatment with ACE inhibitors.

Renin-Angiotensin Inhibitors Decrease Recurrence after Transurethral Resection of Bladder Tumor in Patients with Nonmuscle Invasive Bladder Cancer.

Science.gov (United States)

Blute, Michael L; Rushmer, Timothy J; Shi, Fangfang; Fuller, Benjamin J; Abel, E Jason; Jarrard, David F; Downs, Tracy M

2015-11-01

Prior reports suggest that renin-angiotensin system inhibition may decrease nonmuscle invasive bladder cancer recurrence. We evaluated whether angiotensin converting enzyme inhibitor or angiotensin receptor blocker treatment at initial surgery was associated with decreased recurrence or progression in patients with nonmuscle invasive bladder cancer. Using an institutional bladder cancer database we identified 340 patients with data available on initial transurethral resection of bladder tumor. Progression was defined as an increase to stage T2. Cox proportional hazards models were used to evaluate associations with recurrence-free and progression-free survival. Median patient age was 69.6 years. During a median followup of 3 years (IQR 1.3-6.1) 200 patients (59%) had recurrence and 14 (4.1%) had stage progression. Of those patients 143 were receiving angiotensin converting enzyme inhibitor/angiotensin receptor blockers at the time of the first transurethral resection. On univariate analysis factors associated with improved recurrence-free survival included carcinoma in situ (p = 0.040), bacillus Calmette-Guérin therapy (p = 0.003) and angiotensin converting enzyme inhibitor/angiotensin receptor blocker therapy (p = 0.009). Multivariate analysis demonstrated that patients treated with bacillus Calmette-Guérin therapy (HR 0.68, 95% CI 0.47-0.87, p = 0.002) or angiotensin converting enzyme inhibitor/angiotensin receptor blocker therapy (HR 0.61, 95% CI 0.45-0.84, p = 0.005) were less likely to experience tumor recurrence. The 5-year recurrence-free survival rate was 45.6% for patients treated with angiotensin converting enzyme inhibitor/angiotensin receptor blockers and 28.1% in those not treated with angiotensin converting enzyme inhibitor/angiotensin receptor blockers (p = 0.009). Subgroup analysis was performed to evaluate nonmuscle invasive bladder cancer pathology (Ta, T1 and carcinoma in situ) in 85 patients on bacillus Calmette-Guérin therapy alone and in

A Mixed-Ligand Approach Enables the Asymmetric Hydrogenation of an α-Isopropylcinnamic Acid en Route to the Renin Inhibitor Aliskiren

NARCIS (Netherlands)

Boogers, Jeroen A.F.; Felfer, Ulfried; Kotthaus, Martina; Lefort, Laurent; Steinbauer, Gerhard; Vries, André H.M. de; Vries, Johannes G. de

2007-01-01

An asymmetric hydrogenation process for an α-isopropyl dihydrocinnamic acid derivative, an intermediate for the renin inhibitor aliskiren, has been developed using a rhodium catalyst ligated with a chiral monodentate phosphoramidite and a nonchiral phosphine. Whereas catalysts based on two

Direct renin inhibition in chronic kidney disease

DEFF Research Database (Denmark)

Persson, Frederik; Rossing, Peter; Parving, Hans-Henrik

2013-01-01

that renin inhibition could hold potential for improved treatment in patients with chronic kidney disease, with diabetic nephropathy as an obvious group of patients to investigate, as the activity of the renin-angiotensin-aldosterone system is enhanced in these patients and as there is an unmet need....... In addition, combination treatment seemed safe and effective also in patients with impaired kidney function. These initial findings formed the basis for the design of a large morbidity and mortality trial investigating aliskiren as add-on to standard treatment. The study has just concluded, but was terminated...... early as a beneficial effect was unlikely and there was an increased frequency of side effects. Also in non-diabetic kidney disease a few intervention studies have been carried out, but there is no ongoing hard outcome study. In this review we provide the current evidence for renin inhibition in chronic...

Dual Blockade of the Renin-angiotensin-aldosterone System in Type 2 Diabetic Kidney Disease

Directory of Open Access Journals (Sweden)

Yan-Huan Feng

2016-01-01

Full Text Available Objective: To examine the efficacy and safety of dual blockade of the renin-angiotensin-aldosterone system (RAAS among patients with type 2 diabetic kidney disease. Data Sources: We searched the major literature repositories, including the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE, for randomized clinical trials published between January 1990 and October 2015 that compared the efficacy and safety of the use of dual blockade of the RAAS versus the use of monotherapy, without applying any language restrictions. Keywords for the searches included "diabetic nephropathy," "chronic kidney disease," "chronic renal insufficiency," "diabetes mellitus," "dual therapy," "combined therapy," "dual blockade," "renin-angiotensin system," "angiotensin-converting enzyme inhibitor," "angiotensin-receptor blocker," "aldosterone blockade," "selective aldosterone blockade," "renin inhibitor," "direct renin inhibitor," "mineralocorticoid receptor blocker," etc. Study Selection: The selected articles were carefully reviewed. We excluded randomized clinical trials in which the kidney damage of patients was related to diseases other than diabetes mellitus. Results: Combination treatment with an angiotensin-converting enzyme inhibitor supplemented by an angiotensin II receptor blocking agent is expected to provide a more complete blockade of the RAAS and a better control of hypertension. However, existing literature has presented mixed results, in particular, related to patient safety. In view of this, we conducted a comprehensive literature review in order to explain the rationale for dual blockade of the RAAS, and to discuss the pros and cons. Conclusions: Despite the negative results of some recent large-scale studies, it may be immature to declare that the dual blockade is a failure because of the complex nature of the RAAS surrounding its diversified functions and utility. Further trials are warranted to study the combination therapy as an

Combination therapy with renin-angiotensin-aldosterone system inhibitor telmisartan and serine protease inhibitor camostat mesilate provides further renoprotection in a rat chronic kidney disease model

Directory of Open Access Journals (Sweden)

Yuki Narita

2016-02-01

Full Text Available We previously reported that camostat mesilate (CM had renoprotective and antihypertensive effects in rat CKD models. In this study, we examined if CM has a distinct renoprotective effect from telmisartan (TE, a renin-angiotensin-aldosterone system (RAS inhibitor, on the progression of CKD. We evaluated the effect of CM (400 mg/kg/day and/or TE (10 mg/kg/day on renal function, oxidative stress, renal fibrosis, and RAS components in the adenine-induced rat CKD model following 5-weeks treatment period. The combination therapy with CM and TE significantly decreased the adenine-induced increase in serum creatinine levels compared with each monotherapy, although all treatment groups showed similar reduction in blood pressure. Similarly, adenine-induced elevation in oxidative stress markers and renal fibrosis markers were significantly reduced by the combination therapy relative to each monotherapy. Furthermore, the effect of the combination therapy on plasma renin activity (PRA and plasma aldosterone concentration (PAC was similar to that of TE monotherapy, and CM had no effect on both PRA and PAC, suggesting that CM has a distinct pharmacological property from RAS inhibition. Our findings indicate that CM could be a candidate drug for an add-on therapy for CKD patients who had been treated with RAS inhibitors.

Preoperative renin-angiotensin system inhibitors protect renal function in aging patients undergoing cardiac surgery.

Science.gov (United States)

Barodka, Viachaslau; Silvestry, Scott; Zhao, Ning; Jiao, Xiangyin; Whellan, David J; Diehl, James; Sun, Jian-Zhong

2011-05-15

Renal failure (RF) represents a major postoperative complication for elderly patients undergoing cardiac surgery. This observational cohort study examines effects of preoperative use of renin-angiotensin system (RAS) inhibitors on postoperative renal failure in aging patients undergoing cardiac surgery. We retrospectively analyzed a cohort of 1287 patients who underwent cardiac surgery at this institution (2003-2007). The patients included were ≥65 years old, scheduled for elective cardiac surgery, and without preexisting RF (defined by the criteria of the Society of Thoracic Surgeons as described in Method). Of all patients evaluated, 346 patients met the inclusion criteria and were divided into two groups: using (n = 122) or not using (n = 224) preoperative RAS inhibitors. A comparison of the two groups showed no significant differences in baseline parameters, including creatinine clearance, body mass index, history of diabetes and smoking, preoperative medicines (except that more patients with RAS inhibitors had a history of hypertension or congestive heart failure, fewer RAS inhibitor patients had chronic lung disease), in intraoperative perfusion and aortic cross-clamp time, and in postoperative complications and 30-d mortality. Multivariate logistic regression analysis demonstrated, however, that preoperative RAS inhibitors significantly and independently reduced the incidence of postoperative RF in the patients undergoing cardiac surgery compared with those not taking RAS inhibitors: 1.6% versus 7.6%, yielding an odds ratio of 0.19 (95 % CI 0.04-0.84, P = 0.029). Preoperative RAS inhibitors may have significant renoprotective effects for aging patients undergoing elective cardiac surgery. Copyright © 2011 Elsevier Inc. All rights reserved.

Increased activity of digoxin-like substance in low-renin hypertension in acromegaly

Energy Technology Data Exchange (ETDEWEB)

Soszynski, P.; Slowinska-Srzednicka, J.; Zgliczynski, S. (Medical Center for Postgraduate Education, Warsaw (Poland))

1990-01-01

Arterial hypertension is common in acromegaly, but the pathogenesis of this complication remains unknown. To determine the role of an endogenous Na,K pump inhibitor/digoxin-like substance (DLS) in the pathogenesis of hypertension in acromegaly 76 subjects: 28 with acromegaly, 20 with essential hypertension and 28 healthy controls were studied. Serum DLS was measured with the use of radioimmunoassay and bioassay by the inhibition of digoxin-sensitive erythrocyte 86-Rb uptake. In acromegaly, the activity of DLS was significantly increased and plasma renin activity decreased in the hypertensive group, as compared with that of the normotensive group and controls. Moreover, DLS was elevated in the low-renin group of essential hypertension, as compared with that of the normal/high-renin group or controls. The activity of DLS correlated positively with mean arterial pressure and negatively with plasma renin activity, but not with growth hormone levels. In conclusion, an endogenous sodium pump inhibitor/digoxin-like substance may play a role in the pathogenesis of low-renin hypertension in acromegaly.

Increased activity of digoxin-like substance in low-renin hypertension in acromegaly

International Nuclear Information System (INIS)

Soszynski, P.; Slowinska-Srzednicka, J.; Zgliczynski, S.

1990-01-01

Arterial hypertension is common in acromegaly, but the pathogenesis of this complication remains unknown. To determine the role of an endogenous Na,K pump inhibitor/digoxin-like substance (DLS) in the pathogenesis of hypertension in acromegaly 76 subjects: 28 with acromegaly, 20 with essential hypertension and 28 healthy controls were studied. Serum DLS was measured with the use of radioimmunoassay and bioassay by the inhibition of digoxin-sensitive erythrocyte 86-Rb uptake. In acromegaly, the activity of DLS was significantly increased and plasma renin activity decreased in the hypertensive group, as compared with that of the normotensive group and controls. Moreover, DLS was elevated in the low-renin group of essential hypertension, as compared with that of the normal/high-renin group or controls. The activity of DLS correlated positively with mean arterial pressure and negatively with plasma renin activity, but not with growth hormone levels. In conclusion, an endogenous sodium pump inhibitor/digoxin-like substance may play a role in the pathogenesis of low-renin hypertension in acromegaly

The renin-angiotensin system in kidney development

DEFF Research Database (Denmark)

Jensen, B L; Stubbe, J; Madsen, K

2004-01-01

Recent data from studies in rodents with targeted gene disruption and pharmacological antagonists have shown that the renin-angiotensin-aldosterone system (RAAS) and cyclooxygenase type-2 (COX-2) are necessary for late stages of kidney development. The present review summarizes data on the develo......Recent data from studies in rodents with targeted gene disruption and pharmacological antagonists have shown that the renin-angiotensin-aldosterone system (RAAS) and cyclooxygenase type-2 (COX-2) are necessary for late stages of kidney development. The present review summarizes data...... on the developmental changes of RAAS and COX-2 and the pathways by which they are activated; their possible interplay and the mechanisms by which they affect kidney development. Intrarenal and circulating renin and angiotensin II (ANG II) are stimulated at birth in most mammals. In rats, renin and ANG II stay...... glucocorticoid concentration and by a low NaCl intake. Studies with selective inhibitors of COX-2 and COX-2 null mice show that COX-2 activity stimulates renin secretion from JG-cells during postnatal kidney development and that lack of COX-2 activity leads to pathological change in cortical architecture...

A study of dose-proportionality in the pharmacokinetics of the oral direct renin inhibitor aliskiren in healthy subjects.

Science.gov (United States)

Limoges, D; Dieterich, H A; Yeh, C-M; Vaidyanathan, S; Howard, D; Dole, W P

2008-05-01

To evaluate the dose-proportionality of the pharmacokinetics of aliskiren, the first in a new class of orally active direct renin inhibitors approved for the treatment of hypertension. This was an open-label, single-center, single-dose, randomized, 4-period crossover study. Following a 21-day screening period, 32 healthy male or female subjects (ages 18 - 45 years) were randomized to 1 of 4 aliskiren dosing sequence groups (8 subjects per group): 75, 150, 300 and 600 mg. Blood samples were obtained for determination of plasma aliskiren concentrations (HPLC/MS/MS) for 96 h post dose. Log-transformed pharmacokinetic parameters AUC and C(max) were analyzed to determine dose-proportionality using the power model, parameter = A*(Dose)(beta), where A = intercept and beta = dose-proportionality coefficient. The predefined dose-proportionality criteria over the dose range 75 â 600 mg were 90% confidence intervals (CI) for beta contained within the range 0.89 - 1.11. AUC and Cmax values increased with increasing doses of aliskiren. Both AUC and C(max) were associated with high variability (coefficient of variation 55 - 64% for AUC and 59 - 117% for C(max)). The estimated proportionality coefficients (beta) for AUC(0-infiniti), AUC(0-t) and C(max) were 1.18 (90% CI 1.10, 1.25), 1.29 (90% CI 1.22, 1.36) and 1.42 (90% CI 1.31, 1.52), respectively. Dose-proportionality was, therefore, not demonstrated across the entire 8-fold dose range. For the clinical dose range of 150 â 300 mg, increases of 2.3- and 2.6-fold were observed for AUC and C(max), respectively. All doses of aliskiren were well tolerated. Exposure to aliskiren was greater than proportional over the dose range of 75 - 600 mg. Over the therapeutic dose range of 150 â 300 mg approved for the treatment of hypertension, AUC and Cmax increased by 2.3- and 2.6-fold, respectively. The pharmacokinetics of aliskiren show relatively high intersubject variability.

Radioimmunoassay of renin in human renal tissues

International Nuclear Information System (INIS)

Wowra, B.

1981-01-01

A method has been developed to quantitatively determine renin in human kidney tissue. The angiotensin I split off angiotensinogs by renin was radioimmunologically determined. The renin-renin substrate reaction rate followed a saturation kinetics, as it increased the larger the substrate content in the incubation medium until it acquired a maximum value; the reaction rate decreased with substrate concentrations over 40 mg/ml incubation medium. The discontinuance of the renin reaction after incubation by adding acid, boiling and neutralizing again, gave highest renin values. The RIA scattering was 8.3% for double determination of the same sample, for the determination in different RIA additions 7.0%. The detection limit was 20 pg angiotensin I. A direct comparison of radioimmunoassay and bioassay exhibited a very significant agreement of both methods, where the radioimmunologically measured renin values were on average four times larger than those obtained using biological technique. The definition of the so-called normal values for absolute and specific renin concentration in human kidney tissue enabled one to assess the renin values in various syndromes. (orig./MG) [de

Impact of glycaemic control on the effect of direct renin inhibition in the AVOID study

DEFF Research Database (Denmark)

Persson, Frederik; Lewis, Julia B; Lewis, Edmund J

2012-01-01

Hyperglycaemia induces development and progression of microvascular complications in diabetes. A direct link between high glucose levels and intrarenal renin-angiotensin activation has been demonstrated. This post-hoc analysis assessed the influence of baseline glycaemic control on the reduction ...

Epistatic effects of polymorphisms in genes from the renin-angiotensin, bradykinin, and fibrinolytic systems on plasma t-PA and PAI-1 levels

NARCIS (Netherlands)

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

Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) directly influence thrombus formation and degradation and thereby risk for arterial thrombosis. Activation of the renin-angiotensin system has been linked to the production of PAI-1 expression via the angiotensin II

Direct renin inhibition in addition to or as an alternative to angiotensin converting enzyme inhibition in patients with chronic systolic heart failure: rationale and design of the Aliskiren Trial to Minimize OutcomeS in Patients with HEart failuRE (ATMOSPHERE) study

DEFF Research Database (Denmark)

Krum, Henry; Massie, Barry; Abraham, William T

2011-01-01

AIMS: The renin-angiotensin-aldosterone system (RAAS) represents a key therapeutic target in heart failure (HF) management. However, conventional agents that block this system induce a reflex increase in plasma renin activity (PRA), which may lead to RAAS 'escape'. Direct renin inhibitors (DRIs......S for Patients with HEart failuRE (ATMOSPHERE) study is to evaluate the effect of both aliskiren and enalapril monotherapy and aliskiren/enalapril combination therapy on cardiovascular death and HF hospitalization in patients with chronic systolic HF, NYHA functional class II-IV symptoms, and elevated plasma...... levels of BNP. Methods Patients tolerant to at least 10 mg or equivalent of enalapril will undergo an open-label run-in period where they receive enalapril then aliskiren. Approximately 7000 patients tolerating this run-in period will then be randomized 1:1:1 to aliskiren monotherapy, enalapril...

Aliskiren, a Direct Renin Inhibitor, Improves Vascular Endothelial Function in Patients on Hemodialysis Independent of Antihypertensive Effect ∼ a Pilot Study∼

Directory of Open Access Journals (Sweden)

Hidekazu Moriya

2013-05-01

Full Text Available Aims: Aliskiren inhibits the first step in the renin-angiotensin system (RAS and recently has been shown to modulate vascular diseases via RAS-dependent and independent pathways. This study aimed to determine the effect of aliskiren-associated direct renin inhibition on endothelial function in patients on hemodialysis via flow-mediated dilatation (FMD and platelet-derived microparticles (PDMP, as biomarkers of atherosclerosis. Methods: A 12-week prospective study was performed with 24 patients on hemodialysis who were administered 150 mg orally aliskiren once daily for 12 weeks. Results: No significant difference were observed between pre-dialysis, home, and weekly averaged blood pressure at baseline and at 12 weeks (151.5 ± 8.5/80.9 ± 12.9 mmHg vs 150.3 ± 15.3/78.9 ± 21.2 mmHg, 151.4 ± 9.7/82.3 ± 14.7 mmHg vs 151.2 ± 17.7/81.4 ± 10.6 mmHg, and 156.0 ± 18.3/81.9 ± 9.4 mmHg vs 152.5 ± 18.9/81.7 ± 12.3 mmHg, respectively. FMD significantly increased from 2.54% ± 1.45% at baseline to 3.11% ± 1.37% at 12 weeks (P = 0.0267, and PDMP significantly decreased from 13.9 ± 5.8 U/mL at baseline to 10.9 ± 4.5 U/mL at 12 weeks (P = 0.0002. Conclusion: Aliskiren improved vascular endothelial function and platelet-endothelium activation in patients on hemodialysis independent of antihypertensive effect.

Prevention of microalbuminuria using early intervention with renin-angiotensin system inhibitors in patients with type 2 diabetes

DEFF Research Database (Denmark)

Persson, Frederik; Lindhardt, Morten; Rossing, Peter

2016-01-01

Hypothesis/objectives: Early prevention of diabetic nephropathy by way of blocking the renin-angiotensin system (RAS) in patients with normoalbuminuria seems rational, but trials have so far shown conflicting results. The present meta-analysis was undertaken to investigate if such treatment can...... prevent development of microalbuminuria. Materials and methods: We searched MEDLINE, EMBASE and the Cochrane Library (2 June 2014) for randomised controlled trials, with a population of patients with type 2 diabetes and normoalbuminuria, comparing angiotensin-converting enzyme inhibitors (ACEis......-cause mortality(p=0.07). Conclusions: We conclude that in patients with type 2 diabetes and normoalbuminuria, early intervention with ACEis or ARBs reduces the risk for development of microalbuminuria....

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

Science.gov (United States)

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

2013-01-01

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

Effect of the Direct Renin Inhibitor Aliskiren on Urinary Albumin Excretion in Spontaneous Type 2 Diabetic KK-A y Mouse

Science.gov (United States)

Furukawa, Masako; Horikoshi, Satoshi; Funabiki, Kazuhiko; Tomino, Yasuhiko

2013-01-01

Objective. Although angiotensin II-mediated inflammation and extracellular matrix accumulation are considered to be associated with the progression of diabetic nephropathy, these processes have not yet been sufficiently clarified. The objective of this study was to determine whether the correction of the abnormal renal expression of MMPs and its inhibitors (MMPs/TIMPs) and cytokines following the administration of aliskiren to KK-A y mice results in a renoprotective effect. Methods. KK-A y mice were divided into two groups, that is, untreated (saline) and treated (aliskiren) groups. Systolic BP, HbA1c levels, and the albumin-creatinine ratio (ACR) were measured. The renal expression of MMPs/TIMPs, fibronectin, type IV collagen, MCP-1, and (pro)renin receptor ((P)RR) was examined using real-time PCR and/or immunohistochemical staining. Renal MAPK and NF-κB activity were also examined by Western blot analyses and ELISA, respectively. Results. Significant decreases in systolic BP and ACR levels were observed in treated KK-A y mice compared with the findings in untreated KK-A y mice. Furthermore, increases in MMPs/TIMPs, fibronectin, type IV collagen, MCP-1, and (P)RR expression, in addition to MAPK and NF-κB activity, were significantly attenuated by aliskiren administration. Conclusions. It appears that aliskiren improves albuminuria and renal fibrosis by regulating inflammation and the alteration of collagen synthesis and degradation. PMID:23819050

Direct demonstration of macula densa-mediated renin secretion

DEFF Research Database (Denmark)

Skøtt, O; Briggs, J P

1987-01-01

An in vitro method has been used to examine whether secretion of renin from the juxtaglomerular apparatus is affected by changes in the sodium chloride concentration of the tubular fluid at the macula densa. Single juxtaglomerular apparatuses were microdissected from rabbits and the tubule segmen...

The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production

DEFF Research Database (Denmark)

Tinning, Anne Robdrup; Jensen, Boye L; Schweda, Frank

2014-01-01

Processing and release of secretory granules involve water movement across granule membranes. It was hypothesized that the water channel aquaporin-1 (AQP-1) contributes directly to recruitment of renin-positive cells in the afferent arteriole. AQP1(-/-) and (+/+) mice were fed a low NaCl diet (LS...... to baseline with no difference between genotypes. Plasma nitrite/nitrate concentration was unaffected by genotype and LS-ACEI. In AQP1(-/-) mice, the number of afferent arterioles with recruitment was significantly lower compared to (+/+) after LS-ACEI. It is concluded that aquaporin-1 is not necessary...... for acutely stimulated renin secretion in vivo and from isolated perfused kidney, whereas recruitment of renin-positive cells in response to chronic stimulation is attenuated or delayed in AQP1(-/-) mice....

Control of the renal renin system by local factors

DEFF Research Database (Denmark)

Wagner, C; Jensen, B L; Krämer, B K

1998-01-01

prostanoid, both stimulate renin secretion and renin gene expression by activating cAMP formation in JG cells. Although the direct effect of NO on JG cells is less clear, its overall effect in vivo seems to be to stimulate the renin system. Evidence is emerging that stimulation by NO is related to the c......AMP pathway, and cGMP-induced inhibition of cAMP-phosphodiesterase III (PDE-III) may mediate this effect. ETs, on the other hand, appear to inhibit the renin system, in particular in those pathways activated by cAMP, acting via Ca2+- and protein kinase C-related mechanisms. There is increasing evidence...... that both NO and PGs could be involved in the physiological regulatory mechanisms by which salt intake affects the renin system....

Renin blood test

Science.gov (United States)

... page: //medlineplus.gov/ency/article/003698.htm Renin blood test To use the sharing features on this page, ... renin test measures the level of renin in blood. How the Test is Performed A blood sample is needed . How ...

Role of the inhibitors of angiotensin renin system on the DNA integrity of irradiated spermatozoids

International Nuclear Information System (INIS)

Spadella, Maria A.; Mansano, Naira S.; Schwarz, Franciele C.; Viani, Gustavo A.; Chies, Agnaldo B.

2016-01-01

Radiation action in the testes can significantly affect the reproductive capacity due to oxidative stress generated; phenomenon in which there is evidence of involvement of the Renin Angiotensin System (RAS). This study evaluated the role of AT1 receptor inhibitors, in mitigating the radioinduced DNA damage sperm from semen samples left vas deferens. Male Wistar rats were divided into six experimental groups: Control, 5Gy, Telmisartan (12mg/kg/day) and Losartan (34mg/kg/2x/day), 5 Gy + Telmisartan and 5 Gy + Losartan. The results showed increase in the percentage of sperm with fragmented DNA in irradiated groups when compared to controls, which was not reversed in the irradiated and treated groups. The radiation of 5Gy (single dose) affected the DNA-protein complex of the sperm and the treatments did not influence in reversing this damage, considering the experimental protocol used. (author)

Regulation of human renin expression in chorion cell primary cultures

International Nuclear Information System (INIS)

Duncan, K.G.; Haidar, M.A.; Baxter, J.D.; Reudelhuber, T.L.

1990-01-01

The human renin gene is expressed in the kidney, placenta, and several other sites. The release of renin or its precursor, prorenin, can be affected by several regulatory agents. In this study, primary cultures of human placental cells were used to examine the regulation of prorenin release and renin mRNA levels and of the transfected human renin promoter linked to chloramphenicol acetyltransferase reporter sequences. Treatment of the cultures with a calcium ionophore alone, calcium ionophore plus forskolin (that activates adenylate cyclase), or forskolin plus a phorbol ester increased prorenin release and renin mRNA levels 1.3 endash to 6 endash fold, but several classes of steroids did not affect prorenin secretion or renin RNA levels. These results suggest that (i) the first 584 base pairs of the renin gene 5'endash flanking DNA do not contain functional glucocorticoid or estrogen response elements, (ii) placental prorenin release and renin mRNA are regulated by calcium ion and by the combinations of cAMP with either C kinase or calcium ion, and (iii) the first 100 base pairs of the human renin 5'endash flanking DNA direct accurate initiation of transcription and can be regulated by cAMP. Thus, some control of renin release in the placenta (and by inference in other tissues) occurs via transcriptional influences on its promoter

Renin-angiotensin-aldosterone system inhibitors lower hemoglobin and hematocrit only in renal transplant recipients with initially higher levels.

Science.gov (United States)

Mikolasevic, I; Zaputovic, L; Zibar, L; Begic, I; Zutelija, M; Klanac, A; Majurec, I; Simundic, T; Minazek, M; Orlic, L

2016-04-01

We have analyzed the effects of renin-angiotensin-aldosterone system (RAAS) inhibitors on evolution of hemoglobin (Hb) and hematocrit (Htc) levels as well as on the evaluation of kidney graft function in stable renal transplant recipients (RTRs) in respect with initially higher or lower Hb and Htc values. The study group comprised of 270 RTRs with stable graft function. Besides other prescribed antihypertensive therapy, 169 of them have been taking RAAS inhibitors. We wanted to analyze the effect of the use of RAAS inhibitors on Hb and Htc in patients with initially higher or lower Hb/Htc values. For this analysis, only RTRs that were taking RAAS inhibitors were stratified into two groups: one with higher Hb and Htc (initial Hb≥150g/L and Htc≥45%) and another one with lower Hb and Htc (initial Hb<150g/L and Htc<45%) values. Thirty-four RTRs with initially higher Hb and 41 RTRs with initially higher Htc had a statistically significant decrease in Hb (p=0.006) and Htc (p<0.0001) levels after 12-months of follow-up. In the group of patients with initially lower Hb (135 RTRs) and Htc (128 RTRs) there was a significant increase in Hb (p=0.0001) and Htc (p=0.004) levels through the observed period. The use of RAAS inhibitors has been associated with a trend of slowing renal insufficiency in RTRs (p=0.03). RAAS inhibitors lower Hb and Htc only in RTRs with initially higher levels. In patients with initially lower Hb and Htc levels, the use of these drugs is followed by beneficial impact on erythropoiesis and kidney graft function. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Functional interactions between 7TM receptors in the renin-angiotensin system--dimerization or crosstalk?

DEFF Research Database (Denmark)

Lyngsø, Christina; Erikstrup, Niels; Hansen, Jakob L

2008-01-01

. The importance of the RAS is clearly emphasised by the widespread use of drugs targeting this system in clinical practice. These include, renin inhibitors, angiotensin II receptor type I blockers, and inhibitors of the angiotensin converting enzyme. Some of the important effectors within the system are 7...... be important for receptor function, and in the development of cardiovascular diseases. This is very significant, since "dimers" may provide pharmacologists with novel targets for improved drug therapy. However, we know that 7TM receptors can mediate signals as monomeric units, and so far it has been very......The Renin-Angiotensin System (RAS) is important for the regulation of cardiovascular physiology, where it controls blood pressure, and salt- and water homeostasis. Dysregulation of RAS can lead to severe diseases including hypertension, diabetic nephropathy, and cardiac arrhythmia, and -failure...

Isotope-edited proton NMR study on the structure of a pepsin/inhibitor complex

International Nuclear Information System (INIS)

Fesik, S.W.; Luly, J.R.; Erickson, J.W.; Abad-Zapatero, C.

1988-01-01

A general approach is illustrated for providing detailed structural information on large enzyme/inhibitor complexes using NMR spectroscopy. The method involves the use of isotopically labeled ligands to simplify two-dimensional NOE spectra of large molecular complexes by isotope-editing techniques. With this approach, the backbone and side-chain conformations (at the P 2 and P 3 sites) of a tightly bound inhibitor of porcine pepsin have bene determined. In addition, structural information on the active site of pepsin has been obtained. Due to the sequence homology between porcine pepsin and human renin, this structural information may prove useful for modeling renin/inhibitor complexes with the ultimate goal of designing more effective renin inhibitors. Moreover, this general approach can be applied to study other biological systems of interest such as other enzyme/inhibitor complexes, ligands bound to soluble receptors, and enzyme/substrate interactions

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

Science.gov (United States)

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 (Pdiuretics were associated with worse prognosis with HR 1.32 and 1.56, respectively (both Pdiuretics. 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).

Renin secretion from permeabilized juxtaglomerular cells requires a permeant cation

DEFF Research Database (Denmark)

Jensen, B L; Ellekvist, Peter; Skøtt, O

1999-01-01

The cytosolic concentration of chloride correlates directly with renin secretion from renal juxtaglomerular granular (JG) cells. In the present study, the mechanism by which chloride stimulates renin release was investigated in a preparation of permeabilized rat glomeruli with attached JG cells....... An isosmotic increase in the concentration of chloride by 129 mM stimulated renin release 16- to 20-fold. Substitution of K+ by the impermeant cation N-methyl-d-glucamine (NMDG) abolished this response, while substitution with Na+ caused marginal inhibition. Substitution with Cs+ had no effect. Addition...... of sucrose, which permeates the secretory granules poorly, also abolished the stimulation of renin secretion by KCl. The response to KCl was not affected by K+-channel antagonists or by agonists of K+ channels. Chloride channel blockers were also without effect on the secretory response to KCl. When the ATP...

Interleukin-1 inhibits renin gene expression in As4.1 cells but not in native juxtaglomerular cells

DEFF Research Database (Denmark)

Jensen, B L; Lehle, U; Müller, Maja

1998-01-01

) cells and in the mouse tumor cell line As4.1, which expresses renin mRNA. Renin mRNA levels and secretion of active renin were not significantly changed by IL-1beta in native JG cells. Activation of adenylyl cyclase by forskolin increased renin secretion and renin mRNA levels three- and fivefold......, respectively. These stimulatory responses to forskolin were not altered by IL-1beta. In contrast to native JG cells, renin mRNA abundance was markedly suppressed by IL-1beta in As4.1 cells, whereas secretion of active renin and the stability of renin mRNA were not changed. In As4.1 cells forskolin did...... not change renin secretion or renin mRNA abundance in the absence or in the presence of IL-1beta. These findings suggest that IL-1beta has no direct influence on renin secretion and renin mRNA abundance at the level of native JG cells....

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

Science.gov (United States)

Reid, Ian A.

1994-01-01

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

Severe hypoglycaemia in type 1 diabetes: impact of the renin-angiotensin system and other risk factors

DEFF Research Database (Denmark)

Pedersen-Bjergaard, Ulrik

2009-01-01

this thesis was conducted to assess the significance of severe hypoglycaemia as a clinical problem in the type 1 diabetic population, to evaluate the impact of known risk factors on occurrence of severe hypoglycaemia, and to identify new markers that could contribute to improved prediction of, and inspire...... targets and thereby open for prevention of severe hypoglycaemia. Furthermore, subjects with elevated renin-angiotensin system activity and a high rate of severe hypoglycaemia might benefit from pharmacological blockade of the renin-angiotensin system by ACE inhibitors or angiotensin II receptor blockers...

Radioimmunoassay - renin - angiotensin. Principles of radioimmunoassay and their application in measuring renin and angiotensin

Energy Technology Data Exchange (ETDEWEB)

Krause, D K; Hummerich, W; Poulsen, K [eds.

1978-01-01

Typical pitfalls such as impurity of 'standard', tracer damage, crossreactivity of antiserum, unspecific binding of protecting proteins, blank effects with negative results, charcoal stripping, invisible coprecipitate or uncertainty in the analysis of the calibration curve (graph, logit-log, polynormal or spline function) can occur in any type of radioimmunoassay; they are detailed in the general part of this book. The special position occupied by radioimmunological quantification of parameters of the renin-angiotensin system creates additional, even more serious problems. While the radioimmunological determination of the decapeptide angiotensin I no longer causes major obstacles, measurement of the biologically active octapeptide angiotensin II is still only possible in a few centers. The (indirect) determination of plasma renin is characterized by a situation where the enzyme renin may be clearly defined in theory as a specific 10-11-leucine-leucine-endopeptidase cleaving only a decapeptide, but the actual renin assay, however, measures various forms of renin and other angiotensin-forming (or angiotensin-destroying) enzymes at the same time.

Active immunization against renin in normotensive marmoset

International Nuclear Information System (INIS)

Michel, J.B.; Guettier, C.; Philippe, M.; Galen, F.X.; Corvol, P.; Menard, J.

1987-01-01

Primate renins (human and monkey) are very similar. We used pure human renin to immunize marmosets (Callithrix jacchus) and thereby produce a chronic blockade of the renin-angiotensinogen reaction. After a control period of 2 months, five male marmosets, on their usual sodium-poor diet, were immunized against pure human renin by three subcutneous injections of 30 μg each, with complete and then incomplete Freund's adjuvant. Three marmosets were injected with adjuvant only and served as controls. Blood sampling and blood pressure measurements were performed weekly. After the third injection, the five marmosets immunized against renin developed a high titer of renin antibodies (50% binding of 125 I-labeled human renin at a dilution of ≥ 1:10,000). The antibodies inhibited the enzymatic activity of both marmoset and human renins. At the same time, systolic blood pressure decreased significantly. Plasma renin enzyme activity was undetectable in the animals. Plasma aldosterone decreased significantly. After 1-4 months with low blood pressure, a normal urinary output, and a normal plasma creatinine, the five marmosets became sick and died within one month. At autopsy an immunological renal disease, characterize by the presence of immunoglobulin and macrophage infiltration colocalized with renin, was found. No immunoglobulin was detectable in extrarenal vessels or in other organs. These experiments demonstrate that, in this primate, a chronic blockade of the renin-angiotensin system can be achieved by active immunization against homologous renin, but this blockade is associated with the development of an autoimmune disease localized in the kidney

Methodologic issues in the measurement of urinary renin

NARCIS (Netherlands)

L.C.W. Roksnoer (Lodi); K. Verdonk (Koen); I.M. Garrelds (Ingrid); J.M. van Gool (Jeanette); R. Zietse (Bob); E.J. Hoorn (Ewout); A.H.J. Danser (Jan)

2014-01-01

textabstractBackground and objectives Alge et al. recently reported that urinary renin may be a prognostic biomarker for AKI after cardiac surgery. However, their urinary renin levels far exceeded published plasma renin levels, whereas normally, urinary renin is,10%of plasma renin. This result

Renin-Angiotensin System Inhibitors, Type 2 Diabetes and Fibrosis Progression: An Observational Study in Patients with Nonalcoholic Fatty Liver Disease.

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Serena Pelusi

Full Text Available The clinical determinants of fibrosis progression in nonalcoholic fatty liver disease (NAFLD are still under definition.To assess the clinical determinants of fibrosis progression rate (FPR in NAFLD patients with baseline and follow-up histological evaluation, with a special focus on the impact of pharmacological therapy.In an observational cohort of 118 Italian patients from tertiary referral centers, liver histology was evaluated according to Kleiner. Independent predictors of FPR were selected by a stepwise regression approach.Median follow-up was 36 months (IQR 24-77. Twenty-five patients (18% showed some amelioration, 63 (53% had stability, 30 (25% had progression of fibrosis. Patients with nonalcoholic steatohepatitis (NASH had similar demographic and anthropometric features, but a higher prevalence of type 2 diabetes (T2D; p = 0.010, and use of renin-angiotensin axis system (RAS inhibitors (p = 0.005. Fibrosis progression was dependent of the length of follow-up, and was associated with, but did not require, the presence of NASH (p<0.05. Both fibrosis progression and faster FPR were independently associated with higher APRI score at follow-up, absence of treatment with RAS inhibitors, and T2D diagnosis at baseline (p<0.05. There was a significant interaction between use of RAS inhibitors and T2D on FPR (p = 0.002. RAS inhibitors were associated with slower FPR in patients with (p = 0.011, but not in those without (p = NS T2D.NASH is not required for fibrosis progression in NAFLD, whereas T2D seems to drive fibrogenesis independently of hepatic inflammation. Use of RAS inhibitors may contrast fibrosis progression especially in high-risk patients affected by T2D.

Peptides and neurotransmitters that affect renin secretion

Science.gov (United States)

Ganong, W. F.; Porter, J. P.; Bahnson, T. D.; Said, S. I.

1984-01-01

Substance P inhibits renin secretion. This polypeptide is a transmitter in primary afferent neurons and is released from the peripheral as well as the central portions of these neurons. It is present in afferent nerves from the kidneys. Neuropeptide Y, which is a cotransmitter with norepinephrine and epinephrine, is found in sympathetic neurons that are closely associated with and presumably innervate the juxtagolmerular cells. Its effect on renin secretion is unknown, but it produces renal vasoconstriction and natriuresis. Vasoactive intestinal polypeptide (VIP) is a cotransmitter with acetylocholine in cholinergic neurons, and this polypeptide stimulates renin secretion. We cannot find any evidence for its occurence in neurons in the kidneys, but various stimuli increase plasma VIP to levels comparable to those produced by doses of exogenous VIP which stimulated renin secretion. Neostigmine increases plasma VIP and plasma renin activity, and the VIP appears to be responsible for the increase in renin secretion, since the increase is not blocked by renal denervation or propranolol. Stimulation of various areas in the brain produces sympathetically mediated increases in plasma renin activity associated with increases in blood pressure. However, there is pharmacological evidence that the renin response can be separated from the blood pressure response. In anaesthetized dogs, drugs that increase central serotonergic discharge increase renin secretion without increasing blood pressure. In rats, activation of sertonergic neurons in the dorsal raphe nucleus increases renin secretion by a pathway that projects from this nucleus to the ventral hypothalamus, and from there to the kidneys via the sympathetic nervous system. The serotonin releasing drug parachloramphetamine also increases plasma VIP, but VIP does not appear to be the primary mediator of the renin response. There is preliminary evidence that the serotonergic neurons in the dorsal raphe nucleus are part of the

Studies on renin release in vitro

DEFF Research Database (Denmark)

Skøtt, O

1989-01-01

1) Measurements of renin secretion from single arterioles at time intervals down to 20 seconds showed that the renin secretion is episodic, the amount of renin released during each episode corresponding to the estimated content of one secretory granule. 2) A decrease in osmolality elicits episodi...

Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism.

Directory of Open Access Journals (Sweden)

Ting-Ting Chang

Full Text Available Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day using an osmotic pump or hydralazine (2 or 10 mg/kg/day given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF and stromal cell-derived factor (SDF-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.

Effect of Sodium-Glucose Co-Transporter 2 Inhibitor, Dapagliflozin, on Renal Renin-Angiotensin System in an Animal Model of Type 2 Diabetes.

Science.gov (United States)

Shin, Seok Joon; Chung, Sungjin; Kim, Soo Jung; Lee, Eun-Mi; Yoo, Young-Hye; Kim, Ji-Won; Ahn, Yu-Bae; Kim, Eun-Sook; Moon, Sung-Dae; Kim, Myung-Jun; Ko, Seung-Hyun

2016-01-01

Renal renin-angiotensin system (RAS) activation is one of the important pathogenic mechanisms in the development of diabetic nephropathy in type 2 diabetes. The aim of this study was to investigate the effects of a sodium-glucose co-transporter 2 (SGLT-2) inhibitor, dapagliflozin, on renal RAS in an animal model with type 2 diabetes. Dapagliflozin (1.0 mg/kg, OL-DA) or voglibose (0.6 mg/kg, OL-VO, diabetic control) (n = 10 each) was administered to Otsuka Long-Evans Tokushima Fatty (OLETF) rats for 12 weeks. We used voglibose, an alpha-glucosidase inhibitor, as a comparable counterpart to SGLT2 inhibitor because of its postprandial glucose-lowering effect without proven renoprotective effects. Control Long-Evans Tokushima Otsuka (LT) and OLETF (OL-C) rats received saline (n = 10, each). Changes in blood glucose, urine albumin, creatinine clearance, and oxidative stress were measured. Inflammatory cell infiltration, mesangial widening, and interstitial fibrosis in the kidney were evaluated by histological analysis. The effects of dapagliflozin on renal expression of the RAS components were evaluated by quantitative RT-PCR in renal tissue. After treatment, hyperglycemia and urine microalbumin levels were attenuated in both OL-DA and OL-VO rather than in the OL-C group (P renal RAS component expression, oxidative stress and interstitial fibrosis in OLETF rats. We suggest that, in addition to control of hyperglycemia, partial suppression of renal RAS with an SGLT2 inhibitor would be a promising strategy for the prevention of treatment of diabetic nephropathy.

Between-patient differences in the renal response to renin-angiotensin system intervention : clue to optimising renoprotective therapy?

NARCIS (Netherlands)

Laverman, GD; de Zeeuw, D; Navis, G

2002-01-01

Renin-angiotensin-aldosterone system (RAAS) blockade with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin II (Ang II), AT(1)-receptor blockers (ARB) is the cornerstone of renoprotective therapy. Still, the number of patients with end-stage renal disease is increasing worldwide,

Influence of Aging on Plasma Renin Activity

International Nuclear Information System (INIS)

Cho, K. W.; Kim, S. H.; Kang, S. K.; Choi, H. Y.

1982-01-01

Influence of aging on plasma renin activity was evaluated in healthy normotensive subjects(age range 21-63 years, 413 males) devoid of cardiorenal or endocrinological problems. The age-related decrease of plasma renin activity in the subjects between 21-28 years group and 36-42 years group was slight, but over the 43 years groups was significantly different. The age-related suppression of plasma renin activity was much more smooth and continuous all over the age ranges evaluated. The sexual difference in plasma renin activity was noticed between the subjects of 22 years old group (34 males) and 19 years group (34 females) (p<0.003). The data suggest that the age-related suppression of plasma renin activity appeared in healthy normotensive subjects should be considered in the case of evaluation of low renin essential hypertension.

Nephroprotective action of renin-angiotensin-aldosterone system blockade in chronic kidney disease patients: the landscape after ALTITUDE and VA NEPHRON-D trails.

Science.gov (United States)

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.

Increased renin production in mice with deletion of peroxisome proliferator-activated receptor-gamma in juxtaglomerular cells

DEFF Research Database (Denmark)

Desch, Michael; Schreiber, Andrea; Schweda, Frank

2010-01-01

We recently found that endogenous (free fatty acids) and pharmacological (thiazolidinediones) agonists of nuclear receptor Peroxisome proliferator-activated receptor (PPAR)gamma stimulate renin transcription. In addition, the renin gene was identified as a direct target of PPARgamma. The mouse re...

Vanadate-induced inhibition of renin secretion is unrelated to inhibition Na,K-ATPase activity

Energy Technology Data Exchange (ETDEWEB)

Churchill, P.C.; Rossi, N.F.; Churchill, M.C.; Ellis, V.R. (Wayne State Univ. School of Medicine, Detroit, MI (USA))

1990-01-01

There is evidence that three inhibitors of Na,K-ATPase activity-ouabain, K-free extracellular fluid, and vanadate--inhibit renin secretion by increasing Ca{sup 2+} concentration in juxtaglomerular cells, but in the case of vanadate, it is uncertain whether the increase in Ca{sup 2+} is due to a decrease in Ca{sup 2+} efflux or to an increase in Ca{sup 2+} influx through potential operated Ca channels. In the present experiments, the rat renal cortical slice preparation was used to compare and contrast the effects of ouabain, of K-free fluid, and of vanadate on renin secretion, in the absence and presence of methoxyverapamil, A Ca channel blocker. Basal renin secretory rate averaged 7.7 {plus minus} 0.3 GU/g/60 min, and secretory rate was reduced to nearly zero by 1 mM ouabain, by K-free fluid, by 0.5 mM vanadate, and by K-depolarization. Although 0.5 {mu}M methoxyverapamil completely blocked the inhibitory effect of K-depolarization, it failed to antagonize the inhibitory effects of ouabain, of K-free fluid, and of vanadate.

Potential impact of renin-angiotensin system inhibitors and calcium channel blockers on plasma high-molecular-weight adiponectin levels in hemodialysis patients

International Nuclear Information System (INIS)

Nakagawa, Naoki; Yao, Naoyuki; Hirayama, Tomoya

2011-01-01

Although metabolic syndrome confers an increased risk of cardiovascular disease in the general population, little is known about the alteration of abdominal adiposity and its association with adipocytokines in hemodialysis patients. We investigated the plasma high-molecular-weight (HMW) adiponectin level and its relationship to visceral fat area (VFA) and various markers of atherosclerosis in hemodialysis patients. In a cross-sectional study, conventional cardiovascular risk factors, plasma total and HMW adiponectin, the number of components of the metabolic syndrome and, using computed tomography, the distribution of abdominal adiposity were assessed in 144 hemodialysis patients (90 men and 54 women; mean age, 60.7 years) and 30 age- and sex-matched patients with chronic kidney disease (CKD). Plasma HMW adiponectin levels in hemodialysis patients were significantly higher than those in patients with CKD, negatively associated with VFA and serum triglycerides and positively associated with plasma total adiponectin, as well as the HMW-to-total adiponectin ratio in men and women (all P<0.05) in a simple regression analysis. In a multiple regression analysis, VFA was a significant determinant of HMW adiponectin in hemodialysis patients. Furthermore, after adjustment for classical risk factors, HMW adiponectin levels were significantly higher in patients undergoing treatment with renin-angiotensin system inhibitors or calcium channel blockers compared with patients not undergoing such treatment. This study shows that plasma HMW adiponectin levels were negatively associated with VFA and positively associated with treatment with blockade of the renin-angiotensin system and of the calcium channel. Therefore, these drugs might be effective for improving adipocytokine-related metabolic abnormalities in hemodialysis patients. (author)

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

Science.gov (United States)

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

2017-05-01

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

Comparative biochemistry of renins and angiotensins in the vertebrates.

Science.gov (United States)

Nakajima, T; Khosla, M C; Sakakibara, S

1978-09-01

Comparative biochemistry of renins and angiotensins was discussed. Renin extracted from hog kidney was different from that from mouse submaxillary glands in immunoreactivity and carbohydrate content. Rat kidney renin was also different from hog kidney renin in the amino acid composition. The presence of big and big-big renins was pointed out immunochemically. These big renins were considered to be precursors of kidney renin. Angiotensins in mammalian and nonmammalian species produced by renal or extrarenal renin have been differentiated by some biochemical and pharmacological criteria. Some of these angiotensins were analyzed sequentially. The replacements of amino acid residues at positions 1, 5, and/or 9 of angiotensin I have been demonstrated in nonmammalian species. Specific pressor activities have been determined using synthetic angiotensins by a 4 point assay in rat. Specific pressor activities of various angiotensins were obtained from the dose-blood pressure-response curves using a single angiotensin sample per assay rat.

Plasma renin activity profile in normal and hypertensive Filipinos

International Nuclear Information System (INIS)

Guevara, R.; Torres, J. Jr.; Abundo, H.P.; Perez, A.P.

To establish a base line profile of plasma renin activity in normotensive and hypertensive Filipinos, 1.019 cases, 479 males and 540 females with an age range 14 - 89 years (mean - 46 + -20) were studied at the Santo Tomas University Hospital of various life styles from the Metro-Manila area, 248 comprised the normotensive group (male - 122 or 49.2 %, female 126 or 50.8 %) and 771 were hypertensive. Of these, 711 (92.6 %) has essential hypertension and are presented in this report. Plasma Renin Activity was determined by radioimmunoassay using Dainabot Renin-Ricket. Concurrent 24 hr. urine sodium and potassium were determined. Nomograms of plasma renin activity as related to urine sodium excretion were drawn after computerized statistical analysis of data. The normal mean value of plasma renin activity was found to be 1.64 + - 0.81 ng./ml./hr. in the upright position and 1.15 + - .68 ng./ml./hr. in the supine position. Based on the nomogram derived, the values obtained in the 711 cases of essential hypertension were classified into High Renin - 14.3 % Normal Renin - 56.1 % and Low Renin - 29.6 %. This study establishes normal levels of plasma renin activity as well as define and classify same renin activity among hypertensive Filipinos, a useful and practicable guide for treatment and can be of prognostic significance. (author)

Effect of additive renin inhibition with aliskiren on renal blood flow in patients with Chronic Heart Failure and Renal Dysfunction (Additive Renin Inhibition with Aliskiren on renal blood flow and Neurohormonal Activation in patients with Chronic Heart Failure and Renal Dysfunction)

NARCIS (Netherlands)

Schroten, Nicolas F.; Damman, Kevin; Hemmelder, Marc H.; Voors, Adriaan A.; Navis, Gerjan; Gaillard, Carlo A. J. M.; van Veldhuisen, Dirk J.; van Gilst, Wiek H.; Hillege, Hans L.

AIMS: We examined the effect of the renin inhibitor, aliskiren, on renal blood flow (RBF) in patients with heart failure with reduced ejection fraction (HFREF) and decreased glomerular filtration rate (GFR). Renal blood flow is the main determinant of GFR in HFREF patients. Both reduced GFR and RBF

Urinary renin and angiotensinogen in type 2 diabetes

DEFF Research Database (Denmark)

Persson, Frederik; Lu, Xifeng; Rossing, Peter

2013-01-01

Urinary levels of renin-angiotensin-aldosterone system (RAAS) components may reflect renal RAAS activity and/or the renal efficacy of RAAS inhibition. Our aim was to determine whether urinary angiotensinogen and renin are circulating RAAS-independent markers during RAAS blockade.......Urinary levels of renin-angiotensin-aldosterone system (RAAS) components may reflect renal RAAS activity and/or the renal efficacy of RAAS inhibition. Our aim was to determine whether urinary angiotensinogen and renin are circulating RAAS-independent markers during RAAS blockade....

Safe use of NSAIDs and RAS-inhibitors at Agogo Presbyterian Hospital, Ghana

NARCIS (Netherlands)

Meulendijks, L.G.; Adomako, E.A.; Appiah, E.B.; Kramers, C.

2016-01-01

BACKGROUND: Preventable adverse events of medication are an important cause of hospital admissions in the developed world, in which non-steroidal anti-inflammatory drugs (NSAIDs) and renin-angiotensin system (RAS-) inhibitors are frequently involved. NSAIDs and RAS-inhibitors are also often used in

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

Science.gov (United States)

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

2018-05-30

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

Renin-angiotensin system antagonists, glomerular filtration rate and blood pressure

Directory of Open Access Journals (Sweden)

D.D. Ivanov

2018-02-01

Full Text Available The article deals with the mModern data on the influence of renin-angiotensin system blockers on the glomerular filtration rate, the level of arterial pressure and the outcome of chronic kidney disease. The strategy of  rennin-angiotensine blockade is offered to be changed depending on the criteria va­lues of glomerular filtration rate: a combination of inhibitors of angiotensin-converting enzyme + angiotensin receptors blo­ckers, monotherapy and drug withdrawal in glomerular filtration rate under 15–30 ml/min/m2. The formula BRIMONEL for treatment of chronic kidney disease is given.

On the origin of urinary renin: A translational approach

NARCIS (Netherlands)

L.C.W. Roksnoer (Lodi); Heijnen, B.F.J. (Bart F.J.); Nakano, D. (Daisuke); Peti-Peterdi, J. (Janos); S.B. Walsh (Stephen); I.M. Garrelds (Ingrid); J.M. van Gool (Jeanette); R. Zietse (Bob); H.A.J. Struijker Boudier (Harry A.); E.J. Hoorn (Ewout); A.H.J. Danser (Jan)

2016-01-01

textabstractUrinary angiotensinogen excretion parallels albumin excretion, which is not the case for renin, while renin's precursor, prorenin, is undetectable in urine. We hypothesized that renin and prorenin, given their smaller size, are filtered through the glomerulus in larger amounts than

Active renin mass concentration to determine aldosterone-to-renin ratio in screening for primary aldosteronism

Directory of Open Access Journals (Sweden)

Corbin F

2011-07-01

Full Text Available François Corbin1, Pierre Douville2, Marcel Lebel3 1Division of Biochemistry, l'Université de Sherbrooke, Sherbrooke, Quebec, Canada; 2Division of Biochemistry; 3Division of Nephrology, L'Hôtel-Dieu de Québec Hospital and l'Université Laval, Quebec, CanadaBackground: Active renin mass concentration (ARC is independent of the endogenous level of angiotensinogen, and less variable and more reproducible than plasma renin activity. Reference values for the aldosterone-to-renin ratio (ARR using ARC are still undefined. The objective of the present study was to determine the threshold of ARR using ARC measurement to screen for primary aldosteronism.Methods: A total of 211 subjects were included in the study, comprising 78 healthy normotensive controls, 95 patients with essential hypertension, and 38 patients with confirmed primary aldosteronism (20 with surgery-confirmed aldosterone-producing adenoma and 18 with idiopathic adrenal hyperplasia. Blood samples were drawn from ambulatory patients and volunteers in the mid-morning without specific dietary restriction for measuring plasma aldosterone concentration, ARC, and serum potassium.Results: Most normotensive controls and essential hypertension patients had ARR results below 100 pmol/ng, a value which corresponded to 3.3 times the median of these two groups.Conclusion: Patients with ARR values above this level should be considered for further investigation (confirmatory tests or for repeat testing should ARR values be borderline. This study indicates that ARC can be used reliably in determining ARR for primary aldosteronism screening.Keywords: primary aldosteronism, active renin mass concentration, aldosterone-to-renin ratio

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

Science.gov (United States)

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

1999-01-01

We have reported previously that thyroid hormone activates the circulating and tissue renin-angiotensin systems without involving the sympathetic nervous system, which contributes to cardiac hypertrophy in hyperthyroidism. This study examined whether the circulating or tissue renin-angiotensin system plays the principal role in hyperthyroidism-induced cardiac hypertrophy. The circulating renin-angiotensin system in Sprague-Dawley rats was fixed by chronic angiotensin II infusion (40 ng/min, 28 days) via mini-osmotic pumps. Daily i.p. injection of thyroxine (0.1 mg/kg per day, 28 days) was used to mimic hyperthyroidism. Serum free tri-iodothyronine, plasma renin activity, plasma angiotensin II, cardiac renin and cardiac angiotensin II were measured with RIAs. The cardiac expression of renin mRNA was evaluated by semiquantitative reverse transcriptase-polymerase chain reaction. Plasma renin activity and plasma angiotensin II were kept constant in the angiotensin II and angiotensin II+thyroxine groups (0.12+/-0.03 and 0.15+/-0.03 microgram/h per liter, 126+/-5 and 130+/-5 ng/l respectively) (means+/-s.e.m.). Despite stabilization of the circulating renin-angiotensin system, thyroid hormone induced cardiac hypertrophy (5.0+/-0.5 vs 3.5+/-0.1 mg/g) in conjunction with the increases in cardiac expression of renin mRNA, cardiac renin and cardiac angiotensin II (74+/-2 vs 48+/-2%, 6.5+/-0.8 vs 3.8+/-0.4 ng/h per g, 231+/-30 vs 149+/-2 pg/g respectively). These results indicate that the local renin-angiotensin system plays the primary role in the development of hyperthyroidism-induced cardiac hypertrophy.

Renal renin secretion as regulator of body fluid homeostasis

DEFF Research Database (Denmark)

Damkjær, Mads; Isaksson, Gustaf L; Stubbe, Jane

2013-01-01

The renin-angiotensin system is essential for body fluid homeostasis and blood pressure regulation. This review focuses on the homeostatic regulation of the secretion of active renin in the kidney, primarily in humans. Under physiological conditions, renin secretion is determined mainly by sodium...

Total renin after gonadotropin stimulation in polycystic ovarian disease.

Science.gov (United States)

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

1995-02-01

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

Mechanisms of renin release from juxtaglomerular cells

DEFF Research Database (Denmark)

Skøtt, O; Salomonsson, Max; Sellerup Persson, Anja

1991-01-01

In microdissected, nonperfused afferent arterioles changes in intravascular pressure did not affect renin secretion. On the contrary, renin release from isolated afferent arterioles perfused in a free-flow system has been reported to be sensitive to simultaneous changes in luminal pressure and fl....... Hence local blood flow may be involved in the baroreceptor control of renin release. If flow is sensed, the sensor is likely to be located near the endothelial cell layer, where ion channels have been shown to be influenced by variations in shear stress....

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

Science.gov (United States)

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

2015-01-01

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

The renin-angiotensin system in malignant hypertension revisited: plasma renin activity, microangiopathic hemolysis, and renal failure in malignant hypertension

NARCIS (Netherlands)

van den Born, Bert-Jan H.; Koopmans, Richard P.; van Montfrans, Gert A.

2007-01-01

BACKGROUND: Malignant hypertension is a renin-dependent form of hypertension. However, the variations in renin-angiotensin system (RAS) activation in malignant hypertension are not completely understood. A proposed mechanism for ongoing RAS activation is the presence of microangiopathic hemolysis

Combination inhibition of the renin-angiotensin system: is more better?

Science.gov (United States)

Krause, Michelle W; Fonseca, Vivian A; Shah, Sudhir V

2011-08-01

Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers are considered the standard of care for treatment of cardiovascular disease and chronic kidney disease. Combination therapy with both angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers effectively inhibits the renin-angiotensin system as well as potentiates the vasodilatory effects of bradykinin. It has been advocated that this dual blockade approach theoretically should result in improved clinical outcomes in both cardiovascular disease and chronic kidney disease. Clinical trial evidence for the use of combination therapy with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in cardiovascular disease has provided conflicting results in hypertension, congestive heart failure, and ischemic heart disease. Clinical trial evidence to support combination therapy with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers in chronic kidney disease has largely been based on proteinuria reduction as a surrogate marker for clinically meaningful outcomes. Recent large-scale randomized clinical trials have not been able to validate protection in halting progression in chronic kidney disease with a dual blockade approach. This review serves as an appraisal on the clinical evidence of combination angiotensin-converting enzyme inhibition and angiotensin II receptor blockade in both cardiovascular disease and chronic kidney disease.

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

Science.gov (United States)

Henriksen, Erik J; Prasannarong, Mujalin

2013-09-25

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

A Study on Plasma Renin Activity in Essential Hypertension

International Nuclear Information System (INIS)

Choe, Kang Won; Lee, Jung Sang; Cho, Bo Yeon; Koh, Chang Soon; Lee, Mun Ho

1975-01-01

Radioimmunoassay for the measurement of plasma renin activity (PRA) was performed in 43 normal Koreans and 45 patients with essential hypertension. Plasma samples were drawn in supine position in the morning and after upright posture for 4 hours. Urinary sodium excretion rates were measured in the concurrent 24 hour urine samples, an index of their sodium balance. The results were as follows: 1) There was an inverse correlation between 24 hr sodium excretion and PRA. The normal values of PRA in supine position ranged from 1.0 to 7.0 ng/ml/hr. when 24 hour sodium excretion were between 50 to 150 mEq. PRA in elderly tended to be low. 2) When stimulated by 4 hour upright posture, PRA increased by 2.6 times from the baseline value. 3) Of the 45 patients with essential hypertension, PRA was low in 10 cases (22.2%), normal in 28 cases (62.2%), and high in 7 cases (15.6%). 4) In the normal and high renin groups, who tended to be younger in ages, mean diastolic blood pressure and BUN were higher than in low renin group. Though hypertensive retinopathy and left ventricular hypertrophy in ECG were more prevalent in the former, no significant differences were noted as in the case of serum cholesterol. 5) There were 8 cases of cardiovascular complications (7 with cerebral vascular accident, 1 with myocardial infarction); 3 in low renin group (30%), 2 in normal renin (7.1%) and 3 in higher renin group (42.9%). This figure indicated higher rate of cardiovascular complications in higher renin groups, and lower rate in normal renin group. But the incidence of the complication was not significantly low in low renin group.

Renin release

DEFF Research Database (Denmark)

Schweda, Frank; Friis, Ulla; Wagner, Charlotte

2007-01-01

in the walls of renal afferent arterioles at the entrance of the glomerular capillary network. It has been known for a long time that renin synthesis and secretion are stimulated by the sympathetic nerves and the prostaglandins and are inhibited in negative feedback loops by angiotensin II, high blood pressure...

Cardiovascular and Renal Outcomes of Renin-Angiotensin System Blockade in Adult Patients with Diabetes Mellitus: A Systematic Review with Network Meta-Analyses.

Science.gov (United States)

Catalá-López, Ferrán; Macías Saint-Gerons, Diego; González-Bermejo, Diana; Rosano, Giuseppe M; Davis, Barry R; Ridao, Manuel; Zaragoza, Abel; Montero-Corominas, Dolores; Tobías, Aurelio; de la Fuente-Honrubia, César; Tabarés-Seisdedos, Rafael; Hutton, Brian

2016-03-01

Medications aimed at inhibiting the renin-angiotensin system (RAS) have been used extensively for preventing cardiovascular and renal complications in patients with diabetes, but data that compare their clinical effectiveness are limited. We aimed to compare the effects of classes of RAS blockers on cardiovascular and renal outcomes in adults with diabetes. Eligible trials were identified by electronic searches in PubMed/MEDLINE and the Cochrane Database of Systematic Reviews (1 January 2004 to 17 July 2014). Interventions of interest were angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and direct renin (DR) inhibitors. The primary endpoints were cardiovascular mortality, myocardial infarction, and stroke-singly and as a composite endpoint, major cardiovascular outcome-and end-stage renal disease [ESRD], doubling of serum creatinine, and all-cause mortality-singly and as a composite endpoint, progression of renal disease. Secondary endpoints were angina pectoris and hospitalization for heart failure. In all, 71 trials (103,120 participants), with a total of 14 different regimens, were pooled using network meta-analyses. When compared with ACE inhibitor, no other RAS blocker used in monotherapy and/or combination was associated with a significant reduction in major cardiovascular outcomes: ARB (odds ratio [OR] 1.02; 95% credible interval [CrI] 0.90-1.18), ACE inhibitor plus ARB (0.97; 95% CrI 0.79-1.19), DR inhibitor plus ACE inhibitor (1.32; 95% CrI 0.96-1.81), and DR inhibitor plus ARB (1.00; 95% CrI 0.73-1.38). For the risk of progression of renal disease, no significant differences were detected between ACE inhibitor and each of the remaining therapies: ARB (OR 1.10; 95% CrI 0.90-1.40), ACE inhibitor plus ARB (0.97; 95% CrI 0.72-1.29), DR inhibitor plus ACE inhibitor (0.99; 95% CrI 0.65-1.57), and DR inhibitor plus ARB (1.18; 95% CrI 0.78-1.84). No significant differences were showed between ACE inhibitors and ARBs with

Cardiovascular and Renal Outcomes of Renin-Angiotensin System Blockade in Adult Patients with Diabetes Mellitus: A Systematic Review with Network Meta-Analyses.

Directory of Open Access Journals (Sweden)

Ferrán Catalá-López

2016-03-01

Full Text Available Medications aimed at inhibiting the renin-angiotensin system (RAS have been used extensively for preventing cardiovascular and renal complications in patients with diabetes, but data that compare their clinical effectiveness are limited. We aimed to compare the effects of classes of RAS blockers on cardiovascular and renal outcomes in adults with diabetes.Eligible trials were identified by electronic searches in PubMed/MEDLINE and the Cochrane Database of Systematic Reviews (1 January 2004 to 17 July 2014. Interventions of interest were angiotensin-converting enzyme (ACE inhibitors, angiotensin receptor blockers (ARBs, and direct renin (DR inhibitors. The primary endpoints were cardiovascular mortality, myocardial infarction, and stroke-singly and as a composite endpoint, major cardiovascular outcome-and end-stage renal disease [ESRD], doubling of serum creatinine, and all-cause mortality-singly and as a composite endpoint, progression of renal disease. Secondary endpoints were angina pectoris and hospitalization for heart failure. In all, 71 trials (103,120 participants, with a total of 14 different regimens, were pooled using network meta-analyses. When compared with ACE inhibitor, no other RAS blocker used in monotherapy and/or combination was associated with a significant reduction in major cardiovascular outcomes: ARB (odds ratio [OR] 1.02; 95% credible interval [CrI] 0.90-1.18, ACE inhibitor plus ARB (0.97; 95% CrI 0.79-1.19, DR inhibitor plus ACE inhibitor (1.32; 95% CrI 0.96-1.81, and DR inhibitor plus ARB (1.00; 95% CrI 0.73-1.38. For the risk of progression of renal disease, no significant differences were detected between ACE inhibitor and each of the remaining therapies: ARB (OR 1.10; 95% CrI 0.90-1.40, ACE inhibitor plus ARB (0.97; 95% CrI 0.72-1.29, DR inhibitor plus ACE inhibitor (0.99; 95% CrI 0.65-1.57, and DR inhibitor plus ARB (1.18; 95% CrI 0.78-1.84. No significant differences were showed between ACE inhibitors and ARBs with

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

Science.gov (United States)

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

2013-10-01

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

The Protective Arm of the Renin Angiotensin System (RAS)

DEFF Research Database (Denmark)

understanding of the protective side of the Renin Angiotensin System (RAS) involving angiotensin AT2 receptor, ACE2, and Ang(1-7)/Mas receptor Combines the knowledge of editors who pioneered research on the protective renin angiotensin system including; Dr. Thomas Unger, one of the founders of AT2 receptor......The Protective Arm of the Renin Angiotensin System: Functional Aspects and Therapeutic Implications is the first comprehensive publication to signal the protective role of a distinct part of the renin-angiotensin system (RAS), providing readers with early insight into a complex system which...... will become of major medical importance in the near future. Focusing on recent research, The Protective Arm of the Renin Angiotensin System presents a host of new experimental studies on specific components of the RAS, namely angiotensin AT2 receptors (AT2R), the angiotensin (1-7) peptide with its receptor...

KATP channels are not essential for pressure-dependent control of renin secretion

DEFF Research Database (Denmark)

Jensen, B L; Gambaryan, S; Scholz, H

1998-01-01

(IPRK). Cromakalim (0.1-10 muM) stimulated basal renin secretion up to threefold and caused vasorelaxation in the IPRK. Both effects of cromakalim were attenuated by glibenclamide. Cromakalim stimulated renin secretion from isolated juxtaglomerular (JG) cells and from microdissected afferent arterioles......This study aimed to investigate the functional role of ATP-sensitive K+ (KATP) channels in the control of renin secretion by renal perfusion pressure. We studied the effect of openers and blockers of KATP-channels on basal- and low-pressure-induced renin secretion from isolated perfused rat kidneys......, all of which suggests that KATP channel openers stimulate renin secretion at the level of JG cells. A decrease in the perfusion pressure from 13.3 to 9.33 kPa (100 mmHg to 70 mmHg) increased renin secretion twofold, and cromakalim further increased renin secretion. At 5.33 kPa (40 mmHg) renin...

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

Science.gov (United States)

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

1979-01-01

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

Regulation of renin secretion by renal juxtaglomerular cells

DEFF Research Database (Denmark)

Friis, Ulla G; Madsen, Kirsten; Stubbe, Jane

2013-01-01

A major rate-limiting step in the renin-angiotensin-aldosterone system is the release of active renin from endocrine cells (juxtaglomerular (JG) cells) in the media layer of the afferent glomerular arterioles. The number and distribution of JG cells vary with age and the physiological level...

Giant renin secretory granules in beige mouse renal afferent arterioles

DEFF Research Database (Denmark)

Jensen, B L; Rasch, Ruth; Nyengaard, Jens Randel

1997-01-01

The mutant beige mouse (C57BL/6 bg) has a disease characterised by abnormally enlarged cytoplasmic granules in a variety of cells. With the purpose of establishing a suitable cellular model for studying renin secretion, the present study was undertaken to compare renin granule morphology in beige...... (average granular volume 0.681 microm3), whereas 1-2 large granules were present per cell in beige mice. The volume of afferent arteriole that contained secretory granules was lower in the beige mice. We conclude that the beige mouse synthesizes, stores and releases active renin. Renin secretory granules...... in beige mice are grossly enlarged with 1-2 granules per juxtaglomerular cell. Compared with control mice, a similar amount of total renin granule volume per afferent arteriole is contained in a smaller part of beige mouse afferent arteriole. Granular cells from beige mice could therefore be a valuable...

Human renin biosynthesis and secretion in normal and ischemic kidneys

International Nuclear Information System (INIS)

Pratt, R.E.; Carleton, J.E.; Richie, J.P.; Heusser, C.; Dzau, V.J.

1987-01-01

The pathway of renin biosynthesis and secretion in normal and ischemic human kidneys has been investigated by pulse-labeling experiments. The results indicate that in normal human kidney, preprorenin is rapidly processed to 47-kDa prorenin. Microradiosequencing showed that this molecule was generated by cleavage between Gly-23 and Leu-24, yielding a 43-amino acid proregion. Analysis of prorenin secreted by the kidney tissue yielded an identical sequence, indicating that prorenin is secreted without any further proteolysis. An examination of the kinetics of processing and secretion suggested that a majority of the newly synthesized prorenin is quickly secreted, while only a small fraction is processed intracellularly to the mature renin. The differences in secretion kinetics between prorenin and mature renin and the selective inhibition of prorenin secretion by monensin suggest that they are secreted independently via two pathways: a constitutive pathway probably from the Golgi or protogranules that rapidly release prorenin and a regulated pathway that secretes mature renin from the mature granules. A comparison of the kinetics of processing between normal and ischemic tissues suggests that renal ischemia leads to an overall increase in the rate of processing or prorenin to mature renin. In addition, prolonged biosynthetic labeling of renin in the ischemic kidney yielded two smaller molecular weight immunoreactive forms suggestive of renin fragments that may be degradative products. These fragments were not detected in normal kidney tissue labeled for similar lengths of time

[Acute renal failure due to RAAS-inhibitors combined with dehydration].

NARCIS (Netherlands)

Scherpbier-de Haan, N.D.; Grauw, W.J.C. de; Wetzels, J.F.M.; Vervoort, G.M.M.

2010-01-01

Two men (61 and 81 years old) with mild impaired kidney function developed acute renal failure due to dehydration combined with the use of inhibitors of the renin-angiotensin-aldosterone system (RAAS). After rehydration, correction of hyperkalaemia and stopping RAAS-inhibition and diuretics, they

Expression and nutritional regulation of the (pro)renin receptor in rat visceral adipose tissue.

Science.gov (United States)

Achard, V; Tassistro, V; Boullu-Ciocca, S; Grino, M

2011-12-01

Early life nutritional environment plays an important role in the development of visceral adipose tissue and interacts with nutritional regulations in adulthood, leading to metabolic dysregulations. We hypothesized that the renin-angiotensin system may play a role in the programming-induced development of visceral adipose tissue. We studied, using a model of programming of overweight and glucose intolerance, obtained by post-natal overfeeding with consecutive highfat diet, the status of plasma renin activity and mesenteric adipose renin-angiotensin system, including the recently identified (pro)renin receptor, in adult rats. Post-natal overfeeding or high-fat feeding lead to overweight with increased visceral fat mass and adipocytes surface. When both paradigms were associated, adipocytes surface showed a disproportionate increase. A strong immunoreactivity for (pro)renin receptor was found in stromal cells. Plasma renin activity increased in programmed animals whereas (pro)renin receptor expressing cells density was stimulated by high-fat diet. There was a positive, linear relationship between plasma renin activity and (pro)renin receptor expressing cells density and adipocytes surface. Our experiments demonstrate that association of post-natal overfeeding and high-fat diet increased plasma renin activity and adipose (pro)renin receptor expression. Such phenomenon could explain, at least in part, the associated disproportionate adipocyte hypertrophy and its accompanying increased glucose intolerance.

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

DEFF Research Database (Denmark)

Aachmann-Andersen, Niels J.; Christensen, Soren J.; Lisbjerg, Kristian

2018-01-01

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...... 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....

Urinary Angiotensinogen and Renin Excretion are Associated with Chronic Kidney Disease

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Annett Juretzko

2017-04-01

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

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

Science.gov (United States)

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

2017-01-01

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

SGLT2 inhibitors: a novel choice for the combination therapy in diabetic kidney disease.

Science.gov (United States)

Zou, Honghong; Zhou, Baoqin; Xu, Gaosi

2017-05-16

Diabetic kidney disease (DKD) is the most common cause of end stage renal disease. The comprehensive management of DKD depends on combined target-therapies for hyperglycemia, hypertension, albuminuria, and hyperlipaemia, etc. Sodium-glucose co-transporter 2 (SGLT2) inhibitors, the most recently developed oral hypoglycemic agents acted on renal proximal tubules, suppress glucose reabsorption and increase urinary glucose excretion. Besides improvements in glycemic control, they presented excellent performances in direct renoprotective effects and the cardiovascular (CV) safety by decreasing albuminuria and the independent CV risk factors such as body weight and blood pressure, etc. Simultaneous use of SGLT-2 inhibitors and renin-angiotensin-aldosterone system (RAAS) blockers are novel strategies to slow the progression of DKD via reducing inflammatory and fibrotic markers induced by hyperglycaemia more than either drug alone. The available population and animal based studies have described SGLT2 inhibitors plus RAAS blockers. The present review was to systematically review the potential renal benefits of SGLT2 inhibitors combined with dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, mineralocorticoid receptor antagonists, and especially the angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Intracellular renin disrupts chemical communication between heart cells. Pathophysiological implications

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Walmor eDe Mello

2015-01-01

Full Text Available The influence of intracellular renin on the process of chemical communication between cardiac cells was investigated in cell pairs isolated from the left ventricle of adult Wistar Kyoto rats. The enzyme together with Lucifer yellow CH was dialyzed into one cell of the pair using the whole cell clamp technique. The diffusion of the dye in the dialyzed and in non-dialyzed cell was followed by measuring the intensity of fluorescence in both cells as a function of time. The results indicated that; 1 under normal conditions, Lucifer Yellow flows from cell-to-cell through gap junctions; 2 the intracellular dialysis of renin (100nM disrupts chemical communication-an effect enhanced by simultaneous administration of angiotensinogen (100nM; 3 enalaprilat (10-9M administered to the cytosol together with renin reduced drastically the uncoupling action of the enzyme; 4 aliskiren (10-8M inhibited the effect of renin on chemical communication;5 the possible role of intracellular renin independently of angiotensin II (Ang II was evaluated including the increase of the inward calcium current elicited by the enzyme and the possible role of oxidative stress on the disruption of cell communication; 6 the possible harmful versus the beneficial effect of intracellular renin during myocardial infarction was discussed;7 the present results indicate that intracellular renin due to internalization or in situ synthesis, causes a severe impairment of chemical communication in the heart resulting in derangement of metabolic cooperation with serious consequences for heart function.

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

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

2017-09-01

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

Radioimmunoassay of renin-angiotensin-aldosterone in patients with adrenal tumors

International Nuclear Information System (INIS)

Slavnov, V.N.; Yakovlev, A.A.; Yugrinov, O.G.; Gandzha, T.I.

1983-01-01

The results are presented of a study of the renin-angiotensin-aldosterone system in 89 patients with aldosteronoma, corticosteroma, pheochromocytoma and hypertension. Radioimmunoassay was used to measure aldosterone concentration and renin activity in the peripheral blood and blood from vena cava inferior, the renal and adrenal veins, the circadian cycle of their content and the responsiveness of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under the influence of lasix intake and the change over from a horizontal into vertical position. Patients with adrenal tumors have shown disorders of renin-angiotensin-aldosterone function. Radioimmunoassay of the renin-angiotensin-aldosterone system promotes early detection of adrenal tumors in the general population of patients with hypertension and can be used for control over therapeutic efficacy

Plasma Renin Activity in Diabetes Mellitus

International Nuclear Information System (INIS)

Pyo, Heui Jung; Park Jung Sik; Kim, Sung Kwon; Choi, Kang Won; Lee, Jung Sang; Lee, Mun Ho

1979-01-01

To evaluate the renin-angiotensin-aldosterone system in diabetes mellitus, basal plasma renin activity (PRA) and its response to intravenous furosemide were determined in 40 diabetic subjects. The diabetics were divided into 4 groups according to the presence of nephropathy and/or hypertension. Uncomplicated diabetics (Group I) were taken as control group and the results of the other groups were compared to this group. In diabetics with nephropathy alone (Group II), and with nephropathy and hypertension (Group III), basal PRA values were 0.63±0.59 ng/ml/hr., and 0.79±0.62 ng/ml/hr., respectively, both significantly lower than control group. (1.53±1.09 ng/ml/hr.). (p<0.05) In both of the above groups, the responses to intravenous furosemide tended to be blunted. On the other hand, in diabetics, with hypertension only (Group IV), the basal and stimulated PRA were not significantly different from control. Above results suggests that nephropathy may be one of the factors which suppress renin activity in diabetes mellitus

Plasma Renin Activity in Diabetes Mellitus

Energy Technology Data Exchange (ETDEWEB)

Pyo, Heui Jung; Sik, Park Jung; Kim, Sung Kwon; Choi, Kang Won; Lee, Jung Sang; Lee, Mun Ho [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1979-03-15

To evaluate the renin-angiotensin-aldosterone system in diabetes mellitus, basal plasma renin activity (PRA) and its response to intravenous furosemide were determined in 40 diabetic subjects. The diabetics were divided into 4 groups according to the presence of nephropathy and/or hypertension. Uncomplicated diabetics (Group I) were taken as control group and the results of the other groups were compared to this group. In diabetics with nephropathy alone (Group II), and with nephropathy and hypertension (Group III), basal PRA values were 0.63+-0.59 ng/ml/hr., and 0.79+-0.62 ng/ml/hr., respectively, both significantly lower than control group. (1.53+-1.09 ng/ml/hr.). (p<0.05) In both of the above groups, the responses to intravenous furosemide tended to be blunted. On the other hand, in diabetics, with hypertension only (Group IV), the basal and stimulated PRA were not significantly different from control. Above results suggests that nephropathy may be one of the factors which suppress renin activity in diabetes mellitus

Renin-sodium profile and renal prostaglandins in the pathogenesis ...

African Journals Online (AJOL)

the patients having normal-renin hypertension. At basal level the ... finding was in keeping with their low-renin hypertension. ... pathological factor in the development of hypertension in blacks. ... Subjects and methods .... zero sphygmomanometer. ..... Part 11. Biochemistry and endocrine. Hypertension 1990; 15(6): 681-685.

Effects of adenosine on renin release from isolated rat glomeruli and kidney slices

DEFF Research Database (Denmark)

Skøtt, O; Baumbach, L

1985-01-01

was used. The specificity of the renin release process was validated by measuring adenylate kinase as a marker for cytoplasmatic leak. Adenosine (10 micrograms/ml) halved basal renin release from incubated KS as compared to controls (P less than 0.001, n = 8, 8). Renin release from LAG stimulated...... by calcium depletion was also inhibited (P less than 0.05, n = 8, 9) whereas basal release was not affected (n = 6, 12). No effect was detected neither on basal nor on calcium stimulated renin release from SAG. We conclude that adenosine inhibits renin release in vitro by a mechanism independent...

Prediction of renovascualar hypertension by captopril-stimulated renal vein renin ratios

International Nuclear Information System (INIS)

Roubidoux, M.A.; Dunnick, N.R.; Svetkey, L.; Newmann, G.E.; Cohan, R.H.; Kadir, S.; Klotman, P.

1989-01-01

The authors have prospectively studied 114 patients with suspected renovascular hypertension to determine whether captopril-stimulated, selective, renal vein renin ratios could be used to predict renovascular hypertension. As judged by the response to correction of renal artery lesions, 14 patients had renovascular hypertension, and renal vein renin ratios were significant in eight (sensitivity 57%). Overall, the positive predictive value of renal vein renin ratios was 33%, and the negative predictive value was 89%. The authors concluded that, in patients with renal artery stenosis, renal vein renin ratios predict neither the need for conventional arteriography nor potential benefit from the correction of vascular insufficiency

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

Science.gov (United States)

Haber, E.

1975-01-01

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

Renin-Angiotensin System Blockade Associated with Statin Improves Endothelial Function in Diabetics

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Ronaldo Altenburg Gismondi

2015-01-01

Full Text Available AbstractBackground:Studies suggest that statins have pleiotropic effects, such as reduction in blood pressure, and improvement in endothelial function and vascular stiffness.Objective:To analyze if prior statin use influences the effect of renin-angiotensin-aldosterone system inhibitors on blood pressure, endothelial function, and vascular stiffness.Methods:Patients with diabetes and hypertension with office systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 80 mmHg had their antihypertensive medications replaced by amlodipine during 6 weeks. They were then randomized to either benazepril or losartan for 12 additional weeks while continuing on amlodipine. Blood pressure (assessed with ambulatory blood pressure monitoring, endothelial function (brachial artery flow-mediated dilation, and vascular stiffness (pulse wave velocity were evaluated before and after the combined treatment. In this study, a post hoc analysis was performed to compare patients who were or were not on statins (SU and NSU groups, respectively.Results:The SU group presented a greater reduction in the 24-hour systolic blood pressure (from 134 to 122 mmHg, p = 0.007, and in the brachial artery flow-mediated dilation (from 6.5 to 10.9%, p = 0.003 when compared with the NSU group (from 137 to 128 mmHg, p = 0.362, and from 7.5 to 8.3%, p = 0.820. There was no statistically significant difference in pulse wave velocity (SU group: from 9.95 to 9.90 m/s, p = 0.650; NSU group: from 10.65 to 11.05 m/s, p = 0.586.Conclusion:Combined use of statins, amlodipine, and renin-angiotensin-aldosterone system inhibitors improves the antihypertensive response and endothelial function in patients with hypertension and diabetes.

Therapeutic vaccines against human and rat renin in spontaneously hypertensive rats.

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Zhihua Qiu

Full Text Available Vaccination provides a promising approach for treatment of hypertension and improvement in compliance. As the initiation factor of renin-angiotensin system, renin plays a critical role in hypertension. In this study, we selected six peptides (rR32, rR72, rR215, hR32, hR72, and hR215 belonging to potential epitopes of rat and human renin. The main criteria were as follows: (1 include one of renin catalytic sites or the flap sequence; (2 low/no-similarity when matched with the host proteome; (3 ideal antigenicity and hydrophilicity. The peptides were coupled to keyhole limpet hemocyanin and injected into SpragueDawley (SD rats, spontaneously hypertensive rats (SHRs and Wistar-Kyoto rats. The antisera titers and the binding capacity with renin were detected. The effects of the anti-peptides antibodies on plasma renin activity (PRA and blood pressure were also determined. All peptides elicited strong antibody responses. The antisera titers ranged from 1:32,000 to 1:80,000 in SD rats on day 63. All antisera could bind to renin in vitro. Compared with the control antibody, the antibodies against the rR32, hR32, rR72 and hR72 peptides inhibited PRA level by up to about 50%. Complete cross-reactivity of the anti-rR32 antibody and the anti-hR32 antibody was confirmed. The epitopes rR32 and hR32 vaccines significantly decreased systolic blood pressure (SBP of SHRs up to 15mmHg (175±2 vesus 190±3 mmHg, P = 0.035; 180±2 vesus 195±3 mmHg, P = 0.039, while no obvious effect on SD rats. Additionally, no significant immune-mediated damage was detected in the vaccinated animals. In conclusion, the antigenic peptide hR32 vaccine mimicking the (32Asp catalytic site of human renin may constitute a novel tool for the development of a renin vaccine.

Plasma Renin Activity in Children with Protein Energy Malnutrition ...

African Journals Online (AJOL)

Plasma renin activity was measured by bio-assay in 100 children with kwashiorkor and in 20 healthy children, and also by radio-immunoassay in another 26 children with kwashiorkor and in another 20 healthy children. Both methods showed that (compared with healthy children) renin activity was significantly increased in ...

Renin release from isolated juxtaglomerular apparatus depends on macula densa chloride transport

DEFF Research Database (Denmark)

Lorenz, J N; Weihprecht, H; Schnermann, J

1991-01-01

salts to inhibit renin secretion, starting from a stimulated value produced by low-NaCl perfusion. Perfusion with a high-NaCl solution decreased renin secretion from 58.9 to 14.8 nGU/min, which served as a positive control. Addition of choline chloride decreased renin secretion from 42.7 to 16.6 n...

Characterization of renin mRNA expression and enzyme activity in rat and mouse mesangial cells

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Andrade A.Q.

2002-01-01

Full Text Available Renin is an enzyme involved in the stepwise generation of angiotensin II. Juxtaglomerular cells are the main source of plasma renin, but renin activity has been detected in other cell types. In the present study we evaluated the presence of renin mRNA in adult male Wistar rat and mouse (C-57 Black/6 mesangial cells (MC and their ability to process, store and release both the active and inactive forms of the enzyme. Active renin and total renin content obtained after trypsin treatment were estimated by angiotensinogen consumption analyzed by SDS-PAGE electrophoresis and quantified by angiotensin I generation by HPLC. Renin mRNA, detected by RT-PCR, was present in both rat and mouse MC under basal conditions. Active renin was significantly higher (P<0.05 in the cell lysate (43.5 ± 5.7 ng h-1 10(6 cells than in the culture medium (12.5 ± 2.5 ng h-1 10(6 cells. Inactive prorenin content was similar for the intra- and extracellular compartments (9.7 ± 3.1 and 3.9 ± 0.9 ng h-1 10(6 cells. Free active renin was the predominant form found in both cell compartments. These results indicate that MC in culture are able to synthesize and translate renin mRNA probably as inactive prorenin which is mostly processed to active renin inside the cell. MC secrete both forms of the enzyme but at a lower level compared with intracellular content, suggesting that the main role of renin synthesized by MC may be the intracellular generation of angiotensin II.

Aliskiren inhibits atherosclerosis development and improves plaque stability in APOE*3Leiden.CETP transgenic mice with or without treatment with atorvastatin

NARCIS (Netherlands)

Kühnast, S.; Hoorn, J.W.A. van der; Hoek, A.M. van den; Havekes, L.M.; Liau, G.; Jukema, J.W.; Princen, H.M.G.

2012-01-01

Objective: Aliskiren is the first commercially available, orally active, direct renin inhibitor approved to treat hypertension. The renin-angiotensin system has been shown to be a significant contributor to the development of hypercholesterolemia-induced atherosclerosis. The aim of this study was to

Stimulatory effects of neuronally released norepinephrine on renin release in vitro

Energy Technology Data Exchange (ETDEWEB)

Matsumura, Yasuo; Kawazoe, Shinka; Ichihara, Toshio; Shinyama, Hiroshi; Kageyama, Masaaki; Morimoto, Shiro (Osaka Univ. of Pharmaceutical Sciences (Japan))

1988-10-01

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

The renin-angiotensin-aldosterone system (RAAS – physiology and molecular mechanisms of functioning

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Monika Chaszczewska-Markowska

2016-09-01

Full Text Available Secretion of renin juxtaglomerular cells into bloodstream initiates activation of an enzymatic-hormonal cascade known as the RAAS (renin – angiotensin – aldosterone system. As a result, blood pressure is increased by the means several interrelated mechanisms. Mechanism of Zjednoczoaction of this system has been known for decades, but a few previously unknown components were recently added, such as ACE-2 and Ang(1-7, and their role often seems to be opposite to that of the conventional components. Local tissue systems also have important biological functions. They operate largely independently of the systemic activity, and their activity is observed primarily in the kidney, heart, in blood vessels, adrenal gland and nervous system. Angiotensin-2 (Ang-2, the main RAAS effector, has a wide scope of action, and thus abnormalities in its functioning have many consequences. Excessive activation is accompanied by chronic inflammation, as Ang-2 stimulates inflammatory mediators. As a result, degenerative processes and atherosclerosis are initiated. RAAS imbalance is associated with the most common diseases of civilization, such as cardio-vascular diseases, diabetes, kidney diseases, preeclampsia, osteoporosis and even neurodegenerative diseases. Many of these pathological processes are attributed to the excessive activation of tissue RA system. Therapeutic strategies based on inhibition of the RAAS are commonly used mainly in the treatment of hypertension and other cardiovascular disorders. The benefits of this class of drugs is primarily a decrease in blood pressure, but also the suppression of inflammatory processes and other pathological phenomena resulting from excessive activation of the RAAS. For that reason, some consider to use RAAS inhibitors in other diseases, e.g. Parkinson’s disease. Further studies give hope for the improvement of RAAS inhibitor therapy and the development of new therapeutic strategies

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

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Indu Dhar

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

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

Science.gov (United States)

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

2013-01-01

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

Does the aldosterone: renin ratio predict the efficacy of spironolactone over bendroflumethiazide in hypertension? A clinical trial protocol for RENALDO (RENin-ALDOsterone study

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McInnes Gordon T

2007-05-01

Full Text Available Abstract Background High blood pressure is an important determinant of cardiovascular disease risk. Treated hypertensives do not attain a risk level equivalent to normotensives. This may be a consequence of suboptimal blood pressure control to which indiscriminate use of antihypertensive drugs may contribute. Indeed the recent ALLHAT1study suggests that thiazides should be given first to virtually all hypertensives. Whether this is correct or whether different antihypertensive therapies should be targeted towards different patients is a major unresolved issue, which we address in this study. The measurement of the ratio of aldosterone: renin is used to identify hypertensive subjects who may respond well to treatment with the aldosterone antagonist spironolactone. It is not known if subjects with a high ratio have aldosteronism or aldosterone-sensitive hypertension is debated but it is important to know whether spironolactone is superior to other diuretics such as bendroflumethiazide in this setting. Methods/design The study is a double-blind, randomised, crossover, controlled trial that will randomise 120 hypertensive subjects to 12 weeks treatment with spironolactone 50 mg once daily and 12 weeks treatment with bendroflumethiazide 2.5 mg once daily. The 2 treatment periods are separated by a 2-week washout period. Randomisation is stratified by aldosterone: renin ratio to include equal numbers of subjects with high and low aldosterone: renin ratios. Primary Objective – To test the hypothesis that the aldosterone: renin ratio predicts the antihypertensive response to spironolactone, specifically that the effect of spironolactone 50 mg is greater than that of bendroflumethiazide 2.5 mg in hypertensive subjects with high aldosterone: renin ratios. Secondary Objectives – To determine whether bendroflumethiazide induces adverse metabolic abnormalities, especially in subjects with high aldosterone: renin ratios and if baseline renin measurement

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

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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.

Effect of hypothermic renal ischaemia on renin secretion rate in man

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl; Petersen, H K; Giese, J

1985-01-01

Plasma renin concentration (PRC), renal blood flow (RBF) and renin secretion rate (RSR = renal veno-arterial PRC difference multiplied by renal plasma flow) were measured before and after a period of hypothermic renal ischaemia in seven patients undergoing surgery for renal calculi. After...

Role of the inhibitors of angiotensin renin system on the DNA integrity of irradiated spermatozoids; Papel dos inibidores dos sistema renina angiotensina sobre a integridade do DNA de espermatozoides irradiados

Energy Technology Data Exchange (ETDEWEB)

Spadella, Maria A.; Mansano, Naira S.; Schwarz, Franciele C.; Viani, Gustavo A.; Chies, Agnaldo B. [Faculdade de Medicina de Marilia (FAMEMA), Marilia, SP (Brazil)

2016-07-01

Radiation action in the testes can significantly affect the reproductive capacity due to oxidative stress generated; phenomenon in which there is evidence of involvement of the Renin Angiotensin System (RAS). This study evaluated the role of AT1 receptor inhibitors, in mitigating the radioinduced DNA damage sperm from semen samples left vas deferens. Male Wistar rats were divided into six experimental groups: Control, 5Gy, Telmisartan (12mg/kg/day) and Losartan (34mg/kg/2x/day), 5 Gy + Telmisartan and 5 Gy + Losartan. The results showed increase in the percentage of sperm with fragmented DNA in irradiated groups when compared to controls, which was not reversed in the irradiated and treated groups. The radiation of 5Gy (single dose) affected the DNA-protein complex of the sperm and the treatments did not influence in reversing this damage, considering the experimental protocol used. (author)

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

1995-01-01

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

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

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

1997-08-01

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

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

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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.

The Renal Renin-Angiotensin System

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Harrison-Bernard, Lisa M.

2009-01-01

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

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

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

2015-06-01

Changes in the renin-angiotensin system (RAS), known for its critical role in the regulation of blood pressure and sodium homeostasis, may contribute to aging and age-related diseases. Here we characterized the RAS and kidney pathology in mice with genomic instability due to a defective nucleotide excision repair gene (Ercc1d/- mice). These mice display premature features of aging, including vascular dysfunction. Studies were performed in male and female Ercc1d/- mice and their wild type controls (Ercc1+/+) at the age of 12 or 18 weeks before and after treatment with losartan. The renin-activatable near-infrared fluorescent probe ReninSense 680™ was applied in vivo to allow non-invasive imaging of renin activity. Plasma renin concentrations (PRC) were additionally measured ex vivo by quantifying Ang I generation in the presence of excess angiotensinogen. Kidneys were harvested and examined for markers of aging, and albumin was determined in urine. Kidneys of 12-week old Ercc1d/- mice showed signs of aging, including tubular anisokaryosis, cell-senescence and increased apoptosis. This was even more pronounced at the age of 18 weeks. Yet, urinary albumin was normal at 12 weeks. The ReninSense 680™ probe showed increased intrarenal renin activity in Ercc1d/- mice versus Ercc1+/+ mice, both at 12 and 18 weeks of age, while PRC in these mice tended to be lower compared to Ercc1+/+ mice. Renin was higher in male than female mice, both in the kidney and in plasma, and losartan increased kidney and plasma renin in both Ercc1d/- and Ercc1+/+ mice. Rapidly aging Ercc1d/- mice display an activated intrarenal RAS, as evidenced by the increased fluorescence detected with the ReninSense 680™ probe. This increased RAS activity may contribute to the disturbed kidney pathology in these mice. The increased intrarenal activity detected with the ReninSense 680™ probe in male vs. female mice, as well as after losartan treatment, are in full agreement with the literature, and

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

Science.gov (United States)

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

2010-01-01

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

Effect of Diuresis on Plasma Renin Activity and Aldosterone Concentration in Normal and Toxemic Pregnancy

Energy Technology Data Exchange (ETDEWEB)

Sung, H. K.; Lee, H. S.; Cho, S. S.; Koh, J. H.; Lee, J. K.; Kim, H. S. [Korea Atomic Emergy Research Institute, Seoul (Korea, Republic of)

1973-03-15

The changes of plasma renin activity, aldosterone concentration, serum sodium, and potassium levels were studied before and after the water loading followed by diuretics injection. The materials were: 13 non-, 11 normal-, and 11 toxemic pregnancy cases. The plasma renin activity and aldosterone concentration of the cord and postpartum blood were also measured. Following were the results: 1. The plasma renin activity was elevated significantly in normal pregnancy, and slightly in toxemic pregnancy. The serum sodium levels were decreased in pregnancy. 2. The plasma aldosterone concentration was slightly decreased in normal pregnancy, and slightly increased in toxemic pregnancy, however, statistically insignificant. 3. The plasma renin activity of the cord and postpartum blood were lower than those of pregnancy cases. 4. The changes of plasma renin activity after the diuretic administration showed an initial increase, which recovered within 2 hours. These changes were the least in normal pregnancy, and the most in toxemic pregnancy. 5. The changes of plasma aldosterone concentration after the diuretic administration were similar to those of plasma renin activity, although the variations were not so wide.

Effect of Diuresis on Plasma Renin Activity and Aldosterone Concentration in Normal and Toxemic Pregnancy

International Nuclear Information System (INIS)

Sung, H. K.; Lee, H. S.; Cho, S. S.; Koh, J. H.; Lee, J. K.; Kim, H. S.

1973-01-01

The changes of plasma renin activity, aldosterone concentration, serum sodium, and potassium levels were studied before and after the water loading followed by diuretics injection. The materials were: 13 non-, 11 normal-, and 11 toxemic pregnancy cases. The plasma renin activity and aldosterone concentration of the cord and postpartum blood were also measured. Following were the results: 1. The plasma renin activity was elevated significantly in normal pregnancy, and slightly in toxemic pregnancy. The serum sodium levels were decreased in pregnancy. 2. The plasma aldosterone concentration was slightly decreased in normal pregnancy, and slightly increased in toxemic pregnancy, however, statistically insignificant. 3. The plasma renin activity of the cord and postpartum blood were lower than those of pregnancy cases. 4. The changes of plasma renin activity after the diuretic administration showed an initial increase, which recovered within 2 hours. These changes were the least in normal pregnancy, and the most in toxemic pregnancy. 5. The changes of plasma aldosterone concentration after the diuretic administration were similar to those of plasma renin activity, although the variations were not so wide.

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

Science.gov (United States)

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

2016-06-01

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

Renal graft failure after addition of an angiotensin II receptor antagonist to an angiotensin-converting enzyme inhibitor

DEFF Research Database (Denmark)

Kamper, Anne-Lise; Nielsen, Arne Høj; Baekgaard, Niels

2002-01-01

Combined treatment with an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II (Ang II) receptor blocker (ARB) has been suggested in order to achieve a more complete blockade of the renin-angiotensin-aldosterone system in cardiovascular and renal disease. The present report descri...

Brain renin angiotensin system in cardiac hypertrophy and failure

Directory of Open Access Journals (Sweden)

Luciana eCampos

2012-01-01

Full Text Available Brain renin-angiotensin system (RAS is significantly involved in the roles of the endocrine RAS in cardiovascular regulation. Our studies indicate that the brain RAS participates in the development of cardiac hypertrophy and fibrosis through sympathetic activation. Inhibition of sympathetic hyperactivity after myocardial infarction through suppression of the brain RAS appears beneficial. The brain RAS is involved in the modulation of circadian rhythms of arterial pressure, contributing to nondipping hypertension. We conclude that the brain RAS in pathophysiological states interacts synergistically with the chronically overactive RAS through a positive biofeedback in order to maintain a state of alert diseased conditions, such as cardiac hypertrophy and failure. Therefore, targeting brain RAS with drugs such as angiotensin converting inhibitors or receptor blockers having increased brain penetrability could be of advantage. These RAS-targeting drugs are first-line therapy for all heart failure patients. Since the RAS has both endocrine and local tissue components, RAS drugs are being developed to attain increased tissue penetrability and volume of distribution and consequently an efficient inhibition of both RAS components.

SGLT2 Inhibitors and the Diabetic Kidney.

Science.gov (United States)

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

2016-08-01

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

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

Science.gov (United States)

Kralberg, B E; Tolagen, K

1976-05-31

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

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

Science.gov (United States)

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

2016-07-01

The discovery of a receptor that binds prorenin and renin in human endothelial and mesangial cells highlights the possible effect of renin-independent prorenin in the resumption of meiosis in oocytes that was postulated in the 1980s.This study aimed to identify the (pro)renin receptor in the ovary and to assess the effect of prorenin on meiotic resumption. The (pro)renin receptor protein was detected in bovine cumulus-oocyte complexes, theca cells, granulosa cells, and in the corpus luteum. Abundant (pro)renin receptor messenger ribonucleic acid (mRNA) was detected in the oocytes and cumulus cells, while prorenin mRNA was identified in the cumulus cells only. Prorenin at concentrations of 10(-10), 10(-9), and 10(-8)M incubated with oocytes co-cultured with follicular hemisections for 15h caused the resumption of oocyte meiosis. Aliskiren, which inhibits free renin and receptor-bound renin/prorenin, at concentrations of 10(-7), 10(-5), and 10(-3)M blocked this effect (Pmeiosis resumption, cumulus-oocyte complexes and follicular hemisections were treated with prorenin and with angiotensin II or saralasin (angiotensin II antagonist). Prorenin induced the resumption of meiosis independently of angiotensin II. Furthermore, cumulus-oocyte complexes cultured with forskolin (200μM) and treated with prorenin and aliskiren did not exhibit a prorenin-induced resumption of meiosis (Pmeiosis in cattle. Copyright © 2016 Elsevier Inc. All rights reserved.

MboI RFLP at the human renin (ren) gene locus

Energy Technology Data Exchange (ETDEWEB)

Masharani, U; Frossard, P M

1988-03-25

1.5kb full length human renin cDNA was isolated from a human kidney cDNA library and subcloned into pUC9. MboI (GATC) detects a single two allele polymorphism with fragments at either 1.4kb or 1.0kb. The frequency was studied in 80 unrelated North American. The human renin gene was assigned to chromosome 1 by southern blot analysis of DNA from human-rodent somatic cell hybrids. Codominant segregation was observed in 1 family (7 individuals).

Effect of adenosine1-receptor blockade on renin release from rabbit isolated perfused juxtaglomerular apparatus

DEFF Research Database (Denmark)

Weihprecht, H; Lorenz, J N; Schnermann, J

1990-01-01

Adenosine has been proposed to act within the juxtaglomerular apparatus (JGA) as a mediator of the inhibition of renin secretion produced by a high NaCl concentration at the macula densa. To test this hypothesis, we studied the effects of the adenosine1 (A1)-receptor blocker 8-cyclopentyl-1......,3-dipropylxanthine (CPX) on renin release from single isolated rabbit JGAs with macula densa perfused. The A1-receptor agonist, N6-cyclohexyladenosine (CHA), applied in the bathing solution at 10(-7) M, was found to inhibit renin secretion, an effect that was completely blocked by adding CPX (10(-5) M) to the bath....... Applied to the lumen, 10(-5) M CPX produced a modest stimulation of renin secretion rates suppressed by a high NaCl concentration at the macula densa (P less than 0.05). The effect of changing luminal NaCl concentration on renin secretion rate was examined in the presence of CPX (10(-7) and 10(-5) M...

Characterization of the macula densa stimulus for renin secretion

DEFF Research Database (Denmark)

Lorenz, J N; Weihprecht, H; Schnermann, J

1990-01-01

These studies utilize the isolated perfused rabbit juxtaglomerular apparatus (JGA) to study the macula densa signal for renin secretion in the absence of the confounding influences of intravascular pressure and renal nerve activity. In the first experimental series, JGAs were perfused alternately...... and decreases in macula densa NaCl concentration, and these changes are rapid and largely reversible, 2) the full renin response occurs within the concentration range normally occurring at the macula densa, i.e., below 80 mM Na+ and 61 mM Cl-, and 3) RSR responds with a larger change to alterations in Na...

ENALAPRIL: PHARMACOKINETIC/DYNAMIC INFERENCES FOR COMPARATIVE DEVELOPMENTAL TOXICITY

Science.gov (United States)

Enalapril is an antihypertensive drug of the class of angiotensin-converting enzyme inhibitors (ACEI) used in pregnancy for treatment of pre-existing or pregnancy-induced hypertension. The use of ACE inhibitors (drugs that act directly on the renin-angiotensin system) during the ...

Effects of short-term addition of NSAID to diuretics and/or RAAS-inhibitors on blood pressure and renal function

NARCIS (Netherlands)

Nygard, Peder; Jansman, Frank G. A.; Kruik-Kolloffel, Willemien J.; Barnaart, Alex F. W.; Brouwers, Jacobus R. B. J.

Background The combined post-operative use of diuretics and/or renin-angiotensin-aldosterone system (RAAS) inhibitors may increase the risk of nonsteroidal anti-inflammatory drug (NSAID) associated renal failure because of a drug-drug interaction. Objective The aim of this study was to investigate

Acute kidney injury secondary to a combination of renin-angiotensin system inhibitors, diuretics and NSAIDS: "The Triple Whammy".

Science.gov (United States)

Camin, Rosa Maria Garcia; Cols, Montse; Chevarria, Julio Leonel; Osuna, Rosa García; Carreras, Marc; Lisbona, Josep Maria; Coderch, Jordi

2015-01-01

Renin-angiotensin system inhibitors (ACEI/ARB-II), diuretics and NSAIDs, a combination known as "Triple Whammy", can result in decreased glomerular filtration rate (GFR) and acute kidney injury (AKI). Objectives: To describe the incidence of AKI for each drug type and their combinations. To define the profile of patients admitted for drug-related AKI secondary to Triple Whammy drugs (AKITW), with an assessment of costs and mortality. A retrospective observational 15-month study developed in three stages: - First: a cross-sectional stage to identify and describe hospitalizations due to AKITW. - Second: a follow-up stage of an outpatient cohort consuming these drugs (15,307 subjects). - Third: a cohort stage to assess costs and mortality, which compared 62 hospitalized patients with AKITW and 62 without AKI, paired by medical specialty, sex, age and comorbidity according to their Clinical Risk Groups. There were 85 hospitalization episodes due to AKITW, and 78% of patients were over the age of 70. The incidence of AKITW in the population was 3.40 cases/1000 users/year (95% CI: 2.59-4.45). By categories, these were: NSAIDs + diuretics 8.99 (95% CI: 3.16-25.3); Triple Whammy 8.82 (95% CI: 4.4-17.3); ACEI/ARB-II + diuretics 6.87 (95% CI: 4.81-9.82); and monotherapy with diuretics 3.31 (95% CI: 1.39-7.85). Mean hospital stay was 7.6 days (SD 6.4), and mean avoidable costs were estimated at €214,604/100,000 inhabitants/year. Mortality during hospitalization and at 12 months was 11.3% and 38.7% respectively, and there were no significant differences when compared with the control group. Treatment with ACEI, ARB-II, diuretics and/or NSAIDs shows a high incidence of hospitalization episodes due to AKI; diuretics as monotherapy or dual and triple combination therapy cause the highest incidence. AKITW involves high health care costs and avoidable mortality. Copyright © 2015. Published by Elsevier España, S.L.U.

Molecular Mechanisms Underlying Renin-Angiotensin-Aldosterone System Mediated Regulation of BK Channels

Directory of Open Access Journals (Sweden)

Zhen-Ye Zhang

2017-09-01

Full Text Available Large-conductance calcium-activated potassium channels (BK channels belong to a family of Ca2+-sensitive voltage-dependent potassium channels and play a vital role in various physiological activities in the human body. The renin-angiotensin-aldosterone system is acknowledged as being vital in the body's hormone system and plays a fundamental role in the maintenance of water and electrolyte balance and blood pressure regulation. There is growing evidence that the renin-angiotensin-aldosterone system has profound influences on the expression and bioactivity of BK channels. In this review, we focus on the molecular mechanisms underlying the regulation of BK channels mediated by the renin-angiotensin-aldosterone system and its potential as a target for clinical drugs.

Calcium channel blocker prevents stress-induced activation of renin and aldosterone in conscious pig

International Nuclear Information System (INIS)

Ceremuzynski, L.K.; Klos, J.; Barcikowski, B.; Herbaczynska-Cedro, K.

1991-01-01

A considerable amount of data suggest the involvement of calcium-mediated processes in the activation of the renin-angiotensin-aldosterone (RAA) cascade. To investigate the effect of calcium-channel inhibition on the RAA system, the authors studied 21 conscious pigs. Blood renin and aldosterone levels increased by subjecting animals to 24 hours of immobilization stress. Renin and aldosterone levels were repeatedly measured by radioimmunoassay in blood samples taken periodically over 24 hours from a chronically implanted arterial cannula. Pretreatment of the animals (N = 11) with nisoldipine, 2 x 20 mg p.o. daily for 2 days before and on the day of immobilization, transiently attenuated the stress-induced increase of plasma renin activity and completely prevented the rise of aldosterone, as compared to nontreated controls (N = 10). The finding that nisoldipine suppresses RAA activation induced by a nonpharmacologic stimulus in the conscious intact animal may have clinical implications

Prevention of atrial fibrillation by Renin-Angiotensin system inhibition a meta-analysis

DEFF Research Database (Denmark)

Schneider, Markus; Hua, Tsushung A; Böhm, Michael

2010-01-01

The authors reviewed published clinical trial data on the effects of renin-angiotensin system (RAS) inhibition for the prevention of atrial fibrillation (AF), aiming to define when RAS inhibition is most effective.......The authors reviewed published clinical trial data on the effects of renin-angiotensin system (RAS) inhibition for the prevention of atrial fibrillation (AF), aiming to define when RAS inhibition is most effective....

Influence of antihypertensive therapy, sodium intake and the concentration of potassium in plasma on concentration of aldosterone and plasma renin activity

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Lalić Tijana

2013-01-01

Full Text Available Introduction: Primary aldosteronism (PA is a group of disorders which are characterized by inadequate and non-suppressible production of aldosterone. The prevalence of PA is increasing in hypertensive population. The golden standard of screening for primary aldosteronism, determination of aldosterone/plasma renin activity (ARR, is influenced by numerous exogenous and endogenous factors. Testing cannot always be conducted under optimal conditions. Objective: To determine influence of antihypertensive drugs and concentrations of potassium and sodium in blood and urine on values of aldosterone and plasma renin activity. Methods: In this retrospective study, we analyzed medical reports of patients admitted to Department of thyroid gland disease in the period from 2009 to 2011, with increased risk for primary aldosteronism. Body weight and height, sodium and potassium in serum and urine, plasma aldosterone concentrations and plasma renin activity, data on medicines and comorbidity were analyzed in all patients. In processing data, statistical methods descriptive analysis, Student T test and univariate linear regression were applied. Result: Of 137 patients, there were more patients with resistant hypertension (53,28% than with adrenal tumors (46,72%. Most patients used calcium channel blockers. Treatment with alpha blockers and calcium channel blockers does not influence ARR. Beta blockers and ACE inhibitors can influence ARR and diuretics and vasodilatators have definite influence. Diabetes mellitus can have higher risk of false negative results. Urine sodium excretion is significantly correlated with plasma aldosteron and serum potassium. Plasma aldosteron and PRA are significantly correlated with concentrations of electrolites in urine. Conclusion: Increased prevalence of primary aldosteronism necessitates need for accurate and better diagnostics.

Radioimmunologic analysis of the state of the renin-angiotensin-aldosterone-system in arterial hypertension

International Nuclear Information System (INIS)

Slavnov, V.N.; Yakovlev, A.A.; Gandzha, T.I.; Yugrinov, O.G.

1985-01-01

In 110 patients suffering from various forms of arterial hypertension (hypertension, aldosteronoma, phaeochromocytoma, corticosteroma) the parameters of the system renin-angiotensin-aldosterone were measured. Basal values of aldosterone, renin activity in blood as well as their concentration in blood taken from the vena cava inferior, renal and adrenal veins during selective renography were determined. The 24-hours rhythm of the hormones in the blood, the reaction of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under acute Lasix (furosemide) stress was evaluated. It was found, that the system renin-angiotensin-aldosterone is disturbed in all patients with arterial hypertension. This is indicated by changes of aldosterone concentration, renin activity in peripheral blood and in the blood from the vena cava inferior, renal and adrenal veins, the 24-hours rhythm of their concentrations in serum and the reaction to acute Lasix stress. The radioimmunoassays of quantitative parameters of the renin-angiotensin-aldosterone system are decisive for the differential diagnosis of hypertension and adrenal gland tumors connected with a hypertension syndrome. They facilitate a rational choice of the hypertension therapy and the daily distribution of the medicaments for patients with hypertension. The radioimmunoassays can be used for checking the efficiency of medicaments and surgery. (author)

Inhibition of calcineurin phosphatase promotes exocytosis of renin from juxtaglomerular cells

DEFF Research Database (Denmark)

Madsen, Kirsten; Friis, Ulla Glenert; Gooch, Jennifer L

2010-01-01

. Simultaneous exposure to EGTA and CsA had no additive effect. The protein kinase A (PKA) blocker RpcAMPs had no effect on the CsA-induced increase in membrane capacitance. Intra- and extracellular application of tacrolimus did not alter membrane capacitance. A calmodulin antagonist (calmidazolium) and Cs...... after CsA treatment of the A-alpha knockout, while renin mRNA was suppressed. We conclude that calcineurin and calcium/calmodulin suppress exocytosis of renin from juxtaglomerular cells independent of PKA....

Studies on renin stimulation in normal controls and in patients with essential hypertension

International Nuclear Information System (INIS)

Koh, C.S.; Choe, K.W.; Lee, H.K.; Lee, J.S.

1978-01-01

To find out a convenient and reliable method of detecting low renin status, we employed intravenous furosemine injection as a stimulatory maneuver. The results thus obtained were compared with those from the postural stimuli and basal plasma renin activity (PRA) in relation to sodium excretion. Intravenous furosemide test was performed in 66 control subjects and 44 patients with essential hypertension. The results were as follow; 1) Mean PRA in control subjects rose from 2.5+-1.95 ng/ml/hr (basal) to 4.5+-2.51, 5.2+-2.49 and 4.2+-2.44 ng/ml/hr at 1, 2 and 3hrs after IV injection. One-hour response is more convenient in clinical practice. 2) Postural stimuli by assuming an upright posture for 3hrs gave rise to considerable increase in PRA (4.0+-2.92 from 2.4+-1.85), but we found it less convenient than stimulation with furosemide. 3) The increase in PRA was much less marked in patients with essential hypertension as a whole (2.9+-2.75). Hyporesponsiveness to furosemide stimuli was found in 34.1%. Of these hyporesponders, a third had a normal basal PRA, indicating the need for this kind stimulatory procedure. 4) Younger age group showed greater renin responsiveness than older age group after furosemide stimuli. Likewise mean age of low renin patients (52.9+-5.38 years old) was significantly higher than that of high and normal renin patients (44.1+-13.78 years old). (author)

Studies on Renin Stimulation in Normal Controls and in Patients with Essential Hypertension

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Koh, Chang Soon; Choe, Kang Won; Lee, Hong Kyu; Lee, Jung Sang [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1978-03-15

To find out a convenient and reliable method of detecting low renin status, we employed intravenous furosemide injection as a stimulatory maneuver. The results thus obtained were compared with those from the postural stimuli and basal plasma renin activity (PRA) in relation to sodium excretion. Intravenous furosemide test was performed in 66 control subjects and 44 patients with essential hypertension. The results were as follow; 1) Mean PRA in control subjects rose from 2.5+-1.95 ng/ml/hr (basal) to 4.5+-2.51, 5.2+-2.49 and 4.2+-2.44 ng/ml/hr at 1, 2 and 3 hrs after IV injection. One-hour response is more convenient in clinical practice. 2) Postural stimuli by assuming an upright posture for 3 hrs gave rise to considerable increase in PRA (4.0+-2.92 from 2.4+-1.85), but we found it less convenient than stimulation with furosemide. 3) The increase in PRA was much less marked in patients with essential hypertension as a whole (2.9+-2.75). Hyporesponsiveness to furosemide stimuli was found in 34.1%. Of these hyporesponders, a third had a normal basal PRA, indicating the need for this kind stimulatory procedure. 4) Younger age group showed greater renin responsiveness than older age group after furosemide stimuli. Likewise mean age of low renin patients (52.9+-5.38 years old) was significantly higher than that of high and normal renin patients (44.1+-13.78 years old).

Studies on Renin Stimulation in Normal Controls and in Patients with Essential Hypertension

International Nuclear Information System (INIS)

Koh, Chang Soon; Choe, Kang Won; Lee, Hong Kyu; Lee, Jung Sang

1978-01-01

To find out a convenient and reliable method of detecting low renin status, we employed intravenous furosemide injection as a stimulatory maneuver. The results thus obtained were compared with those from the postural stimuli and basal plasma renin activity (PRA) in relation to sodium excretion. Intravenous furosemide test was performed in 66 control subjects and 44 patients with essential hypertension. The results were as follow; 1) Mean PRA in control subjects rose from 2.5±1.95 ng/ml/hr (basal) to 4.5±2.51, 5.2±2.49 and 4.2±2.44 ng/ml/hr at 1, 2 and 3 hrs after IV injection. One-hour response is more convenient in clinical practice. 2) Postural stimuli by assuming an upright posture for 3 hrs gave rise to considerable increase in PRA (4.0±2.92 from 2.4±1.85), but we found it less convenient than stimulation with furosemide. 3) The increase in PRA was much less marked in patients with essential hypertension as a whole (2.9±2.75). Hyporesponsiveness to furosemide stimuli was found in 34.1%. Of these hyporesponders, a third had a normal basal PRA, indicating the need for this kind stimulatory procedure. 4) Younger age group showed greater renin responsiveness than older age group after furosemide stimuli. Likewise mean age of low renin patients (52.9±5.38 years old) was significantly higher than that of high and normal renin patients (44.1±13.78 years old).

Hemodynamic, morphometric and autonomic patterns in hypertensive rats - renin-angiotensin system modulation

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Fernanda S. Zamo

2010-01-01

Full Text Available BACKGROUND: Spontaneously hypertensive rats develop left ventricular hypertrophy, increased blood pressure and blood pressure variability, which are important determinants of heart damage, like the activation of renin-angiotensin system. AIMS: To investigate the effects of the time-course of hypertension over 1 hemodynamic and autonomic patterns (blood pressure; blood pressure variability; heart rate; 2 left ventricular hypertrophy; and 3 local and systemic Renin-angiotensin system of the spontaneously hypertensive rats. METHODS: Male spontaneously hypertensive rats were randomized into two groups: young (n=13 and adult (n=12. Hemodynamic signals (blood pressure, heart rate, blood pressure variability (BPV and spectral analysis of the autonomic components of blood pressure were analyzed. LEFT ventricular hypertrophy was measured by the ratio of LV mass to body weight (mg/g, by myocyte diameter (μm and by relative fibrosis area (RFA, %. ACE and ACE2 activities were measured by fluorometry (UF/min, and plasma renin activity (PRA was assessed by a radioimmunoassay (ng/mL/h. Cardiac gene expressions of Agt, Ace and Ace2 were quantified by RT-PCR (AU. RESULTS: The time-course of hypertension in spontaneously hypertensive rats increased BPV and reduced the alpha index in adult spontaneously hypertensive rats. Adult rats showed increases in left ventricular hypertrophy and in RFA. Compared to young spontaneously hypertensive rats, adult spontaneously hypertensive rats had lower cardiac ACE and ACE2 activities, and high levels of PRA. No change was observed in gene expression of Renin-angiotensin system components. CONCLUSIONS: The observed autonomic dysfunction and modulation of Renin-angiotensin system activity are contributing factors to end-organ damage in hypertension and could be interacting. Our findings suggest that the management of hypertensive disease must start before blood pressure reaches the highest stable levels and the consequent

Effect of calcium channels blockers and inhibitors of the renin-angiotensin system on renal outcomes and mortality in patients suffering from chronic kidney disease: systematic review and meta-analysis.

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Zhao, Hong-Jin; Li, Yan; Liu, Shan-Mei; Sun, Xiang-Guo; Li, Min; Hao, Yan; Cui, Lian-Qun; Wang, Ai-Hong

2016-07-01

The renoprotective effect of inhibitors of renin-angiotensin system (RAS) has been identified through placebo-controlled trials. However, the effect of calcium-channel blockers (CCBs) on renal system is still controversial. Our current meta-analysis includes available evidences to compare the effect of dihydropyridine CCBs and ACEIs or ARBs on renal outcomes and mortality. We also further investigate whether CCBs can be used in combination with inhibitors of RAS to improve the prognosis of patients with chronic kidney disease (CKD). Electronic databases were searched up to July 2012, for clinical randomized controlled trials, assessing the effect of dihydropyridine CCBs on the incidence of end-stage renal disease (ESRD) and all-cause mortality in contrast to ACEIs or ARBs. Eight clinical trials were included containing 25,647 participants. ESRD showed significantly higher frequency with CCBs therapy compared with ACEIs or ARBs therapy, though blood pressure was decreased similarly in both groups in every trial (OR, 1.25; 95% CI, 1.05-1.48; p = 0.01). In contrast, there was no significant difference in the incidence of all-cause mortality between these two groups, though ACEIs or ARBs exhibited better renoprotective effect compared to CCBs (OR, 0.96; 95% CI, 0.89-1.03; p = 0.24). CCBs did not increase all-cause mortality incidence in patients with CKD though they displayed weaker renoprotective, compared to ACEIs or ARBs therapy. Our results suggest the combination of a CCB and an ACEI or ARB should be a preferable antihypertensive therapy in patients with CKD, considering their higher effect in decreasing blood pressure and fewer adverse metabolic problems caused.

Renin-angiotensin system inhibition ameliorates CCl4-induced liver fibrosis in mice through the inactivation of nuclear transcription factor kappa B.

Science.gov (United States)

Saber, Sameh; Mahmoud, Amr A A; Helal, Noha S; El-Ahwany, Eman; Abdelghany, Rasha H

2018-06-01

Therapeutic interventions for liver fibrosis are still limited due to the complicated molecular pathogenesis. Renin-angiotensin system (RAS) seems to contribute to the development of hepatic fibrosis. Therefore, we aimed to examine the effect of RAS inhibition on CCl 4 -induced liver fibrosis. Mice were treated with silymarin (30 mg·kg -1 ), perindopril (1 mg·kg -1 ), fosinopril (2 mg·kg -1 ), or losartan (10 mg·kg -1 ). The administration of RAS inhibitors improved liver histology and decreased protein expression of alpha smooth muscle actin (α-SMA) and hepatic content of hydroxyproline. These effects found to be mediated via inactivation of nuclear transcription factor kappa B (NFκB) pathway by the inhibition of NFκB p65 phosphorylation at the Ser536 residue and phosphorylation-induced degradation of nuclear factor kappa-B inhibitor alpha (NFκBia) subsequently inhibited NFκB-induced TNF-α and TGF-β1, leading to lower levels of tissue inhibitor of metalloproteinase-1 (TIMP-1) and vascular endothelial growth factor (VEGF). We concluded that the tissue affinity of the angiotensin converting enzyme inhibitors (ACEIs) has no impact on its antifibrotic activity and that interfering the RAS either through the inhibition of ACE or the blockade of AT1R has the same therapeutic benefit. These results suggest RAS inhibitors as promising candidates for further clinical trials in the management of hepatic fibrosis.

Atrial distension, haemodilution, and acute control of renin release during water immersion in humans

DEFF Research Database (Denmark)

Gabrielsen, A; Pump, B; Bie, P

2002-01-01

immersion. During WI, central venous pressure (CVP) and left atrial diameter (LAD) increased (P ... is not the single pivotal stimulus for the acute suppression of renin release in response to intravascular volume expansion by water immersion in humans. Haemodilution constitutes a significant and conceivably the principal stimulus for the acute immersion-induced suppression of renin-angiotensin system activity....

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

Science.gov (United States)

Ménard, J

1993-04-01

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

Renin-Angiotensin System Blockade Improves Cardiac Indices in Acromegaly Patients.

Science.gov (United States)

Thomas, Julia D J; Dattani, Abhishek; Zemrak, Filip; Burchell, Thomas; Akker, Scott A; Kaplan, Felicity J L; Khoo, Bernard; Aylwin, Simon; Grossman, Ashley B; Davies, L Ceri; Korbonits, Márta

2017-06-01

Blockade of the angiotensin-renin system, with angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs), has been shown to improve cardiac outcomes following myocardial infarction and delay progression of heart failure. Acromegaly is associated with a disease-specific cardiomyopathy, the pathogenesis of which is poorly understood.The cardiac indices of patients with active acromegaly with no hypertension (Group A, n=4), established hypertension not taking ACEi/ARBs (Group B, n=4) and established hypertension taking ACEi/ARBs (Group C, n=4) were compared using cardiac magnetic imaging.Patients taking ACEi/ARBs had lower end diastolic volume index (EDVi) and end systolic volume index (ESVi) than the other 2 groups ([C] 73.24 vs. [A] 97.92 vs. [B] 101.03 ml/m 2 , ANOVA p=0.034, B vs. C pAcromegaly patients on ACEi/ARBs for hypertension demonstrate improved cardiac indices compared to acromegaly patients with hypertension not taking these medications. Further studies are needed to determine if these drugs have a beneficial cardiac effect in acromegaly in the absence of demonstrable hypertension. © Georg Thieme Verlag KG Stuttgart · New York.

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

Science.gov (United States)

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.

Improved interpretation of renal-vein-renin-ratio by simultaneous determination of renal 131I-hippuric-acid-clearance-ratio in patients with renovascular hypertension

International Nuclear Information System (INIS)

Helber, A.; Boenner, G.; Hummerich, W.; Wambach, G.; Meurer, K.A.; Dvorak, K.; Lent, V.; Zehle, A.; Kaufmann, W.; Koeln Univ.; Staedtisches Krankenhaus Koeln-Merheim; Staedtisches Krankenhaus Koeln-Merheim; Koeln Univ.

1979-01-01

In patients with unilateral vascular kidney disease and hypertension, ratio of renal-vein-renin was compared with 131 I-Hippuric-acid clearance and change in blood pressure during Saralasininfusion. The ratio of renal-vein-renin was positively correlated with the ratio in renal plasma flow between the kidneys in all patients studied. The ratio of renins therefore is a result of two factors: The difference in renin secretion and the difference in blood flow in the two kidneys. In patients with angiotensin independent hypertension renin-ratios up to 2.0 were found without relevance to elevated blood pressure. When the difference in renal blood flow between both kidneys was small, even a slight difference in renal vein renin indicated hypertension related to increased renin secretion. (orig./AJ) [de

Osmotically sensitive renin release from permeabilized juxtaglomerular cells

DEFF Research Database (Denmark)

Jensen, B L; Skøtt, O

1993-01-01

Renin secretion from juxtaglomerular (JG) cells is sensitive to external osmolality in a way that has been suggested to depend either on cellular volume or on effects on secretory granules. To distinguish between these possibilities, a technique for permeabilization of JG cell membranes was devel...

Plasma renin activity in patients with ischaemic heart disease

International Nuclear Information System (INIS)

Urbanek, J.; Hofman, O.; Reisenauer, R.; Slaby, A.

1977-01-01

Plasma renin activity (PRA) stimulated by upright posture was measured in 300 men aged 45-64 years using a radioimmunoassay of angiotensin-I. The examined subjects were normotensive or patients with benign essential hypertension and were divided into 6 groups according to the absence of manifest atherosclerosis, the presence of definite angina pectoris or a history of myocardial infarction. Each group contained 50 unselected subjects, with a comparable mean age. Significant differences in mean PRA were found between corresponding groups of hypertensives and normotensives, the values in hypertensives being lower. The percentage of low renin values was higher in hypertensives with ischaemic heart disease than in other groups. It is suggested that this finding might be explained by functional disturbances in the kidneys in hypertensives with ischaemic heart disease. (orig.) [de

Plasma renin activity in patients with ischaemic heart disease

Energy Technology Data Exchange (ETDEWEB)

Urbanek, J; Hofman, O; Reisenauer, R; Slaby, A [Karlova Universita, Prague (Czechoslovakia). Inst. of Biophysics and Nuclear Medicine; Karlova Universita, Prague (Czechoslovakia). IV. Dept. of Internal Medicine; Vyzkumny Ustav Endokrinologicky, Prague [Czechoslovakia

1977-04-01

Plasma renin activity (PRA) stimulated by upright posture was measured in 300 men aged 45 to 64 years using a radioimmunoassay of angiotensin-I. The examined subjects were normotensive or patients with benign essential hypertension and were divided into 6 groups according to the absence of manifest atherosclerosis, the presence of definite angina pectoris or a history of myocardial infarction. Each group contained 50 unselected subjects, with a comparable mean age. Significant differences in mean PRA were found between corresponding groups of hypertensives and normotensives, the values in hypertensives being lower. The percentage of low renin values was higher in hypertensives with ischaemic heart disease than in other groups. It is suggested that this finding might be explained by functional disturbances in the kidneys in hypertensives with ischaemic heart disease.

Role of the renin-angiotensin system in hepatic fibrosis and portal hypertension.

Science.gov (United States)

Shim, Kwang Yong; Eom, Young Woo; Kim, Moon Young; Kang, Seong Hee; Baik, Soon Koo

2018-05-01

The renin-angiotensin system (RAS) is an important regulator of cirrhosis and portal hypertension. As hepatic fibrosis progresses, levels of the RAS components angiotensin (Ang) II, Ang-(1-7), angiotensin-converting enzyme (ACE), and Ang II type 1 receptor (AT1R) are increased. The primary effector Ang II regulates vasoconstriction, sodium homoeostasis, fibrosis, cell proliferation, and inflammation in various diseases, including liver cirrhosis, through the ACE/Ang II/AT1R axis in the classical RAS. The ACE2/Ang-(1-7)/Mas receptor and ACE2/Ang-(1-9)/AT2R axes make up the alternative RAS and promote vasodilation, antigrowth, proapoptotic, and anti-inflammatory effects; thus, countering the effects of the classical RAS axis to reduce hepatic fibrogenesis and portal hypertension. Patients with portal hypertension have been treated with RAS antagonists such as ACE inhibitors, Ang receptor blockers, and aldosterone antagonists, with very promising hemodynamic results. In this review, we examine the RAS, its roles in hepatic fibrosis and portal hypertension, and current therapeutic approaches based on the use of RAS antagonists in patients with portal hypertension.

Cardiorenal end points in a trial of aliskiren for type 2 diabetes

DEFF Research Database (Denmark)

Parving, Hans-Henrik; Brenner, Barry M; McMurray, John J V

2012-01-01

This study was undertaken to determine whether use of the direct renin inhibitor aliskiren would reduce cardiovascular and renal events in patients with type 2 diabetes and chronic kidney disease, cardiovascular disease, or both....

Effect of additive renin inhibition with aliskiren on renal blood flow in patients with Chronic Heart Failure and Renal Dysfunction (Additive Renin Inhibition with Aliskiren on renal blood flow and Neurohormonal Activation in patients with Chronic Heart Failure and Renal Dysfunction).

Science.gov (United States)

Schroten, Nicolas F; Damman, Kevin; Hemmelder, Marc H; Voors, Adriaan A; Navis, Gerjan; Gaillard, Carlo A J M; van Veldhuisen, Dirk J; Van Gilst, Wiek H; Hillege, Hans L

2015-05-01

We examined the effect of the renin inhibitor, aliskiren, on renal blood flow (RBF) in patients with heart failure with reduced ejection fraction (HFREF) and decreased glomerular filtration rate (GFR). Renal blood flow is the main determinant of GFR in HFREF patients. Both reduced GFR and RBF are associated with increased mortality. Aliskiren can provide additional renin-angiotensin-aldosterone system inhibition and increases RBF in healthy individuals. Patients with left ventricular ejection fraction ≤45% and estimated GFR 30 to 75 mL/min per 1.73 m(2) on optimal medical therapy were randomized 2:1 to receive aliskiren 300 mg once daily or placebo. Renal blood flow and GFR were measured using radioactive-labeled (125)I-iothalamate and (131)I-hippuran at baseline and 26 weeks. After 41 patients were included, the trial was halted based on an interim safety analysis showing futility. Mean age was 68 ± 9 years, 82% male, GFR (49 ± 16 mL/min per 1.73 m(2)), RBF (294 ± 77 mL/min per 1.73 m(2)), and NT-proBNP 999 (435-2040) pg/mL. There was a nonsignificant change in RBF after 26 weeks in the aliskiren group compared with placebo (-7.1 ± 30 vs +14 ± 54 mL/min per 1.73 m(2); P = .16). However, GFR decreased significantly in the aliskiren group compared with placebo (-2.8 ± 6.0 vs +4.4 ± 9.6 mL/min per 1.73 m(2); P = .01) as did filtration fraction (-2.2 ± 3.3 vs +1.1 ± 3.1%; P = .01). There were no significant differences in plasma aldosterone, NT-proBNP, urinary tubular markers, or adverse events. Plasma renin activity was markedly reduced in the aliskiren group versus placebo throughout the treatment phase (P = .007). Adding aliskiren on top of optimal HFREF medical therapy did not improve RBF and was associated with a reduction of GFR and filtration fraction. Copyright © 2015 Mosby, Inc. All rights reserved.

Capturing the dynamics of systemic Renin-Angiotensin-Aldosterone System (RAAS) peptides heightens the understanding of the effect of benazepril in dogs.

Science.gov (United States)

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.

Aliskiren and valsartan combination therapy for the management of hypertension

Directory of Open Access Journals (Sweden)

Benjamin J Epstein

2010-08-01

Full Text Available Benjamin J EpsteinDepartments of Pharmacotherapy and Translational Research and Medicine, Colleges of Pharmacy and Medicine, University of Florida, Gainesville, Florida, USA and East Coast Institute for Research, Jacksonville, Florida, USAAbstract: Combination therapy is necessary for most patients with hypertension, and agents that inhibit the renin-angiotensin-aldosterone system (RAAS are mainstays in hypertension management, especially for patients at high cardiovascular and renal risk. Single blockade of the RAAS with an angiotensin-converting enzyme (ACE inhibitor or angiotensin receptor blocker (ARB confers some cardiorenal protection; however, these agents do not extinguish the RAAS as evidenced by a reactive increase in plasma renin activity (PRA, a cardiovascular risk marker, and incomplete cardiorenal protection. Dual blockade with an ACE inhibitor and an ARB offers no additional benefit in patients with hypertension and normal renal and left ventricular function. Indeed, PRA increases synergistically with dual blockade. Aliskiren, the first direct renin inhibitor (DRI to become available has provided an opportunity to study the merit of DRI/ARB combination treatment. By blocking the first and rate-limiting step in the RAAS, aliskiren reduces PRA by at least 70% and buffers the compensatory increase in PRA observed with ACE inhibitors and ARBs. The combination of a DRI and an ARB or an ACE inhibitor is an effective approach for lowering blood pressure; available data indicate that such combinations favorably affect proteinuria, left ventricular mass index, and brain natriuretic peptide in patients with albuminuria, left ventricular hypertrophy, and heart failure, respectively. Ongoing outcome studies will clarify the role of aliskiren and aliskiren-based combination RAAS blockade in patients with hypertension and those at high cardiorenal risk.Keywords: aliskiren, valsartan, single-pill combination, hypertension, renin

Negative captopril renography on patients with renin mediated hypertension due to page kidney and reninoma

International Nuclear Information System (INIS)

Yung, B.C.K.; Wong, K.W.; Fan, W.C.; Chan, J.C.S.; Lo, S.S.S.

1999-01-01

Through a mechanism similar to renal artery stenosis, patients with reninoma and page kidney also suffered from renin mediated hypertension. Captopril renograms performed on our patients with the latter two conditions, however, did not yield diagnostic findings. Therefore, equivocal or negative captopril renography cannot serve to rule out conditions with elevated renin other than renal artery stenosis

(Pro)renin Receptor Is an Amplifier of Wnt/β-Catenin Signaling in Kidney Injury and Fibrosis.

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Li, Zhen; Zhou, Lili; Wang, Yongping; Miao, Jinhua; Hong, Xue; Hou, Fan Fan; Liu, Youhua

2017-08-01

The (pro)renin receptor (PRR) is a transmembrane protein with multiple functions. However, its regulation and role in the pathogenesis of CKD remain poorly defined. Here, we report that PRR is a downstream target and an essential component of Wnt/ β -catenin signaling. In mouse models, induction of CKD by ischemia-reperfusion injury (IRI), adriamycin, or angiotensin II infusion upregulated PRR expression in kidney tubular epithelium. Immunohistochemical staining of kidney biopsy specimens also revealed induction of renal PRR in human CKD. Overexpression of either Wnt1 or β -catenin induced PRR mRNA and protein expression in vitro Notably, forced expression of PRR potentiated Wnt1-mediated β -catenin activation and augmented the expression of downstream targets such as fibronectin, plasminogen activator inhibitor 1, and α -smooth muscle actin ( α -SMA). Conversely, knockdown of PRR by siRNA abolished β -catenin activation. PRR potentiation of Wnt/ β -catenin signaling did not require renin, but required vacuolar H + ATPase activity. In the mouse model of IRI, transfection with PRR or Wnt1 expression vectors promoted β -catenin activation, aggravated kidney dysfunction, and worsened renal inflammation and fibrotic lesions. Coexpression of PRR and Wnt1 had a synergistic effect. In contrast, knockdown of PRR expression ameliorated kidney injury and fibrosis after IRI. These results indicate that PRR is both a downstream target and a crucial element in Wnt signal transmission. We conclude that PRR can promote kidney injury and fibrosis by amplifying Wnt/ β -catenin signaling. Copyright © 2017 by the American Society of Nephrology.

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

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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

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

Science.gov (United States)

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

1981-01-01

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

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

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

2017-06-16

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

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

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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

Effect of Dual Blockade of Renin-Angiotensin Aldosterone System ...

African Journals Online (AJOL)

Methods: Patients with diabetes of > 5 years duration, proteinuria at a ... nephropathy, Azotemia, Proteinuria, Aldosterone, Renin, Blood pressure ... Hypertension is a risk factor that exacerbates all ... Arterial tension values of the patients were measured with an. ERKA sleeve .... receiving treatment remained within normal.

Tissue Renin-Angiotensin Systems: A Unifying Hypothesis of Metabolic Disease

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Jeppe eSkov

2014-02-01

Full Text Available The actions of angiotensin peptides are diverse and locally acting tissue renin-angiotensin systems (RAS are present in almost all tissues of the body. An activated RAS strongly correlates to metabolic disease (e.g. diabetes and its complications and blockers of RAS have been demonstrated to prevent diabetes in humans.Hyperglycemia, obesity, hypertension, and cortisol are well-known risk factors of metabolic disease and all stimulate tissue RAS whereas glucagon-like peptide-1, vitamin D, and aerobic exercise are inhibitors of tissue RAS and to some extent can prevent metabolic disease. Furthermore, an activated tissue RAS deteriorates the same risk factors creating a system with several positive feedback pathways. The primary effector hormone of the RAS, angiotensin II, stimulates reactive oxygen species, induces tissue damage, and can be associated to most diabetic complications. Based on these observations we hypothesize that an activated tissue RAS is the principle cause of metabolic syndrome and type 2 diabetes, and additionally is mediating the majority of the metabolic complications. The involvement of positive feedback pathways may create a self-reinforcing state and explain why metabolic disease initiate and progress. The hypothesis plausibly unify the major predictors of metabolic disease and places tissue RAS regulation in the center of metabolic control.

A case of low renin hyperaldosteronism considered to be aldosterone-producing adrenocortical adenoma by CT image of adrenal gland

International Nuclear Information System (INIS)

Hayashi, Kozo; Tsuchihashi, Yoshihiro; Ito, Kazuro; Ozono, Noboru

1983-01-01

A case was reported in which hypertension, hypopotassemia, low plasma renin activity and hyperaldosteronemia were observed. Imaging suggested adrenocortical adenoma, leading to the diagnosis of low renin hyperaldosteronism. (Chiba, N.)

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

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

2018-01-01

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

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

Science.gov (United States)

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

2018-01-01

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

The renin-angiotensin system; development and differentiation of the renal medulla

DEFF Research Database (Denmark)

Madsen, Kirsten; Robdrup Tinning, Anne; Marcussen, Niels

2013-01-01

on mechanisms of postnatal development the renal medulla and putting medullary developmental lesions into perspective with regard to the programming effect. Moreover, the renin-angiotensin system is critically involved in mammalian kidney development and signaling disorders give rise to developmental renal...... disturbances reaching into adulthood. A review of current knowledge of the role of the renin-angiotensin system for renal medullary development will be given. Acta Physiologica © 2013 Scandinavian Physiological Society....... lesions that has been associated with hypertension later in life. A consistent finding in both experimental animal models and in human case reports is atrophy of the renal medulla with developmental lesions to both medullary nephron segments and vascular development with concomitant functional...

Current concepts in combination therapy for the treatment of hypertension: combined calcium channel blockers and RAAS inhibitors

Directory of Open Access Journals (Sweden)

Alberto F Rubio-Guerra

2009-11-01

Full Text Available Alberto F Rubio-Guerra1, David Castro-Serna2, Cesar I Elizalde Barrera2, Luz M Ramos-Brizuela21Metabolic and Research Clinic, 2Internal Medicine Department, Hospital General de Ticomán SS DF, MéxicoAbstract: Recent guidelines for the management of hypertension recommend target blood pressures <140/90 mmHg in hypertensive patients, or <130/80 mmHg in subjects with diabetes, chronic kidney disease, or coronary artery disease. Despite the availability and efficacy of antihypertensive drugs, most hypertensive patients do not reach the recommended treatment targets with monotherapy, making combination therapy necessary to achieve the therapeutic goal. Combination therapy with 2 or more agents is the most effective method for achieving strict blood pressure goals. Fixed-dose combination simplifies treatment, reduces costs, and improves adherence. There are many drug choices for combination therapy, but few data are available about the efficacy and safety of some specific combinations. Combination therapy of calcium antagonists and inhibitors of the renin-angiotensin-aldosterone system (RAAS are efficacious and safe, and have been considered rational by both the JNC 7 and the 2007 European Society of Hypertension – European Society of Cardiology guidelines for the management of arterial hypertension. The aim of this review is to discuss some relevant issues about the use of combinations with calcium channel blockers and RAAS inhibitors in the treatment of hypertension.Keywords: hypertension, calcium channel blockers, renin-angiotensin-aldosterone system inhibitors, fixed-dose combination, adherence

Effects of long-term inhibition of neuronal nitric oxide synthase on blood pressure and renin release

DEFF Research Database (Denmark)

Ollerstam, A.; Skøtt, O.; Ek, J.

2001-01-01

Nitric oxide (NO) produced by neuronal NO-synthase (nNOS) in macula densa cells may be involved in the control of renin release. 7-Nitro indazole (7-NI) inhibits nNOS, and we investigated the effect of short- (4 days) and long-term (4 weeks) 7-NI treatment on blood pressure (BP), plasma renin...... LS rats (107 +/- 15 vs. 56 +/- 1 mGU mL(-1)). Stimulation of PRC in LS rats was further enhanced by 7-NI after 4 days of treatment, but not affected in rats treated for 4 weeks. This suggests that inhibition of nNOS stimulates renin release but that this stimulatory effect in the long run might...

Control of renin secretion from rat juxtaglomerular cells by cAMP-specific phosphodiesterases

DEFF Research Database (Denmark)

Friis, Ulla G; Jensen, Boye L; Sethi, Shala

2002-01-01

, and the PDE4 inhibitor rolipram enhanced cellular cAMP content. Dialysis of single JG cells with cAMP in whole-cell patch-clamp experiments led to concentration-dependent, biphasic changes in cell membrane capacitance (C(m)) with a marked increase in C(m) at 1 micromol/L, no net change at 10 micromol....../L, and a decrease at 100 micromol/L cAMP. cGMP also had a dual effect on C(m) at 10-fold higher concentration compared with cAMP. Trequinsin, milrinone, and rolipram mimicked the effect of cAMP on C(m). Trequinsin, cAMP, and cGMP enhanced outward current 2- to 3-fold at positive membrane potentials. The effects...... of cAMP, cGMP, and trequinsin on C(m) and cell currents were abolished by inhibition of protein kinase A with Rp-cAMPs. We conclude that degradation of cAMP by PDE3 and PDE4 contributes to regulation of renin release from JG cells. Our data provide evidence at the cellular level that stimulation...

Renin-angiotensin system blockade therapy after transcatheter aortic valve implantation.

Science.gov (United States)

Ochiai, Tomoki; Saito, Shigeru; Yamanaka, Futoshi; Shishido, Koki; Tanaka, Yutaka; Yamabe, Tsuyoshi; Shirai, Shinichi; Tada, Norio; Araki, Motoharu; Naganuma, Toru; Watanabe, Yusuke; Yamamoto, Masanori; Hayashida, Kentaro

2018-04-01

The persistence of left ventricular (LV) hypertrophy is associated with poor clinical outcomes after transcatheter aortic valve implantation (TAVI) for aortic stenosis. However, the optimal medical therapy after TAVI remains unknown. We investigated the effect of renin-angiotensin system (RAS) blockade therapy on LV hypertrophy and mortality in patients undergoing TAVI. Between October 2013 and April 2016, 1215 patients undergoing TAVI were prospectively enrolled in the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI registry. This cohort was stratified according to the postoperative usage of RAS blockade therapy with angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs). Patients with at least two prescriptions dispensed 180 days apart after TAVI and at least a 6-month follow-up constituted the RAS blockade group (n=371), while those not prescribed any ACE inhibitors or ARBs after TAVI were included in the no RAS blockade group (n=189). At 6 months postoperatively, the RAS blockade group had significantly greater LV mass index regression than the no RAS blockade group (-9±24% vs -2±25%, p=0.024). Kaplan-Meier analysis revealed a significantly lower cumulative 2-year mortality in the RAS blockade than that in the no RAS blockade group (7.5% vs 12.5%; log-rank test, p=0.031). After adjusting for confounding factors, RAS blockade therapy was associated with significantly lower all-cause mortality (HR, 0.45; 95% CI 0.22 to 0.91; p=0.025). Postoperative RAS blockade therapy is associated with greater LV mass index regression and reduced all-cause mortality. These data need to be confirmed by a prospective randomised controlled outcome trial. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Increased expression of (pro)renin receptor does not cause hypertension or cardiac and renal fibrosis in mice

NARCIS (Netherlands)

Rosendahl, Alva; Niemann, Gianina; Lange, Sascha; Ahadzadeh, Erfan; Krebs, Christian; Contrepas, Aurelie; van Goor, Harry; Wiech, Thorsten; Bader, Michael; Schwake, Michael; Peters, Judith; Stahl, Rolf; Nguyen, Genevieve; Wenzel, Ulrich

Binding of renin and prorenin to the (pro)renin receptor (PRR) increases their enzymatic activity and upregulates the expression of pro-fibrotic genes in vitro. Expression of PRR is increased in the heart and kidney of hypertensive and diabetic animals, but its causative role in organ damage is

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

Science.gov (United States)

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

2016-01-28

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

A Study on Renin-Angiotensin System and Total Exchangeable Sodium in Hypertension

International Nuclear Information System (INIS)

Choe, Kang Won; Park, Jung Sik; Lee, Jung Sang; Koh, Chang Soon

1976-01-01

The etiologic role of renin-angiotensin system and sodium-volume status in the pathophysiology of various forms of hypertension was investigated. Plasma renin activity (PRA) was measured by radioimmunoassay, while sodium-volume status was evaluated by the determination of total exchangeable sodium(NaE) using isotope dilution method. The subjects consisted of 25 controls, 24 patients with essential hypertension, 22 patients with chronic renal failure (13 with hypertension, 9 without hypertension) and 14 patients with malignant hypertension. The results were as follows: 1) An inverse correlation between NaE and PRA was noted in control subjects (r=-0.598, p 0.1) 3) Absolute value of PRA was not deviated significantly from control group (2.53±1.416 ng/ml/hr) except in malignant hypertension (6.09±2.042, p 0.1). It is suggested that renin-angiotensin system plays a predominant role in the pathogenesis of malignant hypertension and in hypertension of chronic renal failure, though sodium retention is also contributing factor. PRA variation in essential hypertension does not appear to be associated with any consistent change in Na-volume status, suggesting the existence of another mechanism in the genesis of hypertension and PRA variation.

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

Science.gov (United States)

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

1976-03-31

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

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

Science.gov (United States)

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

2010-01-01

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

Renin-aldosterone-sodium profiling in hypertensive Filipinos. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Guevara, R.; Torres, J. Jr; Abundo, H.P.; Perez, A.P.; Ochoa, W.K.

1981-10-01

Plasma renin activity determination by radioimmunoassay as profiling technique is a useful guide for more rational and precise treatment of hypertension. Statistical nomograms are developed for normals, essential hypertension, diabetic hypertension, renal diseases, renal disease and dialysis, normal pregnancy, toxemic pregnancy and contraceptive pill users with and without hypertension.

Oral direct thrombin inhibitors or oral factor Xa inhibitors for the treatment of pulmonary embolism.

Science.gov (United States)

Robertson, Lindsay; Kesteven, Patrick; McCaslin, James E

2015-12-04

Pulmonary embolism is a potentially life-threatening condition in which a clot can travel from the deep veins, most commonly in the leg, up to the lungs. Previously, a pulmonary embolism was treated with the anticoagulants heparin and vitamin K antagonists. Recently, however, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTI) and oral factor Xa inhibitors. The new drugs have characteristics that may be favourable over conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or re-dosing and few known drug interactions. To date, no Cochrane review has measured the effectiveness and safety of these drugs in the long-term treatment (minimum duration of three months) of pulmonary embolism. To assess the effectiveness of oral DTIs and oral factor Xa inhibitors for the long-term treatment of pulmonary embolism. The Cochrane Vascular Trials Search Co-ordinator searched the Specialised Register (last searched January 2015) and the Cochrane Register of Studies (last searched January 2015). Clinical trials databases were also searched for details of ongoing or unpublished studies. We searched the reference lists of relevant articles retrieved by electronic searches for additional citations. We included randomised controlled trials in which patients with a pulmonary embolism confirmed by standard imaging techniques were allocated to receive an oral DTI or an oral factor Xa inhibitor for the long-term (minimum duration three months) treatment of pulmonary embolism. Two review authors (LR, JM) independently extracted the data and assessed the risk of bias in the trials. Any disagreements were resolved by discussion with the third author (PK). We used meta-analyses when we considered heterogeneity low. The two primary outcomes were recurrent venous thromboembolism and pulmonary embolism. Other outcomes included all-cause mortality and major bleeding. We calculated all outcomes

Normotensive sodium loading in conscious dogs: Regulation of renin secretion during beta receptor blockade

DEFF Research Database (Denmark)

Bie, Peter; Mølstrøm, Simon; Wamberg, Søren

2009-01-01

Cl (20 micromol/kg/min for 180 min, NaLoad) during regular or low-sodium diet (0.03 mmol/kg/d, LowNa) with and without metoprolol (2 mg/kg plus 0.9 mg/kg/h). Vasopressin V2 receptors were blocked by Otsuka compound OPC31260 to facilitate clearance measurements. Body fluid volume was maintained by servo-controlled...... that in this setting, renin secretion and renin-dependent sodium excretion are controlled by via the renal nerves and therefore eliminated or reduced by blocking the action of norepinephrine on the juxtaglomerular cells with the beta1-receptor antagonist metoprolol. This was tested in conscious dogs by infusion of Na...... irrespective of diet. In conclusion, PRC depended on dietary sodium and beta1-adrenergic control as expected; however, the acute sodium-driven decrease in PRC at constant MAP and GFR was unaffected by beta1-receptor blockade demonstrating that renin may be regulated without changes in MAP, GFR, or beta1...

TO THE 110-TH ANNIVERSARY OF RENIN FINDING. FIGHT OF TITANS: ANGIOTENSIN CONVERTING ENZYME INHIBITORS AND SARTANS

Directory of Open Access Journals (Sweden)

L. N. Malay

2009-01-01

Full Text Available Angiotensin converting enzyme (ACE inhibitors and angiotensin II receptor blockers (ARB slow down progression of cardiovascular diseases and reduce risk of mortality and life threatening complications. What it is better to prescribe for patient in a concrete clinical case – ACE inhibitors or ARB? Authors compare these drug classes (mechanism of action, indications, evidense base of clinical trails, treatment costs and safety. The place of ACE inhibitors and ARB in modern therapy of cardiovascular diseases is defined. Results of the recent trails (ONTARGET, TRANCEND, PRoFESS, I-PRESERVE are discussed.

Activity assays and immunoassays for plasma Renin and prorenin: information provided and precautions necessary for accurate measurement

DEFF Research Database (Denmark)

Campbell, Duncan J; Nussberger, Juerg; Stowasser, Michael

2009-01-01

into focus the differences in information provided by activity assays and immunoassays for renin and prorenin measurement and has drawn attention to the need for precautions to ensure their accurate measurement. CONTENT: Renin activity assays and immunoassays provide related but different information...... provided by these assays and of the precautions necessary to ensure their accuracy....

Role of aliskiren in cardio-renal protection and use in hypertensives with multiple risk factors

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Eduardo Pimenta

2009-05-01

Full Text Available Eduardo Pimenta1, Suzanne Oparil21Endocrine Hypertension Research Center and Clinical Center of Research Excellence in Cardiovascular Disease and Metabolic Disorders, University of Queensland School of Medicine, Princess Alexandra Hospital, Brisbane, QLD, Australia; 2Vascular Biology and Hypertension Program, University of Alabama at Birmingham, Birmingham, AL, USAbstract: The renin-angiotensin-aldosterone system (RAAS is an important mediator of blood pressure (BP and volume regulation in both normotensive and hypertensive persons and is a major contributor to hypertension-related target organ damage. The concept of renin inhibition for managing hypertension by blocking the RAAS pathway at its point of activation is very attractive since the renin-angiotensinogen reaction is the first and rate-limiting step in the generation of angiotensin II (Ang II. Aliskiren, the first in a new class of orally effective direct renin inhibitors (DRIs, is approved for the treatment of hypertension. It is effective in reducing BP in the general population of hypertensive patients and in special patient groups such as obese persons, and has a tolerability and safety profile similar to placebo. Aliskiren has renoprotective, cardioprotective and anti-atherosclerotic effects in animal models that appear to be independent of BP lowering. It reduces proteinuria in diabetic patients and has favorable neurohumoral effects in patients with symptomatic heart failure. Additional outcome trials are needed to establish the role of this novel class of antihypertensive medication in the therapeutic armamentarium.Keywords: hypertension, renin inhibitors, renin-angiotensin-aldosterone system

Renin-aldosterone-sodium profiling in hypertensive Filipinos. Pt. 2

International Nuclear Information System (INIS)

Guevara, R.; Torres, J. Jr; Abundo, H.P.; Perez, A.P.; Ochoa, W.K.

1981-01-01

Plasma renin activity determination by radioimmunoassay as profiling technique is a useful guide for more rational and precise treatment of hypertension. Statistical nomograms are developed for normals, essential hypertension, diabetic hypertension, renal diseases, renal disease and dialysis, normal pregnancy, toxemic pregnancy and contraceptive pill users with and without hypertension. (orig.) [de

Oral direct thrombin inhibitors or oral factor Xa inhibitors for the treatment of deep vein thrombosis.

Science.gov (United States)

Robertson, Lindsay; Kesteven, Patrick; McCaslin, James E

2015-06-30

Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately 1 in 1,000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of novel oral anticoagulants (NOACs) have been developed: oral direct thrombin inhibitors (DTI) and oral factor Xa inhibitors. The new drugs have characteristics that may be favourable over conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or re-dosing and few known drug interactions. To date, no Cochrane review has measured the effectiveness and safety of these drugs in the treatment of DVT. To assess the effectiveness of oral DTIs and oral factor Xa inhibitors for the treatment of DVT. The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched January 2015) and the Cochrane Register of Studies (last searched January 2015). We searched clinical trials databases for details of ongoing or unpublished studies and the reference lists of relevant articles retrieved by electronic searches for additional citations. We included randomised controlled trials in which people with a DVT confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor for the treatment of DVT. Two review authors (LR, JM) independently extracted the data and assessed the risk of bias in the trials. Any disagreements were resolved by discussion with the third review author (PK). We performed meta-analyses when we considered heterogeneity low. The two primary outcomes were recurrent VTE and PE. Other outcomes included all-cause mortality and major bleeding. We calculated all outcomes using an odds ratio (OR) with a 95% confidence interval (CI). We included

Anti-stress and nootropic activity of drugs affecting the renin-angiotensin system in rats based on indirect biochemical evidence.

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Anil Kumar, K V; Nagwar, Shrasti; Thyloor, Rama; Satyanarayana, Sreemantula

2015-12-01

Various stress hormones are responsible for bringing out stress-related changes and are implicated in learning and memory processes. The extensive clinical experience of angiotensin receptor blockers (ARBs) and direct renin inhibitor as antihypertensive agents provides anecdotal evidence of improvements in cognition. The neurochemical basis underlying the anti-stress and nootropic effects are unclear. This study was aimed to determine the effects of aliskiren, valsartan and their combination on the neuromediators of the central nervous system (CNS) and periphery as well as on cognitive function. Groups of rats were subjected to a forced swim stress for one hour after daily treatment with aliskiren, valsartan and their combination. The 24 h urinary excretion of vanillylmandellic acid (VMA), 5-hydroxyindoleacetic acid (5-HIAA), 6-β-hydroxycortisol (6-β-OH) cortisol and homovanillic acid (HVA) was determined in all groups under normal and stressed conditions. Nootropic activity was studied using cook's pole climbing apparatus and acetylcholinesterase (AChE) inhibitory activity by Ellman's method. Administration of aliskiren (10 mg/kg), valsartan (20 mg/kg) and their combination at a dose of 5 and 10 mg/kg respectively reduced the urinary metabolite levels. Further, all drugs showed significant improvement in scopolamine-impaired performance and produced inhibition of the AChE enzyme. The present study provides scientific support for the anti-stress and nootropic activities of aliskiren, valsartan and their combination. © The Author(s) 2014.

Effects of dual renin-angiotensin system blockade on proteinuria in a ...

African Journals Online (AJOL)

Kidney diseases manifesting as proteinuria or elevated creatinine are increasingly prevalent complications of HIV infection. We report the effects of dual renin-angiotensin system blockade on proteinuria in a hypertensive black African HIV-infected patient.

Renin-aldosterone-sodium profiling in normal Filipinos. Pt. 1

International Nuclear Information System (INIS)

Guevara, R.; Torres, J. Jr.; Abundo, H.P.; Perez, A.P.; Ochoa, W.K.

1981-01-01

Plasma renin activity determination by radioimmunoassay is feasible, accurate, reproducible and reliable. This profiling technic is a very useful guide for more rational and precise treatment of the hypertensive state, but even when profiling cannot be done, statistical nomograms can be useful, just as well, as a guide in the treatment of hypertewnsion. (orig.) [de

Renoprotective Effects of SGLT2 Inhibitors: Beyond Glucose Reabsorption Inhibition.

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

2017-01-01

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

Radioimmunoassay for determination of blood aldosterone and renin in the diagnosis of some forms of arterial hypertension

International Nuclear Information System (INIS)

Khamidov, R.I.; Khalmuratova, R.A.; Sattarova, F.K.

1987-01-01

Aldosterone concentration and renin activity in the blood from the ulnar, inferior cava veins at the level of the 12th thoracic vertebra, the left and right renal veins were studied in 60 patients with arterial hypertension by means of a radioimmunoassay kits (France). The patients were divided into 4 groups: with primary and idiopathic hyperaldosteronism, renal-parenchymatous and essential arterial hypertension. The diagnosis of primary and idiopathic hyperaldosteronism was also confirmed by low blood renin activity. Renin activity in the peripheral venous blood was considerably elevated in renal-parenchymatous arterial hypertension and was normal in essential hypertension. Aldosterone concentration in the blood from the vena cava inferior and renal veins was 1.6-2-fold as high on the affected side as on the contralateral one

Renin-Angiotensin System in Diabetes.

Science.gov (United States)

Rein, Johannes; Bader, Michael

2017-11-17

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

Renin secretion and total body sodium: Pathways of integrative control

DEFF Research Database (Denmark)

Bie, Peter; Damkjaer, Mads

2009-01-01

to a spring/shock absorber set-up: Non-adaptive RAAS functions determine the new steady state position while TGF controls the rate of change. Recruitment of renin-secreting cells during sustained stimulation may be essential for chronic adaptation, although details of this afferent arteriolar cell plasticity...

Cortisol-induced inhibition of ovine renin and aldosterone responses to hypotension

International Nuclear Information System (INIS)

Wood, C.E.; Silbiger, J.

1987-01-01

Previous studies from this laboratory have demonstrated that in preterm fetal sheep increases in plasma cortisol (F) concentration equal in amplitude to fetal F stress responses suppress plasma renin activity (PRA). The purpose of this study was to investigate the possibility that this negative interaction exists in adult sheep. Cortisol was measured by radioimmunoassay. Five conscious ewes with chronically prepared carotid arterial loops were infused intravenously with F or vehicle for 5 h. One hour after the end of F or vehicle infusion, renin secretion was stimulated by hypotension produced by infusion of sodium nitroprusside. F infusion increased plasma F; during vehicle infusion plasma F did not change. F infusion decreased hematocrit from 29 +/- 2 to 26 +/- 1%. Basal PRA in vehicle- and F-infused groups were 0.4 +/- 0 and 0.2 +/- 0.1 ng angiotensin I-ml -1 -h -1 and did not change. In vehicle-infused ewes, PRA increased from 0.4 +/- 0 to 4.6 +/- 0.4 and plasma aldosterone from 26.0 +/- 1.0 to 173.1 +/- 21.8 pg/ml, while in F-infused ewes, PRA increased from 0.2 +/- 1 to 3.3 +/- 0.4 ng angiotensin I-ml -1 -h -1 and aldosterone from 25.0 +/- 0 to 48.2 +/- 23.2 pg/ml, significantly smaller responses. These results suggest that repeated stress may modulate the responses of the renin-angiotensin system in this species

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

Science.gov (United States)

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.

Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis

DEFF Research Database (Denmark)

Gribouval, Olivier; Morinière, Vincent; Pawtowski, Audrey

2012-01-01

, pulmonary hypoplasia, and refractory arterial hypotension. The disease is linked to mutations in the genes encoding several components of the renin-angiotensin system (RAS): AGT (angiotensinogen), REN (renin), ACE (angiotensin-converting enzyme), and AGTR1 (angiotensin II receptor type 1). Here, we review...... the series of 54 distinct mutations identified in 48 unrelated families. Most of them are novel and ACE mutations are the most frequent, observed in two-thirds of families (64.6%). The severity of the clinical course was similar whatever the mutated gene, which underlines the importance of a functional RAS...

Severe hypoglycaemia during pregnancy in women with type 1 diabetes: possible role of renin-angiotensin system activity?

DEFF Research Database (Denmark)

Nielsen, L Ringholm; Pedersen-Bjergaard, U; Thorsteinsson, B

2009-01-01

AIMS: To investigate whether increased risk of severe hypoglycaemia in early pregnancy is related to pregnancy-induced changes in renin-angiotensin system (RAS) activity in women with type 1 diabetes (T1DM). METHODS: Severe hypoglycaemic events the year preceding pregnancy were recorded...... retrospectively in 107 consecutive pregnant women with T1DM. Events during pregnancy were recorded prospectively. Measurements of ACE, renin and angiotensinogen were determined at 8, 14, 21, 27 and 33 weeks and postpartum. RESULTS: The rate of severe hypoglycaemia was 1.1 and 5.3 events/patient-year the year...... preceding pregnancy and postpartum ACE activity (relative rate of severe hypoglycaemia above versus below median ACE activity: 4.4 (CI: 1.7-11.9), p=0.003). No association was found between severe hypoglycaemia during pregnancy and renin angiotensin system activity at 8 weeks. CONCLUSIONS: In early...

[The changes in renin-angiotensin-aldosterone-system in different subtypes of Cushing's syndrome].

Science.gov (United States)

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, PCushing'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 (PCushing'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.

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

Science.gov (United States)

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

1986-01-01

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

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

Science.gov (United States)

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.

ACE and SGLT2 inhibitors: the future for non-diabetic and diabetic proteinuric renal disease.

Science.gov (United States)

Perico, Norberto; Ruggenenti, Piero; Remuzzi, Giuseppe

2017-04-01

Most chronic nephropathies progress relentlessly to end-stage kidney disease. Research in animals and humans has helped our understanding of the mechanisms of chronic kidney disease progression. Current therapeutic strategies to prevent or revert renal disease progression focus on reduction of urinary protein excretion and blood pressure control. Blockade of the renin-angiotensin system (RAS) with angiotensin-converting enzyme inhibitors and/or angiotensin II type 1 receptor blockers is the most effective treatment to achieve these purposes in non-diabetic and diabetic proteinuric renal diseases. For those individuals in which nephroprotection by RAS blockade is only partial, sodium-glucose linked cotransporter-2 (SGLT2) inhibitors could be a promising new class of drugs to provide further renoprotective benefit when added on to RAS blockers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of MicroRNAs in Renin-Angiotensin-Aldosterone System-Mediated Cardiovascular Inflammation and Remodeling

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Maricica Pacurari

2015-01-01

Full Text Available MicroRNAs are endogenous regulators of gene expression either by inhibiting translation or protein degradation. Recent studies indicate that microRNAs play a role in cardiovascular disease and renin-angiotensin-aldosterone system- (RAAS- mediated cardiovascular inflammation, either as mediators or being targeted by RAAS pharmacological inhibitors. The exact role(s of microRNAs in RAAS-mediated cardiovascular inflammation and remodeling is/are still in early stage of investigation. However, few microRNAs have been shown to play a role in RAAS signaling, particularly miR-155, miR-146a/b, miR-132/122, and miR-483-3p. Identification of specific microRNAs and their targets and elucidating microRNA-regulated mechanisms associated RAS-mediated cardiovascular inflammation and remodeling might lead to the development of novel pharmacological strategies to target RAAS-mediated vascular pathologies. This paper reviews microRNAs role in inflammatory factors mediating cardiovascular inflammation and RAAS genes and the effect of RAAS pharmacological inhibition on microRNAs and the resolution of RAAS-mediated cardiovascular inflammation and remodeling. Also, this paper discusses the advances on microRNAs-based therapeutic approaches that may be important in targeting RAAS signaling.

Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials

DEFF Research Database (Denmark)

Chaturvedi, Nish; Porta, Massimo; Klein, Ronald

2008-01-01

BACKGROUND: Results of previous studies suggest that renin-angiotensin system blockers might reduce the burden of diabetic retinopathy. We therefore designed the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme to assess whether candesartan could reduce the incidence and progression of ...

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

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V Raghunathan

2017-01-01

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

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

Science.gov (United States)

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

2013-07-01

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

Analysis of renin-angiotensin aldosterone system gene polymorphisms in malaysian essential hypertensive and type 2 diabetic subjects

OpenAIRE

Ramachandran, Vasudevan; Ismail, Patimah; Stanslas, Johnson; Shamsudin, Norashikin

2009-01-01

Abstract Background The renin-angiotensin aldosterone system (RAAS) plays an important role in regulating the blood pressure and the genetic polymorphisms of RAAS genes has been extensively studied in relation to the cardiovascular diseases in various populations with conflicting results. The aim of this study was to determine the association of five genetic polymorphisms (A6G and A20C of angiotensinogen (AGT), MboI of renin, Gly460Trp of aldosterone synthase and Lys173Arg of adducin) of RAAS...

Potent host-directed small-molecule inhibitors of myxovirus RNA-dependent RNA-polymerases.

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Stefanie A Krumm

Full Text Available Therapeutic targeting of host cell factors required for virus replication rather than of pathogen components opens new perspectives to counteract virus infections. Anticipated advantages of this approach include a heightened barrier against the development of viral resistance and a broadened pathogen target spectrum. Myxoviruses are predominantly associated with acute disease and thus are particularly attractive for this approach since treatment time can be kept limited. To identify inhibitor candidates, we have analyzed hit compounds that emerged from a large-scale high-throughput screen for their ability to block replication of members of both the orthomyxovirus and paramyxovirus families. This has returned a compound class with broad anti-viral activity including potent inhibition of different influenza virus and paramyxovirus strains. After hit-to-lead chemistry, inhibitory concentrations are in the nanomolar range in the context of immortalized cell lines and human PBMCs. The compound shows high metabolic stability when exposed to human S-9 hepatocyte subcellular fractions. Antiviral activity is host-cell species specific and most pronounced in cells of higher mammalian origin, supporting a host-cell target. While the compound induces a temporary cell cycle arrest, host mRNA and protein biosynthesis are largely unaffected and treated cells maintain full metabolic activity. Viral replication is blocked at a post-entry step and resembles the inhibition profile of a known inhibitor of viral RNA-dependent RNA-polymerase (RdRp activity. Direct assessment of RdRp activity in the presence of the reagent reveals strong inhibition both in the context of viral infection and in reporter-based minireplicon assays. In toto, we have identified a compound class with broad viral target range that blocks host factors required for viral RdRp activity. Viral adaptation attempts did not induce resistance after prolonged exposure, in contrast to rapid

Radioimmunologic analysis of the state of the renin-angiotensin-aldosterone system in arterial hypertension

International Nuclear Information System (INIS)

Slavnov, V.N.; Yakovlev, A.A.; Gandzha, T.I.; Yugrinov, O.G.

1986-01-01

For 110 patients having various forms of arterial hypertension (hypertension, aldersteronoma, phaeochromocytoma, corticosteroma) the parameters of the system renin-angiotensin-aldosterone (RAA) were measured. Basal values of aldosterone and renin activity in blood were determined as well as their concentration in blood taken from the vena cava inferior, renal and adrenal veins during selective renography. The 24-hours rhythm of the hormones in the blood, the reaction of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under acute lasix stress was evaluated. It was found, that the system RAA is disturbed in all patients with arterial hypertension. This is indicated by changes of aldosterone concentration, renin activity in peripheral blood and in the blood from the vena cava inferior, renal and adrenal veins, the 24-hour rhythm of their concentrations in serum and the reaction to acute lasix stress. The radioimmunoassays of quantitative parameters of the RAA system are decisive for the differential diagnostics of hypertension and suprarenomas connected with a hypertension syndrome. They facilitate a rational choice of the hypertension therapy and the daily distribution of the medicaments for patients with hypertension. The radioimmunoassays can be used for checking the efficiency of medicaments and surgery. (author)

Role of valsartan, amlodipine and hydrochlorothiazide fixed combination in blood pressure control: an update

Directory of Open Access Journals (Sweden)

Maurizio Destro

2010-04-01

Full Text Available Maurizio Destro1, Francesca Cagnoni1, Antonio D’Ospina1, Alessandra Rossi Ricci1, Elena Demichele1, Emmanouil Peros1, Augusto Zaninelli2, Paola Preti31Internal Medicine, Ospedale Unificato Broni-Stradella, Stradella (PV, Italy; 2General Medicine, School of Medicine, University of Florence, Florence, Italy; 3Internal Medicine, University of Pavia, Pavia, ItalyAbstract: The treatment of moderate or severe hypertension in most cases requires the contemporaneous use of multiple antihypertensive agents. The most available two-drug combinations have an agent that addresses renin secretion and another one that is statistically more effective in renin-independent hypertension. The practice of combining agents that counteract different mechanisms is the most likely explanation for the fact that most available two-drug combinations have an agent that addresses renin secretion (beta-blocker, angiotensin converting enzyme inhibitor, angiotensin II receptor blocker or direct renin inhibitor and another one that is more effective in renin-independent hypertension (diuretic, dihydropyridine or non-dihydropyridine calcium channel blocker. Based on these considerations, addition of hydrochlorothiazide to the combination of an antagonist of the renin-angiotensin system with a calcium channel blocker would constitute a logical approach. Inclusion of a diuretic in the triple combination is based on the evidence that these agents are effective and cheap, enhance the effect of other antihypertensive agents, and add a specific effect to individuals with salt-sensitivity of blood pressure. The benefit of triple combination therapy with amlodipine, valsartan and hydrochlorothiazide over its dual component therapies has been demonstrated, and the use of a single pill will simplify therapy resulting in better blood pressure control.Keywords: valsartan, amlodipine, hydrochlorothiazide, HCTZ, blood pressure, hypertension

The Improvement of Hypertension by Probiotics: Effects on Cholesterol, Diabetes, Renin, and Phytoestrogens

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Huey-Shi Lye

2009-08-01

Full Text Available Probiotics are live organisms that are primarily used to improve gastrointestinal disorders such as diarrhea, irritable bowel syndrome, constipation, lactose intolerance, and to inhibit the excessive proliferation of pathogenic intestinal bacteria. However, recent studies have suggested that probiotics could have beneficial effects beyond gastrointestinal health, as they were found to improve certain metabolic disorders such as hypertension. Hypertension is caused by various factors and the predominant causes include an increase in cholesterol levels, incidence of diabetes, inconsistent modulation of renin and imbalanced sexual hormones. This review discusses the antihypertensive roles of probiotics via the improvement and/or treatment of lipid profiles, modulation of insulin resistance and sensitivity, the modulation of renin levels and also the conversion of bioactive phytoestrogens as an alternative replacement of sexual hormones such as estrogen and progesterone.

Oncogenic Receptor Tyrosine Kinases Directly Phosphorylate Focal Adhesion Kinase (FAK) as a Resistance Mechanism to FAK-Kinase Inhibitors.

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Marlowe, Timothy A; Lenzo, Felicia L; Figel, Sheila A; Grapes, Abigail T; Cance, William G

2016-12-01

Focal adhesion kinase (FAK) is a major drug target in cancer and current inhibitors targeted to the ATP-binding pocket of the kinase domain have entered clinical trials. However, preliminary results have shown limited single-agent efficacy in patients. Despite these unfavorable data, the molecular mechanisms that drive intrinsic and acquired resistance to FAK-kinase inhibitors are largely unknown. We have demonstrated that receptor tyrosine kinases (RTK) can directly bypass FAK-kinase inhibition in cancer cells through phosphorylation of FAK's critical tyrosine 397 (Y397). We also showed that HER2 forms a direct protein-protein interaction with the FAK-FERM-F1 lobe, promoting direct phosphorylation of Y397. In addition, FAK-kinase inhibition induced two forms of compensatory RTK reprogramming: (i) the rapid phosphorylation and activation of RTK signaling pathways in RTK High cells and (ii) the long-term acquisition of RTKs novel to the parental cell line in RTK Low cells. Finally, HER2 +: cancer cells displayed resistance to FAK-kinase inhibition in 3D growth assays using a HER2 isogenic system and HER2 + cancer cell lines. Our data indicate a novel drug resistance mechanism to FAK-kinase inhibitors whereby HER2 and other RTKs can rescue and maintain FAK activation (pY397) even in the presence of FAK-kinase inhibition. These data may have important ramifications for existing clinical trials of FAK inhibitors and suggest that individual tumor stratification by RTK expression would be important to predict patient response to FAK-kinase inhibitors. Mol Cancer Ther; 15(12); 3028-39. ©2016 AACR. ©2016 American Association for Cancer Research.

Blockade of chloride channels by DIDS stimulates renin release and inhibits contraction of afferent arterioles

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Jensen, B L; Skøtt, O

1996-01-01

or without ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] and DIDS were not additive. In the absence of chloride, basal renin release was suppressed and the stimulatory effect of DIDS was abolished. The DIDS-induced enhancement of renin release was not dependent on bicarbonate....... Norepinephrine (5 x 10(-7)-1 x 10(-6) M) and angiotensin II (1 x 10(-8)-10(-6) M) evoked reversible and dose-dependent contractions of microperfused rabbit afferent arterioles. DIDS (0.5 mM) did not affect the basal diameter of the arterioles but strongly inhibited the response to angiotensin II and attenuated...

Expressions of renin, angiotensin II and aldosterone in patients with viral hepatitis or hepatic cirrhosis

International Nuclear Information System (INIS)

Huo Ying; Zhu Yalin; Liu Yun

2008-01-01

Objective: To explore the changes of renin, angiotensin and aldosterone system in patients with hepatic disorders. Methods: Plasma renin activity (PRA), AT-II and Ald levels were measured with RIA in 31 patients with viral hepatitis, 35 patients with hepatic cirrhosis and 38 controls. Results: The levels of PRA, AT-II and Ald in patients with viral hepatitis were slightly but non-significantly higher than those in controls (P>0.05). The levels of PRA, AT-II and Ald in patients with cirrhosis were significantly higher than those in controls (P<0.01). Conclusion: RAAS was activated during progression of hepatic disorders and participated in the development of hepatic fibrosis. (authors)

The Relevance of the Renin-Angiotensin System in the Development of Drugs to Combat Preeclampsia

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Norikazu Ueki

2015-01-01

Full Text Available Preeclampsia is a hypertensive disorder that occurs during pregnancy. It has an unknown etiology and affects approximately 5–8% of pregnancies worldwide. The pathophysiology of preeclampsia is not yet known, and preeclampsia has been called “a disease of theories.” The central symptom of preeclampsia is hypertension. However, the etiology of the hypertension is unknown. In this review, we analyze the molecular mechanisms of preeclampsia with a particular focus on the pathogenesis of the hypertension in preeclampsia and its association with the renin-angiotensin system. In addition, we propose potential alternative strategies to target the renin-angiotensin system, which is enhanced during pregnancy.

The renin-angiotensin system and aging in the kidney

OpenAIRE

Yoon, Hye Eun; Choi, Bum Soon

2014-01-01

Aging is associated with progressive functional deterioration and structural changes in the kidney. Changes in the activity or responsiveness of the renin-angiotensin system (RAS) occur with aging. RAS changes predispose the elderly to various fluid and electrolyte imbalances as well as acute kidney injury and chronic kidney disease. Among the multiple pathways involved in renal aging, the RAS plays a central role. This review summarizes the association of the RAS with structural and function...

The role of renin angiotensin system in retinal inflammation

OpenAIRE

Zhu, Tong

2017-01-01

Purpose: Retinopathy of prematurity (ROP) is the main cause of vision loss and blindness in children, and is replicated and intensively studied in rodent models of oxygen-induced retinopathy (OIR). One signature feature of ROP is retinal neovascularization, which is also present in patients with proliferative diabetic retinopathy (PDR). Inflammation is another feature in ROP and PDR. In both diseases, the renin angiotensin system (RAS) is dysregulated, and blockade of RAS via angiotensin II (...

Leptin Mediate High Fat Diet Sensitization of Angiotensin II-elicited Hypertension by Upregulating the Brain Renin-Angiotensin System and Inflammation

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Xue, Baojian; Yu, Yang; Zhang, Zhongming; Guo, Fang; Beltz, Terry G.; Thunhorst, Robert L.; Felder, Robert B.; Johnson, Alan Kim

2016-01-01

Obesity is characterized by increased circulating levels of the adipocyte-derived hormone leptin, which can increase sympathetic nerve activity and raise blood pressure. A previous study revealed that rats fed a high fat diet (HFD) have an enhanced hypertensive response to subsequent angiotensin (Ang) II administration that is mediated at least in part by increased activity of brain renin-angiotensin system (RAS) and proinflammatory cytokines (PICs). The present study tested whether leptin mediates this HFD-induced sensitization of Ang II-elicited hypertension by interacting with brain RAS and PICs mechanisms. Rats fed a HFD for 3 weeks had significant increases in white adipose tissue mass, plasma leptin levels and mRNA expression of leptin and its receptors in the lamina terminalis (LT) and hypothalamic paraventricular nucleus (PVN). Central infusion of a leptin receptor antagonist during HFD feeding abolished HFD sensitization of Ang II-elicited hypertension. Furthermore, central infusion of leptin mimicked the sensitizing action of HFD. Concomitant central infusions of the AT1-R antagonist irbesartan, the TNF-α synthesis inhibitor pentoxifylline, or the inhibitor of microglial activation minocycline prevented the sensitization produced by central infusion of leptin. RT-PCR analysis indicated that either HFD or leptin administration upregulated mRNA expression of several components of the RAS and PICs in the LT and PVN. The leptin antagonist and the inhibitors of AT1-R, TNF-α synthesis and microglial activation all reversed the expression of these genes. The results suggest that HFD-induced sensitization of Ang II-elicited hypertension is mediated by leptin through upregulation of central RAS and PICs. PMID:27021010

Some Aspects of the Renin-Angiotensin-System in Hemodialysis Patients

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Umar Malik

2015-11-01

Full Text Available Understanding of the renin-angiotensin system (RAS has changed remarkably over the past decade. Renin, angiotensin converting enzyme (ACE, angiotensin II (Ang II, and Ang II receptors are the main components of the RAS. Recent studies identified the ACE2/Ang 1-7/Mas receptor axis, which counter-regulates the classical RAS. Many studies have examined the effects of the RAS on the progression of cardiovascular disease and chronic kidney disease (CKD. In addition, many studies have documented increased levels of ACE in hemodialysis (HD patients, raising concerns about the negative effects of RAS activation on the progression of renal disease. Elevated ACE increases the level of Ang II, leading to vasoconstriction and cell proliferation. Ang II stimulation of the sympathetic system leads to renal and cardiovascular complications that are secondary to uncontrolled hypertension. This review provides an overview of the RAS, evaluates new research on the role of ACE2 in dialysis, and reviews the evidence for potentially better treatments for patients undergoing HD. Further understanding of the role of ACE and ACE2 in HD patients may aid the development of targeted therapies that slow the progression of CKD and cardiovascular disease.

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

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Nielsen, Lise Hald; Ovesen, Per; Hansen, Mie R

2016-01-01

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 place...... 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.......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...

RENIN ANGIOTENSIN SYSTEM GENE POLYMORPHISMS IN CHILDREN WITH NEPHROTIC SYNDROM

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Zh.P. Sharnova

2006-01-01

Full Text Available To investigate the role of the reninangiotensin system genes polymorphisms in develop and progression of nephrotic syndrom (NS in children we determined the genotypes of angiotensin converting enzyme (ACE, angiotensinogen (AGT and angiotensin ii receptor (ATII-R of 1 type in 80 russian children with ns including and 15 children with chronic renal failure (CRF. Genotype frequencies did not differ between patients with ns and controls (n = 165. The distribution of ace, AGT and ATII-R 1 type genotypes was similar among ns sub groups, such as focal segmental glomerulosclerosis (FSGS (n = 18, steroid-sensitive nephrotic syndrome (n = 32, nephrotic syndrome with hypertension and hemoturia (n = 22 and with control group. When ns subjects with CRF (n = 15 were compared with control, the prevalence of ace DD genotype was significantly higher (47% VS 21%; χ2 = 4,44; p < 0,05. Our results indicate that the DD genotype ace may be a factor of risk for the dеvеlopment of progressive renal impairment in the children with nephrotic syndrome. The analysis of treatment's effect with inhibitor of ace in groups patients with steroid resistant NS (SRNS demonstrated decreasing of renoprotective effect of this drugs in patients with id and dd genotypes com? Pared with ii genotype: the degree of blood pressure, proteinuria and the rate of glomerular filtration decrease was significantly lower (55,46 ± 9,25 VS 92,74 ± 25; р < 0,05 in these patients.Key words: nephrotic syndrom, chronic renal failure, polymorphism of genes, renin-angiotensin system.

Effect of breed on plasma endothelin-1 concentration, plasma renin activity, and serum cortisol concentration in healthy dogs

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Höglund, K.; Lequarré, A.-S.; Ljungvall, I.

2016-01-01

BACKGROUND: There are breed differences in several blood variables in healthy dogs. OBJECTIVE: Investigate breed variation in plasma endothelin-1 (ET-1) concentration, plasma renin activity, and serum cortisol concentration. ANIMALS: Five-hundred and thirty-one healthy dogs of 9 breeds examined...... at 5 centers (2-4 breeds/center). METHODS: Prospective observational study. Circulating concentrations of ET-1 and cortisol, and renin activity, were measured using commercially available assays. Absence of organ-related or systemic disease was ensured by thorough clinical investigations, including...

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

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

2018-02-01

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

Proteomic prediction and Renin angiotensin aldosterone system Inhibition prevention Of early diabetic nephRopathy in TYpe 2 diabetic patients with normoalbuminuria (PRIORITY)

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Lindhardt, Morten; Persson, Frederik; Currie, Gemma

2016-01-01

INTRODUCTION: 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...... AND DISSEMINATION: 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...

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

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

2018-02-14

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

Normotensive sodium loading in normal man: Regulation of renin secretion during beta-receptor blockade

DEFF Research Database (Denmark)

Mølstrøm, Simon; Larsen, Nils Heden; Simonsen, Jane Angel

2008-01-01

and renal excretion during slow saline loading at constant plasma sodium con-centration (Na-loading: 12 micromol Na(+) kg(-1) min(-1) for 4 h). Normal subjects were studied on low-sodium intake with and without beta1-adrenergic blockade by metoprolol. Metoprolol per se reduced RAAS activity as expected. Na......Saline administration may change renin system (RAAS) activity and sodium excretion at constant mean arterial pressure (MAP). We hypothesized that such responses are elicited mainly by renal sympathetic nerve activity by beta1-receptors (beta1-RSNA), and tested the hypothesis by studying RAAS......-loading decreased plasma renin (PRC) by 1/3, AngII by 1/2, and aldosterone (pAldo) by 2/3, (all psodium excretion increased indistinguishably with and without metoprolol (16+/-2 to 71...

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

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Rene Baudrand

2018-02-01

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

Lack of direct evidence for a functional role of voltage-operated calcium channels in juxtaglomerular cells

DEFF Research Database (Denmark)

Kurtz, A; Skott, O; Chegini, S

1990-01-01

in patch-clamped nor in intact Furaester-loaded cells. Moreover, basal renin secretion from a preparation enriched in mouse juxtaglomerular cells and from rat glomeruli with attached juxtaglomerular cells was not inhibited when extracellular potassium was isoosmotically increased to 56 mmol/l. In mouse...... kidney slices, however, depolarizing potassium concentrations caused a delayed inhibition at 56 mmol/l and a delayed stimulation of renin secretion at 110 mmol/l. Taken together, our study does not provide direct evidence for a role of voltage-activated calcium channels in the regulation of calcium...

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

Science.gov (United States)

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

2015-10-01

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

The renin-angiotensin-aldosterone system and calcium-regulatory hormones.

Science.gov (United States)

Vaidya, A; Brown, J M; Williams, J S

2015-09-01

There is increasing evidence of a clinically relevant interplay between the renin-angiotensin-aldosterone system and calcium-regulatory systems. Classically, the former is considered a key regulator of sodium and volume homeostasis, while the latter is most often associated with skeletal health. However, emerging evidence suggests an overlap in regulatory control. Hyperaldosteronism and hyperparathyroidism represent pathophysiologic conditions that may contribute to or perpetuate each other; aldosterone regulates parathyroid hormone and associates with adverse skeletal complications, and parathyroid hormone regulates aldosterone and associates with adverse cardiovascular complications. As dysregulation in both systems is linked to poor cardiovascular and skeletal health, it is increasingly important to fully characterize how they interact to more precisely understand their impact on human health and potential therapies to modulate these interactions. This review describes the known clinical interactions between these two systems including observational and interventional studies. Specifically, we review studies describing the inhibition of renin activity by calcium and vitamin D, and a potentially bidirectional and stimulatory relationship between aldosterone and parathyroid hormone. Deciphering these relationships might clarify variability in outcomes research, inform the design of future intervention studies and provide insight into the results of prior and ongoing intervention studies. However, before these opportunities can be addressed, more effort must be placed on shifting observational data to the proof of concept phase. This will require reallocation of resources to conduct interventional studies and secure the necessary talent.

Renin inhibition improves cardiac function and remodeling after myocardial infarction independent of blood pressure

NARCIS (Netherlands)

D. Westermann (Dirk); A. Riad (Alexander); O. Lettau (Olga); A.J.M. Roks (Anton); K. Sawatis (Konstantinos); P.M. Becher (Peter Moritz); F. Escher (Felicitas); A.H.J. Danser (Jan); H.P. Schultheiss (Heinz-Peter); C. Tschöpe (Carsten)

2008-01-01

textabstractPharmacological renin inhibition with aliskiren is an effective antihypertensive drug treatment, but it is currently unknown whether aliskiren is able to attenuate cardiac failure independent of its blood pressure-lowering effects. We investigated the effect of aliskiren on cardiac

Renin-angiotensin system (RAS) blockade attenuates growth and metastatic potential of renal cell carcinoma in mice.

Science.gov (United States)

Araújo, Wedson F; Naves, Marcelo A; Ravanini, Juliana N; Schor, Nestor; Teixeira, Vicente P C

2015-09-01

Renal cell carcinoma (RCC) is the most frequent type of cancer among renal neoplasms in adults and responds poorly to radiotherapy and chemotherapy. There is evidence that blockade of the renin-angiotensin system (RAS) might have antineoplastic effects. The aim of this study was to investigate the effects of RAS blockade on RCC in a murine model. Murine renal cancer cells (Renca) were injected (1 × 10(5)) into the subcapsular space of the left kidney of BALB/c mice (8 wk of age). The animals were divided into 4 groups: a control group (no treatment), angiotensin-receptor blockers group (losartan 100mg/kg/d), angiotensin-converting enzyme inhibitor group (captopril 10mg/kg/d), and angiotensin-receptor blockers +angiotensin-converting enzyme inhibitor group (losartan 100mg/kg/d +captopril 10mg/kg/d). The animals received the drugs by gavage for 21 days after inoculation, beginning 2 days before tumor induction, and were then euthanized. After killing the animals, the kidneys and lungs were removed, weighed, and processed for histopathological and immunohistochemical analyses. Angiogenesis and vascular microvessels were assessed with the antibodies anti-vascular endothelial growth factor and anti-CD34. Angiotensin II-inoculated animals developed renal tumors. Treated animals presented smaller tumors, regardless of the therapeutic regimen, and far fewer lung metastases in both quantity and dimension compared with the controls. The expression of vascular endothelial growth factor and CD34 were significantly decreased in renal tumors of treated animals compared with the controls. Our findings suggest that blockade of RAS decreases tumor proliferation and metastatic capacity of RCC in this experimental model. Copyright © 2015 Elsevier Inc. All rights reserved.

Thyroxine-induced cardiac hypertrophy: influence of adrenergic nervous system versus renin-angiotensin system on myocyte remodeling.

Science.gov (United States)

Hu, L W; Benvenuti, L A; Liberti, E A; Carneiro-Ramos, M S; Barreto-Chaves, M L M

2003-12-01

The present study assessed the possible involvement of the renin-angiotensin system (RAS) and the sympathetic nervous system (SNS) in thyroxine (T4)-induced cardiac hypertrophy. Hemodynamic parameters, heart weight (HW), ratio of HW to body weight (HW/BW), and myocyte width were evaluated in absence of thyroid hormone (hypothyroidism) and after T4 administration. Male Wistar rats were used. Some were subjected to thyroidectomies, whereas hyperthyroidism was induced in others via daily intraperitoneal injection of T4 (25 or 100 microg x 100 g BW(-1) x day(-1)) for 7 days. In some cases, T4 administration was combined with the angiotensin I-converting enzyme inhibitor enalapril (Ena), with the angiotensin type 1 (AT1) receptor blocker losartan (Los) or with the beta-adrenergic blocker propanolol (Prop). Hemodynamics and morphology were then evaluated. Systolic blood pressure (SBP) was not altered by administration of either T4 alone or T4 in combination with the specific inhibitors. However, SBP decreased significantly in hypothyroid rats. An increased heart rate was seen after administration of either T4 alone or T4 in combination with either Los or Ena. Although the higher dose of T4 significantly increased HW, HW/BW increased in both T4-treated groups. Ena and Prop inhibited the increase in HW or HW/BW in hyperthyroid rats. Morphologically, both T4 dose levels significantly increased myocyte width, an occurrence prevented by RAS or SNS blockers. There was a good correlation between changes in HW/BW and myocyte width. These results indicate that T4-induced cardiac hypertrophy is associated with both the SNS and the RAS.

Cardiac remodeling during and after renin-angiotensin system stimulation in Cyp1a1-Ren2 transgenic rats

DEFF Research Database (Denmark)

Heijnen, Bart Fj; Pelkmans, Leonie Pj; Danser, Ah Jan

2013-01-01

This study investigated renin-angiotensin system (RAS)-induced cardiac remodeling and its reversibility in the presence and absence of high blood pressure (BP) in Cyp1a1-Ren2 transgenic inducible hypertensive rats (IHR). In IHR (pro)renin levels and BP can be dose-dependently titrated by oral...... administration of indole-3-carbinol (I3C). Young (four-weeks old) and adult (30-weeks old) IHR were fed I3C for four weeks (leading to systolic BP >200 mmHg). RAS-stimulation was stopped and animals were followed-up for a consecutive period. Cardiac function and geometry was determined echocardiographically...

Renin-angiotensin system inhibitors, angiotensin I-converting enzyme gene insertion/deletion polymorphism, and cancer: The Rotterdam study

NARCIS (Netherlands)

R. van der Knaap (Ronald); C. Siemes (Claire); J.W.W. Coebergh (Jan Willem); P. Tikka-Kleemola (Päivi); A. Hofman (Albert); B.H.Ch. Stricker (Bruno)

2008-01-01

textabstractBACKGROUND. Angiotensin I-converting enzyme (ACE) inhibitors, angiotensin II antagonists, and the ACE insertion/deletion (I/D) gene polymorphism all influence serum angiotensin II action. Because angiotensin II levels have been associated with cancer, the objective of the current

Prostaglandin E2 EP2 and EP4 receptor activation mediates cAMP-dependent hyperpolarization and exocytosis of renin in juxtaglomerular cells

DEFF Research Database (Denmark)

Friis, Ulla Glenert; Stubbe, Jane; Uhrenholt, Torben Rene

2005-01-01

/l), AE1-259-01 (1 nmol/l), EP4-selective agonist AE1-329 (1 nmol/l), and IP agonist iloprost (1 micromol/l) significantly increased C(m) mediated by PKA. The EP4 antagonist AE3-208 (10 nmol/l) blocked the effect of EP4 agonist but did not alter the response to PGE(2). Application of both EP4 antagonist....... The membrane potential hyperpolarized significantly after PGE(2), butaprost, AE1-329 and AE1-259 and outward current was augmented in a PKA-dependent fashion. PGE(2)-stimulated outward current, but not C(m) change, was abolished by the BK(Ca) channel inhibitor iberiotoxin (300 nmol/l). EP2 and EP4 m......RNA was detected in sampled JG cells, and the preglomerular and glomerular vasculature was immunopositive for EP4. Thus IP, EP2, and EP4 receptors are associated with JG cells, and their activation leads to rapid PKA-mediated exocytotic fusion and release of renin granules....

Genetic variation and activity of the renin-angiotensin system and severe hypoglycemia in type 1 diabetes

DEFF Research Database (Denmark)

Pedersen-Bjergaard, U.; Dhamrait, S.S.; Sethi, A.A.

2008-01-01

BACKGROUND: The deletion-allele of the angiotensin-converting enzyme (ACE) gene and elevated ACE activity are associated with increased risk of severe hypoglycemia in type 1 diabetes. We explored whether genetic and phenotypic variations in other components of the renin-angiotensin system...... are similarly associated. METHODS: Episodes of severe hypoglycemia were recorded in 171 consecutive type 1 diabetic outpatients during a 1-year follow-up. Participants were characterized at baseline by gene polymorphisms in angiotensinogen, ACE, angiotensin-II receptor types 1 (AT1R) and 2 (AT2R), and by plasma...... associate with high risk of severe hypoglycemia in type 1 diabetes. A potential preventive effect of renin-angiotensin system blocking drugs in patients with recurrent severe hypoglycemia merits further investigation Udgivelsesdato: 2008/3...

Angiotensin receptor-neprilysin inhibitors: clinical potential in heart failure and beyond

Directory of Open Access Journals (Sweden)

Singh JSS

2015-06-01

Full Text Available Jagdeep SS Singh, Chim C Lang Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK Abstract: Heart failure remains a major concern across the globe as life expectancies and delivery of health care continue to improve. There has been a dearth of new developments in heart failure therapies in the last decade until last year, with the release of the results from the PARADIGM-HF Trial heralding the arrival of a promising new class of drug, ie, the angiotensin receptor-neprilysin inhibitor. In this review, we discuss the evolution of our incremental understanding of the neurohormonal mechanisms involved in the pathophysiology of heart failure, which has led to our success in modulating its various pathways. We start by examining the renin-angiotensin-aldosterone system, followed by the challenges of modulating the natriuretic peptide system. We then delve deeper into the pharmacology and mechanisms by which angiotensin receptor-neprilysin inhibitors achieve their significant cardiovascular benefits. Finally, we also consider the potential application of this new class of drug in other areas, such as heart failure with preserved ejection fraction, hypertension, patients with renal impairment, and following myocardial infarction. Keywords: heart failure, angiotensin receptor-neprilysin inhibitor, heart failure with preserved ejection fraction, nesiritide, candoxatril, omapatrilat, hypertension, renal impairment, myocardial infarction

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

Science.gov (United States)

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.

(Pro)renin receptor: Involvement in diabetic retinopathy and development of molecular targeted therapy.

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Kanda, Atsuhiro; Ishida, Susumu

2018-03-25

The renin-angiotensin system (RAS), a crucial regulator of systemic blood pressure (circulatory RAS), plays distinct roles in pathological angiogenesis and inflammation in various organs (tissue RAS), such as diabetic microvascular complications. Using ocular clinical samples and animal disease models, we elucidated molecular mechanisms in which tissue RAS excites the expression of vascular endothelial growth factor (VEGF)-A responsible for retinal inflammation and angiogenesis, the two major pathological events in diabetic retinopathy (DR). Furthermore, we showed the involvement of (pro)renin receptor [(P)RR] in retinal RAS activation and its concurrent intracellular signal transduction (e.g., extracellular signal-regulated kinase); namely, the (P)RR-induced dual pathogenic bioactivity referred to as the receptor-associated prorenin system. Indeed, neovascular endothelial cells in the fibrovascular tissue collected from eyes with proliferative DR were immunoreactive for the receptor-associated prorenin system components including prorenin, (P)RR, phosphorylated extracellular signal-regulated kinase and VEGF-A. Protein levels of soluble (P)RR increased with its positive correlations with prorenin, renin enzymatic activity and VEGF in the vitreous of proliferative DR eyes, suggesting a close link between (P)RR and VEGF-A-driven angiogenic activity. Furthermore, we revealed an unsuspected, PAPS-independent role of (P)RR in glucose-induced oxidative stress. Recently, we developed an innovative single-strand ribonucleic acid interference molecule selectively targeting human and mouse (P)RR, and confirmed its efficacy in suppressing diabetes-induced retinal inflammation in mice. Our data using clinical samples and animal models suggested the significant implication of (P)RR in the pathogenesis of DR, and the potential usefulness of the ribonucleic acid interference molecule as a therapeutic agent to attenuate ocular inflammation and angiogenesis. © 2018 The Authors

Contribution of the basolateral isoform of the Na-K-2Cl- cotransporter (NKCC1/BSC2) to renin secretion

DEFF Research Database (Denmark)

Castrop, Hayo; Lorenz, John N; Hansen, Pernille B

2005-01-01

Acute administration of loop diuretics like furosemide leads to a stimulation of renin secretion, an effect thought to result from inhibition of Na-K-2Cl cotransporter (NKCC2)-mediated salt transport at the luminal surface of the macula densa (MD). However, loop diuretics also inhibit NKCC1......, the second isoform of the Na-K-2Cl cotransporter, with similar potency. In the present study, we examined the influence of furosemide on renin secretion in NKCC1-deficient mice to distinguish between effects of the loop diuretic involving NKCC2 and, by implication, the MD pathway, and effects that might...

Discovery of potent 1H-imidazo[4,5-b]pyridine-based c-Met kinase inhibitors via mechanism-directed structural optimization.

Science.gov (United States)

An, Xiao-De; Liu, Hongyan; Xu, Zhong-Liang; Jin, Yi; Peng, Xia; Yao, Ying-Ming; Geng, Meiyu; Long, Ya-Qiu

2015-02-01

Starting from our previously identified novel c-Met kinase inhibitors bearing 1H-imidazo[4,5-h][1,6]naphthyridin-2(3H)-one scaffold, a global structural exploration was conducted to furnish an optimal binding motif for further development, directed by the enzyme inhibitory mechanism. First round SAR study picked two imidazonaphthyridinone frameworks with 1,8- and 3,5-disubstitution pattern as class I and class II c-Met kinase inhibitors, respectively. Further structural optimization on type II inhibitors by truncation of the imidazonaphthyridinone core and incorporation of an N-phenyl cyclopropane-1,1-dicarboxamide pharmacophore led to the discovery of novel imidazopyridine-based c-Met kinase inhibitors, displaying nanomolar enzyme inhibitory activity and improved Met kinase selectivity. More significantly, the new chemotype c-Met kinase inhibitors effectively inhibited Met phosphorylation and its downstream signaling as well as the proliferation of Met-dependent EBC-1 human lung cancer cells at submicromolar concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bioassay-directed fractionation of a blood coagulation factor Xa inhibitor, betulinic acid from Lycopus lucidus

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Tan Yin-Feng

2018-03-01

Full Text Available Thrombosis is a major cause of morbidity and mortality worldwide and plays a pivotal role in the pathogenesis of several cardiovascular disorders, including acute coronary syndrome, unstable angina, myocardial infarction, sudden cardiac death, peripheral arterial occlusion, ischemic stroke, deep-vein thrombosis, and pulmonary embolism. Anticoagulants, antiplatelet agents, and fibrinolytics can reduce the risks of these clinical events. Especially, the blood coagulation factor Xa (FXa inhibitor is a proven anticoagulant. Promoting blood circulation, using traditional Chinese medicine (TCM, for the treatment of these diseases has been safely used for thousands of years in clinical practice. Therefore, highly safe and effective anticoagulant ingredients, including FXa inhibitors, could be found in TCM for activating the blood circulation. One FXa inhibitor, a pentacyclic triterpene (compound 1, betulinic acid characterized by IR, MS and NMR analyses, was isolated from the ethyl acetate fraction of Lycopus lucidus by bioassay-directed fractionation. Compound 1 exhibited an inhibitory effect on FXa with IC50 25.05 μmol/L and reduced the thrombus weight in an animal model at 25-100 mg/kg. These results indicate that betulinic acid could be the potential for anticoagulant therapy.

The renin-angiotensin system and its blockers

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Igić Rajko

2014-01-01

Full Text Available Research on the renin-angiotensin system (RAS has contributed significantly to advances in understanding cardiovascular and renal homeostasis and to the treatment of cardiovascular diseases. This review offers a brief history of the RAS with an overview of its major components and their functions, as well as blockers of the RAS, their clinical usage and current research that targets various components of the RAS. Because angiotensin-converting enzyme (ACE metabolizes two biologically active peptides, one in the kallikrein-kinin system (KKS and one in the RAS, it is the essential connection between the two systems. ACE releases very powerful hypertensive agent, angiotensin II and also inactivates strong hypotensive peptide, bradykinin. Inhibition of ACE thus has a dual effect, resulting in decreased angiotensin II and increased bradykinin. We described the KKS as well.

Half-of-the-sites reactivity of outer-membrane phospholipase A against an active-site-directed inhibitor.

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Ubarretxena-Belandia, I; Cox, R C; Dijkman, R; Egmond, M R; Verheij, H M; Dekker, N

1999-03-01

The reaction of a novel active-site-directed phospholipase A1 inhibitor with the outer-membrane phospholipase A (OMPLA) was investigated. The inhibitor 1-p-nitrophenyl-octylphosphonate-2-tridecylcarbamoyl-3-et hanesulfonyl -amino-3-deoxy-sn-glycerol irreversibly inactivated OMPLA. The inhibition reaction did not require the cofactor calcium or an unprotonated active-site His142. The inhibition of the enzyme solubilized in hexadecylphosphocholine micelles was characterized by a rapid (t1/2 = 20 min) and complete loss of enzymatic activity, concurrent with the covalent modification of 50% of the active-site serines, as judged from the amount of p-nitrophenolate (PNP) released. Modification of the remaining 50% occurred at a much lower rate, indicative of half-of-the-sites reactivity against the inhibitor of this dimeric enzyme. Inhibition of monomeric OMPLA solubilized in hexadecyl-N,N-dimethyl-1-ammonio-3-propanesulfonate resulted in an equimolar monophasic release of PNP, concurrent with the loss of enzymatic activity (t1/2 = 14 min). The half-of-the-sites reactivity is discussed in view of the dimeric nature of this enzyme.

Antitubercular drugs for an old target: GSK693 as a promising InhA direct inhibitor

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María Martínez-Hoyos

2016-06-01

Full Text Available Despite being one of the first antitubercular agents identified, isoniazid (INH is still the most prescribed drug for prophylaxis and tuberculosis (TB treatment and, together with rifampicin, the pillars of current chemotherapy. A high percentage of isoniazid resistance is linked to mutations in the pro-drug activating enzyme KatG, so the discovery of direct inhibitors (DI of the enoyl-ACP reductase (InhA has been pursued by many groups leading to the identification of different enzyme inhibitors, active against Mycobacterium tuberculosis (Mtb, but with poor physicochemical properties to be considered as preclinical candidates. Here, we present a series of InhA DI active against multidrug (MDR and extensively (XDR drug-resistant clinical isolates as well as in TB murine models when orally dosed that can be a promising foundation for a future treatment.

Neuronal nitric oxide synthase supports Renin release during sodium restriction through inhibition of phosphodiesterase 3

DEFF Research Database (Denmark)

Sällström, Johan; Jensen, Boye L; Skøtt, Ole

2010-01-01

NOS supports renin release by cyclic guanosine monophosphate (cGMP)-mediated inhibition of cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase 3 (PDE3) in juxtaglomerular (JG) cells. METHODS: The experiments were performed in conscious nNOS⁻(/)⁻ and wild types after 10 days on a low-sodium diet...... by measurements of inulin- and para-amino hippuric acid (PAH) clearances, respectively. RESULTS: The basal PRC was reduced in nNOS⁻(/)⁻ compared to the wild types. Administration of milrinone caused a more pronounced PRC increase in nNOS⁻(/)⁻, resulting in normalized renin levels, whereas PDE5 inhibition did...... not affect PRC in any genotype. The blood pressure was similar in both genotypes, and milrinone did not affect blood pressure compared to vehicle. GFR and RPF were similar at baseline and were reduced by milrinone. CONCLUSIONS: The present study provides in vivo evidence supporting the view that NO...

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

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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 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.

Pharmacokinetic/Pharmacodynamic Modeling of Renin-Angiotensin Aldosterone Biomarkers Following Angiotensin-Converting Enzyme (ACE) Inhibition Therapy with Benazepril in Dogs.

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Mochel, Jonathan P; Fink, Martin; Peyrou, Mathieu; Soubret, Antoine; Giraudel, Jérôme M; Danhof, Meindert

2015-06-01

The objective of this research was to provide a comprehensive description of the effect of benazepril on the dynamics of the renin-angiotensin aldosterone system (RAAS) in dogs. Blood specimens for renin activity (RA), angiotensin II (AII), and aldosterone (ALD) quantitation in plasma were drawn from 12 healthy adult beagle dogs randomly allocated to 2 treatment groups: (i) benazepril 5 mg PO, q24 h (n: 6) and (ii) placebo (n: 6), in a cross-over design. A mechanism-based pharmacokinetic/pharmacodynamic model, which includes the periodic nature of RA, AII, and ALD during placebo treatment and the subsequent changes in dynamics following repeated dosing with benazepril, was developed. The disposition kinetics of benazepril active metabolite, benazeprilat, was characterized using a saturable binding model to the angiotensin converting enzyme. The modulatory effect of benazeprilat on the RAAS was described using a combination of immediate response models. Our data show that benazepril noticeably influences the dynamics of the renin cascade, resulting in a substantial decrease in AII and ALD, while increasing RA throughout the observation span. The model provides a quantitative framework for better understanding the effect of ACE inhibition on the dynamics of the systemic RAAS in dogs.

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

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

2013-01-01

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

The role of renin angiotensin system intervention in stage B heart failure.

LENUS (Irish Health Repository)

Collier, Patrick

2012-04-01

This article outlines the link between the renin angiotensin aldosterone system (RAAS) and various forms of cardiomyopathy, and also reviews the understanding of the effectiveness of RAAS intervention in this phase of ventricular dysfunction. The authors focus their discussion predominantly on patients who have had previous myocardial infarction or those who have left ventricular hypertrophy and also briefly discuss the role of RAAS activation and intervention in patients with alcoholic cardiomyopathy.

The Impact of Renin-Angiotensin System Blockade on Renal Outcomes and Mortality in Pre-Dialysis Patients with Advanced Chronic Kidney Disease.

Science.gov (United States)

Oh, Yun Jung; Kim, Sun Moon; Shin, Byung Chul; Kim, Hyun Lee; Chung, Jong Hoon; Kim, Ae Jin; Ro, Han; Chang, Jae Hyun; Lee, Hyun Hee; Chung, Wookyung; Lee, Chungsik; Jung, Ji Yong

2017-01-01

Renin-angiotensin-system (RAS) blockade is thought to slow renal progression in patients with chronic kidney disease (CKD). However, it remains uncertain if the habitual use of RAS inhibitors affects renal progression and outcomes in pre-dialysis patients with advanced CKD. In this multicenter retrospective cohort study, we identified 2,076 pre-dialysis patients with advanced CKD (stage 4 or 5) from a total of 33,722 CKD patients. RAS blockade users were paired with non-users for analyses using inverse probability of treatment-weighted (IPTW) and propensity score (PS) matching. The outcomes were renal death, all-cause mortality, hospitalization for hyperkalemia, and interactive factors as composite outcomes. RAS blockade users showed an increased risk of renal death in PS-matched analysis (hazard ratio [HR], 1.381; 95% CI, 1.071-1.781; P = 0.013), which was in agreement with the results of IPTW analysis (HR, 1.298; 95% CI, 1.123-1.500; P renal outcome without improving all-cause mortality. Further studies are warranted to determine whether withholding RAS blockade may lead to better outcomes in these patients.

Hyponatremic hypertensive syndrome secondary to renal ischemia – Case report

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Joana Cunha Oliveira

2018-01-01

Full Text Available Hyponatremic hypertensive syndrome (HHS is characterized by hypertensive crisis, and hyponatremia secondary to unilateral renal damage with glomerular and tubular dysfunction. Elevated plasma levels of renin in most cases suggest that the stimulation of renin release from the ischemic kidney plays an important pathophysiologic role. Activation of the renin-angiotensin system results in hypertension and causes secondary hyperfiltration, pressure diuresis and sodium loss from contralateral non-damaged kidney. An elevated renin level is a pathognomonic finding in HHS. Potassium deficiency from hyperaldosteronism may further stimulate renin secretion and intensify this vicious circle.We report a female term newborn, who presented with hypertensive crisis on the seventh day after traumatic birth. The first three days of life were uneventful. Initial treatment with captopril resulted in severe hypotension and hemodynamic instability. Lab work revealed hyponatremia, hypokalemia, and elevated peripheral renin activity and aldosterone levels. Complementary sonography and magnetic resonance confirmed right adrenal gland hematoma and several ischemic areas in the upper pole of the right kidney. The diagnosis of HHS secondary to renal ischemia was evoked.HHS is a rare condition in the neonatal period, though still under-recognized. In the neonatal and early infancy period, renovascular disease is the most common cause of secondary hypertension. In this case, there was no sign of vascular disease, the renin-angiotensin system was activated secondary to direct renal ischemia and infarction. The intense renin stimulation and pressure through the contralateral normal kidney results in high pressure natriuresis facilitating a severe volume-depleted state. Although the use of renin-angiotensin system inhibitors is the treatment of choice, it is imperative to re-establish hydration and renal perfusion before starting this antihypertensive medication. We aimed to

Structural adaptation to ischemia in skeletal muscle: effects of blockers of the renin-angiotensin system

NARCIS (Netherlands)

Scheidegger, K. J.; Nelissen-Vrancken, M. H.; Leenders, P. J.; Daemen, M. J.; Smits, J. F.; Wood, J. M.

1997-01-01

To investigate the effects of long-term treatment with blockers of the renin-angiotensin system on capillarization and growth of fibers in ischemic hind-limb muscles and in muscles under normal growth conditions. Ischemia was induced by partial ligation of the left common iliac artery. Ischemia

Dexamethasone-responsive hypertension in young women with suppressed renin and aldosterone

International Nuclear Information System (INIS)

Hoefnagels, W.H.L.; Hofman, J.A.; Smals, A.G.H.; Drayer, J.I.M.; Kloppenborg, P.W.C.; Benraad, T.J.

1978-01-01

Pronounced hypoaldosteronism was found in three young women with hypertension and symptoms of mineralocorticoid overproduction - i.e., hyporeninaemia, hypokalaemia, and a fall in blood-pressure after diuretic therapy. Plasma 11-deoxycorticosterone and 18-hydroxy-11-deoxycorticosterone concentrations were normal. Treatment with dexamethasone induced a return to normal of blood-pressure and plasma-potassium and an increase in plasma-renin activity and urinary aldosterone excretion. The data suggest that hypertension in these patients is maintained by overproduction of an unknown adrenocorticotropin-dependent mineralocortocoid. (author)

Role of proteinuria in the regulation of renal renin-angiotensin system components in unilateral proteinuric rats

NARCIS (Netherlands)

Deelman, LE; Navis, G; Wietses, M; de Zeeuw, D; Henning, RH

Renin-angiotensin system (RAS) overactivity has been implied in progressive renal function loss. We investigated whether changes in the renal expression of RAS components are specifically associated with the proteinuric kidney. Unilateral adriamycin-induced proteinuria was obtained by clamping the

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

Science.gov (United States)

Sabharwal, Rasna; Chapleau, Mark W

2014-04-01

New Findings What is the topic of this review? This symposium report summarizes autonomic, cardiac and skeletal muscle abnormalities in sarcoglycan-δ-deficient mice (Sgcd-/-), a mouse model of limb girdle muscular dystrophy, with emphasis on the roles of autonomic dysregulation and activation of the renin-angiotensin system at a young age. What advances does it highlight? The contributions of the autonomic nervous system and the renin-angiotensin system to the pathogenesis of muscular dystrophy are highlighted. Results demonstrate that autonomic dysregulation precedes and predicts later development of cardiac dysfunction in Sgcd-/- mice and that treatment of young Sgcd-/- mice with the angiotensin type 1 receptor antagonist losartan or with angiotensin-(1-7) abrogates the autonomic dysregulation, attenuates skeletal muscle pathology and increases spontaneous locomotor activity. Muscular dystrophies are a heterogeneous group of genetic muscle diseases characterized by muscle weakness and atrophy. Mutations in sarcoglycans and other subunits of the dystrophin-glycoprotein complex cause muscular dystrophy and dilated cardiomyopathy in animals and humans. Aberrant autonomic signalling is recognized in a variety of neuromuscular disorders. We hypothesized that activation of the renin-angiotensin system contributes to skeletal muscle and autonomic dysfunction in mice deficient in the sarcoglycan-δ (Sgcd) gene at a young age and that this early autonomic dysfunction contributes to the later development of left ventricular (LV) dysfunction and increased mortality. We demonstrated that young Sgcd-/- mice exhibit histopathological features of skeletal muscle dystrophy, decreased locomotor activity and severe autonomic dysregulation, but normal LV function. Autonomic regulation continued to deteriorate in Sgcd-/- mice with age and was accompanied by LV dysfunction and dilated cardiomyopathy at older ages. Autonomic dysregulation at a young age predicted later development of

[Changes in the renin-angiotensin-aldosterone system and water-salt exchange in mining workers in coal mines].

Science.gov (United States)

Rebrov, B A

1996-01-01

Blood and urine content of electrolytes and creatinine was determined in 76 essentially healthy miners before and after work shift, as was activity of plasma renin, blood plasma level of aldosterone and its urinary excretion, with the aid of radioimmunoassay. The greatest activity of the renin-angiotensine-aldosterone system (RAAS) occurred in those individuals engaged in hard physical labour under most harsh conditions of underground workings, this being recordable not only is response to the load but also from the very start. Controls and miners doing jobs of medium-level strenuousness demonstrated changes in the correlations between RAAS and water-salt balance after the work shift as compared with those before the work shift, while in those miners engaged in hard work correlations RAAS-water-salt exchange remained practically the same throughout the study.

Renin-Angiotensin Activation and Oxidative Stress in Early Heart Failure with Preserved Ejection Fraction

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Smita I. Negi

2015-01-01

Full Text Available Animal models have suggested a role of renin-angiotensin system (RAS activation and subsequent cardiac oxidation in heart failure with preserved ejection fraction (HFpEF. Nevertheless, RAS blockade has failed to show efficacy in treatment of HFpEF. We evaluated the role of RAS activation and subsequent systemic oxidation in HFpEF. Oxidative stress markers were compared in 50 subjects with and without early HFpEF. Derivatives of reactive oxidative metabolites (DROMs, F2-isoprostanes (IsoPs, and ratios of oxidized to reduced glutathione (Eh GSH and cysteine (Eh CyS were measured. Angiotensin converting enzyme (ACE levels and activity were measured. On univariate analysis, HFpEF was associated with male sex (p=0.04, higher body mass index (BMI (p=0.003, less oxidized Eh CyS (p=0.001, lower DROMs (p=0.02, and lower IsoP (p=0.03. Higher BMI (OR: 1.3; 95% CI: 1.1–1.6 and less oxidized Eh CyS (OR: 1.2; 95% CI: 1.1–1.4 maintained associations with HFpEF on multivariate analysis. Though ACE levels were higher in early HFpEF (OR: 1.09; 95% CI: 1.01–1.05, ACE activity was similar to that in controls. HFpEF is not associated with significant systemic RAS activation or oxidative stress. This may explain the failure of RAS inhibitors to alter outcomes in HFpEF.

Changing the inhibitory specificity and function of Cucurbita maxima trypsin inhibitor-V by site-directed mutagenesis.

Science.gov (United States)

Wen, L; Lee, I; Chen, G; Huang, J K; Gong, Y; Krishnamoorthi, R

1995-02-27

Cucurbita maxima trypsin inhibitor-V (CMTI-V) is also a specific inhibitor of human blood coagulation factor beta-factor XIIa. A recombinant version of CMTI-V has allowed probing of roles of individual amino acid residues including the reactive site residue, lysine (P1), by site-directed mutagenesis. The K44R showed at least a 5-fold increase in inhibitory activity toward human beta-factor XIIa, while there was no change toward bovine trypsin. This result demonstrates that beta-factor-XIIa prefers an arginine residue over lysine residue, while trypsin is non-specific to lysine or arginine in its binding pocket. On the other hand, the specificity of CMTI-V could be changed from trypsin to chymotrypsin inhibition by mutation of the P1 residue to either leucine or methionine (K44L or K44M).

Regulation of the renin-angiotensin-aldosterone system in fibromyalgia.

Science.gov (United States)

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.

Role of aliskiren in cardio-renal protection and use in hypertensives with multiple risk factors

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Eduardo Pimenta

2009-06-01

Full Text Available Eduardo Pimenta1, Suzanne Oparil21Endocrine Hypertension Research Centre and Clinical Centre of Research Excellence in Cardiovascular Disease and Metabolic Disorders, University of Queensland School of Medicine, Greenslopes Princess Alexandra Hospitals, Brisbane, QLD, Australia; 2Vascular Biology and Hypertension Program, University of Alabama at Birmingham, Birmingham, AL, USAAbstract: The renin–angiotensin–aldosterone system (RAAS is a key mediator of blood pressure (BP and volume regulation in both normotensive and hypertensive persons. Stimulation of RAAS also contributes to hypertension-related target organ damage. The renin–angiotensinogen reaction is the first and rate-limiting step in the generation of angiotensin II (Ang II and has been a target of antihypertensive drug development for decades. Aliskiren is the first in a new class of orally effective direct renin inhibitors (DRIs and is approved for the treatment of hypertension in humans. It effectively reduces BP in the general population of hypertensive patients and has a tolerability and safety profile similar to placebo. Aliskiren has favorable effects on vascular inflammation and remodeling, on neurohumoral mediators of various forms of cardiovascular disease, including heart failure, and on proteinuria in diabetic patients. Additional outcome trials are needed to establish the role of this novel class of antihypertensive medication in preventing cardiovascular disease morbidity and mortality.Keywords: hypertension, renin inhibitors, renin-angiotensin-aldosterone system

Graz Endocrine Causes of Hypertension (GECOH study: a diagnostic accuracy study of aldosterone to active renin ratio in screening for primary aldosteronism

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Dobnig Harald

2009-04-01

Full Text Available Abstract Background Primary aldosteronism (PA affects approximately 5 to 10% of all patients with arterial hypertension and is associated with an excess rate of cardiovascular complications that can be significantly reduced by a targeted treatment. There exists a general consensus that the aldosterone to renin ratio should be used as a screening tool but valid data about the accuracy of the aldosterone to renin ratio in screening for PA are sparse. In the Graz endocrine causes of hypertension (GECOH study we aim to prospectively evaluate diagnostic procedures for PA. Methods and design In this single center, diagnostic accuracy study we will enrol 400 patients that are routinely referred to our tertiary care center for screening for endocrine hypertension. We will determine the aldosterone to active renin ratio (AARR as a screening test. In addition, all study participants will have a second determination of the AARR and will undergo a saline infusion test (SIT as a confirmatory test. PA will be diagnosed in patients with at least one AARR of ≥ 5.7 ng/dL/ng/L (including an aldosterone concentration of ≥ 9 ng/dL who have an aldosterone level of ≥ 10 ng/dL after the saline infusion test. As a primary outcome we will calculate the receiver operating characteristic curve of the AARR in diagnosing PA. Secondary outcomes include the test characteristics of the saline infusion test involving a comparison with 24 hours urine aldosterone levels and the accuracy of the aldosterone to renin activity ratio in diagnosing PA. In addition we will evaluate whether the use of beta-blockers significantly alters the accuracy of the AARR and we will validate our laboratory methods for aldosterone and renin. Conclusion Screening for PA with subsequent targeted treatment is of great potential benefit for hypertensive patients. In the GECOH study we will evaluate a standardised procedure for screening and diagnosing of this disease.

ROS inhibitor N-acetyl-L-cysteine antagonizes the activity of proteasome inhibitors.

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Halasi, Marianna; Wang, Ming; Chavan, Tanmay S; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L

2013-09-01

NAC (N-acetyl-L-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H₂O₂. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabilization, apoptosis and accumulation of ubiquitin conjugates. These observations suggest that NAC has a dual activity as an inhibitor of ROS and proteasome inhibitors. Recently, NAC was used as a ROS inhibitor to functionally characterize a novel anticancer compound, piperlongumine, leading to its description as a ROS inducer. In contrast, our own experiments showed that this compound depicts features of proteasome inhibitors including suppression of FOXM1 (Forkhead box protein M1), stabilization of cellular proteins, induction of ROS-independent apoptosis and enhanced accumulation of ubiquitin conjugates. In addition, NAC, but not catalase or Trolox, interfered with the activity of piperlongumine, further supporting that piperlongumine is a proteasome inhibitor. Most importantly, we showed that NAC, but not other ROS scavengers, directly binds to proteasome inhibitors. To our knowledge, NAC is the first known compound that directly interacts with and antagonizes the activity of proteasome inhibitors. Taken together, the findings of the present study suggest that, as a result of the dual nature of NAC, data interpretation might not be straightforward when NAC is utilized as an antioxidant to demonstrate ROS involvement in drug-induced apoptosis.

The Evaluation of Angiotensin-Converting Enzyme Inhibitors in Renal Elimination with Selected Molecular Descriptors

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Trbojevic Jovana

2017-06-01

Full Text Available Angiotensin-converting enzyme (ACE inhibitors modulate the function of the renin-angiotensin-aldosterone system, and they are commonly prescribed antihypertensive drugs especially in patients with renal failure. In this study, the relationships between several molecular properties of eight ACE inhibitors (enalapril, quinapril, fosinopril, ramipril, benazepril, perindopril, moexipril, trandolapril and their renal elimination data, from relevant literature, were investigated. The ’molecular descriptors of the ACE inhibitors, which included aqueous solubility data (logS; an electronic descriptor, polar surface area (PSA;, a constitutional parameter, molecular mass (Mr; and a geometric descriptor, volume value (Vol, as well as lipophilicity descriptors (logP values, were calculated using different software packages. Simple linear regression analysis showed the best correlation between renal elimination data and lipophilicity descriptor AClogP values (R2 = 0.5742. In the next stage of the study, multiple linear regression was applied to assess a higher correlation between the ACE inhibitors’ renal elimination data and lipophilicity, AClogP, with one additional descriptor as an independent variable. Good correlations were established between renal elimination data from the literature and the AClogP lipophilicity descriptor using the constitutional parameter (molecular mass (R2 = 0.7425 or the geometric descriptor (volume value (R2 = 0.7224 as an independent variable. The application of computed molecular descriptors in evaluating drug elimination is of great importance in drug research.

Blockade of AT1 receptors by losartan did not affect renin gene expression in kidney medulla

Czech Academy of Sciences Publication Activity Database

Tybitanclová, K.; Szabová, L.; Grima, M.; Ingert, C.; Železná, Blanka; Zórad, Š.

2006-01-01

Roč. 25, č. 1 (2006), s. 43-51 ISSN 0231-5882 Grant - others:VEGA(SK) 2/5090/25 Institutional research plan: CEZ:AV0Z50520514 Keywords : AT1 receptor * renin-angiotensin system * kidneys Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.771, year: 2006

Salt sensitivity of renin secretion, glomerular filtration rate and blood pressure in conscious Sprague-Dawley rats

DEFF Research Database (Denmark)

Isaksson, G L; Stubbe, J; Hansen, Per Lyngs

2014-01-01

We hypothesized that in normal rats in metabolic steady state, (i) the plasma renin concentration (PRC) is log-linearly related to Na(+) intake (NaI), (ii) the concurrent changes in mean arterial pressure (MABP) and glomerular filtration rate (GFR) are negligible and (iii) the function PRC...

High-resolution crystal structures of Drosophila melanogaster angiotensin-converting enzyme in complex with novel inhibitors and antihypertensive drugs.

Science.gov (United States)

Akif, Mohd; Georgiadis, Dimitris; Mahajan, Aman; Dive, Vincent; Sturrock, Edward D; Isaac, R Elwyn; Acharya, K Ravi

2010-07-16

Angiotensin I-converting enzyme (ACE), one of the central components of the renin-angiotensin system, is a key therapeutic target for the treatment of hypertension and cardiovascular disorders. Human somatic ACE (sACE) has two homologous domains (N and C). The N- and C-domain catalytic sites have different activities toward various substrates. Moreover, some of the undesirable side effects of the currently available and widely used ACE inhibitors may arise from their targeting both domains leading to defects in other pathways. In addition, structural studies have shown that although both these domains have much in common at the inhibitor binding site, there are significant differences and these are greater at the peptide binding sites than regions distal to the active site. As a model system, we have used an ACE homologue from Drosophila melanogaster (AnCE, a single domain protein with ACE activity) to study ACE inhibitor binding. In an extensive study, we present high-resolution structures for native AnCE and in complex with six known antihypertensive drugs, a novel C-domain sACE specific inhibitor, lisW-S, and two sACE domain-specific phosphinic peptidyl inhibitors, RXPA380 and RXP407 (i.e., nine structures). These structures show detailed binding features of the inhibitors and highlight subtle changes in the orientation of side chains at different binding pockets in the active site in comparison with the active site of N- and C-domains of sACE. This study provides information about the structure-activity relationships that could be utilized for designing new inhibitors with improved domain selectivity for sACE. 2010 Elsevier Ltd. All rights reserved.

Severe hypoglycaemia in type 1 diabetes: impact of the renin-angiotensin system and other risk factors

DEFF Research Database (Denmark)

Pedersen-Bjergaard, Ulrik

2009-01-01

Hypoglycaemia is an unavoidable side effect to insulin therapy of diabetes. In daily life some hypoglycaemic episodes are recognised by the patients and corrected by ingestion of glucose, but occasionally unrecognised episodes progress into severe hypoglycaemia with cognitive impairment and the n......Hypoglycaemia is an unavoidable side effect to insulin therapy of diabetes. In daily life some hypoglycaemic episodes are recognised by the patients and corrected by ingestion of glucose, but occasionally unrecognised episodes progress into severe hypoglycaemia with cognitive impairment...... both subjects at low and at high risk within a one-year period were identified. Preliminary data suggest that this is explained by impaired capability of subjects with high renin-angiotensin system activity to maintain cognitive function during hypoglycaemia. The clinical implications of this finding...... which, however, must await additional independent confirmation, include prediction and possibly some prevention of severe hypoglycaemia. An evaluation of renin-angiotensin system activity may - together with assessment of other risk factors - contribute to rational individualized setting of glycaemic...

Involvement of Renin-Angiotensin System in Retinopathy of Prematurity - A Possible Target for Therapeutic Intervention.

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Madhu Nath

Full Text Available Examining the Retinal Renin Angiotensin System (RRAS in the ROP neonates and analyzing the possibility of modulating the RRAS to prevent the progression in Oxygen Induced Retinopathy (OIR model.Vitreous of ROP patients (n = 44, median age 5.5 months was quantified for RRAS components, VEGF, HIF-1α and compared with age matched control. The involvement of RRAS in ROP was tested in the rat model of OIR and compared with normoxia. Expressions of RAS components, VEGF and HIF-1α in retina were analyzed using qPCR and retinal structure and function was also analyzed. Effect of Angiotensin Converting Enzyme Inhibitor (ACEI and Angiotensin Receptor Blocker (ARB was evaluated and compared with Bevacizumab which served as a positive control. Drug penetration into retina was confirmed by liquid chromatography coupled ESI-tandem mass spectroscopy (LC-MS/MS.Multifold increase in the expression of RAS components in human vitreous and rat retina showed their involvement in ROP. ERG & fundus studies in OIR revealed the altered function of retina and were successfully prevented by ARB (telmisartan, ACEI (lisinopril and bevacizumab. Retinal analysis revealed the presence of ACEI and ARB in their therapeutic levels.This study for the first time demonstrates the upregulated level of RAS components in human ROP vitreous and further that the pharmacological intervention in RRAS can functionally and structurally preserve retina against the progression of ROP in the OIR model.

The role of vascular protein and renin in chronic two-kidney, one clip Goldblatt hypertension

International Nuclear Information System (INIS)

Nakada, T.; Yamori, Y.

1982-01-01

Chronic hypertension was induced in rats by application of a clip for 17 or 20 weeks to the unilateral renal artery and leaving the contrarenal vessel intact. Some of the rats received antihypertensive treatment with phenoxybenzamine (POB). 3 H-proline was injected into all rats in the 17th experimental week to observe the in vivo incorporation rates of 3 H-proline into vascular non-collagenous protein and vascular collagen. Plasma renin activity (PRA) of decapitated rats was assayed in the terminal stage of the experiment. Significant differences were noted between 2K-1C hypertensive rats and sham-operated normotensive rats, the former rats having significantly higher incorporation rates of 3 H-proline into non-collagenous protein and collagen of testicular or mesenteric artery. These results indicate that increased synthesis of vascular non-collagenous protein as well as collagen, especially of small arteries, plays a major role for the pathogenesis of chronic hypertension in 2K-1C rats, and renin does not contribute to elevation of the blood pressure in the maintenance phase of this type of experimental hypertension

Direct modulation of T-box riboswitch-controlled transcription by protein synthesis inhibitors.

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Stamatopoulou, Vassiliki; Apostolidi, Maria; Li, Shuang; Lamprinou, Katerina; Papakyriakou, Athanasios; Zhang, Jinwei; Stathopoulos, Constantinos

2017-09-29

Recently, it was discovered that exposure to mainstream antibiotics activate numerous bacterial riboregulators that control antibiotic resistance genes including metabolite-binding riboswitches and other transcription attenuators. However, the effects of commonly used antibiotics, many of which exhibit RNA-binding properties, on the widespread T-box riboswitches, remain unknown. In Staphylococcus aureus, a species-specific glyS T-box controls the supply of glycine for both ribosomal translation and cell wall synthesis, making it a promising target for next-generation antimicrobials. Here, we report that specific protein synthesis inhibitors could either significantly increase T-box-mediated transcription antitermination, while other compounds could suppress it, both in vitro and in vivo. In-line probing of the full-length T-box combined with molecular modelling and docking analyses suggest that the antibiotics that promote transcription antitermination stabilize the T-box:tRNA complex through binding specific positions on stem I and the Staphylococcal-specific stem Sa. By contrast, the antibiotics that attenuate T-box transcription bind to other positions on stem I and do not interact with stem Sa. Taken together, our results reveal that the transcription of essential genes controlled by T-box riboswitches can be directly modulated by commonly used protein synthesis inhibitors. These findings accentuate the regulatory complexities of bacterial response to antimicrobials that involve multiple riboregulators. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

The PGE(2)-EP4 receptor is necessary for stimulation of the renin-angiotensin-aldosterone system in response to low dietary salt intake in vivo

DEFF Research Database (Denmark)

Pöschke, Antje; Kern, Niklas; Maruyama, Takayuki

2012-01-01

, creatinine clearance, and plasma antidiuretic hormone (ADH) concentration. Following salt restriction, plasma renin and aldosterone concentrations and kidney renin mRNA level rose significantly in EP4(+/+) but not in EP4(-/-) and in wild-type mice treated with EP4 antagonist ONO-AE3-208. In the latter two...... groups, the low-salt diet caused a significantly greater rise in PGE(2) excretion. Furthermore, mRNA expression for COX-2 and PGE(2) synthetic activity was significantly greater in EP4(-/-) than in EP4(+/+) mice. We conclude that low dietary salt intake induces expression of COX-2 followed by enhanced...... renal PGE(2) synthesis, which stimulates the renin-angiotensin-aldosterone system by activation of EP4 receptor. Most likely, defects at the step of EP4 receptor block negative feedback mechanisms on the renal COX system, leading to persistently high PGE(2) levels, diuresis, and K(+) loss....

Neuronal nitric oxide synthase-deficient mice have impaired Renin release but normal blood pressure

DEFF Research Database (Denmark)

Sällström, Johan; Carlström, Mattias; Jensen, Boye L

2008-01-01

BackgroundNitric oxide deficiency is involved in the development of hypertension, but the mechanisms are currently unclear. This study was conducted to further elucidate the role of neuronal nitric oxide synthase (nNOS) in blood pressure regulation and renin release in relation to different sodiu......-116; doi:10.1038/ajh.2007.16American Journal of Hypertension (2008) 21 111-116; doi:10.1038/ajh.2007.16....

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

OpenAIRE

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

1997-01-01

This study was conducted to examine whether the renin-angiotensin system contributes to hyperthyroidism-induced cardiac hypertrophy without involving the sympathetic nervous system. Sprague-Dawley rats were divided into control-innervated, control-denervated, hyperthyroid-innervated, and hyperthyroid-denervated groups using intraperitoneal injections of thyroxine and 6-hydroxydopamine. After 8 wk, the heart-to-body weight ratio increased in hyperthyroid groups (63%), and this increase was onl...

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

Science.gov (United States)

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

2017-09-01

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

The renin-angiotensin system and aging in the kidney.

Science.gov (United States)

Yoon, Hye Eun; Choi, Bum Soon

2014-05-01

Aging is associated with progressive functional deterioration and structural changes in the kidney. Changes in the activity or responsiveness of the renin-angiotensin system (RAS) occur with aging. RAS changes predispose the elderly to various fluid and electrolyte imbalances as well as acute kidney injury and chronic kidney disease. Among the multiple pathways involved in renal aging, the RAS plays a central role. This review summarizes the association of the RAS with structural and functional changes in the aging kidney and age-related renal injury, and describes the underlying mechanisms of RAS-related renal aging. An improved understanding of the renal aging process may lead to better individualized care of the elderly and improved renal survival in age-related diseases.

Oxidative Stress/Angiotensinogen/Renin-Angiotensin System Axis in Patients with Diabetic Nephropathy

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Masumi Kamiyama

2013-11-01

Full Text Available Although recent studies have proven that renin-angiotensin system (RAS blockades retard the progression of diabetic nephropathy, the detailed mechanisms of their reno-protective effects on the development of diabetic nephropathy remain uncertain. In rodent models, it has been reported that reactive oxygen species (ROS are important for intrarenal angiotensinogen (AGT augmentation in the progression of diabetic nephropathy. However, no direct evidence is available to demonstrate that AGT expression is enhanced in the kidneys of patients with diabetes. To examine whether the expression levels of ROS- and RAS-related factors in kidneys are increased with the progression of diabetic nephropathy, biopsied samples from 8 controls and 27 patients with type 2 diabetes were used. After the biopsy, these patients were diagnosed with minor glomerular abnormality or diabetes mellitus by clinical and pathological findings. The intensities of AGT, angiotensin II (Ang II, 4-hydroxy-2-nonenal (4-HNE, and heme oxygenase-1 (HO-1 were examined by fluorescence in situ hybridization and/or immunohistochemistry. Expression levels were greater in patients with diabetes than in control subjects. Moreover, the augmented intrarenal AGT mRNA expression paralleled renal dysfunction in patients with diabetes. These data suggest the importance of the activated oxidative stress/AGT/RAS axis in the pathogenesis of diabetic nephropathy.

Heart-specific overexpression of (pro)renin receptor induces atrial fibrillation in mice.

Science.gov (United States)

Lian, Hong; Wang, Xiaojian; Wang, Juan; Liu, Ning; Zhang, Li; Lu, Yingdong; Yang, Yanmin; Zhang, Lianfeng

2015-04-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia, causing substantial cardiovascular morbidity and mortality. The renin-angiotensin system (RAS) has been shown to be involved in the pathophysiology of AF. The (pro)renin receptor [(p)RR] is the last identified member of RAS. However, the role of (p)RR in AF is still unknown. Circulating levels of (p)RR were determined using an immunosorbent assay in 22 patients with AF (paroxysmal or persistent) and 22 healthy individuals. The plasma levels of (p)RR increased 3.6-fold in AF patients (Patrial flutter since 2 months, then spontaneously converted to atrial fibrillation by 10 months. The atria of the transgenic mice demonstrated significant dilation and fibrosis, and exhibited a high incidence of sudden death. Additionally, the genes of SERCA and HCN4, which are involved in the electrophysiology of AF, were significantly down-regulated and up-regulated respectively in transgenic mice atria. The phosphorylation of Erk1/2 significantly increased in the atria of the transgenic mice, and the activated Erk1/2 was found predominantly in cardiac fibroblasts, suggesting that the transgenic (p)RR gene may induce atrial fibrillation by activation of Erk1/2 in the cardiac fibroblasts of the atria. (p)RR promotes atrial structural and electrical remodeling in vivo, which indicates that (p)RR plays an important role in the pathological development of AF. Copyright © 2015. Published by Elsevier Ireland Ltd.

A Study on Plasma Renin Activity in Korean Hemorrhagic Fever

International Nuclear Information System (INIS)

Kim, Suhng Gwon; Cho, Bo Yun; Lee, Jung Sang; Koh, Won Soon; Lee, Mun Ho; Kim, Won Dong; Yun, Hong Jin

1976-01-01

To evaluate the possible pathophysiologic role of renin in acute renal failure observed in Korean hemorrhagic fever (KHF), the author measured the basal plasma renin activity (PRA) and the stimulated PRA by radioimmunoassay for angiotensin I in 15 normal controls and 42 KHF patients who are admitted in Seoul National University Hospital and Nation Army Hospital from Jan. 1975 to Jan. 1976. The results obtained were as follows:The mean basal PRA in normal control group was 2.9±2.16 ng/ml/hr in the patients during the oliguric phase of KHF, the mean basal PRA was 4.7±2.13 ng/ml/hr, and there was statistically significant increase compared to the normal control. In the patients during the diuretic phase of KHF, the mean basal PRA was 3.4±2.09 ng/ml/hr, and there was statistically significant decrease compared to the oliguric phase of KHF. In normal control group, the mean basal PRA was 2.9±2.16 ng/ml/hr. And the PRA 1 hour after the administration of Lasix 40 mg intravenously (stimulated PRA) was 5.3±2.20 ng/ml/hr and there was statistically significant increase compared to basal level. In oliguric phase of KHF, the mean basal PRA was 4.6±2.01 ng/ml/hr. And stimulated PRA was 4.4±2.34 ng/ml/hr and there was no significant changes. In diuretic phase of KHF, the mean basal PR was 3.3±1.86 ng/ml/hr. And stimulated PRA was 5.2±2.58 ng/ml/hr and there was statistically significant increase compared to basal level. There were statistically no significant correlations between basal PRA and stimulated PRA and serum creatinine. BUN, urine volume and peritoneal dialysis.

Aliskiren increases aquaporin-2 expression and attenuates lithium-induced nephrogenic diabetes insipidus.

Science.gov (United States)

Lin, Yu; Zhang, Tiezheng; Feng, Pinning; Qiu, Miaojuan; Liu, Qiaojuan; Li, Suchun; Zheng, Peili; Kong, Yonglun; Levi, Moshe; Li, Chunling; Wang, Weidong

2017-10-01

The direct renin inhibitor aliskiren has been shown to be retained and persist in medullary collecting ducts even after treatment is discontinued, suggesting a new mechanism of action for this drug. The purpose of the present study was to investigate whether aliskiren regulates renal aquaporin expression in the collecting ducts and improves urinary concentrating defect induced by lithium in mice. The mice were fed with either normal chow or LiCl diet (40 mmol·kg dry food -1 ·day -1 for 4 days and 20 mmol·kg dry food -1 ·day -1 for the last 3 days) for 7 days. Some mice were intraperitoneally injected with aliskiren (50 mg·kg body wt -1 ·day -1 in saline). Aliskiren significantly increased protein abundance of aquaporin-2 (AQP2) in the kidney inner medulla in mice. In inner medulla collecting duct cell suspension, aliskiren markedly increased AQP2 and phosphorylated AQP2 at serine 256 (pS256-AQP2) protein abundance, which was significantly inhibited both by adenylyl cyclase inhibitor MDL-12330A and by PKA inhibitor H89, indicating an involvement of the cAMP-PKA signaling pathway in aliskiren-induced increased AQP2 expression. Aliskiren treatment improved urinary concentrating defect in lithium-treated mice and partially prevented the decrease of AQP2 and pS256-AQP2 protein abundance in the inner medulla of the kidney. In conclusion, the direct renin inhibitor aliskiren upregulates AQP2 protein expression in inner medullary collecting duct principal cells and prevents lithium-induced nephrogenic diabetes insipidus likely via cAMP-PKA pathways. Copyright © 2017 the American Physiological Society.

Local Bone Marrow Renin-Angiotensin System and Atherosclerosis

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Yavuz Beyazit

2011-01-01

Full Text Available Local hematopoietic bone marrow (BM renin-angiotensin system (RAS affects the growth, production, proliferation differentiation, and function of hematopoietic cells. Angiotensin II (Ang II, the dominant effector peptide of the RAS, regulates cellular growth in a wide variety of tissues in pathobiological states. RAS, especially Ang II and Ang II type 1 receptor (AT1R, has considerable proinflammatory and proatherogenic effects on the vessel wall, causing progression of atherosclerosis. Recent investigations, by analyzing several BM chimeric mice whose BM cells were positive or negative for AT1R, disclosed that AT1R in BM cells participates in the pathogenesis of atherosclerosis. Therefore, AT1R blocking not only in vascular cells but also in the BM could be an important therapeutic approach to prevent atherosclerosis. The aim of this paper is to review the function of local BM RAS in the pathogenesis of atherosclerosis.

Structural Basis for the Inhibition of RNase H Activity of HIV-1 Reverse Transcriptase by RNase H Active Site-Directed Inhibitors

Energy Technology Data Exchange (ETDEWEB)

Su, Hua-Poo; Yan, Youwei; Prasad, G. Sridhar; Smith, Robert F.; Daniels, Christopher L.; Abeywickrema, Pravien D.; Reid, John C.; Loughran, H. Marie; Kornienko, Maria; Sharma, Sujata; Grobler, Jay A.; Xu, Bei; Sardana, Vinod; Allison, Timothy J.; Williams, Peter D.; Darke, Paul L.; Hazuda, Daria J.; Munshi, Sanjeev (Merck)

2010-09-02

HIV/AIDS continues to be a menace to public health. Several drugs currently on the market have successfully improved the ability to manage the viral burden in infected patients. However, new drugs are needed to combat the rapid emergence of mutated forms of the virus that are resistant to existing therapies. Currently, approved drugs target three of the four major enzyme activities encoded by the virus that are critical to the HIV life cycle. Although a number of inhibitors of HIV RNase H activity have been reported, few inhibit by directly engaging the RNase H active site. Here, we describe structures of naphthyridinone-containing inhibitors bound to the RNase H active site. This class of compounds binds to the active site via two metal ions that are coordinated by catalytic site residues, D443, E478, D498, and D549. The directionality of the naphthyridinone pharmacophore is restricted by the ordering of D549 and H539 in the RNase H domain. In addition, one of the naphthyridinone-based compounds was found to bind at a second site close to the polymerase active site and non-nucleoside/nucleotide inhibitor sites in a metal-independent manner. Further characterization, using fluorescence-based thermal denaturation and a crystal structure of the isolated RNase H domain reveals that this compound can also bind the RNase H site and retains the metal-dependent binding mode of this class of molecules. These structures provide a means for structurally guided design of novel RNase H inhibitors.

Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE): rationale and study design

DEFF Research Database (Denmark)

Parving, Hans-Henrik; Brenner, Barry M; McMurray, John J V

2009-01-01

BACKGROUND: Patients with type 2 diabetes are at increased risk of macro- and microvascular disease, and the presence of albuminuria and/or reduced kidney function further enhances macrovascular risk. Angiotensin-converting-enzyme inhibitors reduce both macro- and microvascular events, yet......, which will include three categories of high-risk patients with type 2 diabetes (aged > or =35 years): those with either urinary albumin/creatinine ratio (UACR) > or =200 mg/g; microalbuminuria (UACR) > or =20 or =30 ... whether dual RAAS blockade with the direct renin inhibitor aliskiren in combination with an ACEi or ARB will reduce major morbidity and mortality in a broad range of high-risk patients with type 2 diabetes....

Study of the components of renin-angiotensinaldosterone system and KalliKrein -Kinin system in normal pregnancy

International Nuclear Information System (INIS)

Abreu Fagundes, V.G. de.

1984-01-01

The alterations in the renin-angiotensin-aldosterone system and Kallikrein-Kinin system were studied. The possible interferences of these systems on the arterial pressure and on the evolution of normal pregnancy were presented in the following situations: when the pregnant change from dorsal decumbency to left lateral decumbency and to orthostatic position. (M.A.C.) [pt

Interference with Gsα-Coupled Receptor Signaling in Renin-Producing Cells Leads to Renal Endothelial Damage

DEFF Research Database (Denmark)

Lachmann, Peter; Hickmann, Linda; Steglich, Anne

2017-01-01

Intracellular cAMP, the production of which is catalyzed by the α-subunit of the stimulatory G protein (Gsα), controls renin synthesis and release by juxtaglomerular (JG) cells of the kidney, but may also have relevance for the physiologic integrity of the kidney. To investigate this possibility...... in the maintenance and protection of the renal microvascular endothelium....

Low plasma aldosterone despite normal plasma renin activity in uncomplicated type 1 diabetes mellitus : effects of RAAS stimulation

NARCIS (Netherlands)

Luik, PT; Kerstens, MN; Hoogenberg, K; Navis, GJ; Dullaart, RPF

Background Data on levels and responsiveness of PRA and aldosterone in type 1 diabetes mellitus are conflicting. Earlier studies were not standardized with respect to the type of diabetes mellitus, the presence of diabetic complications or sodium intake. Therefore, we studied plasma renin activity

The efficacy and safety of dual blockage of the renin-angiotensin-aldosterone system in patients with type 2 diabetes, hypertension and obesity without renal dysfunction

Directory of Open Access Journals (Sweden)

2012-09-01

Full Text Available The purpose of the study was to evaluate the clinical efficacy and safety of dual RAAS blockage during treatment with angiotensin-converting enzyme (ACE inhibitors in combination with a direct renin inhibitor (PIR aliskiren versus combination therapy with ACE inhibitors and angiotensin receptor blocker II (ARB valsartan in patients with type 2 diabetes mellitus (T2DM, arterial hypertension (AH and obesity, without renal dysfunction. Materials and methods. The study included 26 patients with T2DM (10 men and 16 women, mean age 59,0±6,2 years with inadequate control of blood pressure (over 130 and/or 80 mm Hg on prior antihypertensive therapy and without renal dysfunctions (glomerular filtration rate (GFR> 60 ml/min/1, 73 m2 and the of albumin/creatinine (A/C ratio in the morning urine sample <10 mg/mol. After screening with the continuation of the initial therapy, including ACE inhibitors, 14 patients were added aliskiren 150–300 mg/day, 12 patients – valsartan 80–160 mg/day. Evaluation of the treatment effectiveness in terms of blood pressure (mean of three consecutive measurements in the sitting position and the parameters of renal function (serum creatinine and potassium, GFR, A/C ratio in the urine was performed at 4, 12 and 24 weeks of therapy. Results. In the group of patients treated with aliskiren, after 4 weeks of treatment a significant decrease in systolic and diastolic blood pressure (SBP and DBP, respectively was noted as compared to baseline: 146,1 and 138,9 mm Hg, p<0,05, 87,1 and 81,1 mm Hg, p <0,05, respectively; with systolic BP after 24 weeks of treatment decreased to 127,8 (-18,2 mm Hg, p<0,05, diastolic BP to 75,0 (-12, 1 mm Hg, p<0,05, the target blood pressure (≤130/80 mm Hg was achieved in 83% of patients. The group of patients treated with valsartan, after 4 weeks of therapy showed a significant reduction in systolic BP 148 and 141,6 mm Hg, p <0,05, diastolic BP - to 85,8 and 81,7 mm Hg, p=0,059; after 24 weeks

Changes in the renin angiotensin system during the development of colorectal cancer liver metastases

International Nuclear Information System (INIS)

Neo, Jaclyn H; Ager, Eleanor I; Angus, Peter W; Zhu, Jin; Herath, Chandana B; Christophi, Christopher

2010-01-01

Blockade of the renin angiotensin system (RAS) via angiotensin I converting enzyme (ACE) inhibition reduces growth of colorectal cancer (CRC) liver metastases in a mouse model. In this work we defined the expression of the various components of the RAS in both tumor and liver during the progression of this disease. Immunohistochemistry and quantitative RT-PCR was used to examine RAS expression in a mouse CRC liver metastases model. CRC metastases and liver tissue was assessed separately at key stages of CRC liver metastases development in untreated (control) mice and in mice treated with the ACE inhibitor captopril (750 mg/kg/day). Non-tumor induced (sham) mice indicated the effect of tumors on normal liver RAS. The statistical significance of multiple comparisons was determined using one-way analysis of variance followed by Bonferroni adjustment with SAS/STAT software. Reduced volume of CRC liver metastases with captopril treatment was evident. Local RAS of CRC metastases differed from the surrounding liver, with lower angiotensin II type 1 receptor (AT1R) expression but increased ANG-(1-7) receptor (MasR) compared to the liver. The AT1R localised to cancer and stromal infiltrating cells, while other RAS receptors were detected in cancer cells only. Tumor induction led to an initial increase in AT1R and ACE expression while captopril treatment significantly increased ACE expression in the final stages of tumor growth. Conversely, captopril treatment decreased expression of AT1R and angiotensinogen. These results demonstrate significant changes in RAS expression in the tumor-bearing captopril treated liver and in CRC metastases. The data suggests the existence of a tumor-specific RAS that can be independently targeted by RAS blockade

Analysis of renin-angiotensin aldosterone system gene polymorphisms in malaysian essential hypertensive and type 2 diabetic subjects

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Stanslas Johnson

2009-02-01

Full Text Available Abstract Background The renin-angiotensin aldosterone system (RAAS plays an important role in regulating the blood pressure and the genetic polymorphisms of RAAS genes has been extensively studied in relation to the cardiovascular diseases in various populations with conflicting results. The aim of this study was to determine the association of five genetic polymorphisms (A6G and A20C of angiotensinogen (AGT, MboI of renin, Gly460Trp of aldosterone synthase and Lys173Arg of adducin of RAAS genes in Malaysian essential hypertensive and type 2 diabetic subjects. Methods RAAS gene polymorphisms were determined using mutagenically separated PCR and PCR-RFLP method in a total of 270 subjects consisting of 70 hypertensive subjects without type 2 diabetes mellitus (T2DM, 60 T2DM, 65 hypertensive subjects with T2DM and 75 control subjects. Results There was significant difference found in age, body mass index, systolic/diastolic blood pressure, fasting plasma glucose and high density lipoprotein cholesterol levels between the hypertensive subjects with or without T2DM and control subjects. No statistically significant differences between groups were found in the allele frequency and genotype distribution for A20C variant of AGT gene, MboI of renin, Gly460Trp of aldosterone and Lys173Arg of adducin (p > 0.05. However, the results for A6G of AGT gene revealed significant differences in allele and genotype frequencies in essential hypertension with or without T2DM (p Conclusion Among the five polymorphisms of RAAS genes only A6G variant of AGT gene was significantly associated in Malaysian essential hypertensive and type 2 diabetic subjects. Therefore, A6G polymorphism of the AGT gene could be a potential genetic marker for increased susceptibility to essential hypertension with or without T2DMin Malaysian subjects.

Fixed combinations in the pragmatic management of hypertension: focus on aliskiren and hydrochlorothiazide as a single pill

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Michel Burnier

2010-05-01

Full Text Available Michel BurnierService of Nephrology and Hypertension, University Hospital, Lausanne, SwitzerlandAbstract: A majority of hypertensive patients need more than one antihypertensive drug to control their blood pressure. For this reason, most guidelines have introduced the possibility of prescribing fixed-dose combination therapies as first-line treatment in hypertension. Today, the concept of fixed-dose combinations has evolved and the term single pill combination might become more appropriate to reflect the large choice of drug combinations available on the market. Recently, a new single pill combination has been launched which combines the first direct renin inhibitor aliskiren and low doses of hydrochlorothiazide. This paper reviews the potential advantages of single pill combinations and presents the first results obtained with the aliskiren/HCTZ single pill combination in hypertension.Keywords: hypertension, drug adherence, combination therapies, diuretics, renin inhibition

Exercise training modulates the hepatic renin-angiotensin system in fructose-fed rats.

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Frantz, Eliete Dalla Corte; Medeiros, Renata Frauches; Giori, Isabele Gomes; Lima, Juliana Bittencourt Silveira; Bento-Bernardes, Thais; Gaique, Thaiane Gadioli; Fernandes-Santos, Caroline; Fernandes, Tiago; Oliveira, Edilamar Menezes; Vieira, Carla Paulo; Conte-Junior, Carlos Adam; Oliveira, Karen Jesus; Nobrega, Antonio Claudio Lucas

2017-09-01

What is the central question of this study? What are the effects of exercise training on the hepatic renin-angiotensin system and their contribution to damage resulting from fructose overload in rats? What is the main finding and its importance? Exercise training attenuated the deleterious actions of the angiotensin-converting enzyme/angiotensin II/angiotensin II type 1 receptor axis and increased expression of the counter-regulatory (angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor) axis in the liver. Therefore, our study provides evidence that exercise training modulates the hepatic renin-angiotensin system, which contributes to reducing the progression of metabolic dysfunction and non-alcoholic fatty liver disease in fructose-fed rats. The renin-angiotensin system (RAS) has been implicated in the development of metabolic syndrome. We investigated whether the hepatic RAS is modulated by exercise training and whether this modulation improves the deleterious effects of fructose overload in rats. Male Wistar rats were divided into (n = 8 each) control (CT), exercise control (CT-Ex), high-fructose (HFr) and exercise high-fructose (HFr-Ex) groups. Fructose-drinking rats received d-fructose (100 g l -1 ). After 2 weeks, CT-Ex and HFr-Ex rats were assigned to a treadmill training protocol at moderate intensity for 8 weeks (60 min day -1 , 4 days per week). We assessed body mass, glucose and lipid metabolism, hepatic histopathology, angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity, the angiotensin concentration and the expression profile of proteins affecting the hepatic RAS, gluconeogenesis and inflammation. Neither fructose overload nor exercise training influenced body mass gain and serum ACE and ACE2 activity. The HFr group showed hyperinsulinaemia, but exercise training normalized this parameter. Exercise training was effective in preventing hepatic steatosis and in preventing triacylglycerol and

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

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

2018-03-11

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

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

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

2016-09-01

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

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

Science.gov (United States)

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

1986-01-01

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

Effects of low-sodium diet vs. high-sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride (Cochrane Review)

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Graudal, Niels A; Hubeck-Graudal, Thorbjørn; Jürgens, Gesche

2012-01-01

The question of whether reduced sodium intake is effective as a health prophylaxis initiative is unsolved. The purpose was to estimate the effects of low-sodium vs. high-sodium intake on blood pressure (BP), renin, aldosterone, catecholamines, and lipids....

Cathepsin D inhibitors

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M. Gacko

2007-11-01

Full Text Available Inhibitors of cathepsin D belong to chemical compounds that estrify carboxyl groups of the Asp33 and Asp231residues of its catalytic site, penta-peptides containing statin, i.e. the amino acid similar in structure to the tetraedric indirectproduct, and polypeptides found in the spare organs of many plants and forming permanent noncovalent complexes withcathepsin. Cathepsin D activity is also inhibited by alpha2-macroglobulin and antibodies directed against this enzyme.Methods used to determine the activity and concentration of these inhibitors and their analytical, preparative and therapeuticapplications are discussed.

The catalytic mechanism of mouse renin studied with QM/MM calculations.

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Brás, Natércia F; Ramos, Maria J; Fernandes, Pedro A

2012-09-28

Hypertension is a chronic condition that affects nearly 25% of adults worldwide. As the Renin-Angiotensin-Aldosterone System is implicated in the control of blood pressure and body fluid homeostasis, its combined blockage is an attractive therapeutic strategy currently in use for the treatment of several cardiovascular conditions. We have performed QM/MM calculations to study the mouse renin catalytic mechanism in atomistic detail, using the N-terminal His6-Asn14 segment of angiotensinogen as substrate. The enzymatic reaction (hydrolysis of the peptidic bond between residues in the 10th and 11th positions) occurs through a general acid/base mechanism and, surprisingly, it is characterized by three mechanistic steps: it begins with the creation of a first very stable tetrahedral gem-diol intermediate, followed by protonation of the peptidic bond nitrogen, giving rise to a second intermediate. In a final step the peptidic bond is completely cleaved and both gem-diol hydroxyl protons are transferred to the catalytic dyad (Asp32 and Asp215). The final reaction products are two separate peptides with carboxylic acid and amine extremities. The activation energy for the formation of the gem-diol intermediate was calculated as 23.68 kcal mol(-1), whereas for the other steps the values were 15.51 kcal mol(-1) and 14.40 kcal mol(-1), respectively. The rate limiting states were the reactants and the first transition state. The associated barrier (23.68 kcal mol(-1)) is close to the experimental values for the angiotensinogen substrate (19.6 kcal mol(-1)). We have also tested the influence of the density functional on the activation and reaction energies. All eight density functionals tested (B3LYP, B3LYP-D3, X3LYP, M06, B1B95, BMK, mPWB1K and B2PLYP) gave very similar results.

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

NARCIS (Netherlands)

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

2016-01-01

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

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

NARCIS (Netherlands)

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

BACKGROUND: 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.

Chronic Renin-Angiotensin System (RAS) Blockade May Not Induce Hypotension During Anaesthesia for Bariatric Surgery.

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Salvetti, Guido; Di Salvo, Claudio; Ceccarini, Giovanni; Abramo, Antonio; Fierabracci, Paola; Magno, Silvia; Piaggi, Paolo; Vitti, Paolo; Santini, Ferruccio

2016-06-01

The use of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) for the treatment of hypertensive obese patients is steadily increasing. Some studies have reported that the use of these drugs was associated with an increased risk of hypotensive episodes, during general anaesthesia. The number of bariatric procedures is also increasing worldwide, but there is a lack of studies investigating the hypotensive effect of renin-angiotensin system (RAS) blockers in severely obese patients during general anaesthesia for bariatric surgery. The aim of this pilot study was to evaluate hemodynamic changes induced by general anaesthesia in obese patients chronically treated with ACE-I or ARB compared to a control group not treated with antihypertensive therapy. Fourteen obese subjects (mean body mass index (BMI) 47.5 kg/m(2)) treated with ACE-I or ARB and twelve obese (mean BMI 45.7 kg/m2) controls not treated with antihypertensive therapy underwent general anaesthesia to perform laparoscopic bariatric surgery. Systolic blood pressure, diastolic blood pressure, and heart rate were monitored continuously and registered at different time points: T0 before induction, then at 2, 5, 7, 10, 15, 20, 30, 60, 90, 120, and 150 min after induction, and the last time point taken following recovery from anaesthesia. A progressive reduction of both systolic and diastolic blood pressure values was observed without significant differences between the two groups. A similar trend of heart rate values was observed. In conclusion, our pilot study suggests that RAS blockers may be continued during the perioperative period in patients undergoing bariatric surgery, without increasing the risk of hypotensive episodes.

Altered renal expression of angiotensin II receptors, renin receptor, and ACE-2 precede the development of renal fibrosis in aging rats.

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Schulman, Ivonne Hernandez; Zhou, Ming-Sheng; Treuer, Adriana V; Chadipiralla, Kiranmai; Hare, Joshua M; Raij, Leopoldo

2010-01-01

The susceptibility to fibrosis and progression of renal disease is mitigated by inhibition of the renin-angiotensin system (RAS). We hypothesized that activation of the intrarenal RAS predisposes to renal fibrosis in aging. Intrarenal expression of angiotensin II type 1 (AT(1)R), type 2 (AT(2)R), and (pro)renin receptors, ACE and ACE-2, as well as pro- and antioxidant enzymes were measured in 3-month-old (young), 14-month-old (middle-aged), and 24-month-old (old) male Sprague-Dawley rats. Old rats manifested glomerulosclerosis and severe tubulointerstitial fibrosis with increased fibronectin and TGF-β expression (7-fold). AT(1)R /AT(2)R ratios were increased in middle-aged (cortical 1.6-fold, medullary 5-fold) and old rats (cortical 2-fold, medullary 4-fold). Similarly, (pro)renin receptor expression was increased in middle-aged (cortical 2-fold, medullary 3-fold) and old (cortical 5-fold, medullary 3-fold) rats. Cortical ACE was increased (+35%) in old rats, whereas ACE-2 was decreased (-50%) in middle-aged and old rats. NADPH oxidase activity was increased (2-fold), whereas antioxidant capacity and expression of the mitochondrial enzyme manganese superoxide dismutase (cortical -40%, medullary -53%) and medullary endothelial nitric oxide synthase (-48%) were decreased in old rats. Age-related intrarenal activation of the RAS preceded the development of severe renal fibrosis, suggesting that it contributes to the increased susceptibility to renal injury observed in the elderly. Copyright © 2010 S. Karger AG, Basel.

Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials

DEFF Research Database (Denmark)

Chaturvedi, N.; Porta, M.; Klein, R.

2008-01-01

of retinopathy in type 1 diabetes. METHODS: Two randomised, double-blind, parallel-design, placebo-controlled trials were done in 309 centres worldwide. Participants with normotensive, normoalbuminuric type 1 diabetes without retinopathy were recruited to the DIRECT-Prevent 1 trial and those with existing...... retinopathy were recruited to DIRECT-Protect 1, and were assigned to candesartan 16 mg once a day or matching placebo. After 1 month, the dose was doubled to 32 mg. Investigators and participants were unaware of the treatment allocation status. The primary endpoints were incidence and progression......BACKGROUND: Results of previous studies suggest that renin-angiotensin system blockers might reduce the burden of diabetic retinopathy. We therefore designed the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme to assess whether candesartan could reduce the incidence and progression...

Renal blood flow, early distal sodium, and plasma renin concentrations during osmotic diuresis

DEFF Research Database (Denmark)

Leyssac, P P; Holstein-Rathlou, N H; Skøtt, O

2000-01-01

.6 mmHg. Urine flow increased 10-fold, and sodium excretion increased by 177%. Plasma renin concentration (PRC) increased by 58%. Renal blood flow and glomerular filtration rate decreased, however end-proximal flow remained unchanged. After a similar volume of hypotonic glucose (152 mM), ED......(NaCl) increased by 3.6 mM, (P renal hemodynamics, urine flow, sodium excretion rate, or PRC. Infusion of 300 micromol NaCl in a smaller volume caused ED(NaCl) to increase by 6.4 mM without significant changes in PRC. Urine flow and sodium excretion increased significantly...

Aldosterone to Active Renin Ratio Is Associated With Nocturnal Blood Pressure in Obese and Treated Hypertensive Patients: The Styrian Hypertension Study

NARCIS (Netherlands)

Grubler, M.R.; Kienreich, K.; Gaksch, M.; Verheyen, N.; Fahrleitner-Pammer, A.; Schmid, J.; Grogorenz, J.; Ablasser, K.; Pieske, B.; Tomaschitz, A.; Pilz, S.

2014-01-01

High aldosterone levels are considered to play a key role in arterial hypertension. Data on the relationship between the aldosterone to active renin ratio (AARR), a quantity of aldosterone excess, and ambulatory blood pressure (BP) monitoring (ABPM) during the night are, however, sparse.

Direct-to-consumer advertising of COX-2 inhibitors: effect on appropriateness of prescribing.

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Spence, Michele M; Teleki, Stephanie S; Cheetham, T Craig; Schweitzer, Stuart O; Millares, Mirta

2005-10-01

Spending on direct-to-consumer advertising (DTCA) of prescription drugs has increased dramatically in the past several years. An unresolved question is whether such advertising leads to inappropriate prescribing. In this study, the authors use survey and administrative data to determine the association of DTCA with the appropriate prescribing of cyclooxygenase-2 (COX-2) inhibitors for 1,382 patients. Treatment with either a COX-2 or a traditional nonsteroidal anti-inflammatory drug (NSAID) was defined as appropriate or not according to three different definitions of gastrointestinal risk. Patients who saw or heard a COX-2 advertisement and asked their physician about the advertised drug were significantly more likely to be prescribed a COX-2 (versus a NSAID, as recommended by evidence-based guidelines) than all other patients. Findings also suggest that some patients may benefit from DTCA. The authors discuss the need for balanced drug information for consumers, increased physician vigilance in prescribing appropriately, and further study of DTCA.

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

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

2013-02-28

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Directional Migration in Esophageal Squamous Cell Carcinoma (ESCC) is Epigenetically Regulated by SET Nuclear Oncogene, a Member of the Inhibitor of Histone Acetyltransferase Complex

OpenAIRE

Xiang Yuan; Xinshuai Wang; Bianli Gu; Yingjian Ma; Yiwen Liu; Man Sun; Jinyu Kong; Wei Sun; Huizhi Wang; Fuyou Zhou; Shegan Gao

2017-01-01

Directional cell migration is of fundamental importance to a variety of biological events, including metastasis of malignant cells. Herein, we specifically investigated SET oncoprotein, a subunit of the recently identified inhibitor of acetyltransferases (INHAT) complex and identified its role in the establishment of front–rear cell polarity and directional migration in Esophageal Squamous Cell Carcinoma (ESCC). We further define the molecular circuits that govern these processes by showing t...

Vascular endothelial growth factor during hypoglycemia in patients with type 1 diabetes mellitus: relation to cognitive function and renin-angiotensin system activity

DEFF Research Database (Denmark)

Kristensen, Peter Lommer; Høi-Hansen, Thomas; Boomsma, Frans

2009-01-01

hypoglycemia. High activity in the renin-angiotensin system (RAS) is associated with an increased risk of severe hypoglycemia in patients with type 1 diabetes mellitus. Renin-angiotensin system possibly exerts its mechanism in hypoglycemia via VEGF. We studied the impact of mild hypoglycemia on plasma VEGF...... in patients with type 1 diabetes mellitus and high or low RAS activity and analyzed associations between VEGF levels and cognitive function during hypoglycemia. Eighteen patients with type 1 diabetes mellitus-9 with high and 9 with low RAS activity-underwent a single-blinded, placebo-controlled, crossover...... study with either mild hypoglycemia or stable glycemia. Cognitive function was assessed by the California Cognitive Assessment Package and the Alzheimer Quick Test. Nadir plasma glucose was 2.2 (0.3) mmol/L. During the control study, plasma VEGF did not change. During hypoglycemia, plasma VEGF increased...

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

Science.gov (United States)

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

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

Body fluids, circadian blood pressure and plasma renin during growth hormone administration: a placebo-controlled study with two growth hormone doses in healthy adults

DEFF Research Database (Denmark)

Møller, Jens; Jørgensen, Jens Otto Lunde; Frandsen, Erik

1995-01-01

Abstract Side effects that can be related to fluid retention are common during the initial phases of growth hormone (GH) administration. The aim of this study was to examine the changes in body fluid compartments, diurnal blood pressure and plasma renin concentration during GH administration......-2, 20.65 +/- 0.94; pbody water (l) increased significantly during GH administration (placebo, 50.8 +/- 2.6; 3 IU m-2, 52.6 +/- 2.3; 6 IU m-2, 53.9 +/- 1.8, p... of treatment a significant increase in renin (p = 0.03) was observed. Mean diurnal blood pressure levels remained unchanged, whereas mean diurnal heart rate (min-1) increased significantly (placebo, 75 +/- 3.6; 3 IU m-2, 79 +/- 3.2; 6 IU m-2, 79 +/- 3.7; p

Renin-angiotensin system blockers protect pancreatic islets against diet-induced obesity and insulin resistance in mice.

Directory of Open Access Journals (Sweden)

Eliete Dalla Corte Frantz

Full Text Available BACKGROUND: The associations between obesity, hypertension and diabetes are well established, and the renin-angiotensin system (RAS may provide a link among them. The effect of RAS inhibition on type 2 diabetes is still unclear; however, RAS seems to play an important role in the regulation of the pancreas and glucose intolerance of mice fed high-fat (HF diet. METHODS: C57BL/6 mice fed a HF diet (8 weeks were treated with aliskiren (50 mg/kg/day, enalapril (30 mg/kg/day or losartan (10 mg/kg/day for 6 weeks, and the protective effects were extensively compared among groups by morphometry, stereological tools, immunostaining, Western blotting and hormonal analysis. RESULTS: All RAS inhibitors significantly attenuated the increased blood pressure in mice fed a HF diet. Treatment with enalapril, but not aliskiren or losartan, significantly attenuated body mass (BM gain, glucose intolerance and insulin resistance, improved the alpha and beta cell mass and prevented the reduction of plasma adiponectin. Furthermore, enalapril treatment improved the protein expression of the pancreatic islet Pdx1, GLUT2, ACE2 and Mas receptors. Losartan treatment showed the greatest AT2R expression. CONCLUSION: Our findings indicate that ACE inhibition with enalapril attenuated several of the deleterious effects of the HF diet. In summary, enalapril appears to be responsible for the normalization of islet morphology and function, of alpha and beta cell mass and of Pdx1 and GLUT2 expression. These protective effects of enalapril were attributed, primarily, to the reduction in body mass gain and food intake and the enhancement of the ACE2/Ang (1-7 /Mas receptor axis and adiponectin levels.

Control plasma renin activity and changes in sympathetic tone as determinants of minoxidil-induced increase in plasma renin activity.

Science.gov (United States)

O'Malley, K; Velasco, M; Wells, J; McNay, J L

1975-01-01

A study was made of the possible mechanism(s) underlying minoxidil-induced increase in plasma renin activity (PRA). 10 patients with essential hypertension were treated with minoxidil and subsequently with a combination of minoxidil plus propranolol. Minoxidil lowered mean arterial pressure 31.6 plus or minus 3.3 mm Hg, mean plus or minus SEM. There was an associated increase in both PRA, 6.26 plus or minus 2.43 NG/ML/H, and heart rate, 21.4 plus or minus 2.7 beats/min. The changes in PRA and heart rate were positively correlated, r, 0.79. Addition of propranolol reduced mean arterial pressure by a further 10.1 plus or minus 1.5 mm Hg and returned heart rate to control levels. Propranolol reduced PRA significantly but not to control levels. Control PRA positively correlated with PRA on minoxidil, r, 0.97, and with PRA on minoxidil plus propranolol, r, 0.98. We conclude that control PRA is a major determinant of change in PRA with minoxidil. Minoxidil increased PRA by at least two mechanisms: (a) an adrenergic mechanism closely related to change in heart rate and blocked by propranolol, and (b) a mechanism(s) not sensitive to propranolol and possibly related to decrease in renal perfusion pressure. PMID:1127099

Role of Renin-Angiotensin System and Oxidative Stress on Vascular Inflammation in Insulin Resistence Model

OpenAIRE

Renna, N. F.; Lembo, C.; Diez, E.; Miatello, R. M.

2013-01-01

(1) is study aims to demonstrate the causal involvement of renin angiotensin system (RAS) and oxidative stress (OS) on vascular inammation in an experimental model of metabolic syndrome (MS) achieved by fructose administration to spontaneously hypertensive rats (FFHR) during 12 weeks. (2) Chronic treatment with candesartan (C) (10 mg/kg per day for the last 6 weeks) or 4OH-Tempol (T) (10−3 mmol/L in drinking water for the last 6 weeks) reversed the increment in metabolic variables and systo...

Efficient Isothermal Titration Calorimetry Technique Identifies Direct Interaction of Small Molecule Inhibitors with the Target Protein.

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Gal, Maayan; Bloch, Itai; Shechter, Nelia; Romanenko, Olga; Shir, Ofer M

2016-01-01

Protein-protein interactions (PPI) play a critical role in regulating many cellular processes. Finding novel PPI inhibitors that interfere with specific binding of two proteins is considered a great challenge, mainly due to the complexity involved in characterizing multi-molecular systems and limited understanding of the physical principles governing PPIs. Here we show that the combination of virtual screening techniques, which are capable of filtering a large library of potential small molecule inhibitors, and a unique secondary screening by isothermal titration calorimetry, a label-free method capable of observing direct interactions, is an efficient tool for finding such an inhibitor. In this study we applied this strategy in a search for a small molecule capable of interfering with the interaction of the tumor-suppressor p53 and the E3-ligase MDM2. We virtually screened a library of 15 million small molecules that were filtered to a final set of 80 virtual hits. Our in vitro experimental assay, designed to validate the activity of mixtures of compounds by isothermal titration calorimetry, was used to identify an active molecule against MDM2. At the end of the process the small molecule (4S,7R)-4-(4-chlorophenyl)-5-hydroxy-2,7-dimethyl-N-(6-methylpyridin-2-yl)-4,6,7,8 tetrahydrIoquinoline-3-carboxamide was found to bind MDM2 with a dissociation constant of ~2 µM. Following the identification of this single bioactive compound, spectroscopic measurements were used to further characterize the interaction of the small molecule with the target protein. 2D NMR spectroscopy was used to map the binding region of the small molecule, and fluorescence polarization measurement confirmed that it indeed competes with p53.

Mineralocorticoid hypertension

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Vishal Gupta

2011-01-01

Full Text Available Hypertension affects about 10 - 25% of the population and is an important risk factor for cardiovascular and renal disease. The renin-angiotensin system is frequently implicated in the pathophysiology of hypertension, be it primary or secondary. The prevalence of primary aldosteronism increases with the severity of hypertension, from 2% in patients with grade 1 hypertension to 20% among resistant hypertensives. Mineralcorticoid hypertension includes a spectrum of disorders ranging from renin-producing pathologies (renin-secreting tumors, malignant hypertension, coarctation of aorta, aldosterone-producing pathologies (primary aldosteronism - Conns syndrome, familial hyperaldosteronism 1, 2, and 3, non-aldosterone mineralocorticoid producing pathologies (apparent mineralocorticoid excess syndrome, Liddle syndrome, deoxycorticosterone-secreting tumors, ectopic adrenocorticotropic hormones (ACTH syndrome, congenitalvadrenal hyperplasia, and drugs with mineraocorticoid activity (locorice, carbenoxole therapy to glucocorticoid receptor resistance syndromes. Clinical presentation includes hypertension with varying severity, hypokalemia, and alkalosis. Ratio of plasma aldosterone concentraion to plasma renin activity remains the best screening tool. Bilateral adrenal venous sampling is the best diagnostic test coupled with a CT scan. Treatment is either surgical (adrenelectomy for unilateral adrenal disease versus medical therapy for idiopathic, ambiguous, or bilateral disease. Medical therapy focuses on blood pressure control and correction of hypokalemia using a combination of anti-hypertensives (calcium channel blockers, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers and potassium-raising therapies (mineralcorticoid receptor antagonist or potassium sparing diuretics. Direct aldosterone synthetase antagonists represent a promising future therapy.

The adipose renin-angiotensin system modulates sysemic markers of insulin sensitivity activates the intrarenal renin-angiotensin system

Energy Technology Data Exchange (ETDEWEB)

Kim, Suyeon [University of Tennessee, Knoxville (UTK); Soltani-Bejnood, Morvarid [University of Tennessee, Knoxville (UTK); Quignard-Boulange, Annie [Centre Biomedical des Cordeliers, Paris, France; Massiera, Florence [Centre de Biochimie, Nice, France; Teboul, Michele [Centre de Biochimie, Nice, France; Ailhaud, Gerard [Centre de Biochimie, Nice, France; Kim, Jung [University of Tennessee, Knoxville (UTK); Moustaid-Moussa, Naima [University of Tennessee, Knoxville (UTK); Voy, Brynn H [ORNL

2006-07-01

BACKGROUND: A growing body of data provides increasing evidence that the adipose tissue renin-angiotensin system (RAS) contributes to regulation of fat mass. Beyond its paracrine actions within adipose tissue, adipocyte-derived angiotensin II (Ang II) may also impact systemic functions such as blood pressure and metabolism. METHODS AND RESULTS: We used a genetic approach to manipulate adipose RAS activity in mice and then study the consequences on metabolic parameters and on feedback regulation of the RAS. The models included deletion of the angiotensinogen (Agt) gene (Agt-KO), its expression solely in adipose tissue under the control of an adipocyte-specific promoter (aP2-Agt/ Agt-KO), and overexpression in adipose tissue of wild type mice (aP2-Agt). Total body weight, epididymal fat pad weight, and circulating levels of leptin, insulin and resistin were significantly decreased in Agt-KO mice, while plasma adiponectin levels were increased. Overexpression of Agt in adipose tissue resulted in increased adiposity and plasma leptin and insulin levels compared to wild type (WT) controls. Angiotensinogen and type I Ang II receptor protein levels were also markedly elevated in kidney of aP2-Agt mice, suggesting that hypertension in these animals may be in part due to stimulation of the intrarenal RAS. CONCLUSIONS: Taken together, the results from this study demonstrate that alterations in adipose RAS activity significantly alter both local and systemic physiology in a way that may contribute to the detrimental health effects of obesity.

Cognitive performance, symptoms and counter-regulation during hypoglycaemia in patients with type 1 diabetes and high or low renin-angiotensin system activity

DEFF Research Database (Denmark)

Høi-Hansen, Thomas; Pedersen-Bjergaard, Ulrik; Andersen, Rikke Due

2009-01-01

INTRODUCTION: High basal renin-angiotensin system (RAS) activity is associated with increased risk of severe hypoglycaemia in type 1 diabetes. We tested whether this might be explained by more pronounced cognitive dysfunction during hypoglycaemia in patients with high RAS activity than in patient...

Rho-associated kinase inhibitors: a novel glaucoma therapy.

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Inoue, Toshihiro; Tanihara, Hidenobu

2013-11-01

The rho-associated kinase (ROCK) signaling pathway is activated via secreted bioactive molecules or via integrin activation after extracellular matrix binding. These lead to polymerization of actin stress fibers and formation of focal adhesions. Accumulating evidence suggests that actin cytoskeleton-modulating signals are involved in aqueous outflow regulation. Aqueous humor contains various biologically active factors, some of which are elevated in glaucomatous eyes. These factors affect aqueous outflow, in part, through ROCK signaling modulation. Various drugs acting on the cytoskeleton have also been shown to increase aqueous outflow by acting directly on outflow tissue. In vivo animal studies have shown that the trabecular meshwork (TM) actin cytoskeleton in glaucomatous eyes is more disorganized and more randomly oriented than in non-glaucomatous control eyes. In a previous study, we introduced ROCK inhibitors as a potential glaucoma therapy by showing that a selective ROCK inhibitor significantly lowered rabbit IOP. Rho-associated kinase inhibitors directly affect the TM and Schlemm's canal (SC), differing from the target sight of other glaucoma drugs. The TM is affected earlier and more strongly than ciliary muscle cells by ROCK inhibitors, largely because of pharmacological affinity differences stemming from regulatory mechanisms. Additionally, ROCK inhibitors disrupt tight junctions, result in F-actin depolymerization, and modulate intracellular calcium level, effectively increasing SC-cell monolayer permeability. Perfusion of an enucleated eye with a ROCK inhibitor resulted in wider empty spaces in the juxtacanalicular (JCT) area and more giant vacuoles in the endothelial cells of SC, while the endothelial lining of SC was intact. Interestingly, ROCK inhibitors also increase retinal blood flow by relaxing vascular smooth muscle cells, directly protecting neurons against various stresses, while promoting wound healing. These additional effects may help

Protection against death and renal failure by renin-angiotensin system blockers in patients with diabetes and kidney disease.

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Shen, Jian; Huang, Yan-Mei; Song, Xin-Nan; Hong, Xue-Zhi; Wang, Min; Ling, Wei; Zhang, Xiao-Xi; Zhao, Hai-Lu

2016-07-01

Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) are widely used to block the renin-angiotensin system (RAS). Yet it remains uncertain whether these drugs are equally effective and safe. Systematic reviews and meta-analyses of ACEis/ARBs in diabetes and kidney disease published in PubMed, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases were searched for clinical outcomes including all-cause mortality, end-stage renal disease (ESRD), hyperkalemia and cough. Eight meta-analyses included 2177-61,264 patients with follow-up of 6-108 months. RAS blockers reduced mortality (relative risk ratio (RR), 0.90, 95% confidence interval (CI), 0.86-0.95) without heterogeneity. The death protection was significant specifically with ACEis (RR, 0.85, 95% CI, 0.79-0.91), but not with ARBs. Protection against ESRD was homogenously evident by ARBs (RR, 0.79, 95% CI, 0.73-0.87), ACEis (RR, 0.79, 95% , 0.64-0.94), and both (RR, 0.79, 95% CI, 0.73-0.87). Significant side effects were hyperkalemia by ARBs (RR, 2.44, 95% CI, 1.13-5.26), and cough by ACEis (RR, 2.38, 95% CI, 1.75-3.22) CONCLUSIONS: In patients with diabetes and kidney disease, ACEis and ARBs are consistently protective for the development of ESRD. Use of ACEis alone additionally reduces deaths and increases the risk for cough. Use of ARBs alone increases the risk for hyperkalemia without additional benefit of death protection. © The Author(s) 2016.

Multilocus analyses of renin-angiotensin-aldosterone system gene variants on blood pressure at rest and during behavioral stress in young normotensive subjects

NARCIS (Netherlands)

Ge, Dongliang; Zhu, Haidong; Huang, Ying; Treiber, Frank A.; Harshfield, Gregory A.; Snieder, Harold; Dong, Yanbin

The renin-angiotensin-aldosterone system (RAAS) is a proteolytic cascade that regulates and maintains blood pressure (BP). This study aimed to explore the interactive and integrative effects of multiple RAAS polymorphisms on BP at rest and during behavioral stress in a normotensive population. A

Free Fatty Acids Activate Renin-Angiotensin System in 3T3-L1 Adipocytes through Nuclear Factor-kappa B Pathway

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Jia Sun

2016-01-01

Full Text Available The activity of a local renin-angiotensin system (RAS in the adipose tissue is closely associated with obesity-related diseases. However, the mechanism of RAS activation in adipose tissue is still unknown. In the current study, we found that palmitic acid (PA, one kind of free fatty acid, induced the activity of RAS in 3T3-L1 adipocytes. In the presence of fetuin A (Fet A, PA upregulated the expression of angiotensinogen (AGT and angiotensin type 1 receptor (AT1R and stimulated the secretion of angiotensin II (ANG II in 3T3-L1 adipocytes. Moreover, the activation of RAS in 3T3-L1 adipocytes was blocked when we blocked Toll-like receptor 4 (TLR4 signaling pathway using TAK242 or NF-κB signaling pathway using BAY117082. Together, our results have identified critical molecular mechanisms linking PA/TLR4/NF-κB signaling pathway to the activity of the local renin-angiotensin system in adipose tissue.

Thiocarbamate-Directed Tandem Olefination-Intramolecular Sulfuration of Two Ortho C-H Bonds: Application to Synthesis of a COX-2 Inhibitor.

Science.gov (United States)

Li, Wendong; Zhao, Yingwei; Mai, Shaoyu; Song, Qiuling

2018-02-16

A palladium-catalyzed dual ortho C-H bond activation of aryl thiocarbamates is developed. This tandem reaction initiates by thiocarbamate-directed ortho C-H palladation, which leads to favorable olefin insertion rather than reductive elimination. The oxidative Heck reaction followed by another C-H activation and sulfuration affords the dual-functionalized products. This reaction provides a concise route to the S,O,C multisubstituted benzene skeleton which could be successfully applied for the synthesis of a COX-2 inhibitor.

A direct thrombin inhibitor suppresses protein C activation and factor Va degradation in human plasma: Possible mechanisms of paradoxical enhancement of thrombin generation.

Science.gov (United States)

Kamisato, Chikako; Furugohri, Taketoshi; Morishima, Yoshiyuki

2016-05-01

We have demonstrated that antithrombin (AT)-independent thrombin inhibitors paradoxically increase thrombin generation (TG) in human plasma in a thrombomodulin (TM)- and protein C (PC)-dependent manner. We determined the effects of AT-independent thrombin inhibitors on the negative-feedback system, activation of PC and production and degradation of factor Va (FVa), as possible mechanisms underlying the paradoxical enhancement of TG. TG in human plasma containing 10nM TM was assayed by means of the calibrated automated thrombography. As an index of PC activation, plasma concentration of activated PC-PC inhibitor complex (aPC-PCI) was measured. The amounts of FVa heavy chain and its degradation product (FVa(307-506)) were examined by western blotting. AT-independent thrombin inhibitors, melagatran and dabigatran (both at 25-600nM) and 3-30μg/ml active site-blocked thrombin (IIai), increased peak levels of TG. Melagatran, dabigatran and IIai significantly decreased plasma concentration of aPC-PCI complex at 25nM or more, 75nM or more, and 10 and 30μg/ml, respectively. Melagatran (300nM) significantly increased FVa and decreased FVa(307-506). In contrast, a direct factor Xa inhibitor edoxaban preferentially inhibited thrombin generation (≥25nM), and higher concentrations were required to inhibit PC activation (≥150nM) and FVa degradation (300nM). The present study suggests that the inhibitions of protein C activation and subsequent degradation of FVa and increase in FVa by antithrombin-independent thrombin inhibitors may contribute to the paradoxical TG enhancement, and edoxaban may inhibit PC activation and FVa degradation as a result of TG suppression. Copyright © 2016 Elsevier Ltd. All rights reserved.

Addition of vitamin D reverses the decline in GFR following treatment with ACE inhibitors/angiotensin receptor blockers in patients with chronic kidney disease.

Science.gov (United States)

Soares, Abel Esteves; Maes, Michael; Godeny, Paula; Matsumoto, Andressa Keiko; Barbosa, Décio Sabbatini; da Silva, Taysa Antonia F; Souza, Flávio Henrique M O; Delfino, Vinicius Daher Alvares

2017-12-15

Vitamin D has anti-inflammatory, anti-fibrotic effect, and may block the intrarenal renin-angiotensin system. Adequate vitamin D levels in conjunction with the use of Angiotensin-converting Enzyme Inhibitors/Angiotensin Receptor Blockers may help to slow down chronic kidney disease progression. To study a possible beneficial effect of vitamin D supplementation in chronic kidney disease patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers on chronic kidney disease progression we performed a clinical study involving vitamin D supplementation in patients with deficiency of this vitamin. This study was conducted in two chronic kidney disease clinics in the city of Londrina, Brazil, from October 2010 to December 2012. It was involved stage 3 and 4 chronic kidney disease (estimated glomerular filtration rate between 60 and 15mL/min/1.73m 2 ) patients with and without vitamin D deficiency. The patients ingested six-month cholecalciferol 50,000IU oral supplementation to chronic kidney disease patients with vitamin D deficiency. We hypothesize changes in estimated glomerular filtration rate over study period. Our data demonstrate reservation of estimated glomerular filtration with cholecalciferol supplementation to chronic kidney disease patients taking angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. The combination treatment of angiotensin converting enzyme inhibitors/angiotensin receptor blockers with cholecalciferol prevents the decline in estimated glomerular filtration in patients with chronic kidney disease following treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and may represent a valid approach to reduce renal disease progression in chronic kidney disease patients with vitamin D deficiency. This result needs confirmation in prospective controlled clinical trials. Copyright © 2017. Published by Elsevier Inc.

Addition of ETA receptor blockade increases renoprotection provided by renin-angiotensin system blockade in 5/6 nephrectomized Ren-2 transgenic rats

Czech Academy of Sciences Publication Activity Database

Čertíková; Chábová, V.; Vernerová, Z.; Kujal, P.; Husková, Z.; Škaroupková, P.; Tesař, V.; Kramer, H. J.; Kompanowska; Jezierska, E.; Walkowska, A.; Sadowski, J.; Červenka, L.; Vaněčková, Ivana

2014-01-01

Roč. 118, č. 2 (2014), s. 297-305 ISSN 0024-3205 R&D Projects: GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : renal failure * 5/6 nephrectomy * renin-angiotensin * endothelin * survival Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.702, year: 2014

Laura: Soybean variety lacking Kunitz trypsin inhibitor

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Srebrić Mirjana

2010-01-01

Full Text Available Grain of conventional soybean varieties requires heat processing to break down trypsin inhibitor's activity before using as food or animal feed. At the same time, protein denaturation and other qualitative changes occur in soybean grain, especially if the temperature of heating is not controlled. Two types of trypsin inhibitor were found in soybean grain the Kunitz trypsin inhibitor and the Bowman-Birk inhibitor. Mature grain of soybean Laura is lacking Kunitz trypsin inhibitor. Grain yield of variety Laura is equal to high yielding varieties from the maturity group I, where it belongs. Lacking of Kunitz-trypsin inhibitor makes soybean grain suitable for direct feeding in adult non ruminant animals without previous thermal processing. Grain of variety Laura can be processed for a shorter period of time than conventional soybeans. This way we save energy, and preserve valuable nutritional composition of soybean grain, which is of interest in industrial processing.

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

Science.gov (United States)

Scheen, A J; Delanaye, P

2017-04-01

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

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

Science.gov (United States)

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

2018-03-01

This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabetic mice. Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. Compared with control mice, diabetic mice had significantly higher blood glucose concentrations (p diabetic mice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2 + pericytes were observed in diabetic mice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabetic mice. Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabetic mice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.

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

Science.gov (United States)

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

2015-11-01

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

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

Science.gov (United States)

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.

Sildenafil Protects against Myocardial Ischemia-Reperfusion Injury Following Cardiac Arrest in a Porcine Model: Possible Role of the Renin-Angiotensin System

Science.gov (United States)

Wang, Guoxing; Zhang, Qian; Yuan, Wei; Wu, Junyuan; Li, Chunsheng

2015-01-01

Sildenafil, a phosphodiesterase-5 inhibitor sold as Viagra, is a cardioprotector against myocardial ischemia/reperfusion (I/R) injury. Our study explored whether sildenafil protects against I/R-induced damage in a porcine cardiac arrest and resuscitation (CAR) model via modulating the renin-angiotensin system. Male pigs were randomly divided to three groups: Sham group, Saline group, and sildenafil (0.5 mg/kg) group. Thirty min after drug infusion, ventricular fibrillation (8 min) and cardiopulmonary resuscitation (up to 30 min) was conducted in these animals. We found that sildenafil ameliorated the reduced cardiac function and improved the 24-h survival rate in this model. Sildenafil partly attenuated the increases of plasma angiotensin II (Ang II) and Ang (1–7) levels after CAR. Sildenafil also decreased apoptosis and Ang II expression in myocardium. The increases of expression of angiotensin-converting-enzyme (ACE), ACE2, Ang II type 1 receptor (AT1R), and the Ang (1–7) receptor Mas in myocardial tissue were enhanced after CAR. Sildenafil suppressed AT1R up-regulation, but had no effect on ACE, ACE2, and Mas expression. Sildenafilfurther boosted the upregulation of endothelial nitric oxide synthase (eNOS), cyclic guanosine monophosphate (cGMP) and inducible nitric oxide synthase(iNOS). Collectively, our results suggest that cardioprotection of sildenafil in CAR model is accompanied by an inhibition of Ang II-AT1R axis activation. PMID:26569234

Sildenafil Protects against Myocardial Ischemia-Reperfusion Injury Following Cardiac Arrest in a Porcine Model: Possible Role of the Renin-Angiotensin System

Directory of Open Access Journals (Sweden)

Guoxing Wang

2015-11-01

Full Text Available Sildenafil, a phosphodiesterase-5 inhibitor sold as Viagra, is a cardioprotector against myocardial ischemia/reperfusion (I/R injury. Our study explored whether sildenafil protects against I/R-induced damage in a porcine cardiac arrest and resuscitation (CAR model via modulating the renin-angiotensin system. Male pigs were randomly divided to three groups: Sham group, Saline group, and sildenafil (0.5 mg/kg group. Thirty min after drug infusion, ventricular fibrillation (8 min and cardiopulmonary resuscitation (up to 30 min was conducted in these animals. We found that sildenafil ameliorated the reduced cardiac function and improved the 24-h survival rate in this model. Sildenafil partly attenuated the increases of plasma angiotensin II (Ang II and Ang (1–7 levels after CAR. Sildenafil also decreased apoptosis and Ang II expression in myocardium. The increases of expression of angiotensin-converting-enzyme (ACE, ACE2, Ang II type 1 receptor (AT1R, and the Ang (1–7 receptor Mas in myocardial tissue were enhanced after CAR. Sildenafil suppressed AT1R up-regulation, but had no effect on ACE, ACE2, and Mas expression. Sildenafilfurther boosted the upregulation of endothelial nitric oxide synthase (eNOS, cyclic guanosine monophosphate (cGMP and inducible nitric oxide synthase(iNOS. Collectively, our results suggest that cardioprotection of sildenafil in CAR model is accompanied by an inhibition of Ang II-AT1R axis activation.

Relative Atrial Natriuretic Peptide Deficiency and Inadequate Renin and Angiotensin II Suppression in Obese Hypertensive Men

DEFF Research Database (Denmark)

Asferg, Camilla L; Nielsen, Søren J; Andersen, Ulrik B

2013-01-01

Obesity is a strong risk factor for hypertension, but the mechanisms by which obesity leads to hypertension are incompletely understood. On this background, we assessed dietary sodium intake, serum levels of natriuretic peptides (NPs), and the activity of the renin-angiotensin system in 63 obese...... hypertensive men (obeseHT: body mass index, ≥30.0 kg/m(2); 24-hour ambulatory blood pressure, ≥130/80 mm Hg), in 40 obese normotensive men (obeseNT: body mass index, ≥30.0 kg/m(2); 24-hour ambulatory blood pressure,...

The secretory phospholipase A2 group IIA: a missing link between inflammation, activated renin-angiotensin system, and atherogenesis?

Directory of Open Access Journals (Sweden)

Dimitar Divchev

2008-06-01

Full Text Available Dimitar Divchev, Bernhard SchiefferDepartment of Cardiology and Angiology, Medizinische Hochschule Hannover, GermanyAbstract: Inflammation, lipid peroxidation and chronic activation of the renin–angiotensin system (RAS are hallmarks of the development of atherosclerosis. Recent studies have suggested the involvement of the pro-inflammatory secretory phospholipase A2 (sPLA2-IIA in atherogenesis. This enzyme is produced by different cell types through stimulation by proinflammatory cytokines. It is detectable in the intima and in media smooth muscle cells, not only in atherosclerotic lesions but also in the very early stages of atherogenesis. sPLA2-IIA can hydrolyse the phospholipid monolayers of low density lipoproteins (LDL. Such modified LDL show increased affinity to proteoglycans. The modified particles have a greater tendency to aggregate and an enhanced ability to insert cholesterol into cells. This modification may promote macrophage LDL uptake leading to the formation of foam cells. Furthermore, sPLA2-IIA is not only a mediator for localized inflammation but may be also used as an independent predictor of adverse outcomes in patients with stable coronary artery disease or acute coronary syndromes. An interaction between activated RAS and phospholipases has been indicated by observations showing that inhibitors of sPLA2 decrease angiotensin (Ang II-induced macrophage lipid peroxidation. Meanwhile, various interactions between Ang II and oxLDL have been demonstrated suggesting a central role of sPLA2-IIA in these processes and offering a possible target for treatment. The role of sPLA2-IIA in the perpetuation of atherosclerosis appears to be the missing link between inflammation, activated RAS and lipidperoxidation.Keywords: secretory phospholipase A2, lipoproteins, renin-angiotensin system, inflammation, atherosclerosis

Targeting the renin-angiotensin system as novel therapeutic strategy for pulmonary diseases.

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Tan, Wan Shun Daniel; Liao, Wupeng; Zhou, Shuo; Mei, Dan; Wong, Wai-Shiu Fred

2017-12-27

The renin-angiotensin system (RAS) plays a major role in regulating electrolyte balance and blood pressure. RAS has also been implicated in the regulation of inflammation, proliferation and fibrosis in pulmonary diseases such as asthma, acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and pulmonary arterial hypertension (PAH). Current therapeutics suffer from some drawbacks like steroid resistance, limited efficacies and side effects. Novel intervention is definitely needed to offer optimal therapeutic strategy and clinical outcome. This review compiles and analyses recent investigations targeting RAS for the treatment of inflammatory lung diseases. Inhibition of the upstream angiotensin (Ang) I/Ang II/angiotensin receptor type 1 (AT 1 R) pathway and activation of the downstream angiotensin-converting enzyme 2 (ACE2)/Ang (1-7)/Mas receptor pathway are two feasible strategies demonstrating efficacies in various pulmonary disease models. More recent studies favor the development of targeting the downstream ACE2/Ang (1-7)/Mas receptor pathway, in which diminazene aceturate, an ACE2 activator, GSK2586881, a recombinant ACE2, and AV0991, a Mas receptor agonist, showed much potential for further development. As the pathogenesis of pulmonary diseases is so complex that RAS modulation may be used alone or in combination with existing drugs like corticosteroids, pirfenidone/nintedanib or endothelin receptor antagonists for different pulmonary diseases. Personalized medicine through genetic screening and phenotyping for angiotensinogen or ACE would aid treatment especially for non-responsive patients. This review serves to provide an update on the latest development in the field of RAS targeting for pulmonary diseases, and offer some insights into future direction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early renin-angiotensin system intervention is more beneficial than late intervention in delaying end-stage renal disease in patients with type 2 diabetes

DEFF Research Database (Denmark)

Schievink, B; Kröpelin, T; Mulder, S

2016-01-01

AIMS: To develop and validate a model to simulate progression of diabetic kidney disease (DKD) from early onset until end-stage renal disease (ESRD), and to assess the effect of renin-angiotensin system (RAS) intervention in early, intermediate and advanced stages of DKD. METHODS: We used data from...

Effect of all-trans retinoic acid treatment on prohibitin and renin-angiotensin-aldosterone system expression in hypoxia-induced renal tubular epithelial cell injury.

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Zhou, Tian-Biao; Ou, Chao; Rong, Liang; Drummen, Gregor P C

2014-09-01

All-trans retinoic acid (ATRA) exerts various effects on physiological processes such as cell growth, differentiation, apoptosis and inflammation. Prohibitins (PHB), including prohibitin 1 (PHB1) and prohibitin 2 (PHB2), are evolutionary conserved and pleiotropic proteins implicated in various cellular functions, including proliferation, tumor suppression, apoptosis, transcription, and mitochondrial protein folding. The renin-angiotensin-aldosterone system plays a pivotal role in the regulation of blood pressure and volume homeostasis. All these factors and systems have been implicated in renal interstitial fibrosis. Therefore, the objective of this study was to investigate the effect of ATRA treatment on the renin-angiotensin-aldosterone system and expression of prohibitins to further understand its role in the processes leading to renal interstitial fibrosis. The hypoxic and oxidative stress conditions in obstructive renal disease were simulated in a hypoxia/reoxygenation model with renal tubular epithelial cells (RTEC) as a model system. Subsequently, the effect of ATRA on mRNA and protein expression levels was determined and correlations were established between factors involved in the renin-angiotensin-aldosterone system, the prohibitins, cellular redox status, renal interstitial fibrosis and ATRA treatment. Correlation analysis showed that both PHB1 and PHB2 protein levels were negatively correlated with angiotensin I, ACE1, angiotensin II, TGF-β1, Col-IV, FN, ROS, and MDA (PHB1: r = -0.792, -0.834, -0.805, -0.795, -0.778, -0.798, -0.751, -0.682; PHB2: r = -0.872, -0.799, -0.838, -0.773, -0.769, -0.841, -0.794, -0.826; each p system under hypoxia/reoxygenation conditions. © The Author(s) 2014.

New synthetic thrombin inhibitors: molecular design and experimental verification.

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Sinauridze, Elena I; Romanov, Alexey N; Gribkova, Irina V; Kondakova, Olga A; Surov, Stepan S; Gorbatenko, Aleksander S; Butylin, Andrey A; Monakov, Mikhail Yu; Bogolyubov, Alexey A; Kuznetsov, Yuryi V; Sulimov, Vladimir B; Ataullakhanov, Fazoyl I

2011-01-01

The development of new anticoagulants is an important goal for the improvement of thromboses treatments. The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Molecular Force Field. This program takes into account the effects of solvent. The designed molecules with the best scoring functions (calculated binding energies) were synthesized and their thrombin inhibitory activity evaluated experimentally in vitro using a chromogenic substrate in a buffer system and using a thrombin generation test in isolated plasma and in vivo using the newly developed model of hemodilution-induced hypercoagulation in rats. The acute toxicities of the most promising new thrombin inhibitors were evaluated in mice, and their stabilities in aqueous solutions were measured. New compounds that are both effective direct thrombin inhibitors (the best K(I) was 50) in the thrombin generation assay of approximately 100 nM) were discovered. These compounds contain one of the following new residues as the basic fragment: isothiuronium, 4-aminopyridinium, or 2-aminothiazolinium. LD(50) values for the best new inhibitors ranged from 166.7 to >1111.1 mg/kg. A plasma-substituting solution supplemented with one of the new inhibitors prevented hypercoagulation in the rat model of hemodilution-induced hypercoagulation. Activities of the best new inhibitors in physiological saline (1 µM solutions) were stable after sterilization by autoclaving, and the inhibitors remained stable at long-term storage over more than 1.5 years at room temperature and at 4°C. The high efficacy, stability and low acute toxicity reveal that the inhibitors that were developed may be promising for potential medical applications.

Direct Regulation of Androgen Receptor Activity by Potent CYP17 Inhibitors in Prostate Cancer Cells*

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Soifer, Harris S.; Souleimanian, Naira; Wu, Sijian; Voskresenskiy, Anatoliy M.; Kisaayak Collak, Filiz; Cinar, Bekir; Stein, Cy A.

2012-01-01

TOK-001 and abiraterone are potent 17-heteroarylsteroid (17-HAS) inhibitors of Cyp17, one of the rate-limiting enzymes in the biosynthesis of testosterone from cholesterol in prostate cancer cells. Nevertheless, the molecular mechanism underlying the prevention of prostate cell growth by 17-HASs still remains elusive. Here, we assess the effects of 17-HASs on androgen receptor (AR) activity in LNCaP and LAPC-4 cells. We demonstrate that both TOK-001 and abiraterone reduced AR protein and mRNA expression, and antagonized AR-dependent promoter activation induced by androgen. TOK-001, but not abiraterone, is an effective apparent competitor of the radioligand [3H]R1881 for binding to the wild type and various mutant AR (W741C, W741L) proteins. In agreement with these data, TOK-001 is a consistently superior inhibitor than abiraterone of R1881-induced transcriptional activity of both wild type and mutant AR. However, neither agent was able to trans-activate the AR in the absence of R1881. Our data demonstrate that phospho-4EBP1 levels are significantly reduced by TOK-001 and to a lesser extent by abiraterone alcohol, and suggest a mechanism by which cap-dependent translation is suppressed by blocking assembly of the eIF4F and eIF4G complex to the mRNA 5′ cap. Thus, the effects of these 17-HASs on AR signaling are complex, ranging from a decrease in testosterone production through the inhibition of Cyp17 as previously described, to directly reducing both AR protein expression and R1881-induced AR trans-activation. PMID:22174412

New synthetic thrombin inhibitors: molecular design and experimental verification.

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Elena I Sinauridze

Full Text Available BACKGROUND: The development of new anticoagulants is an important goal for the improvement of thromboses treatments. OBJECTIVES: The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. METHODS: Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Molecular Force Field. This program takes into account the effects of solvent. The designed molecules with the best scoring functions (calculated binding energies were synthesized and their thrombin inhibitory activity evaluated experimentally in vitro using a chromogenic substrate in a buffer system and using a thrombin generation test in isolated plasma and in vivo using the newly developed model of hemodilution-induced hypercoagulation in rats. The acute toxicities of the most promising new thrombin inhibitors were evaluated in mice, and their stabilities in aqueous solutions were measured. RESULTS: New compounds that are both effective direct thrombin inhibitors (the best K(I was 1111.1 mg/kg. A plasma-substituting solution supplemented with one of the new inhibitors prevented hypercoagulation in the rat model of hemodilution-induced hypercoagulation. Activities of the best new inhibitors in physiological saline (1 µM solutions were stable after sterilization by autoclaving, and the inhibitors remained stable at long-term storage over more than 1.5 years at room temperature and at 4°C. CONCLUSIONS: The high efficacy, stability and low acute toxicity reveal that the inhibitors that were developed may be promising for potential medical applications.

Skeletal muscle wasting: new role of nonclassical renin-angiotensin system.

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Cabello-Verrugio, Claudio; Rivera, Juan C; Garcia, Dominga

2017-05-01

Skeletal muscle can be affected by many physiological and pathological conditions that contribute to the development of muscle weakness, including skeletal muscle loss, inflammatory processes, or fibrosis. Therefore, research into therapeutic treatment alternatives or alleviation of these effects on skeletal muscle is of great importance. Recent studies have shown that angiotensin (1-7) [Ang-(1-7)] - a vasoactive peptide of the nonclassical axis in the renin-angiotensin system (RAS) - and its Mas receptor are expressed in skeletal muscle. Ang-(1-7), through its Mas receptor, prevents or diminishes deleterious effects induced by skeletal muscle disease or injury. Specifically, the Ang-(1-7)-Mas receptor axis modulates molecular mechanisms involved in muscle mass regulation, such as the ubiquitin proteasome pathway, the insulin-like growth factor type 1/Akt (protein kinase B) pathway, or myonuclear apoptosis, and also inflammation and fibrosis pathways. Although further research into this topic and the possible side effects of Ang-(1-7) is necessary, these findings are promising, and suggest that the Ang-(1-7)-Mas axis can be considered a possible therapeutic target for treating patients with muscular disorders.

The use of direct analysis in real time (DART) to assess the levels of inhibitors co-extracted with DNA and the associated impact in quantification and amplification.

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Moreno, Lilliana I; McCord, Bruce R

2016-10-01

The measure of quality in DNA sample processing starts with an effective nucleic acid isolation procedure. Most problems with DNA sample typing can be attributed to low quantity DNA and/or to the presence of inhibitors in the sample. Therefore, establishing which isolation method is best at removing potential inhibitors may help overcome some of the problems analysts encounter by providing useful information in the determination of the optimal approach for any given sample. Direct analysis in real time (DART) mass spectrometry was used in this study to investigate the ability of different extraction methods to remove PCR inhibitors. Methods investigated included both liquid/liquid (phenol-chloroform) and solid phase based robotic procedures, (PrepFiler™ and EZ1 chemistries). Following extraction, samples were analyzed by DART in order to determine the level of remaining inhibitors and then quantified and amplified to determine the effect any remaining inhibitor had on the overall results. The data suggests that organic extraction methods result in detrimental amounts of phenol carryover while automated methods may produce carry-over of bile salts and other chemicals that preferentially bind the solid phase matrix. Both of these effects can have a negative impact in downstream sample processing and genotyping by PCR. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Calcium and osmotic stimulation in renin release from isolated rat glomeruli

DEFF Research Database (Denmark)

Skøtt, O

1986-01-01

of the RR rate preceding the stimulus. Removal of calcium stimulated the RR by 10 times (n = 5, p less than 0.001) and a subsequent decrease in osmolality of 20 mOsm/kg stimulated the RR proportionally to that observed in the series containing 2 mM calcium. A decrease in osmolality was able to stimulate RR......The effects of changes in osmolality and calcium concentration on renin release (RR) from isolated superfused rat glomeruli were studied. The undisturbed RR followed a first order fall with a half-time of about 100 min (n = 45). Changes in the osmolality between 270 and 350 mOsm/kg resulted in dose......-dependent changes in the RR rates. Hypoosmotic treatment stimulated the RR transiently, whereas hyperosmotic treatment produced a sustained inhibition. The dose-response relationship was log-linear between 270 and 320 mOsm/kg. A decrease in osmolality of 20 mOsm/kg gave proportional increases in RR irrespectively...

First steps in the direction of synthetic, allosteric, direct inhibitors of thrombin and factor Xa.

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Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R

2009-08-01

Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that (i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; (ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and (iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes.

First Steps in the Direction of Synthetic, Allosteric, Direct Inhibitors of Thrombin and Factor Xa

Science.gov (United States)

Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R.

2009-01-01

Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes. PMID:19540113

Differences in cortical and pituitary activity in response to hypoglycaemia and cognitive testing in healthy men with different basal activity of the renin-angiotensin system

DEFF Research Database (Denmark)

Bie-Olsen, Lise G; Pedersen-Bjergaard, Ulrik; Kjaer, Troels W

2010-01-01

INTRODUCTION: High renin-angiotensin system (RAS) activity has been associated with a high risk of severe hypoglycaemia in patients with type 1 diabetes and with cognitive deterioration during experimental hypoglycaemia in healthy subjects. The aim of this study was to describe possible differenc...

DNA-directed control of enzyme-inhibitor complex formation: a modular approach to reversibly switch enzyme activity

NARCIS (Netherlands)

Janssen, B.M.G.; Engelen, W.; Merkx, M.

2015-01-01

DNA-templated reversible assembly of an enzyme–inhibitor complex is presented as a new and highly modular approach to control enzyme activity. TEM1-ß-lactamase and its inhibitor protein BLIP were conjugated to different oligonucleotides, resulting in enzyme inhibition in the presence of template

Cost of care of haemophilia with inhibitors.

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Di Minno, M N D; Di Minno, G; Di Capua, M; Cerbone, A M; Coppola, A

2010-01-01

In Western countries, the treatment of patients with inhibitors is presently the most challenging and serious issue in haemophilia management, direct costs of clotting factor concentrates accounting for >98% of the highest economic burden absorbed for the healthcare of patients in this setting. Being designed to address questions of resource allocation and effectiveness, decision models are the golden standard to reliably assess the overall economic implications of haemophilia with inhibitors in terms of mortality, bleeding-related morbidity, and severity of arthropathy. However, presently, most data analyses stem from retrospective short-term evaluations, that only allow for the analysis of direct health costs. In the setting of chronic diseases, the cost-utility analysis, that takes into account the beneficial effects of a given treatment/healthcare intervention in terms of health-related quality of life, is likely to be the most appropriate approach. To calculate net benefits, the quality adjusted life year, that significantly reflects such health gain, has to be compared with specific economic impacts. Differences in data sources, in medical practice and/or in healthcare systems and costs, imply that most current pharmacoeconomic analyses are confined to a narrow healthcare payer perspective. Long-term/lifetime prospective or observational studies, devoted to a careful definition of when to start a treatment; of regimens (dose and type of product) to employ, and of inhibitor population (children/adults, low-responding/high responding inhibitors) to study, are thus urgently needed to allow for newer insights, based on reliable data sources into resource allocation, effectiveness and cost-utility analysis in the treatment of haemophiliacs with inhibitors.

Determinants of the renin-angiotensin-aldosterone system in cirrhosis with special emphasis on the central blood volume

DEFF Research Database (Denmark)

Møller, Søren; Bendtsen, Flemming; Henriksen, Jens H

2006-01-01

OBJECTIVE: Several studies have shown activation of the renin-angiotensin-aldosterone system (RAAS) in cirrhosis. Although the activated RAAS may have several determinants, the system is often considered a surrogate marker of effective hypovolaemia. In this study we investigated the activity...... of the RAAS and its potential determinants with special focus on the central and arterial blood volume (CBV). MATERIAL AND METHODS: Eighty-nine patients (Child class A/B/C: 19/41/29) and 32 controls were included in the study. All were given a haemodynamic examination with measurement of determinants...

Elevated Plasma Levels of Soluble (Pro)Renin Receptor in Patients with Obstructive Sleep Apnea Syndrome in Parallel with the Disease Severity.

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Nishijima, Tsuguo; Tajima, Kazuki; Yamashiro, Yoshihiro; Hosokawa, Keisuke; Suwabe, Akira; Takahashi, Kazuhiro; Sakurai, Shigeru

2016-04-01

(Pro)renin receptor ((P)RR), a receptor for renin and prorenin, is implicated in the pathophysiology of diabetes mellitus, hypertension and their complications. Soluble (P)RR (s(P)RR) is composed of extracellular domain of (P)RR and thus exists in blood. We have reported that plasma concentrations of s(P)RR were elevated in male patients with obstructive sleep apnea syndrome (OSAS). The aim of the present study was to clarify the difference in plasma s(P)RR concentrations between male and female OSAS patients. Plasma s(P)RR concentrations were studied in 289 subjects (206 males and 83 females) consisting of 259 OSAS patients and 30 non-OSAS control subjects. The 259 OSAS patients were classified into mild (5 ≤ apnea hypopnea index (AHI) value found in male subjects (male r = 0.413, p < 0.0001; female r = 0.263, p < 0.05). Importantly, when OSAS patients (26 males and 15 females) with AHI ≥ 20 underwent continuous positive airway pressure treatment, plasma s(P)RR levels were significantly decreased. In conclusion, plasma s(P)RR levels are elevated in both male and female OSAS patients in parallel with the disease severity.

Varying patterns of the antihypertensive and antialbuminuric response to higher doses of renin-angiotensin-aldosterone system blockade in albuminuric hypertensive type 2 diabetes mellitus patients

DEFF Research Database (Denmark)

Weir, Matthew R; Hollenberg, Norman K; Remuzzi, Giuseppe

2011-01-01

In patients with type 2 diabetes mellitus (T2DM), blocking of the renin-angiotensin-aldosterone system (RAAS) has demonstrated efficacy in lowering blood pressure (BP) and urinary albumin excretion rate (UAER). Nonetheless, not all patients successfully respond to RAAS blockade with a reduction...

8C.03: A KEY ROLE FOR ENDOTHELIN-1 IN THE PATHOGENESIS OF PREECLAMPSIA AND THE ASSOCIATED SUPPRESSION OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM.

Science.gov (United States)

Verdonk, K; Saleh, L; Smilde, J E; van Ingen, M M; Garrelds, I M; Friesema, E C; Russcher, H; Steegers, E A P; van den Meiracker, A H; Visser, W; Danser, A H J

2015-06-01

Women with preeclampsia (PE) display low renin-angiotensin-aldosterone system (RAAS) activity and a high anti-angiogenic state, the latter characterized by high levels of soluble Fms-like tyrosine kinase-1(sFlt-1) and reduced levels of placental growth factor (PlGF). In the present study, we hypothesized that the RAAS suppression in PE is the consequence of the disturbed angiogenic balance. In a group of pregnant women with hypertensive disease of pregnancy and a group of healthy pregnant women, matched for gestational age (GA) we measured mean arterial blood pressure (MAP), urinary protein-to-creatinine ratio (PCR), and the plasma levels of sFlt-1, PlGF, albumin, creatinine, endothelin-1 (ET-1), renin (concentration and activity, PRC and PRA), angiotensinogen, and aldosterone. Since initial analysis revealed that these parameters strongly correlated with each other, multiple regression analysis was applied to establish independent determinants of ET-1, PRC, aldosterone and PCR. A sFlt-1/PlGF ratio >85 was considered to be representative for a high anti-angiogenic state. Of the 103 pregnant women included, 65 had a sFlt-1/PlGF ratio 85. Plasma ET-1 and creatinine levels were increased in women with a high ratio, whereas PRA and the plasma levels of renin, angiotensinogen, aldosterone and albumin were decreased in these women. The PRA-aldosterone relationship was identical in both groups. Multiple regression analysis revealed that PRC correlated independently with MAP and plasma ET-1 (R2 0.30). In turn, plasma ET-1 correlated positively with sFlt-1 and negatively with PRC (R2 0.52). Independent determinants of plasma aldosterone were GA and PRA (R2 0.56). Finally we found that plasma PlGF, plasma ET-1 and MAP determined PCR (R2 0.69). The high anti-angiogenic state in PE induces ET-1 activation. Together with the increased MAP in PE this factor suppresses renin release, and in parallel (via PRA reduction) aldosterone synthesis. The identical reduction in PRA and

The effect of postural changes on plasma renin activity during normal and pathologic pregnancies.

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Brandes, J M; Abramovici, H; Katz, M; Diengott, D; Spindel, A; Kahana, L

1978-11-01

A study of the effect of posture on plasma renin activity (PRA) in the third trimester in 27 gravidas revealed a significantly greater increase in PRA in the supine position, compared to the left lateral. The women were classified into 3 groups: normal pregnancy, preeclampsia, intrauterine fetal death. There was no statistical difference in PRA among the 3 groups. It is assumed that the increase of PRA in the supine position was due mainly to mechanical pressure by the gravid uterus on the great vessels (regardless of whether the fetus was dead or alive) and that effective circulatory volume was thus reduced. However, low PRA in the left lateral position in women with preeclampsia seemed to correlate with more severe disease in these women.

Direct oral anticoagulants: An update.

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Franco Moreno, Ana Isabel; Martín Díaz, Rosa María; García Navarro, María José

2017-12-30

Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Effect of kinase inhibitors on the therapeutic properties of monoclonal antibodies.

Science.gov (United States)

Duong, Minh Ngoc; Matera, Eva-Laure; Mathé, Doriane; Evesque, Anne; Valsesia-Wittmann, Sandrine; Clémenceau, Béatrice; Dumontet, Charles

2015-01-01

Targeted therapies of malignancies currently consist of therapeutic monoclonal antibodies and small molecule kinase inhibitors. The combination of these novel agents raises the issue of potential antagonisms. We evaluated the potential effect of 4 kinase inhibitors, including the Bruton tyrosine kinase inhibitor ibrutinib, and 3 PI3K inhibitors idelalisib, NVP-BEZ235 and LY294002, on the effects of the 3 monoclonal antibodies, rituximab and obinutuzumab (directed against CD20) and trastuzumab (directed against HER2). We found that ibrutinib potently inhibits antibody-dependent cell-mediated cytotoxicity exerted by all antibodies, with a 50% inhibitory concentration of 0.2 microM for trastuzumab, 0.5 microM for rituximab and 2 microM for obinutuzumab, suggesting a lesser effect in combination with obinutuzumab than with rituximab. The 4 kinase inhibitors were found to inhibit phagocytosis by fresh human neutrophils, as well as antibody-dependent cellular phagocytosis induced by the 3 antibodies. Conversely co-administration of ibrutinib with rituximab, obinutuzumab or trastuzumab did not demonstrate any inhibitory effect of ibrutinib in vivo in murine xenograft models. In conclusion, some kinase inhibitors, in particular, ibrutinib, are likely to exert inhibitory effects on innate immune cells. However, these effects do not compromise the antitumor activity of monoclonal antibodies in vivo in the models that were evaluated.

Bardoxolone methyl in type 2 diabetes and stage 4 chronic kidney disease

DEFF Research Database (Denmark)

de Zeeuw, Dick; Akizawa, Tadao; Audhya, Paul

2013-01-01

Although inhibitors of the renin-angiotensin-aldosterone system can slow the progression of diabetic kidney disease, the residual risk is high. Whether nuclear 1 factor (erythroid-derived 2)-related factor 2 activators further reduce this risk is unknown....

Recent advances in botulinum neurotoxin inhibitor development.

Science.gov (United States)

Kiris, Erkan; Burnett, James C; Kane, Christopher D; Bavari, Sina

2014-01-01

Botulinum neurotoxins (BoNTs) are endopeptidases that target motor neurons and block acetylcholine neurotransmitter release. This action results in the muscle paralysis that defines the disease botulism. To date, there are no FDA-approved therapeutics to treat BoNT-mediated paralysis after intoxication of the motor neuron. Importantly, the rationale for pursuing treatments to counter these toxins is driven by their potential misuse. Current drug discovery efforts have mainly focused on small molecules, peptides, and peptidomimetics that can directly and competitively inhibit BoNT light chain proteolytic activity. Although this is a rational approach, direct inhibition of the Zn(2+) metalloprotease activity has been elusive as demonstrated by the dearth of candidates undergoing clinical evaluation. Therefore, broadening the scope of viable targets beyond that of active site protease inhibitors represents an additional strategy that could move the field closer to the clinic. Here we review the rationale, and discuss the outcomes of earlier approaches and highlight potential new targets for BoNT inhibition. These include BoNT uptake and processing inhibitors, enzymatic inhibitors, and modulators of neuronal processes associated with toxin clearance, neurotransmitter potentiation, and other pathways geared towards neuronal recovery and repair.

Effect of PTA on blood pressure, renal plasma flow and renal venous renin activity in renovascular hypertension

International Nuclear Information System (INIS)

Arlart, I.P.; Dewitz, H. von; Rosenthal, J.

1983-01-01

Percutaneous transluminal angioplasty (PTA) is more and more accepted for interventional management of renal artery stenosis in hypertensive patients. This study was carried out to assess the behaviour of arterial blood-pressure, renal plasma flow and renal venous rening activity in renovascular hypertension following catheter dilatation. Using the data the possibility is calculated to predict the effect of PTA on blood pressure preinterventionally. The results demonstrate that a successful employment of PTA depends on a normal contralateral renal plasma flow and a normalization of plasma flow of the poststenotic kidney. Determination of plasma renin activity is only of restricted value. (orig.)

Effects of high doses of enalapril and benazepril on the pharmacologically activated renin-angiotensin-aldosterone system in clinically normal dogs.

Science.gov (United States)

Ames, Marisa K; Atkins, Clarke E; Lee, Seunggon; Lantis, Andrea C; zumBrunnen, James R

2015-12-01

To determine whether high doses of enalapril and benazepril would be more effective than standard doses of these drugs in suppressing the furosemide-activated renin-angiotensin-aldosterone system (RAAS). 6 healthy Beagles. 2 experiments were conducted; each lasted 10 days, separated by a 2-week washout period. In experiment 1, all dogs received furosemide (2 mg/kg, PO, q 12 h) and enalapril (1 mg/kg, PO, q 12 h) for 8 days (days 0 through 7). In experiment 2, dogs received furosemide (2 mg/kg, PO, q 12 h) and benazepril (1 mg/kg, PO, q 12 h) for 8 days. Effects on the RAAS were determined by assessing serum angiotensin-converting enzyme (ACE) activity on days -1, 3, and 7; serum aldosterone concentration on days -2, -1, 1, 3, and 7; and the urinary aldosterone-creatinine ratio (UAldo:C) in urine collected in the morning and evening of days -2, -1, 1, 3, and 7. High doses of enalapril and benazepril caused significant reductions in serum ACE activity on all days but were not more effective than standard doses used in other studies. Mean UAldo:C remained significantly higher on days 2 through 7, compared with baseline values. Serum aldosterone concentration also increased after drug administration, which mirrored changes in the UAldo:C. In this study, administration of high doses of enalapril and benazepril significantly inhibited ACE activity, yet did not prevent increases in mean urine and serum aldosterone concentrations resulting from furosemide activation of RAAS. This suggested that aldosterone breakthrough from ACE inhibition was a dose-independent effect of ACE inhibitors.

Endoplasmic reticulum stress increases brain MAPK signaling, inflammation and renin-angiotensin system activity and sympathetic nerve activity in heart failure.

Science.gov (United States)

Wei, Shun-Guang; Yu, Yang; Weiss, Robert M; Felder, Robert B

2016-10-01

We previously reported that endoplasmic reticulum (ER) stress is induced in the subfornical organ (SFO) and the hypothalamic paraventricular nucleus (PVN) of heart failure (HF) rats and is reduced by inhibition of mitogen-activated protein kinase (MAPK) signaling. The present study further examined the relationship between brain MAPK signaling, ER stress, and sympathetic excitation in HF. Sham-operated (Sham) and HF rats received a 4-wk intracerebroventricular (ICV) infusion of vehicle (Veh) or the ER stress inhibitor tauroursodeoxycholic acid (TUDCA, 10 μg/day). Lower mRNA levels of the ER stress biomarkers GRP78, ATF6, ATF4, and XBP-1s in the SFO and PVN of TUDCA-treated HF rats validated the efficacy of the TUDCA dose. The elevated levels of phosphorylated p44/42 and p38 MAPK in SFO and PVN of Veh-treated HF rats, compared with Sham rats, were significantly reduced in TUDCA-treated HF rats as shown by Western blot and immunofluorescent staining. Plasma norepinephrine levels were higher in Veh-treated HF rats, compared with Veh-treated Sham rats, and were significantly lower in the TUDCA-treated HF rats. TUDCA-treated HF rats also had lower mRNA levels for angiotensin converting enzyme, angiotensin II type 1 receptor, tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, and NF-κB p65, and a higher mRNA level of IκB-α, in the SFO and PVN than Veh-treated HF rats. These data suggest that ER stress contributes to the augmented sympathetic activity in HF by inducing MAPK signaling, thereby promoting inflammation and renin-angiotensin system activity in key cardiovascular regulatory regions of the brain.

SGLT2 Inhibitors May Predispose to Ketoacidosis.

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Taylor, Simeon I; Blau, Jenny E; Rother, Kristina I

2015-08-01

Sodium glucose cotransporter 2 (SGLT2) inhibitors are antidiabetic drugs that increase urinary excretion of glucose, thereby improving glycemic control and promoting weight loss. Since approval of the first-in-class drug in 2013, data have emerged suggesting that these drugs increase the risk of diabetic ketoacidosis. In May 2015, the Food and Drug Administration issued a warning that SGLT2 inhibitors may lead to ketoacidosis. Using PubMed and Google, we conducted Boolean searches including terms related to ketone bodies or ketoacidosis with terms for SGLT2 inhibitors or phlorizin. Priority was assigned to publications that shed light on molecular mechanisms whereby SGLT2 inhibitors could affect ketone body metabolism. SGLT2 inhibitors trigger multiple mechanisms that could predispose to diabetic ketoacidosis. When SGLT2 inhibitors are combined with insulin, it is often necessary to decrease the insulin dose to avoid hypoglycemia. The lower dose of insulin may be insufficient to suppress lipolysis and ketogenesis. Furthermore, SGLT2 is expressed in pancreatic α-cells, and SGLT2 inhibitors promote glucagon secretion. Finally, phlorizin, a nonselective inhibitor of SGLT family transporters decreases urinary excretion of ketone bodies. A decrease in the renal clearance of ketone bodies could also increase the plasma ketone body levels. Based on the physiology of SGLT2 and the pharmacology of SGLT2 inhibitors, there are several biologically plausible mechanisms whereby this class of drugs has the potential to increase the risk of developing diabetic ketoacidosis. Future research should be directed toward identifying which patients are at greatest risk for this side effect and also to optimizing pharmacotherapy to minimize the risk to patients.

The physiology of a local renin-angiotensin system in the pancreas.

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Leung, Po Sing

2007-04-01

The systemic renin-angiotensin system (RAS) plays an important role in regulating blood pressure, electrolyte and fluid homeostasis. However, local RASs also exist in diverse tissues and organs, where they play a multitude of autocrine, paracrine and intracrine physiological roles. The existence of a local RAS is now recognized in pancreatic acinar, islet, duct, endothelial and stellate cells, the expression of which is modulated in response to physiological and pathophysiological stimuli such as hypoxia, pancreatitis, islet transplantation, hyperglycaemia, and diabetes mellitus. This pancreatic RAS has been proposed to have important endocrine and exocrine roles in the pancreas, regulating local blood flow, duct cell sodium bicarbonate secretion, acinar cell digestive enzyme secretion, islet beta-cell (pro)insulin biosynthesis, and thus, glucose-stimulated insulin release, delta-cell somatostatin secretion, and pancreatic cell proliferation and differentiation. It may further mediate oxidative stress-induced cell inflammation, apoptosis and fibrosis. Further exploration of this system would probably offer new insights into the pathogenesis of pancreatitis, diabetes, cystic fibrosis and pancreatic cancer formation. New therapeutic targets and strategies might thus be suggested.

Organophosphate acetylcholine esterase inhibitor poisoning from a home-made shampoo.

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Sadaka, Yair; Broides, Arnon; Tzion, Raffi Lev; Lifshitz, Matitiahu

2011-07-01

Organophosphate acetylcholine esterase inhibitor poisoning is a major health problem in children. We report an unusual cause of organophosphate acetylcholine esterase inhibitor poisoning. Two children were admitted to the pediatric intensive care unit due to organophosphate acetylcholine esterase inhibitor poisoning after exposure from a home-made shampoo that was used for the treatment of head lice. Owing to no obvious source of poisoning, the diagnosis of organophosphate acetylcholine esterase inhibitor poisoning in one of these patients was delayed. Both patients had an uneventful recovery. Organophosphate acetylcholine esterase inhibitor poisoning from home-made shampoo is possible. In cases where the mode of poisoning is unclear, direct questioning about the use of home-made shampoo is warranted, in these cases the skin and particularly the scalp should be rinsed thoroughly as soon as possible.

Regulation of the renin–angiotensin system in coronary atherosclerosis: A review of the literature

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Ramadan A Hammoud

2008-01-01

Full Text Available Ramadan A Hammoud, Christopher S Vaccari, Sameer H Nagamia, Bobby V KhanEmory University School of Medicine, Division of Cardiology, Grady Memorial Hospital Vascular Research Laboratory, Atlanta, Georgia, USAAbstract: Activation of the renin–angiotensin system (RAS is significant in the pathogenesis of cardiovascular disease and specifically coronary atherosclerosis. There is strong evidence that the RAS has effects on the mechanisms of action of atherosclerosis, including fibrinolytic balance, endothelial function, and plaque stability. Pharmacological inhibition of the renin angiotensin system includes angiotensin converting enzyme (ACE inhibitors, angiotensin receptor blockers (ARBs, and renin inhibitors. These agents have clinical benefits in reducing morbidity and mortality in the management of hypertension. In addition, ACE inhibitors and ARBs have shown to be effective in the management of congestive heart failure and acute myocardial infarction. This review article discusses the biochemical and molecular mechanisms involving the RAS in coronary atherosclerosis as well as the effects of RAS inhibition in clinical studies involving coronary atherosclerosis.Keywords: angiotensin II, atherosclerosis, endothelium, inflammation, vasculature

The proton pump inhibitor, omeprazole, but not lansoprazole or pantoprazole, is a metabolism-dependent inhibitor of CYP2C19: implications for coadministration with clopidogrel.

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Ogilvie, Brian W; Yerino, Phyllis; Kazmi, Faraz; Buckley, David B; Rostami-Hodjegan, Amin; Paris, Brandy L; Toren, Paul; Parkinson, Andrew

2011-11-01

As a direct-acting inhibitor of CYP2C19 in vitro, lansoprazole is more potent than omeprazole and other proton pump inhibitors (PPIs), but lansoprazole does not cause clinically significant inhibition of CYP2C19 whereas omeprazole does. To investigate this apparent paradox, we evaluated omeprazole, esomeprazole, R-omeprazole, lansoprazole, and pantoprazole for their ability to function as direct-acting and metabolism-dependent inhibitors (MDIs) of CYP2C19 in pooled human liver microsomes (HLM) as well as in cryopreserved hepatocytes and recombinant CYP2C19. In HLM, all PPIs were found to be direct-acting inhibitors of CYP2C19 with IC(50) values varying from 1.2 μM [lansoprazole; maximum plasma concentration (C(max)) = 2.2 μM] to 93 μM (pantoprazole; C(max) = 6.5 μM). In addition, we identified omeprazole, esomeprazole, R-omeprazole, and omeprazole sulfone as MDIs of CYP2C19 (they caused IC(50) shifts after a 30-min preincubation with NADPH-fortified HLM of 4.2-, 10-, 2.5-, and 3.2-fold, respectively), whereas lansoprazole and pantoprazole were not MDIs (IC(50) shifts lansoprazole, or pantoprazole, as irreversible (or quasi-irreversible) MDIs of CYP2C19. These results have important implications for the mechanism of the clinical interaction reported between omeprazole and clopidogrel, as well as other CYP2C19 substrates.

Prolonged fasting increases the response of the renin-angiotensin-aldosterone system, but not vasopressin levels, in postweaned northern elephant seal pups

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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.

[Differences of blood plasma renin activity, angiotensin II and aldosterone levels in essential or secondary hypertension].

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Song, Ai-ling; Zeng, Zheng-pei; Tong, An-li; Lu, Lin; Chen, Shi; Li, Ming; Fu, Chun-li; Wang, Yong-hui; Sun, Mei-li

2012-04-01

To study on the difference of plasma renin activity (PRA), angiotensin II (Ang II), and aldosterone levels in patients with essential hypertension (EH) or primary aldosteronism (PA) or pheochromocytoma (PHEO), and to analyze the sensitivity and specificity on the diagnosis of PA among patients with hypertension with aldosterone/PRA ratio (ARR). The plasma aldosterone, Ang II and PRA concentrations in supine and upright positions were measured by radioimmunoassay from 413 patients including idiopathic hyperaldosteronism (IHA, n = 111), aldosterone-producing adenoma (APA, n = 118), PHEO (n = 98) and EH (n = 86). ARR was calculated. Plasma aldosterone concentrations in both of supine and upright positions in PHEO group [374 (294, 465) pmol/L and 629 (449, 997) pmol/L] and PA group [471 (346, 632) pmol/L and 673 (499, 825) pmol/L] were higher than those in EH group [277 (224, 332) pmol/L and 427 (341, 501) pmol/L] (P 0.05). The PRA level in both positions of each group were PHEO group [0.3 (0.2, 1.0) µg · L(-1) · h(-1) and 1.4 (0.6, 3.4) µg · L(-1) · h(-1)] > EH group [0.2 (0.1, 0.4) µg · L(-1) · h(-1) and 0.6 (0.4, 1.0) µg · L(-1) · h(-1)] (P PA group [0.1 (0.1, 0.1) µg · L(-1) · h(-1) and 0.2 (0.1, 0.3) µg · L(-1) · h(-1)] (P < 0.01), and APA group [0.1 (0.1, 0.1) µg · L(-1) · h(-1) and 0.1 (0.1, 0.3) µg · L(-1) · h(-1)] < IHA group [0.1 (0.1, 0.2) µg · L(-1) · h(-1) and 0.2 (0.1, 0.3) µg · L(-1) · h(-1)] (supine P < 0.01; upright P < 0.05). APA was divided into 2 types with renin-Ang II-responsive APA (n = 26) and unresponsive APA (n = 92). The plasma aldosterone concentration was lower in supine position but higher in upright position in renin-Ang II-responsive APA than in unresponsive APA patients. ARR in upright was higher in PA group (P < 0.01) but lower in PHEO group (P < 0.05) compared with EH. ARR was higher in APA than in IHA (P < 0.01). The sensitivity and specificity of ARR as 40 (aldosterone unit: ng/dl; PRA unit: µg · L(-1

Maintenance of serum potassium with sodium zirconium cyclosilicate (ZS-9) in heart failure patients : results from a phase 3 randomized, double-blind, placebo-controlled trial

NARCIS (Netherlands)

Anker, Stefan D.; Kosiborod, Mikhail; Zannad, Faiez; Pina, Ileana L.; McCullough, Peter A.; Filippatos, Gerasimos; van der Meer, Peter; Ponikowski, Piotr; Rasmussen, Henrik S.; Lavin, Philip T.; Singh, Bhupinder; Yang, Alex; Deedwania, Prakash

2015-01-01

AimsHyperkalaemia in heart failure patients limits use of cardioprotective renin-angiotensin-aldosterone system inhibitors (RAASi). Sodium zirconium cyclosilicate (ZS-9) is a selective potassium ion trap, whose mechanism of action may allow for potassium binding in the upper gastrointestinal tract

Sodium intake, RAAS-blockade and progressive renal disease

NARCIS (Netherlands)

de Borst, Martin H; Navis, Gerjan

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

Tracking the stochastic fate of cells of the renin lineage after podocyte depletion using multicolor reporters and intravital imaging.

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Natalya V Kaverina

Full Text Available Podocyte depletion plays a major role in focal segmental glomerular sclerosis (FSGS. Because cells of the renin lineage (CoRL serve as adult podocyte and parietal epithelial cell (PEC progenitor candidates, we generated Ren1cCre/R26R-ConfettiTG/WT and Ren1dCre/R26R-ConfettiTG/WT mice to determine CoRL clonality during podocyte replacement. Four CoRL reporters (GFP, YFP, RFP, CFP were restricted to cells in the juxtaglomerular compartment (JGC at baseline. Following abrupt podocyte depletion in experimental FSGS, all four CoRL reporters were detected in a subset of glomeruli at day 28, where they co-expressed de novo four podocyte proteins (podocin, nephrin, WT-1 and p57 and two glomerular parietal epithelial cell (PEC proteins (claudin-1, PAX8. To monitor the precise migration of a subset of CoRL over a 2w period following podocyte depletion, intravital multiphoton microscopy was used. Our findings demonstrate direct visual support for the migration of single CoRL from the JGC to the parietal Bowman's capsule, early proximal tubule, mesangium and glomerular tuft. In summary, these results suggest that following podocyte depletion, multi-clonal CoRL migrate to the glomerulus and replace podocyte and PECs in experimental FSGS.

Hepatitis C Virus NS3 Inhibitors: Current and Future Perspectives

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Kazi Abdus Salam

2013-01-01

Full Text Available Currently, hepatitis C virus (HCV infection is considered a serious health-care problem all over the world. A good number of direct-acting antivirals (DAAs against HCV infection are in clinical progress including NS3-4A protease inhibitors, RNA-dependent RNA polymerase inhibitors, and NS5A inhibitors as well as host targeted inhibitors. Two NS3-4A protease inhibitors (telaprevir and boceprevir have been recently approved for the treatment of hepatitis C in combination with standard of care (pegylated interferon plus ribavirin. The new therapy has significantly improved sustained virologic response (SVR; however, the adverse effects associated with this therapy are still the main concern. In addition to the emergence of viral resistance, other targets must be continually developed. One such underdeveloped target is the helicase portion of the HCV NS3 protein. This review article summarizes our current understanding of HCV treatment, particularly with those of NS3 inhibitors.

Brain Renin-Angiotensin System and Microglial Polarization: Implications for Aging and Neurodegeneration

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Jose L. Labandeira-Garcia

2017-05-01

Full Text Available Microglia can transform into proinflammatory/classically activated (M1 or anti-inflammatory/alternatively activated (M2 phenotypes following environmental signals related to physiological conditions or brain lesions. An adequate transition from the M1 (proinflammatory to M2 (immunoregulatory phenotype is necessary to counteract brain damage. Several factors involved in microglial polarization have already been identified. However, the effects of the brain renin-angiotensin system (RAS on microglial polarization are less known. It is well known that there is a “classical” circulating RAS; however, a second RAS (local or tissue RAS has been observed in many tissues, including brain. The locally formed angiotensin is involved in local pathological changes of these tissues and modulates immune cells, which are equipped with all the components of the RAS. There are also recent data showing that brain RAS plays a major role in microglial polarization. Level of microglial NADPH-oxidase (Nox activation is a major regulator of the shift between M1/proinflammatory and M2/immunoregulatory microglial phenotypes so that Nox activation promotes the proinflammatory and inhibits the immunoregulatory phenotype. Angiotensin II (Ang II, via its type 1 receptor (AT1, is a major activator of the NADPH-oxidase complex, leading to pro-oxidative and pro-inflammatory effects. However, these effects are counteracted by a RAS opposite arm constituted by Angiotensin II/AT2 receptor signaling and Angiotensin 1–7/Mas receptor (MasR signaling. In addition, activation of prorenin-renin receptors may contribute to activation of the proinflammatory phenotype. Aged brains showed upregulation of AT1 and downregulation of AT2 receptor expression, which may contribute to a pro-oxidative pro-inflammatory state and the increase in neuron vulnerability. Several recent studies have shown interactions between the brain RAS and different factors involved in microglial polarization

Comparison between SGLT2 inhibitors and DPP4 inhibitors added to insulin therapy in type 2 diabetes: a systematic review with indirect comparison meta-analysis.

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Min, Se Hee; Yoon, Jeong-Hwa; Hahn, Seokyung; Cho, Young Min

2017-01-01

Both sodium glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP4) inhibitors can be used to treat patients with type 2 diabetes mellitus (T2DM) that is inadequately controlled with insulin therapy, and yet there has been no direct comparison of these two inhibitors. We searched MEDLINE, EMBASE, LILACS, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov through June 2015. Randomized controlled trials published in English that compare SGLT2 inhibitor plus insulin (SGLT2i/INS) with placebo plus insulin or DPP4 inhibitor plus insulin (DPP4i/INS) with placebo plus insulin in patients with T2DM were selected. Data on the study characteristics, efficacy and safety outcomes were extracted. We compared the efficacy and safety between SGLT2i/INS and DPP4i/INS indirectly with covariates adjustment. Risk of potential bias was assessed. Fourteen eligible randomized controlled trials comprising 6980 patients were included (five SGLT2 inhibitor studies and nine DPP4 inhibitor studies). Covariate-adjusted indirect comparison using meta-regression analyses revealed that SGLT2i/INS achieved greater reduction in HbA 1c [weighted mean difference (WMD) -0.24%, 95% confidence interval (CI) -0.43 to -0.05%], fasting plasma glucose (WMD -18.0 mg/dL, 95% CI -28.5 to -7.6 mg/dL) and body weight (WMD -2.38 kg, 95% CI -3.18 to -1.58 kg) from baseline than DPP4i/INS without increasing the risk of hypoglycaemia (relative risks 1.19, 95% CI 0.78 to 1.82). Sodium glucose cotransporter 2 inhibitors achieved better glycaemic control and greater weight reduction than DPP4 inhibitors without increasing the risk of hypoglycaemia in patients with T2DM that is inadequately controlled with insulin. There has been no direct comparison of SGLT2 inhibitors and DPP4 inhibitors in patients with T2DM inadequately controlled with insulin therapy. In this study, we performed indirect meta-analysis comparing SGLT2 inhibitors and DPP4 inhibitors added to insulin

Living high training low induces physiological cardiac hypertrophy accompanied by down-regulation and redistribution of the renin-angiotensin system

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Shi, Wei; Meszaros, J Gary; Zeng, Shao-ju; Sun, Ying-yu; Zuo, Ming-xue

2013-01-01

Aim: Living high training low” (LHTL) is an exercise-training protocol that refers living in hypoxia stress and training at normal level of O2. In this study, we investigated whether LHTL caused physiological heart hypertrophy accompanied by changes of biomarkers in renin-angiotensin system in rats. Methods: Adult male SD rats were randomly assigned into 4 groups, and trained on living low-sedentary (LLS, control), living low-training low (LLTL), living high-sedentary (LHS) and living high-training low (LHTL) protocols, respectively, for 4 weeks. Hematological parameters, hemodynamic measurement, heart hypertrophy and plasma angiotensin II (Ang II) level of the rats were measured. The gene and protein expression of angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and angiotensin II receptor I (AT1) in heart tissue was assessed using RT-PCR and immunohistochemistry, respectively. Results: LLTL, LHS and LHTL significantly improved cardiac function, increased hemoglobin concentration and RBC. At the molecular level, LLTL, LHS and LHTL significantly decreased the expression of ACE, AGT and AT1 genes, but increased the expression of ACE and AT1 proteins in heart tissue. Moreover, ACE and AT1 protein expression was significantly increased in the endocardium, but unchanged in the epicardium. Conclusion: LHTL training protocol suppresses ACE, AGT and AT1 gene expression in heart tissue, but increases ACE and AT1 protein expression specifically in the endocardium, suggesting that the physiological heart hypertrophy induced by LHTL is regulated by region-specific expression of renin-angiotensin system components. PMID:23377552

A high sodium intake reduces antiproteinuric response to renin-angiotensin-aldosterone system blockade in kidney transplant recipients.

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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.

Cancer Stem Cells in Moderately Differentiated Buccal Mucosal Squamous Cell Carcinoma Express Components of the Renin-Angiotensin System

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Therese Featherston

2016-09-01

Full Text Available Aim We have recently identified and characterized cancer stem cell (CSC subpopulations within moderately differentiated buccal mucosal squamous cell carcinoma (MDBMSCC. We hypothesized that these CSCs express components of the renin-angiotensin system (RAS.Methods 3,3-Diaminobenzidine (DAB immunohistochemical (IHC staining was performed on formalin-fixed paraffin-embedded MDBMSCC samples to investigate the expression of the components of the RAS: pro(renin receptor (PRR, angiotensin converting enzyme (ACE, angiotensin II receptor 1 (ATIIR1 and angiotensin II receptor 2 (ATIIR2. NanoString mRNA gene expression analysis and Western Blotting (WB were performed on snap-frozen MDBMSCC samples to confirm gene expression and translation of these transcripts, respectively. Double immunofluorescent (IF IHC staining of these components of the RAS with the embryonic stem cell markers OCT4 or SALL4 was performed to demonstrate their localization in relation to the CSC subpopulations within MDBMSCC.Results DAB IHC staining demonstrated expression of PRR, ACE, ATIIR1 and ATIIR2 in MDBMSCC. IF IHC staining showed that PRR was expressed by the CSC subpopulations within the tumor nests, the peri-tumoral stroma and the endothelium of the microvessels within the peri-tumoral stroma. ATIIR1 and ATIIR2 were localized to the CSC subpopulations within the tumor nests and the peri-tumoral stroma, while ACE was localized to the endothelium of the microvessels within the peri-tumoral stroma. WB and NanoString analyses confirmed protein expression and transcription activation of PRR, ACE and ATIIR1 but not of ATIIR2, respectively.

Long-term patterns of adherence to medication therapy among patients with type 2 diabetes mellitus in Denmark

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Jensen, Majken Linnemann; Jørgensen, Marit Eika; Hansen, Ebba Holme

2017-01-01

: Adherence to six medicine groups (metformin, sulfonylureas, acetylsalicylic acid, thiazide diuretics, renin angiotensin system inhibitors, and statins) were analysed among 5,232 patients with type 2 diabetes at a tertiary referral hospital during 1998-2009. Rate-ratios of initiation of treatment, recurrent...

Dual blockade with candesartan cilexetil and lisinopril in hypertensive patients with diabetes mellitus

DEFF Research Database (Denmark)

Andersen, Niels H; Knudsen, Søren T; Poulsen, Per L

2003-01-01

BACKGROUND: Blood pressure (BP) reduction is the key to risk reduction of cardiovascular disease or renal failure in hypertensive patients with diabetes mellitus. Inhibition of the renin-angiotensin system by an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin II receptor blocker (...

CHRONIC KIDNEY DISEASE RAAS blockade and diastolic heart failure in chronic kidney disease

NARCIS (Netherlands)

Franssen, Casper F. M.; Navis, Gerjan

New data from Ahmed et al. show that discharge prescriptions for renin-angiotensin-aldosterone inhibitor therapy are associated with a significant reduction in all-cause mortality in elderly patients with diastolic heart failure and chronic kidney disease (CKD). These observational data support the

Acute and chronic role of nitric oxide, renin-angiotensin system and sympathetic nervous system in the modulation of calcium sensitization in Wistar Rats

Czech Academy of Sciences Publication Activity Database

Brunová, Aneta; Bencze, Michal; Behuliak, Michal; Zicha, Josef

2015-01-01

Roč. 64, č. 4 (2015), s. 447-457 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP304/12/0259; GA MZd(CZ) NV15-25396A Institutional support: RVO:67985823 Keywords : blood pressure * kalcium sensitization * Rho kinase * nitric oxide * renin-angiotensin system * sympathetic nervous system * fasudil Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.643, year: 2015

Nifedipine-sensitive blood pressure component in hypertensive models characterized by high activity of either sympathetic nervous system or renin-angiotensin system

Czech Academy of Sciences Publication Activity Database

Zicha, Josef; Dobešová, Zdenka; Behuliak, Michal; Pintérová, Mária; Kuneš, Jaroslav; Vaněčková, Ivana

2014-01-01

Roč. 63, č. 1 (2014), s. 13-26 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/09/0336; GA ČR(CZ) GAP304/12/0259 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : voltage-gated caclium channels * sympathetic nervous system * renin-angiotensin system * nitric oxide Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.293, year: 2014

Direct oral anticoagulants and venous thromboembolism

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Massimo Franchini

2016-09-01

Full Text Available Venous thromboembolism (VTE, consisting of deep vein thrombosis and pulmonary embolism, is a major clinical concern associated with significant morbidity and mortality. The cornerstone of management of VTE is anticoagulation, and traditional anticoagulants include parenteral heparins and oral vitamin K antagonists. Recently, new oral anticoagulant drugs have been developed and licensed, including direct factor Xa inhibitors (e.g. rivaroxaban, apixaban and edoxaban and thrombin inhibitors (e.g. dabigatran etexilate. This narrative review focusses on the characteristics of these direct anticoagulants and the main results of published clinical studies on their use in the prevention and treatment of VTE.

Angiotensin Converting Enzyme Inhibitor Has a Protective Effect on Decompression Sickness in Rats

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Aleksandra Mazur

2018-03-01

Full Text Available Introduction: Commercial divers, high altitude pilots, and astronauts are exposed to some inherent risk of decompression sickness (DCS, though the mechanisms that trigger are still unclear. It has been previously showed that diving may induce increased levels of serum angiotensin converting enzyme. The renin angiotensin aldosterone system (RAAS is one of the most important regulators of blood pressure and fluid volume. The purpose of the present study was to control the influence of angiotensin II on the appearance of DCS.Methods: Sprague Dawley rats have been pre-treated with inhibitor of angiotensin II receptor type 1 (losartan; 10 mg/kg, angiotensin-converting enzyme (ACE inhibitor (enalapril; 10 mg/kg, and calcium-entry blocker (nifedipine; 20 mg/kg. The experimental groups were treated for 4 weeks before exposure to hyperbaric pressure while controls were not treated. Seventy-five rats were subjected to a simulated dive at 1000 kPa absolute pressure for 45 min before starting decompression. Clinical assessment took place over a period of 60 min after surfacing. Blood samples were collected for measurements of TBARS, interleukin 6 (IL-6, angiotensin II (ANG II and ACE.Results: The diving protocol induced 60% DCS in non-treated animals. This ratio was significantly decreased after treatment with enalapril, but not other vasoactive drugs. Enalapril did not change ANG II or ACE concentration, while losartant decreased post dive level of ACE but not ANG II. None of the treatment modified the effect of diving on TBARS and IL-6 values.Conclusion: Results suggests that the rennin angiotensin system is involved in a process of triggering DCS but this has to be further investigated. However, a vasorelaxation mediated process, which potentially could increase the load of inert gas during hyperbaric exposure, and antioxidant properties were excluded by our results.

Dietary Sodium Suppresses Digestive Efficiency via the Renin-Angiotensin System.

Science.gov (United States)

Weidemann, Benjamin J; Voong, Susan; Morales-Santiago, Fabiola I; Kahn, Michael Z; Ni, Jonathan; Littlejohn, Nicole K; Claflin, Kristin E; Burnett, Colin M L; Pearson, Nicole A; Lutter, Michael L; Grobe, Justin L

2015-06-11

Dietary fats and sodium are both palatable and are hypothesized to synergistically contribute to ingestive behavior and thereby obesity. Contrary to this hypothesis, C57BL/6J mice fed a 45% high fat diet exhibited weight gain that was inhibited by increased dietary sodium content. This suppressive effect of dietary sodium upon weight gain was mediated specifically through a reduction in digestive efficiency, with no effects on food intake behavior, physical activity, or resting metabolism. Replacement of circulating angiotensin II levels reversed the effects of high dietary sodium to suppress digestive efficiency. While the AT1 receptor antagonist losartan had no effect in mice fed low sodium, the AT2 receptor antagonist PD-123,319 suppressed digestive efficiency. Correspondingly, genetic deletion of the AT2 receptor in FVB/NCrl mice resulted in suppressed digestive efficiency even on a standard chow diet. Together these data underscore the importance of digestive efficiency in the pathogenesis of obesity, and implicate dietary sodium, the renin-angiotensin system, and the AT2 receptor in the control of digestive efficiency regardless of mouse strain or macronutrient composition of the diet. These findings highlight the need for greater understanding of nutrient absorption control physiology, and prompt more uniform assessment of digestive efficiency in animal studies of energy balance.

Novel multi-target-directed ligands for Alzheimer's disease: Combining cholinesterase inhibitors and 5-HT6 receptor antagonists. Design, synthesis and biological evaluation.

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Więckowska, Anna; Kołaczkowski, Marcin; Bucki, Adam; Godyń, Justyna; Marcinkowska, Monika; Więckowski, Krzysztof; Zaręba, Paula; Siwek, Agata; Kazek, Grzegorz; Głuch-Lutwin, Monika; Mierzejewski, Paweł; Bienkowski, Przemysław; Sienkiewicz-Jarosz, Halina; Knez, Damijan; Wichur, Tomasz; Gobec, Stanislav; Malawska, Barbara

2016-11-29

As currently postulated, a complex treatment may be key to an effective therapy for Alzheimer's disease (AD). Recent clinical trials in patients with moderate AD have shown a superior effect of the combination therapy of donepezil (a selective acetylcholinesterase inhibitor) with idalopirdine (a 5-HT 6 receptor antagonist) over monotherapy with donepezil. Here, we present the first report on the design, synthesis and biological evaluation of a novel class of multifunctional ligands that combines a 5-HT 6 receptor antagonist with a cholinesterase inhibitor. Novel multi-target-directed ligands (MTDLs) were designed by combining pharmacophores directed against the 5-HT 6 receptor (1-(phenylsulfonyl)-4-(piperazin-1-yl)-1H-indole) and cholinesterases (tacrine or N-benzylpiperidine analogues). In vitro evaluation led to the identification of tacrine derivative 12 with well-balanced potencies against the 5-HT 6 receptor (K b  = 27 nM), acetylcholinesterase and butyrylcholinesterase (IC 50 hAChE  = 12 nM, IC 50 hBuChE  = 29 nM). The compound also showed good in vitro blood-brain-barrier permeability (PAMPA-BBB assay), which was confirmed in vivo (open field study). Central cholinomimetic activity was confirmed in vivo in rats using a scopolamine-induced hyperlocomotion model. A novel class of multifunctional ligands with compound 12 as the best derivative in a series represents an excellent starting point for the further development of an effective treatment for AD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Effect of ipsilateral ureteric obstruction on contralateral kidney and role of renin angiotensin system blockade on renal recovery in experimentally induced unilateral ureteric obstruction

Directory of Open Access Journals (Sweden)

Shasanka S Panda

2013-01-01

Full Text Available Aims: To study, the effects of ipsilateral ureteric obstruction on contralateral kidney and the role of renin angiotensin system (RAS blockade on renal recovery in experimentally induced unilateral ureteric obstruction. Materials and Methods: Unilateral upper ureteric obstruction was created in 96 adult Wistar rats that were reversed after pre-determined intervals. Losartan and Enalapril were given to different subgroups of rats following relief of obstruction. Results: The severity of dilatation on the contralateral kidney varied with duration of ipsilateral obstruction longer the duration more severe the dilatation. There is direct correlation between renal parenchymal damage, pelvi-ureteric junction (PUJ fibrosis, inflammation and severity of pelvi-calyceal system dilatation of contralateral kidney with duration of ipsilateral PUJ obstruction. Conclusions: Considerable injury is also inflicted to the contralateral normal kidney while ipsilateral kidney remains obstructed. Use of RAS blocking drugs has been found to significantly improve renal recovery on the contralateral kidney. It can, thus, be postulated that contralateral renal parenchymal injury was mediated through activation of RAS.

Association between polymorphisms in renin-angiotensin system genes and primary ovarian insufficiency in Korean women.

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Jung, Yong Wook; Jeon, Young Joo; Park, Hye Mi; Lee, Bo Eun; Rah, Hyungchul; Lee, Woo Sik; Yoon, Tae Ki; Kim, Nam Keun

2013-05-01

The purpose of this study was to evaluate the relationship between angiotensin-converting enzyme (ACE; insertion/deletion), angiotensinogen (AGT M235T), and angiotensin II type 1 receptor (AT1R 1166A>C) and the prevalence of primary ovarian insufficiency (POI) in Korean women. A total of 133 women with POI and 238 controls were genotyped for polymorphic sites in each gene using polymerase chain reaction-restriction fragment length polymorphism analysis. ACE ID and ID + II variants occurred more frequently in women with POI than in controls (odds ratio [OR], 1.830; 95% CI, 1.040-3.221; P = 0.040; and OR, 1.797; 95% CI, 1.055-3.060; P = 0.031, respectively). The AT1R 1166AC genotype occurred more frequently in participants with POI than in controls (OR, 3.171; 95% CI, 1.562-6.436; P = 0.002). Comparing the combined genotype frequencies of ACE/AT1R revealed that the frequencies of ID/AA, ID/AC, and II/AC were higher in participants than in controls (OR, 1.916; 95% CI, 1.053-3.485; P = 0.043; OR, 3.544; 95% CI, 1.207-10.407; P = 0.036; and OR, 7.875; 95% CI, 2.224-27.881; P = 0.001, respectively). The TT/AC genotype for combined genotyping of AGT/AT1R was more frequently observed in the POI group than in the control group (OR, 3.472; 95% CI, 1.450-8.313; P = 0.006). In multifactor dimensionality reduction-based haplotype analysis, the I-T-C genotype of ACE/AGT/AT1R was a possible predisposing factor for POI (OR, 4.678; 95% CI, 1.721-12.717; P = 0.002). This study demonstrates that polymorphisms in the renin-angiotensin system are related to the prevalence of POI. Thus, these renin-angiotensin system genes may serve as a novel marker for predicting the development of POI.

Effects of Incretin-Based Therapies and SGLT2 Inhibitors on Skeletal Health.

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Egger, Andrea; Kraenzlin, Marius E; Meier, Christian

2016-12-01

Anti-diabetic drugs are widely used and are essential for adequate glycemic control in patients with type 2 diabetes. Recently, marketed anti-diabetic drugs include incretin-based therapies (GLP-1 receptor agonists and DPP-4 inhibitors) and sodium-glucose co-transporter 2 (SGLT2) inhibitors. In contrast to well-known detrimental effects of thiazolidinediones on bone metabolism and fracture risk, clinical data on the safety of incretin-based therapies is limited. Based on meta-analyses of trials investigating the glycemic-lowering effect of GLP-1 receptor agonists and DPP4 inhibitors, it seems that incretin-based therapies are not associated with an increase in fracture risk. Sodium-glucose co-transporter 2 inhibitors may alter calcium and phosphate homeostasis as a result of secondary hyperparathyroidism induced by increased phosphate reabsorption. Although these changes may suggest detrimental effects of SGLT-2 inhibitors on skeletal integrity, treatment-related direct effects on bone metabolism seem unlikely. Observed changes in BMD, however, seem to result from increased bone turnover in the early phase of drug-induced weight loss. Fracture risk, which is observed in older patients with impaired renal function and elevated cardiovascular disease risk treated with SGLT2 inhibitors, seems to be independent of direct effects on bone but more likely to be associated with falls and changes in hydration status secondary to osmotic diuresis.

Does SGLT2 inhibition with dapagliflozin overcome individual therapy resistance to RAAS inhibition?

NARCIS (Netherlands)

Petrykiv, Sergei; Laverman, Gozewijn D.; de Zeeuw, Dick; Heerspink, Hiddo J. L.

Individual patients show a large variation in their response to renin-angiotensin-aldosteron system (RAAS) inhibition (RAASi), both in surrogates such as albuminuria and in hard renal outcomes. Sodium-glucose co-transporter 2 inhibitors (SGLT2) have been shown to lower albuminuria and to confer

Discovery of a Parenteral Small Molecule Coagulation Factor XIa Inhibitor Clinical Candidate (BMS-962212).

Science.gov (United States)

Pinto, Donald J P; Orwat, Michael J; Smith, Leon M; Quan, Mimi L; Lam, Patrick Y S; Rossi, Karen A; Apedo, Atsu; Bozarth, Jeffrey M; Wu, Yiming; Zheng, Joanna J; Xin, Baomin; Toussaint, Nathalie; Stetsko, Paul; Gudmundsson, Olafur; Maxwell, Brad; Crain, Earl J; Wong, Pancras C; Lou, Zhen; Harper, Timothy W; Chacko, Silvi A; Myers, Joseph E; Sheriff, Steven; Zhang, Huiping; Hou, Xiaoping; Mathur, Arvind; Seiffert, Dietmar A; Wexler, Ruth R; Luettgen, Joseph M; Ewing, William R

2017-12-14

Factor XIa (FXIa) is a blood coagulation enzyme that is involved in the amplification of thrombin generation. Mounting evidence suggests that direct inhibition of FXIa can block pathologic thrombus formation while preserving normal hemostasis. Preclinical studies using a variety of approaches to reduce FXIa activity, including direct inhibitors of FXIa, have demonstrated good antithrombotic efficacy without increasing bleeding. On the basis of this potential, we targeted our efforts at identifying potent inhibitors of FXIa with a focus on discovering an acute antithrombotic agent for use in a hospital setting. Herein we describe the discovery of a potent FXIa clinical candidate, 55 (FXIa K i = 0.7 nM), with excellent preclinical efficacy in thrombosis models and aqueous solubility suitable for intravenous administration. BMS-962212 is a reversible, direct, and highly selective small molecule inhibitor of FXIa.

Exocytosis and endocytosis in juxtaglomerular cells

DEFF Research Database (Denmark)

Friis, U G; Jensen, B L; Hansen, Pernille B. Lærkegaard

2000-01-01

fusion events between secretory granules and cell membrane and measurement of intermittent secretion of renin from single afferent arterioles, with a renin content of each secretion episode that corresponds to the renin content of one secretory granule. More recently it has been demonstrated...... that the afferent arterioles lose a large number of renin granules after acute stimulation without changing the average granular volume. Current electrophysiological techniques have now permitted direct measurements of cell membrane capacitance in juxtaglomerular (JG) cells as a measure of net addition (exocytosis...... and endocytosis are regulated processes in the JG-cells and both may be important for the long-term control of renin secretion at the single cell level....

A potential pathophysiological role for galectins and the renin-angiotensin system in preeclampsia.

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Blois, Sandra M; Dechend, Ralf; Barrientos, Gabriela; Staff, Anne Cathrine

2015-01-01

This review discusses a potential role of galectins and the renin-angiotensin system (RAS) in the pathophysiology of preeclampsia (PE). Preeclampsia affects between 3 and 5 % of all pregnancies and is a heterogeneous disease, which may be caused by multiple factors. The only cure is the delivery of the placenta, which may result in a premature delivery and baby. Probably due to its heterogeneity, PE studies in human have hitherto only led to the identification of a limited number of factors involved in the pathogenesis of the disease. Animal models, particularly in mice and rats, have been used to gain further insight into the molecular pathology behind PE. In this review, we discuss the picture emerging from human and animal studies pointing to galectins and the RAS being associated with the PE syndrome and affecting a broad range of cellular signaling components. Moreover, we review the epidemiological evidence for PE increasing the risk of future cardiovascular disease later in life.

Sodium-Glucose Linked Transporter-2 Inhibitors in Chronic Kidney Disease

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L. Zanoli

2015-01-01

Full Text Available SGLT2 inhibitors are new antihyperglycaemic agents whose ability to lower glucose is directly proportional to GFR. Therefore, in chronic kidney disease (CKD the blood glucose lowering effect is reduced. Unlike many current therapies, the mechanism of action of SGLT2 inhibitors is independent of insulin action or beta-cell function. In addition, the mechanism of action of SGLT2 inhibitors is complementary and not alternative to other antidiabetic agents. SGLT2 inhibitors could be potentially effective in attenuating renal hyperfiltration and, consequently, the progression of CKD. Moreover, the reductions in intraglomerular pressure, systemic blood pressure, and uric acid levels induced by SGLT inhibition may potentially be of benefit in CKD subjects without diabetes. However, at present, only few clinical studies were designed to evaluate the effects of SGLT2 inhibitors in CKD. Consequently, safety and potential efficacy beyond blood glucose lowering should be better clarified in CKD. In this paper we provide an updated review of the use of SGLT2 inhibitors in clinical practice, with particular attention on subjects with CKD.

The Effect of the Arg389Gly Beta-1 Adrenoceptor Polymorphism on Plasma Renin Activity and Heart Rate and the Genotype-Dependent Response to Metoprolol Treatment

DEFF Research Database (Denmark)

Petersen, Morten; Andersen, Jon T; Jimenez-Solem, Espen

2012-01-01

A gene-drug interaction has been indicated between beta-1 selective beta-blockers and the Arg389Gly polymorphism (rs1801253) in the adrenergic beta-1 receptor gene (ADRB1). We studied the effect of the ADRB1 Arg389Gly polymorphism on plasma renin activity (PRA) and heart rate (HR) and the genotype...

Study of prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves

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Divya Bhadoo

2015-01-01

Full Text Available Aims: Study on prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves. Materials and Methods: Antenatally diagnosed hydronephrosis patients were included. Postnatally, they were divided into two groups, posterior urethral valve (PUV and non-PUV. The studied parameters were: Gestational age at detection, surgical intervention, ultrasound findings, cord blood and follow up plasma renin activity (PRA values, vesico-ureteric reflux (VUR, renal scars, and glomerular filtration rate (GFR. Results: A total of 25 patients were included, 10 PUV and 15 non-PUV. All infants with PUV underwent primary valve incision. GFR was less than 60 ml/min/1.73 m 2 body surface area in 4 patients at last follow-up. Keyhole sign, oligoamnios, absent bladder cycling, and cortical cysts were not consistent findings on antenatal ultrasound in PUV. Cord blood PRA was significantly higher (P < 0.0001 in PUV compared to non-PUV patients. Gestational age at detection of hydronephrosis, cortical cysts, bladder wall thickness, and amniotic fluid index were not significantly correlated with GFR while PRA could differentiate between poor and better prognosis cases with PUV. Conclusions: Ultrasound was neither uniformly useful in diagnosing PUV antenatally, nor differentiating it from cases with non-PUV hydronephrosis. In congenital hydronephrosis, cord blood PRA was significantly higher in cases with PUV compared to non-PUV cases and fell significantly after valve ablation. Cord blood PRA could distinguish between poor and better prognosis cases with PUV.

Renoprotection by blockade of the renin-angiotensin-aldosterone system in diabetic and non-diabetic chronic kidney disease. Specific involvement of intra-renal angiotensin-converting enzyme activity in therapy resistance?

NARCIS (Netherlands)

Vogt, L.; Kocks, M. J. A.; Laverman, G. D.; Navis, G.

2004-01-01

Data of numerous clinical trials show that lowering of blood pressure is prerequisite for reducing the rate of renal function loss in chronic renal disease. There is evidence supporting that blood pressure lowering obtained by intervention in the renin-angiotensin-aldosterone system (RAAS) has an

Preserved regulation of renal perfusion pressure by small and intermediate conductance K-Ca channels in hypertensive mice with or without renal failure

DEFF Research Database (Denmark)

Waeckel, L.; Bertin, F.; Clavreul, N.

2015-01-01

-transgenic female mice expressing human angiotensinogen and renin (AR) genes received either control or a high-salt diet associated to a nitric oxide (NO) synthase inhibitor treatment (BLSL and ARSL). Changes in renal perfusion pressure (RPP) were measured in isolated perfused kidneys. BLSL and AR were moderately...

No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

DEFF Research Database (Denmark)

Estrup, T M; Paulson, O B; Strandgaard, S

2001-01-01

Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral cir...

Expert consensus document on the management of hyperkalaemia in patients with cardiovascular disease treated with RAAS-inhibitors - Coordinated by the Working Group on Cardiovascular Pharmacotherapy of the European Society of Cardiology.

Science.gov (United States)

Rosano, Giuseppe M C; Tamargo, Juan; Kjeldsen, Keld P; Lainscak, Mitja; Agewall, Stefan; Anker, Stefan D; Ceconi, Claudio; Coats, Andrew J S; Drexel, Heinz; Filippatos, Gerasimos; Kaski, Juan Carlos; Lund, Lars; Niessner, Alexander; Savarese, Gianluigi; Schmidt, Thomas A; Seferovic, Petar; Wassmann, Sven; Walther, Thomas; Lewis, Basil S

2018-05-03

Renin angiotensin aldosterone system inhibitors/antagonists/blockers (RAASi) are a cornerstone in treatment of patients with cardiovascular diseases especially in those with heart failure (HF) due to their proven effect on surrogate and hard end-points. RAASi are also the basis in treatment of arterial hypertension and they are furthermore indicated to reduce events and target organ damage in patients with diabetes and chronic kidney disease, where they have specific indication because of the evidence of benefit. RAASi therapy, however, is associated with an increased risk of hyperkalaemia. Patients with chronic kidney disease and HF are at increased risk of hyperkalaemia and ∼50% of these patients experience two or more yearly recurrences. A substantial proportion of patients receiving RAASi therapy have their therapy down-titrated or more often discontinued even after a single episode of elevated potassium (K+) level.

ACE inhibitors could be therapeutic for antisocial personality disorder.

Science.gov (United States)

Hobgood, Donna K

2013-11-01

Antisocial personality traits are an important topic for research. The societal cost of these behaviors encourages efforts at a better understanding of central nervous system causes. Catecholamine genes are being studied to facilitate this understanding, and some tentative findings are being reached about several of these genes. It seems that many genes play a role to produce antisocial behaviors so complexity of elucidating each gene is obvious. One conclusion that could be drawn from the current research findings is that DA2 like receptors (DRD2, DRD3, DRD4) with alleles that decrease neurotransmission are facilitatory of antisocial behaviors. DA2 like receptors cause neuronal firing to inhibit many peripheral functions through adenylyl cyclase inhibition. When these receptors are less active by genetically decreased density, lower affinity, or by low dopamine levels as final common pathways then inhibition is released and a state of disinhibition can be said to describe this state. Peripheral metabolism is increased and behavioral activation is noted. Renin is disinhibited in this setting thus allowing sympathetic nervous system activation. The fight or flight behaviors thus produced, in the extreme, would be the setting of antisocial behavior. Research validates this hypothesis. Understanding this final common pathway toward antisocial behavior should lead to better treatment for individuals with this pattern of behavior before they have caused harm to themselves and others. ACE inhibitors are well tolerated drugs used in the treatment of hypertension and heart failure and would also treat antisocial behavior disorders. Copyright © 2013 The Author. Published by Elsevier Ltd.. All rights reserved.

Paroxetine Is a Direct Inhibitor of G Protein-Coupled Receptor Kinase 2 and Increases Myocardial Contractility

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Thal, David M. [Univ. of Michigan, Ann Arbor, MI (United States); Homan, Kristoff T. [Univ. of Michigan, Ann Arbor, MI (United States); Chen, Jun [Univ. of New Mexico Health Sciences Center, Albuquerque, NM (United States); Wu, Emily K. [Univ. of Michigan, Ann Arbor, MI (United States); Hinkle, Patricia M. [Univ. of Rochester Medical Center, Rochester, NY (United States); Huang, Z. Maggie [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Chuprun, J. Kurt [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Song, Jianliang [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Gao, Erhe [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Cheung, Joseph Y. [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Sklar, Larry A. [Univ. of New Mexico Health Sciences Center, Albuquerque, NM (United States); Koch, Walter J. [Temple Univ. School of Medicine, Philadelphia, Pennsylvania (United States); Tesmer, John J.G. [Univ. of Michigan, Ann Arbor, MI (United States)

2012-08-10

G protein-coupled receptor kinase 2 (GRK2) is a well-established therapeutic target for the treatment of heart failure. In this paper we identify the selective serotonin reuptake inhibitor (SSRI) paroxetine as a selective inhibitor of GRK2 activity both in vitro and in living cells. In the crystal structure of the GRK2·paroxetine–Gβγ complex, paroxetine binds in the active site of GRK2 and stabilizes the kinase domain in a novel conformation in which a unique regulatory loop forms part of the ligand binding site. Isolated cardiomyocytes show increased isoproterenol-induced shortening and contraction amplitude in the presence of paroxetine, and pretreatment of mice with paroxetine before isoproterenol significantly increases left ventricular inotropic reserve in vivo with no significant effect on heart rate. Neither is observed in the presence of the SSRI fluoxetine. Our structural and functional results validate a widely available drug as a selective chemical probe for GRK2 and represent a starting point for the rational design of more potent and specific GRK2 inhibitors.

Inhibitors

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... JM, and the Hemophilia Inhibitor Research Study Investigators. Validation of Nijmegen-Bethesda assay modifications to allow inhibitor ... webinars on blood disorders Language: English (US) Español (Spanish) File Formats Help: How do I view different ...

Clinical effectiveness of telmisartan alone or in combination therapy for controlling blood pressure and vascular risk in the elderly

Directory of Open Access Journals (Sweden)

Bodh I Jugdutt

2010-12-01

Full Text Available Bodh I JugduttDivision of Cardiology, Department of Medicine, University of Alberta and Hospital, Edmonton, CanadaAbstract: Elderly patients (age≥65 years with hypertension are at high risk for vascular complications, especially when diabetes is present. Antihypertensive drugs that inhibit the renin-angiotensin system have been shown to be effective for controlling blood pressure in adult and elderly patients. Importantly, renin-angiotensin system inhibitors were shown to have benefits beyond their classic cardioprotective and vasculoprotective effects, including reducing the risk of new-onset diabetes and associated cardiovascular effects. The discovery that the renin-angiotensin system inhibitor and angiotensin II type 1 (AT1 receptor blocker (ARB, telmisartan, can selectively activate the peroxisome proliferator-activated receptor-γ (PPARγ, an established antidiabetic drug target provides the unique opportunity to prevent and treat cardiovascular complications in high-risk elderly patients with hypertension and new-onset diabetes. Two large clinical trials, ONTARGET (Ongoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial and TRANSCEND (Telmisartan Randomized AssessmeNt Study in ACE-I iNtolerant subjects with cardiovascular disease have assessed the cardioprotective and antidiabetic effects of telmisartan. The collective data suggest that telmisartan is a promising drug for controlling hypertension and reducing vascular risk in high-risk elderly patients with new-onset diabetes.Keywords: elderly, hypertension, telmisartan, angiotensin II type 1 receptor blocker, peroxisome proliferator-activated receptor-γ, diabetes, vascular risk

High-intensity interval training has beneficial effects on cardiac remodeling through local renin-angiotensin system modulation in mice fed high-fat or high-fructose diets.

Science.gov (United States)

de Oliveira Sá, Guilherme; Dos Santos Neves, Vívian; de Oliveira Fraga, Shyrlei R; Souza-Mello, Vanessa; Barbosa-da-Silva, Sandra

2017-11-15

HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS (renin-angiotensin system) in mice fed high-fat or high-fructose diets still need to be fully addressed. Sixty male C57BL/6 mice (12weeks old) were randomly divided into three groups, control (C), High-fat (HF), or High-fructose diet (HRU) and were monitored for eight weeks before being submitted to the HIIT. Each group was randomly assigned to 2 subgroups, one subgroup was started on a 12-week HIIT protocol (T=trained group), while the other subgroup remained non-exercised (NT=not-trained group). HIIT reduced BM and systolic blood pressure in high-fat groups, while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy in HF-T and HFRU-T. Notably, HIIT modulated key factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE (Angiotensin-converting enzyme), and (Angiotensin type 2 receptor) AT2R in HF-T and HFRU-T groups but reduced (Angiotensin type 1 receptor) AT1R protein expression only in the high-fat trained group. HIIT modulated ACE2/Ang (1-7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HF-T and HFRU-T groups, complying with elevated Mas (Mas proto-oncogene, G protein-coupled receptor) receptor mRNA gene expression after HIIT. This study shows the effectiveness of HIIT sessions in producing improvements in insulin sensitivity and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to HIIT protocol. Local RAS system in the heart mediates these findings and receptor MAS seems to play a pivotal role when it comes to the amelioration of cardiac structural and functional remodeling due to HIIT. Copyright © 2017 Elsevier Inc. All rights reserved.

Preadmission use of renin-angiotensin blockers and rupture of abdominal aortic aneurysm

DEFF Research Database (Denmark)

Wemmelund, Holger; Høgh, Annette; Hundborg, Heidi H.

2016-01-01

PURPOSE: Rupture of abdominal aortic aneurysms (rAAA) is associated with high mortality. Use of angiotensin converting enzyme inhibitors (ACE-inhibitors) and angiotensin receptor blockers (ARBs) has been suggested to reduce the risk of rAAA. This nationwide, combined case-control and follow-up st...

ERK mutations confer resistance to mitogen-activated protein kinase pathway inhibitors.

Science.gov (United States)

Goetz, Eva M; Ghandi, Mahmoud; Treacy, Daniel J; Wagle, Nikhil; Garraway, Levi A

2014-12-01

The use of targeted therapeutics directed against BRAF(V600)-mutant metastatic melanoma improves progression-free survival in many patients; however, acquired drug resistance remains a major medical challenge. By far, the most common clinical resistance mechanism involves reactivation of the MAPK (RAF/MEK/ERK) pathway by a variety of mechanisms. Thus, targeting ERK itself has emerged as an attractive therapeutic concept, and several ERK inhibitors have entered clinical trials. We sought to preemptively determine mutations in ERK1/2 that confer resistance to either ERK inhibitors or combined RAF/MEK inhibition in BRAF(V600)-mutant melanoma. Using a random mutagenesis screen, we identified multiple point mutations in ERK1 (MAPK3) and ERK2 (MAPK1) that could confer resistance to ERK or RAF/MEK inhibitors. ERK inhibitor-resistant alleles were sensitive to RAF/MEK inhibitors and vice versa, suggesting that the future development of alternating RAF/MEK and ERK inhibitor regimens might help circumvent resistance to these agents. ©2014 American Association for Cancer Research.

Tranexamic Acid Failed to Reverse the Anticoagulant Effect and Bleeding by an Oral Direct Factor Xa Inhibitor Edoxaban.

Science.gov (United States)

Honda, Yuko; Furugohri, Taketoshi; Morishima, Yoshiyuki

2018-01-01

Agents to reverse the anticoagulant effect of edoxaban, an oral direct factor Xa inhibitor, would be desirable in emergency situations. The aim of this study is to determine the effect of tranexamic acid, an antifibrinolytic agent, on the anticoagulant activity and bleeding by edoxaban in rats. A supratherapeutic dose of edoxaban (3 mg/kg) was intravenously administered to rats. Three minutes after dosing, tranexamic acid (100 mg/kg) was given intravenously. Bleeding was induced by making an incision with a blade on the planta 8 min after edoxaban injection and bleeding time was measured. Prothrombin time (PT) and clot lysis were examined. A supratherapeutic dose of edoxaban significantly prolonged PT and bleeding time. Tranexamic acid did not affect PT or bleeding time prolonged by edoxaban, although tranexamic acid significantly inhibited clot lysis in rat plasma. An antifibrinolytic agent tranexamic acid failed to reverse the anticoagulant effect and bleeding by edoxaban in rats. © 2017 S. Karger AG, Basel.

A novel method for screening the glutathione transferase inhibitors

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Węgrzyn Grzegorz

2009-03-01

Full Text Available Abstract Background Glutathione transferases (GSTs belong to the family of Phase II detoxification enzymes. GSTs catalyze the conjugation of glutathione to different endogenous and exogenous electrophilic compounds. Over-expression of GSTs was demonstrated in a number of different human cancer cells. It has been found that the resistance to many anticancer chemotherapeutics is directly correlated with the over-expression of GSTs. Therefore, it appears to be important to find new GST inhibitors to prevent the resistance of cells to anticancer drugs. In order to search for glutathione transferase (GST inhibitors, a novel method was designed. Results Our results showed that two fragments of GST, named F1 peptide (GYWKIKGLV and F2 peptide (KWRNKKFELGLEFPNL, can significantly inhibit the GST activity. When these two fragments were compared with several known potent GST inhibitors, the order of inhibition efficiency (measured in reactions with 2,4-dinitrochlorobenzene (CDNB and glutathione as substrates was determined as follows: tannic acid > cibacron blue > F2 peptide > hematin > F1 peptide > ethacrynic acid. Moreover, the F1 peptide appeared to be a noncompetitive inhibitor of the GST-catalyzed reaction, while the F2 peptide was determined as a competitive inhibitor of this reaction. Conclusion It appears that the F2 peptide can be used as a new potent specific GST inhibitor. It is proposed that the novel method, described in this report, might be useful for screening the inhibitors of not only GST but also other enzymes.

Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

Science.gov (United States)

Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

2015-01-01

The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The release of the inhibitors from the microparticles in basic solution was studied. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, incorporated directly and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

Discovery of novel STAT3 small molecule inhibitors via in silico site-directed fragment-based drug design.

Science.gov (United States)

Yu, Wenying; Xiao, Hui; Lin, Jiayuh; Li, Chenglong

2013-06-13

Constitutive activation of signal transducer and activator of transcription 3 (STAT3) has been validated as an attractive therapeutic target for cancer therapy. To stop both STAT3 activation and dimerization, a viable strategy is to design inhibitors blocking its SH2 domain phosphotyrosine binding site that is responsible for both actions. A new fragment-based drug design (FBDD) strategy, in silico site-directed FBDD, was applied in this study. A designed novel compound, 5,8-dioxo-6-(pyridin-3-ylamino)-5,8-dihydronaphthalene-1-sulfonamide (LY5), was confirmed to bind to STAT3 SH2 by fluorescence polarization assay. In addition, four out of the five chosen compounds have IC50 values lower than 5 μM for the U2OS cancer cells. 8 (LY5) has an IC50 range in 0.5-1.4 μM in various cancer cell lines. 8 also suppresses tumor growth in an in vivo mouse model. This study has demonstrated the utility of this approach and could be used to other drug targets in general.

Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

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Aline Cristina Piratello

2010-01-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation. METHODS: Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses. RESULTS: Hypertensive groups (controls and denervated showed an increase on mean blood pressure compared with normotensive ones (controls and denervated. Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1-7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups. CONCLUSION: Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.

The regulatory mechanism of fruit ripening revealed by analyses of direct targets of the tomato MADS-box transcription factor RIPENING INHIBITOR

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Fujisawa, Masaki; Ito, Yasuhiro

2013-01-01

The developmental process of ripening is unique to fleshy fruits and a key factor in fruit quality. The tomato (Solanum lycopersicum) MADS-box transcription factor RIPENING INHIBITOR (RIN), one of the earliest-acting ripening regulators, is required for broad aspects of ripening, including ethylene-dependent and -independent pathways. However, our knowledge of direct RIN target genes has been limited, considering the broad effects of RIN on ripening. In a recent work published in The Plant Cell, we identified 241 direct RIN target genes by chromatin immunoprecipitation coupled with DNA microarray (ChIP-chip) and transcriptome analysis. Functional classification of the targets revealed that RIN participates in the regulation of many biological processes including well-known ripening processes such as climacteric ethylene production and lycopene accumulation. In addition, we found that ethylene is required for the full expression of RIN and several RIN-targeting transcription factor genes at the ripening stage. Here, based on our recently published findings and additional data, we discuss the ripening processes regulated by RIN and the interplay between RIN and ethylene. PMID:23518588

The influence of a tilt training programme on the renin-angiotensin-aldosterone system activity in patients with vasovagal syncope.

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Gajek, Jacek; Zyśko, Dorota; Krzemińska, Sylwia; Mazurek, Walentyna

2009-08-01

We assessed the influence of short-term and long-term tilt training on the activity of the renin-angiotensin-aldosterone system (RAAS) in vasovagal patients. Thirty-nine patients (28 F, 11 M) aged 39.7 +/- 11.2 years with a history of vasovagal syncope and a positive head-up tilt test (HUT) were studied. Blood samples for plasma renin activity (PRA) and aldosterone (ALDO) concentration were drawn at the baseline, immediately after HUT and 10 min after HUT, during the diagnostic, the negative short-term (2-5 days) follow-up HUT and long-term (1-3 months) follow-up HUT. Tilt training was started after diagnostic HUT. In diagnostic HUT, PRA increased significantly immediately after HUT comparing to the baseline, during recovery the values did not change. ALDO concentration increased after HUT comparing to baseline and further increased during recovery. After short-term tilt training, PRA and ALDO concentrations did not significantly change compared to their corresponding values in diagnostic HUT. After long-term tilt training, PRA did not significantly change compared to the values in the diagnostic and short-term follow-up HUT. ALDO concentration also did not change significantly at the baseline and immediately after HUT, and 10 min after HUT ALDO concentration was significantly lower than after diagnostic HUT. Tilt training changes the response of RAAS to the prolonged orthostasis in vasovagal patients. The coupling between PRA and ALDO after diagnostic HUT has been found to be altered and the physiological relationship was restored after long-term tilt training. The beneficial effect of tilt training depends partially on changed RAAS activation.

Dual Angiotensin Receptor and Neprilysin Inhibition with Sacubitril/Valsartan in Chronic Systolic Heart Failure: Understanding the New PARADIGM.

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Lillyblad, Matthew P

2015-11-01

To evaluate the clinical role of sacubitril/valsartan, a novel angiotensin-neprilysin inhibitor, for the treatment of chronic heart failure with a reduced ejection fraction (HFrEF). A search of PubMed was conducted using a combination of the search terms sacubitril, valsartan, LCZ696, neprilysin inhibition, natriuretic peptide system, renin-angiotensin system, and heart failure with reduced ejection fraction. Bibliographies of all retrieved articles were reviewed for relevant literature. All references included were published between 1980 and May 2015. All studies and review articles that contained data describing the use of sacubitril/valsartan in HFrEF were reviewed. HFrEF remains a disease of high morbidity and mortality. Natriuretic peptide (NP) augmentation has emerged as a most promising neurohormonal target in HFrEF. NPs provide vasodilatory, natriuretic, diuretic, and antiproliferative actions to help support the failing heart. Neprilysin, a neutral endopeptidase, is a primary pathway for NP metabolism. Combined inhibition of the renin angiotensin aldosterone system and neprilysin augments the beneficial natriuretic peptide pathway while providing direct antagonism to increases in angiotensin II. In the landmark PARADIGM HF trial, the neprilysin inhibitor sacubitril added to valsartan significantly improved morbidity and mortality over enalapril, a standard of care in HFrEF. Application of these results to clinical practice requires careful considerations of trial design, study patient population, and clinical monitoring. Sacubitril/valsartan significantly improved morbidity and mortality in patients with chronic HFrEF but will require careful application to "real-world" populations of HFrEF. © The Author(s) 2015.

Effect of hypovolemia, infusion, and oral rehydration on plasma electrolytes, ADH, renin activity, and +G/z/ tolerance

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Greenleaf, J. E.; Brock, P. J.; Haines, R. F.; Rositano, S. A.; Montgomery, L. D.; Keil, L. C.

1977-01-01

Effects on plasma volume, electrolyte shifts, and +G(z) tolerance induced by: (1) blood withdrawal; (2) blood infusion; and (3) oral fluid intake, were determined at 0.5 G/min in centrifugation tests of six ambulatory male patients, aged 21 to 27 yrs. Hypovolemia induced by withdrawal of 400 ml blood, blood infusion followed by repeated centrifugation, effects of consuming an isotonic drink (0.9% NaCl) to achieve oral rehydration, and donning of red adaptation goggles were studied for effects on acceleration tolerance, pre-acceleration and post-acceleration plasma renin activity (PRA) and plasma vasopressin levels. No significant changes in post-acceleration PRA compared to pre-acceleration PRA were found, and administration of oral rehydration is found as effective as blood replacement in counteracting hypovolemic effects.

Renin angiotensin system and gender differences in dopaminergic degeneration

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Rodriguez-Perez Ana I

2011-08-01

Full Text Available Abstract Background There are sex differences in dopaminergic degeneration. Men are approximately two times as likely as premenopausal women of the same age to develop Parkinson's disease (PD. It has been shown that the local renin angiotensin system (RAS plays a prominent role in sex differences in the development of chronic renal and cardiovascular diseases, and there is a local RAS in the substantia nigra and dopaminergic cell loss is enhanced by angiotensin via type 1 (AT1 receptors. Results In the present study, we observed that intrastriatal injection of 6-hydroxydopamine induced a marked loss of dopaminergic neurons in the substantia nigra of male rats, which was significantly higher than the loss induced in ovariectomized female rats given estrogen implants (i.e. rats with estrogen. However, the loss of dopaminergic neurons was significantly lower in male rats treated with the AT1 antagonist candesartan, and similar to that observed in female rats with estrogen. The involvement of the RAS in gender differences in dopaminergic degeneration was confirmed with AT1a-null mice lesioned with the dopaminergic neurotoxin MPTP. Significantly higher expression of AT1 receptors, angiotensin converting enzyme activity, and NADPH-oxidase complex activity, and much lower levels of AT2 receptors were observed in male rats than in female rats with estrogen. Conclusions The results suggest that brain RAS plays a major role in the increased risk of developing PD in men, and that manipulation of brain RAS may be an efficient approach for neuroprotective treatment of PD in men, without the feminizing effects of estrogen.

Sex differences in the aging pattern of renin-angiotensin system serum peptidases.

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Fernández-Atucha, A; Izagirre, A; Fraile-Bermúdez, A B; Kortajarena, M; Larrinaga, G; Martinez-Lage, P; Echevarría, E; Gil, J

2017-01-01

Serum peptidases, such as angiotensin-converting enzyme (ACE), angiotensin-converting enzyme-2 (ACE2), neutral endopeptidase (NEP), aminopeptidase N (APN), and aminopeptidase A (APA), are important elements of the renin-angiotensin system (RAS). Dysregulation of these enzymes has been associated with hypertension and cardiovascular risk. In the present study, serum activities of RAS peptidases were analyzed to evaluate the existence of sexual differences, with a possible different pattern in pre- and post-andropausal/post-menopausal participants. One hundred and eighteen healthy men and women between 41 and 70 years of age (58 women and 60 men) were recruited to participate in the study. Serum RAS-regulating enzymes were measured by spectrofluorimetry. Enzymatic activity was recorded as units of enzyme per milliliter of serum (U/mL). Significantly lower serum APA activity was observed in men with respect to women; no sex differences were detected for ACE, ACE2, NEP, or APN. Significantly lower APA and ACE serum activity were observed in older men compared to older women. In contrast, younger (menopausia, on the critical serum enzymatic activities of the RAS, which could correlate with sexual differences in cardiovascular risk.

Effect of MCM09, an active site-directed inhibitor of factor Xa, on B16-BL6 melanoma lung colonies in mice.

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Rossi, C; Hess, S; Eckl, R W; di Lena, A; Bruno, A; Thomas, O; Poggi, A

2006-03-01

Treatment with anticoagulant drugs has shown potential inhibitory effect on tumor invasion, although the relationship with clotting inhibition was not clear. The aim of our study was to evaluate the potential antitumor activity of MCM09, a newly developed, active site-directed, small molecule inhibitor of factor Xa (FXa) [WO0216312], and to relate the findings to anticlotting potency. MCM09 (0.1-10 mg kg(-1)) or heparin (H; 10 mg kg(-1)) was injected intravenously (i.v.), with 5 x 10(4) B16-BL6 melanoma cells, in C57BL/6 mice. Mice were killed after 18 days, to count lung colonies. Ex vivo anticoagulant activity was measured by activated partial thromboplastin time (APTT) on mouse plasma. MCM09, a selective inhibitor of FXa (IC-50 = 2.4 nm against human FXa), inhibited in a dose-dependent manner B16-BL6 melanoma lung colonies in mice. Mean lung metastasis number was 20.9 +/- 4.8 in controls (n = 10), 1.2 +/- 0.4 in mice treated with H, 10 mg kg(-1) i.v. (P < 0.01), 0.9 +/- 0.3, 9.2 +/- 2.2 and 15.5 +/- 2.6 in mice treated with MCM09, at 10 (P < 0.01), 1 (P < 0.05) and 0.1 mg kg(-1) i.v. (ns), respectively. MCM09 (10 mg kg(-1) i.v.) significantly prolonged APTT (57.1 +/- 10.2 s) 30 min after i.v. injection when compared with controls (25.3 +/- 1.6 s; P < 0.05). Lung colonies were 74.2-72.6% reduced by MCM09 (10 mg kg(-1)) given 60 or 120 min before cells, but not by MCM09 given 60 min thereafter, suggesting a direct cell interaction as a mechanism underlying antitumor activity.

Chronic blockade of angiotensin II action prevents glomerulosclerosis, but induces graft vasculopathy in experimental kidney transplantation

NARCIS (Netherlands)

Smit-van Oosten, A; Navis, G; Stegeman, CA; Joles, JA; Klok, PA; Kuipers, F; Tiebosch, ATMG; van Goor, H

Long-term renin-angiotensin system blockade is beneficial in a variety of renal diseases, This study examines the long-term (34 weeks) effects of the angiotensin-converting enzyme inhibitor lisinopril and the angiotensin II receptor type I blocker L158,809 in the Fisher to Lewis rat model of chronic

The gender-specific role of polymorphisms from the fibrinolytic, renin-angiotensin, and bradykinin systems in determining plasma t-PA and PAI-I levels

NARCIS (Netherlands)

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

2006-01-01

Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor I (PAI-I) directly influence thrombus formation and degradation and thus risk for arterial thrombosis. We report here results from a genetic analysis of plasma t-PA and PAI-I levels in a large population-based sample from the

Effects of mineralocorticoid receptor antagonists in patients with hypertension and diabetes mellitus: a systematic review and meta-analysis.

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Takahashi, S; Katada, J; Daida, H; Kitamura, F; Yokoyama, K

2016-09-01

Blood pressure (BP) control is important to ameliorate cardiovascular events in patients with diabetes mellitus (DM). However, achieving the target BP with a single drug is often difficult. The objective of this study was to evaluate the antihypertensive effects of mineralocorticoid receptor antagonists (MRAs) as add-on therapy to renin-angiotensin system (RAS) inhibitor(s) in patients with hypertension and DM. Studies were searched through October 2014 in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials. Randomized, controlled trials or prospective, observational studies regarding concomitant administration of MRA and RAS inhibitor(s) in patients with DM were included. Articles were excluded if the mean systolic BP (SBP) was hypertension and DM already taking RAS inhibitors. Serum potassium levels should be monitored to prevent hyperkalemia.

4-Hydroxyphenylpyruvate Dioxygenase Inhibitors: From Chemical Biology to Agrochemicals.

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Ndikuryayo, Ferdinand; Moosavi, Behrooz; Yang, Wen-Chao; Yang, Guang-Fu

2017-10-04

The development of new herbicides is receiving considerable attention to control weed biotypes resistant to current herbicides. Consequently, new enzymes are always desired as targets for herbicide discovery. 4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an enzyme engaged in photosynthetic activity and catalyzes the transformation of 4-hydroxyphenylpyruvic acid (HPPA) into homogentisic acid (HGA). HPPD inhibitors constitute a promising area of discovery and development of innovative herbicides with some advantages, including excellent crop selectivity, low application rates, and broad-spectrum weed control. HPPD inhibitors have been investigated for agrochemical interests, and some of them have already been commercialized as herbicides. In this review, we mainly focus on the chemical biology of HPPD, discovery of new potential inhibitors, and strategies for engineering transgenic crops resistant to current HPPD-inhibiting herbicides. The conclusion raises some relevant gaps for future research directions.

Structure of a retro-binding peptide inhibitor complexed with human alpha-thrombin.

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Tabernero, L; Chang, C Y; Ohringer, S L; Lau, W F; Iwanowicz, E J; Han, W C; Wang, T C; Seiler, S M; Roberts, D G; Sack, J S

1995-02-10

The crystallographic structure of the ternary complex between human alpha-thrombin, hirugen and the peptidyl inhibitor Phe-alloThr-Phe-O-CH3, which is acylated at its N terminus with 4-guanidino butanoic acid (BMS-183507), has been determined at 2.6 A resolution. The structure reveals a unique "retro-binding" mode for this tripeptide active site inhibitor. The inhibitor binds with its alkyl-guanidine moiety in the primary specificity pocket and its two phenyl rings occupying the hydrophobic proximal and distal pockets of the thrombin active site. In this arrangement the backbone of the tripeptide forms a parallel beta-strand to the thrombin main-chain at the binding site. This is opposite to the orientation of the natural substrate, fibrinogen, and all the small active site-directed thrombin inhibitors whose bound structures have been previously reported. BMS-183507 is the first synthetic inhibitor proved to bind in a retro-binding fashion to thrombin, in a fashion similar to that of the N-terminal residues of the natural inhibitor hirudin. Furthermore, this new potent thrombin inhibitor (Ki = 17.2 nM) is selective for thrombin over other serine proteases tested and may be a template to be considered in designing hirudin-based thrombin inhibitors with interactions at the specificity pocket.

Resistance Patterns Associated with HCV NS5A Inhibitors Provide Limited Insight into Drug Binding

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Moheshwarnath Issur

2014-11-01

Full Text Available Direct-acting antivirals (DAAs have significantly improved the treatment of infection with the hepatitis C virus. A promising class of novel antiviral agents targets the HCV NS5A protein. The high potency and broad genotypic coverage are favorable properties. NS5A inhibitors are currently assessed in advanced clinical trials in combination with viral polymerase inhibitors and/or viral protease inhibitors. However, the clinical use of NS5A inhibitors is also associated with new challenges. HCV variants with decreased susceptibility to these drugs can emerge and compromise therapy. In this review, we discuss resistance patterns in NS5A with focus prevalence and implications for inhibitor binding.

Resveratrol promotes regression of renal carcinoma cells via a renin-angiotensin system suppression-dependent mechanism.

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Li, Jianchang; Qiu, Mingning; Chen, Lieqian; Liu, Lei; Tan, Guobin; Liu, Jianjun

2017-02-01

The aim of the present study was to investigate the effect of resveratrol on renal carcinoma cells and explore possible renin-angiotensin system-associated mechanisms. Subsequent to resveratrol treatment, the cell viability, apoptosis rate, cytotoxicity levels, caspase 3/7 activity and the levels of angiotensin II (AngII), AngII type 1 receptor (AT1R), vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) were evaluated in renal carcinoma cells. The effects of AngII, AT1R, VEGF and COX-2 on resveratrol-induced cell growth inhibition and apoptosis were also examined. The results indicated that resveratrol treatment may suppress growth, induce apoptosis, and decrease AngII, AT1R, VEGF and COX-2 levels in renal carcinoma ACHN and A498 cells. In addition, resveratrol-induced cell growth suppression and apoptosis were reversed when co-culturing with AT1R or VEGF. Thus, resveratrol may suppress renal carcinoma cell proliferation and induce apoptosis via an AT1R/VEGF pathway.

Management of hypertension and heart failure in patients with Addison's disease.

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Inder, Warrick J; Meyer, Caroline; Hunt, Penny J

2015-06-01

Addison's disease may be complicated by hypertension and less commonly by heart failure. We review the pathophysiology of the renin-angiotensin-aldosterone axis in Addison's disease and how this is altered in the setting of hypertension and heart failure. An essential first step in management in both conditions is optimizing glucocorticoid replacement and considering dose reduction if excessive. Following this, if a patient with Addison's disease remains hypertensive, the fludrocortisone dose should be reviewed and reduced if there are clinical and/or biochemical signs of mineralocorticoid excess. In the absence of such signs, where the renin is towards the upper end of the normal range or elevated, an angiotensin II (AII) receptor antagonist or angiotensin converting enzyme (ACE) inhibitor is the treatment of choice, and the fludrocortisone dose should remain unchanged. Dihydropyridine calcium channel blockers are clinically useful as second line agents, but diuretics should be avoided. In the setting of heart failure, there is an increase in total body sodium and water; therefore, it is appropriate to reduce and rarely consider ceasing the fludrocortisone. Loop diuretics may be used, but not aldosterone antagonists such as spironolactone or eplerenone. Standard treatment with ACE inhibitors, or as an alternative, AII receptor antagonists, are appropriate. Measurements of renin are no longer helpful in heart failure to determine the volume status but plasma levels of brain natriuretic peptide (BNP/proBNP) may help guide therapy. © 2014 John Wiley & Sons Ltd.

Application of Molecular Modeling to Urokinase Inhibitors Development

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V. B. Sulimov

2014-01-01

Full Text Available Urokinase-type plasminogen activator (uPA plays an important role in the regulation of diverse physiologic and pathologic processes. Experimental research has shown that elevated uPA expression is associated with cancer progression, metastasis, and shortened survival in patients, whereas suppression of proteolytic activity of uPA leads to evident decrease of metastasis. Therefore, uPA has been considered as a promising molecular target for development of anticancer drugs. The present study sets out to develop the new selective uPA inhibitors using computer-aided structural based drug design methods. Investigation involves the following stages: computer modeling of the protein active site, development and validation of computer molecular modeling methods: docking (SOL program, postprocessing (DISCORE program, direct generalized docking (FLM program, and the application of the quantum chemical calculations (MOPAC package, search of uPA inhibitors among molecules from databases of ready-made compounds to find new uPA inhibitors, and design of new chemical structures and their optimization and experimental examination. On the basis of known uPA inhibitors and modeling results, 18 new compounds have been designed, calculated using programs mentioned above, synthesized, and tested in vitro. Eight of them display inhibitory activity and two of them display activity about 10 μM.

The refined 2.0 A X-ray crystal structure of the complex formed between bovine beta-trypsin and CMTI-I, a trypsin inhibitor from squash seeds (Cucurbita maxima). Topological similarity of the squash seed inhibitors with the carboxypeptidase A inhibitor from potatoes.

Science.gov (United States)

Bode, W; Greyling, H J; Huber, R; Otlewski, J; Wilusz, T

1989-01-02

The stoichiometric complex formed between bovine beta-trypsin and the Cucurbita maxima trypsin inhibitor I (CMTI-I) was crystallized and its X-ray crystal structure determined using Patterson search techniques. Its structure has been crystallographically refined to a final R value of 0.152 (6.0-2.0 A). CMTI-I is of ellipsoidal shape; it lacks helices or beta-sheets, but consists of turns and connecting short polypeptide stretches. The disulfide pairing is CYS-3I-20I, Cys-10I-22I and Cys-16I-28I. According to the polypeptide fold and disulfide connectivity its structure resembles that of the carboxypeptidase A inhibitor from potatoes. Thirteen of the 29 inhibitor residues are in direct contact with trypsin; most of them are in the primary binding segment Val-2I (P4)-Glu-9I (P4') which contains the reactive site bond Arg-5I-Ile-6I and is in a conformation observed also for other serine proteinase inhibitors.

Expression of the Components of the Renin-Angiotensin System in Venous Malformation

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Sam eSiljee

2016-05-01

Full Text Available Background Venous malformation (VM is the most common form of vascular malformation, consisting of a network of thin-walled ectatic venous channels with deficient or absent media. This study investigated the expression of the components of the renin-angiotensin system (RAS, namely (prorenin receptor (PRR, angiotensin converting enzyme (ACE, angiotensin II receptor 1 (ATIIR1 and angiotensin II receptor 2 (AIITR2 in subcutaneous (SC and intramuscular (IM VM. Materials and Methods SC (n=7 and IM (n=7 VM were analyzed for the expression of PRR, ACE, ATIIR1, and ATIIR2 using 3,3-diaminobenzidine (DAB and immunofluorescent (IF immunohistochemical (IHC staining and NanoString gene expression analysis. Results IHC staining showed expression of PRR, ACE, ATIIR1 and faint expression of ATIIR2 in the endothelium of SC and IM VM. Furthermore, ATIIR2 was expressed by cells away from the endothelium in both SC and IM VM lesions examined. NanoString analysis demonstrated the presence of PRR, ACE and ATIIR1 but not ATIIR2.Conclusions The presence of PRR, ACE, ATIIR1 and potentially ATIIR2, in both SC and IM VM suggests a role for the RAS in the biology of VM. This novel finding may lead to a mechanism-based therapy for VM.

Renin-angiotensin system: an old player with novel functions in skeletal muscle.

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Cabello-Verrugio, Claudio; Morales, María Gabriela; Rivera, Juan Carlos; Cabrera, Daniel; Simon, Felipe

2015-05-01

Skeletal muscle is a tissue that shows the most plasticity in the body; it can change in response to physiological and pathological stimuli. Among the diseases that affect skeletal muscle are myopathy-associated fibrosis, insulin resistance, and muscle atrophy. A common factor in these pathologies is the participation of the renin-angiotensin system (RAS). This system can be functionally separated into the classical and nonclassical RAS axis. The main components of the classical RAS pathway are angiotensin-converting enzyme (ACE), angiotensin II (Ang-II), and Ang-II receptors (AT receptors), whereas the nonclassical axis is composed of ACE2, angiotensin 1-7 [Ang (1-7)], and the Mas receptor. Hyperactivity of the classical axis in skeletal muscle has been associated with insulin resistance, atrophy, and fibrosis. In contrast, current evidence supports the action of the nonclassical RAS as a counter-regulator axis of the classical RAS pathway in skeletal muscle. In this review, we describe the mechanisms involved in the pathological effects of the classical RAS, advances in the use of pharmacological molecules to inhibit this axis, and the beneficial effects of stimulation of the nonclassical RAS pathway on insulin resistance, atrophy, and fibrosis in skeletal muscle. © 2015 Wiley Periodicals, Inc.

Structure-guided approach identifies a novel class of HIV-1 ribonuclease H inhibitors: binding mode insights through magnesium complexation and site-directed mutagenesis studies

DEFF Research Database (Denmark)

Poongavanam, Vasanthanathan; Corona, Angela; Steinmann, Casper

2018-01-01

is a long and expensive process that can be speeded up by in silico methods. In the present study, a structure-guided screening is coupled with a similarity-based search on the Specs database to identify a new class of HIV-1 RNase H inhibitors. Out of the 45 compounds selected for experimental testing, 15...... inhibited the RNase H function below 100 μM with three hits exhibiting IC50 values active compound, AA, inhibits HIV-1 RNase H with an IC50 of 5.1 μM and exhibits a Mg-independent mode of inhibition. Site-directed mutagenesis studies provide valuable insight into the binding mode of newly...

The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans

DEFF Research Database (Denmark)

Pauls, Mathilde Mh; Moynihan, Barry; Barrick, Thomas R

2018-01-01

, ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5...... inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated...

A case of posterior reversible encephalopathy syndrome in the setting of post-partum preeclampsia with suppressed plasma aldosterone levels and plasma renin activity

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Aurelio Negro

2013-12-01

Full Text Available Posterior reversible encephalopathy syndrome (PRES is characterized by headache, altered mental status, visual loss, and seizures. PRES is associated with neuroradiological findings: white matter abnormalities, predominantly in the parieto-occipital regions of the brain. PRES has been described in association with hypertensive encephalopathy, eclampsia, renal failure, or following immunosuppressive or anticancer therapy. We report a case of PRES in a severe preeclampsia occurring in the late postpartum period, with suppressed plasma aldosterone levels and plasma renin activity. These laboratory abnormalities may be due to an apparent mineralocorticoid excess syndrome.

Natural products inhibitors of the angiotensin converting enzyme (ACE: a review between 1980 - 2000

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José M. Barbosa-Filho

Full Text Available Inhibition of Angiotensin Converting Enzyme (ACE is a modern therapeutic target in the treatment of hypertension. Within the enzyme cascade of the renin-angiotensin system, ACE removes histidyl-leucine from angiotensin I to form the physiologically active octapeptide angiotensin II, one of the most potent known vasoconstrictors. Therefore, a rationale for treating hypertension would be to administer drugs or natural compounds which selectively inhibit ACE. The present work constitutes a review of the literature of plants and chemically defined molecules from natural sources with in vitro anti-hypertensive potential based on the inhibition of ACE. The review refers to 321 plants, the parts utilized, type of extract and whether they are active or not. It includes also the names of 158 compounds isolated from higher plants, marine sponges and algae, fungi and snake venom. Some aspects of recent research with natural products directed to produce anti-hypertensive drugs are discussed. In this review, 148 references were cited.

Rapid, Automated, and Specific Immunoassay to Directly Measure Matrix Metalloproteinase-9–Tissue Inhibitor of Metalloproteinase-1 Interactions in Human Plasma Using AlphaLISA Technology: A New Alternative to Classical ELISA

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Helena Pulido-Olmo

2017-07-01

Full Text Available The protocol describes a novel, rapid, and no-wash one-step immunoassay for highly sensitive and direct detection of the complexes between matrix metalloproteinases (MMPs and their tissue inhibitor of metalloproteinases (TIMPs based on AlphaLISA® technology. We describe two procedures: (i one approach is used to analyze MMP-9–TIMP-1 interactions using recombinant human MMP-9 with its corresponding recombinant human TIMP-1 inhibitor and (ii the second approach is used to analyze native or endogenous MMP-9–TIMP-1 protein interactions in samples of human plasma. Evaluating native MMP-9–TIMP-1 complexes using this approach avoids the use of indirect calculations of the MMP-9/TIMP-1 ratio for which independent MMP-9 and TIMP-1 quantifications by two conventional ELISAs are needed. The MMP-9–TIMP-1 AlphaLISA® assay is quick, highly simplified, and cost-effective and can be completed in less than 3 h. Moreover, the assay has great potential for use in basic and preclinical research as it allows direct determination of native MMP-9–TIMP-1 complexes in circulating blood as biofluid.

Renin-angiotensin system at the crossroad of hypertension and hypercholesterolemia.

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Borghi, C; Urso, R; Cicero, A F

2017-02-01

The aim of this study is to discuss the reliable scientific evidence of an interactive link between hypertension and hypercholesterolemia considering the metabolic pathways and the pathogenetic mechanisms connecting the two risk factors. Hypertension and hypercholesterolemia are highly prevalent in the general population and their coexistence in the same subjects additively increases the risk of cardiovascular disease. Probably, hypercholesterolemia is also a risk factor for the development of hypertension. On the other side, it is also possible that lipid-lowering treatment could improve blood pressure control. Although the mechanisms of interaction between these two risk factors have not been completely elucidated thus far, there is rapidly growing evidence that the involvement of the renin-angiotensin system (RAS) can be considered as the common link between hypertension and hypercholesterolemia. In particular, hypercholesterolemia seems to promote the upregulation of type 1 angiotensin II (AT1) receptor genes because of an increase in the stability of mRNA followed by structural overexpression of vascular AT1 receptors for angiotensin II. The treatment of both risk factors greatly improves individual risk profile, especially when statins and RAS blockers are used together. Hypertension and hypercholesterolemia are highly coprevalent and strongly related from a pathophysiological point of view. The RAS could be the main mediator of this link. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Real-Time Inhibitor Recession Measurements in Two Space Shuttle Reusable Solid Rocket Motors

Science.gov (United States)

McWhorter, B. B.; Ewing, M. E.; Bolton, D. E.; Albrechtsen, K. U.; Earnest, T. E.; Noble, T. C.; Longaker, M.

2003-01-01

Real-time internal motor insulation char line recession measurements have been evaluated for two full-scale static tests of the Space Shuttle Reusable Solid Rocket Motor (RSRM). These char line recession measurements were recorded on the forward facing propellant grain inhibitors to better understand the thermal performance of these inhibitors. The RSRM propellant grain inhibitors are designed to erode away during motor operation, thus making it difficult to use post-fire observations to determine inhibitor thermal performance. Therefore, this new internal motor instrumentation is invaluable in establishing an accurate understanding of inhibitor recession versus motor operation time. The data for the first test was presented at the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (AIAA 2001-3280) in July 2001. Since that time, a second full scale static test has delivered additional real-time data on inhibitor thermal performance. The evaluation of this data is presented in this paper. The second static test, in contrast to the first test, used a slightly different arrangement of instrumentation in the inhibitors. This instrumentation has yielded a better understanding of the inhibitor time dependent inboard tip recession. Graphs of inhibitor recession profiles with time are presented. Inhibitor thermal ablation models have been created from theoretical principals. The model predictions compare favorably with data from both tests. This verified modeling effort is important to support new inhibitor designs for a five segment Space Shuttle solid rocket motor. The internal instrumentation project on RSRM static tests is providing unique opportunities for other real-time internal motor measurements that could not otherwise be directly quantified.

A historical sketch of the discovery and development of HIV-1 integrase inhibitors.

Science.gov (United States)

Savarino, Andrea

2006-12-01

The long process of HIV-1 integrase inhibitor discovery and development can be attributed to both the complexity of HIV-1 integration and poor 'integration' of these researches into mainstream investigations on antiretroviral therapy in the mid-1990s. Of note, some fungal extracts investigated during this period contain the beta-hydroxyketo group, later recognised to be a key structural requirement for keto-enol acids (also referred to as diketo acids) and other integrase inhibitors. This review reconstructs (in the general context of the history of AIDS research) the principal steps that led to the integrase inhibitors currently in clinical trials, and discusses possible future directions.

Expression of renin-angiotensin system signalling compounds in maternal protein-restricted rats: effect on renal sodium excretion and blood pressure.

Science.gov (United States)

Mesquita, Flávia Fernandes; Gontijo, José Antonio Rocha; Boer, Patrícia Aline

2010-02-01

Intrauterine growth restriction due to low maternal dietary protein during pregnancy is associated with retardation of foetal growth, renal alterations and adult hypertension. The renin-angiotensin system (RAS) is a coordinated hormonal cascade in the control of cardiovascular, renal and adrenal function that governs body fluid and electrolyte balance, as well as arterial pressure. In the kidney, all the components of the renin-angiotensin system including angiotensin II type 1 (AT1) and type 2 (AT2) receptors are expressed locally during nephrogenesis. Hence, we investigated whether low protein diet intake during pregnancy altered kidney and adrenal expression of AT1(R) and AT2(R) receptors, their pathways and if the modified expression of the RAS compounds occurs associated with changes in urinary sodium and in arterial blood pressure in sixteen-week-old males' offspring of the underfed group. The pregnancy dams were divided in two groups: with normal protein diet (pups named NP) (17% protein) or low protein diet (pups LP) (6% protein) during all pregnancy. The present data confirm a significant enhancement in arterial pressure in the LP group. Furthermore, the study showed a significantly decreased expression of RAS pathway protein and Ang II receptors in the kidney and an increased expression in the adrenal of LP rats. The detailed immunohistochemical analysis of RAS signalling proteins in the kidney confirm the immunoblotting results for both groups. The present investigation also showed a pronounced decrease in fractional urinary sodium excretion in maternal protein-restricted offspring, compared with the NP age-matched group. This occurred despite unchanged creatinine clearance. The current data led us to hypothesize that foetal undernutrition could be associated with decreased kidney expression of AT(R) resulting in the inability of renal tubules to handle the hydro-electrolyte balance, consequently causing arterial hypertension.

Virtual screening of selective inhibitors of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis

Science.gov (United States)

Podshivalov, D. D.; Timofeev, V. I.; Sidorov-Biryukov, D. D.; Kuranova, I. P.

2017-05-01

Bacterial phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis (PPAT Mt) is a convenient target protein for the directed search for selective inhibitors as potent antituberculosis drugs. Four compounds suitable for the detailed investigation of their interactions with PPAT Mt were found by virtual screening. The active-site region of the enzyme was chosen as the ligand-binding site. The positions of the ligands found by the docking were refined by molecular dynamics simulation. The nearest environment of the ligands, the positions of which in the active site of the enzyme were found in a computational experiment, was analyzed. The compounds under consideration were shown to directly interact with functionally important active-site amino-acid residues and block access of substrates to the active site. Therefore, these compounds can be used for the design of selective inhibitors of PPAT Mt as potent antituberculosis drugs.

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

DEFF Research Database (Denmark)

Egecioglu, E; Andersson, I J; Bollano, E

2007-01-01

To study the role of the growth hormone receptor (GHR) in the development of cardiovascular structure and function, female GHR gene-disrupted or knockout (KO) and wild-type (WT) mice at age 18 wk were used. GHR KO mice had lower plasma renin levels (12 +/- 2 vs. 20 +/- 4 mGU/ml, P < 0.05) and inc....... These data suggest an important role for an intact GH/IGF-I axis in the maintenance of a normal cardiovascular system....

Discovery of natural mouse serum derived HIV-1 entry inhibitor(s).

Science.gov (United States)

Wei, M; Chen, Y; Xi, J; Ru, S; Ji, M; Zhang, D; Fang, Q; Tang, B

Among rationally designed human immunodeficiency virus 1 (HIV-1) inhibitors, diverse natural factors have showed as potent anti-HIV activity in human blood. We have discovered that the boiled supernatant of healthy mouse serum could suppress HIV-1 entry, and exhibited reduced inhibitory activity after trypsin digestion. Further analysis demonstrated that only the fraction containing 10-25 K proteins could inhibit HIV-1 mediated cell-cell fusion. These results suggest that the 10-25 K protein(s) is novel natural HIV-1 entry inhibitor(s). Our findings provide important information about novel natural HIV entry inhibitors in mouse serum.

Renin Response to Intravenous Furosemide in Hypertension of Chronic Renal Failure

International Nuclear Information System (INIS)

Choe, Kang Won

1978-01-01

It has been suggested that plasma renin activity (PRA) and its response to volume depletion may be abnormal in that it shows little or exaggerated change in patients with chronic renal failure and hypertension. Intravenous furosemide stimulation test was performed in 46 control subjects and 51 patients with chronic renal failure and/or malignant hypertension in order to evaluate PRA response. In contrast to the consistent increase in PRA in control subjects (from 2.5±1.95 to 4.5±2.51 ng/m1/hr), no consistent increase was observed in patients with chronic renal failure, especially in those who showed favorable response to antihypertensive therapy (from 2.5±2.21 to 2.9±2.46 ng/ml/hr). But poor responder to antihypertensive treatment showed considerably higher PRA before and after furosemide stimulation (from 4.9±1.96 to 6.4±1.71 ng/ml/hr) than the responder group did. Moreover, this group seemed to retain the ability to increase PRA in response to intravenous furosemide stimulation. Thus it became apparent that responder group was unable to increase PRA normally in response to furosemide as well as volume depletion, while poor responder seemed to retain that ability. Thus intravenous furosemode may serve as a convenient way to differentiate those who might be benefited by conservative antihypertensive measures from those who would require more drastic measures such as bilateral nephrectomy for their optimal blood pressure control.

Role of tissue-type plasminogen activator and plasminogen activator inhibitor-1 in psychological stress and depression.

Science.gov (United States)

Tsai, Shih-Jen

2017-12-22

Major depressive disorder is a common illness worldwide, but the pathogenesis of the disorder remains incompletely understood. The tissue-type plasminogen activator-plasminogen proteolytic cascade is highly expressed in the brain regions involved in mood regulation and neuroplasticity. Accumulating evidence from animal and human studies suggests that tissue-type plasminogen activator and its chief inhibitor, plasminogen activator inhibitor-1, are related to stress reaction and depression. Furthermore, the neurotrophic hypothesis of depression postulates that compromised neurotrophin brain-derived neurotrophic factor (BDNF) function is directly involved in the pathophysiology of depression. In the brain, the proteolytic cleavage of proBDNF, a BDNF precursor, to mature BDNF through plasmin represents one mechanism that can change the direction of BDNF action. We also discuss the implications of tissue-type plasminogen activator and plasminogen activator inhibitor-1 alterations as biomarkers for major depressive disorder. Using drugs that increase tissue-type plasminogen activator or decrease plasminogen activator inhibitor-1 levels may open new avenues to develop conceptually novel therapeutic strategies for depression treatment.

Rapid Screening of Acetylcholinesterase Inhibitors by Effect-Directed Analysis Using LC × LC Fractionation, a High Throughput in Vitro Assay, and Parallel Identification by Time of Flight Mass Spectrometry.

Science.gov (United States)

Ouyang, Xiyu; Leonards, Pim E G; Tousova, Zuzana; Slobodnik, Jaroslav; de Boer, Jacob; Lamoree, Marja H

2016-02-16

Effect-directed analysis (EDA) is a useful tool to identify bioactive compounds in complex samples. However, identification in EDA is usually challenging, mainly due to limited separation power of the liquid chromatography based fractionation. In this study, comprehensive two-dimensional liquid chromatography (LC × LC) based microfractionation combined with parallel high resolution time of flight (HR-ToF) mass spectrometric detection and a high throughput acetylcholinesterase (AChE) assay was developed. The LC × LC fractionation method was validated using analytical standards and a C18 and pentafluorophenyl (PFP) stationary phase combination was selected for the two-dimensional separation and fractionation in four 96-well plates. The method was successfully applied to identify AChE inhibitors in a wastewater treatment plant (WWTP) effluent. Good orthogonality (>0.9) separation was achieved and three AChE inhibitors (tiapride, amisulpride, and lamotrigine), used as antipsychotic medicines, were identified and confirmed by two-dimensional retention alignment as well as their AChE inhibition activity.

Aliskiren: a clinical profile

Directory of Open Access Journals (Sweden)

Roland E Schmieder

2006-06-01

Full Text Available Aliskiren is a novel oral antihypertensive agent, and the first in the new class of direct renin inhibitors. Here we review the key criteria that a new antihypertensive drug should possess, notably effective blood pressure lowering as monotherapy and combination therapy, 24-hour blood pressure control, safety and tolerability, end-organ protective effects, minimal drug interaction and efficacy during long-term use.Aliskiren fulfils key criteria for a new antihypertensive agent.The drug demonstrates effective blood lowering in a number of studies as monotherapy and in combination with a thiazide diuretic (hydrochlorothiazide, an angiotensin-converting enzyme inhibitor (ramipril and a calcium channel blocker (amlodipine. Other studies applying ambulatory blood pressure monitoring show that aliskiren maintains blood pressure control for more than 24 hours. Aliskiren, 150 mg and 300 mg have demonstrated a placebo-like safety and tolerability profile, with no interactions with a wide range of commonly used drugs. Three studies (AVOID, ALOFT and ALLAY are ongoing properties. with aliskiren to assess end-organ protective properties.

A noncovalent class of papain-like protease/deubiquitinase inhibitors blocks SARS virus replication

Energy Technology Data Exchange (ETDEWEB)

Ratia, Kiira; Pegan, Scott; Takayama, Jun; Sleeman, Katrina; Coughlin, Melissa; Baliji, Surendranath; Chaudhuri, Rima; Fu, Wentao; Prabhakar, Bellur S.; Johnson, Michael E.; Baker, Susan C.; Ghosh, Arun K.; Mesecar, Andrew D. (Loyola); (Purdue); (UIC)

2008-10-27

We report the discovery and optimization of a potent inhibitor against the papain-like protease (PLpro) from the coronavirus that causes severe acute respiratory syndrome (SARS-CoV). This unique protease is not only responsible for processing the viral polyprotein into its functional units but is also capable of cleaving ubiquitin and ISG15 conjugates and plays a significant role in helping SARS-CoV evade the human immune system. We screened a structurally diverse library of 50,080 compounds for inhibitors of PLpro and discovered a noncovalent lead inhibitor with an IC{sub 50} value of 20 {mu}M, which was improved to 600 nM via synthetic optimization. The resulting compound, GRL0617, inhibited SARS-CoV viral replication in Vero E6 cells with an EC{sub 50} of 15 {mu}M and had no associated cytotoxicity. The X-ray structure of PLpro in complex with GRL0617 indicates that the compound has a unique mode of inhibition whereby it binds within the S4-S3 subsites of the enzyme and induces a loop closure that shuts down catalysis at the active site. These findings provide proof-of-principle that PLpro is a viable target for development of antivirals directed against SARS-CoV, and that potent noncovalent cysteine protease inhibitors can be developed with specificity directed toward pathogenic deubiquitinating enzymes without inhibiting host DUBs.

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

Science.gov (United States)

Urushihara, Maki; Kagami, Shoji

2017-09-01

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

Renin-Angiotensin System Genes Polymorphisms and Essential Hypertension in Burkina Faso, West Africa

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Daméhan Tchelougou

2015-01-01

Full Text Available Objective. This study aimed to investigate the association between three polymorphisms of renin-angiotensin system and the essential hypertension in the population of Burkina Faso. Methodology. This was a case-control study including 202 cases and 204 matched controls subjects. The polymorphisms were identified by a classical and a real-time PCR. Results. The AGT 235M/T and AT1R 1166A/C polymorphisms were not associated with the hypertension while the genotype frequencies of the ACE I/D polymorphism between patients and controls (DD: 66.83% and 35.78%, ID: 28.22% and 50.98%, II: 4.95% and 13.24%, resp. were significantly different (p < 10−4. The genotype DD of ACE gene (OR = 3.40, p < 0.0001, the increasing age (OR = 3.83, p < 0.0001, obesity (OR = 4.84, p < 0.0001, dyslipidemia (OR = 3.43, p = 0.021, and alcohol intake (OR = 2.76, p < 0.0001 were identified as the independent risk factors for hypertension by multinomial logistic regression. Conclusion. The DD genotype of the ACE gene is involved in susceptibility to hypertension. Further investigations are needed to better monitor and provide individualized care for hypertensive patients.

The role of local renin-angiotensin system in arterial chemoreceptors in sleep-breathing disorders

Directory of Open Access Journals (Sweden)

Man Lung eFung

2014-09-01

Full Text Available The renin-angiotensin system (RAS plays pivotal roles in the regulation of cardiovascular and renal functions to maintain the fluid and electrolyte homeostasis. Experimental studies have demonstrated a locally expressed RAS in the carotid body, which is functional significant in the effect of angiotensin peptides on the regulation of the activity of peripheral chemoreceptors and the chemoreflex. The physiological and pathophysiological implications of the RAS in the carotid body have been proposed upon recent studies showing a significant upregulation of the RAS expression under hypoxic conditions relevant to altitude acclimation and sleep apnea and also in animal model of heart failure. Specifically, the increased expression of angiotensinogen, angiotensin-converting enzyme and angiotensin AT1 receptors plays significant roles in the augmented carotid chemoreceptor activity and inflammation of the carotid body. This review aims to summarize these results with highlights on the pathophysiological function of the RAS under hypoxic conditions. It is concluded that the maladaptive changes of the RAS in the carotid body plays a pathogenic role in sleep apnea and heart failure, which could potentially be a therapeutic target for the treatment of the pathophysiological consequence of sleep apnea.

Influência do exercício aeróbio na renina de portadores de hipertensão arterial com sobrepeso Influencia del ejercicio aeróbico en la renina de portadores de hipertensión arterial con sobrepeso Effect of aerobic exercise on plasma renin in overweight patients with hypertension

Directory of Open Access Journals (Sweden)

Bruno Martinelli

2010-07-01

Full Text Available FUNDAMENTO: A atividade do sistema renina-angiotensina-aldosterona tem relação direta com sobrepeso e sedentarismo, e essas variáveis se associam à hipertensão arterial (HA. O exercício aeróbio propicia melhor controle da pressão arterial (PA por agir nos mecanismos da regulação pressórica, dentre eles, a atividade de renina plasmática (ARP. OBJETIVO: Avaliar a influência do exercício aeróbio sobre ARP em portadores de HA com sobrepeso. MÉTODOS: Foram avaliados níveis pressóricos, bioquímicos e antropométricos pré e pós-treinamento de 16 semanas, três vezes por semana, a 60%-80% da frequência cardíaca máxima. Os dados foram expressos em média ± desvio padrão ou mediana e intervalo interquartílico, e analisados pelo teste "t", Mann-Withney e ANOVA (p FUNDAMENTO: La actividad del sistema renina-angiotensina-aldosterona tiene relación directa con sobrepeso y sedentarismo, y esas variables se asocian a la hipertensión arterial (HA. El ejercicio aeróbico propicia mejor control de la presión arterial (PA por actuar en los mecanismos de la regulación presórica, entre ellos, la actividad de renina plasmática (ARP. OBJETIVO: Evaluar la influencia del ejercicio aeróbico sobre ARP en portadores de HA con sobrepeso. MÉTODOS: Fueron evaluados niveles presóricos, bioquímicos y antropométricos pre y post-entrenamiento de 16 semanas, tres veces por semana, a 60%-80% da frecuencia cardíaca máxima. Los datos fueron expresados en media ± desvío estándar o media e intervalo intercuartílico, y analizados por el teste "t", Mann-Withney y ANOVA (p BACKGROUND: The activity of the renin-angiotensin-aldosterone system (RAAS is directly related to overweight and sedentary lifestyles, both of which are associated with hypertension. Aerobic exercise helps control blood pressure (BP by acting on mechanisms of blood pressure regulation, such as plasma renin activity (PRA. OBJECTIVE: To assess the effect of aerobic exercise on

Combined use of drugs inhibiting the renin-angiotensin system: prescribing patterns and risk of acute kidney injury in German nursing home residents.

Science.gov (United States)

Dörks, Michael; Herget-Rosenthal, Stefan; Hoffmann, Falk; Jobski, Kathrin

2018-01-01

In 2012, the European Medicines Agency reviewed the safety of dual renin-angiotensin system (RAS) blockade because of potentially increased risks for inter alia acute kidney injury (AKI). Since residents of nursing homes are particularly vulnerable to adverse drug outcomes, the aims of our study were to describe RAS-inhibiting drug use in German nursing home residents and examine the risk of AKI associated with dual RAS blockade. Based on claims data, a nested case-control study within a cohort of RAS-inhibiting drug users was conducted. Using conditional logistic regression, confounder-adjusted odds ratios (aORs) and 95% confidence intervals (CI) were obtained for the risk of AKI associated with dual RAS blockade. Subgroup analyses were performed in patients with diabetes or chronic kidney disease and both comorbidities. Of all 127,227 nursing home residents, the study cohort included 64,567 (50.7%) who were treated with at least one RAS-inhibiting drug. More than three quarters of the study population were female (77.1%). Mean age was 86.0 ± 6.8 years. Most residents were treated with angiotensin-converting enzyme inhibitors (77.8%), followed by angiotensin II receptor blockers (21.6%) and aliskiren (0.2%). Annual prevalence of dual RAS blockade declined from 9.6 (95% CI 7.8-11.8) in 2010 to 4.7 (95% CI 4.0-5.4) per 1,000 users in 2014. In the overall cohort, AKI was not significantly associated with dual RAS blockade (aOR 1.99; 0.77-5.17). However, significantly increased aORs were observed when considering patients with diabetes (3.47; 1.27-9.47), chronic kidney disease (4.74; 1.24-18.13) or both (11.17; 2.65-47.15). Prescribing of drugs inhibiting the RAS is common in German nursing homes. Though the prevalence of dual RAS blockade declined, our study showed an increased risk of AKI in patients with diabetes and/or chronic kidney disease. Therefore, cautious use is warranted in these vulnerable patients.

Chronic activation of plasma renin is log-linearly related to dietary sodium and eliminates natriuresis in response to a pulse change in total body sodium

DEFF Research Database (Denmark)

Kjolby, Mads; Bie, Peter

2008-01-01

rate, urine flow, plasma potassium, and plasma renin activity did not change. The results indicate that sodium excretion is controlled by neurohumoral mechanisms that are quite resistant to acute changes in plasma volume and colloid osmotic pressure and are not down-regulated within 2 h. With previous......Cl administration increased PV (+6.3-8.9%) and plasma sodium concentration (~2%) and decreased plasma protein concentration (-6.4-8.1%). Plasma ANG II and aldosterone concentrations decreased transiently. Potassium excretion increased substantially. Sodium excretion, arterial blood pressure, glomerular filtration...

Proton pump inhibitors and osteoporosis

DEFF Research Database (Denmark)

Andersen, Bjarne Nesgaard; Johansen, Per Birger; Abrahamsen, Bo

2016-01-01

PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months and a di......PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months...... and a discussion of these findings and how this has influenced our understanding of this association, the clinical impact and the underlying pathophysiology. RECENT FINDINGS: New studies have further strengthened existing evidence linking use of PPIs to osteoporosis. Short-term use does not appear to pose a lower...... risk than long-term use. There is a continued lack of conclusive studies identifying the pathogenesis. Direct effects on calcium absorption or on osteoblast or osteoclast action cannot at present plausibly explain the mechanism. SUMMARY: The use of PPIs is a risk factor for development of osteoporosis...

Epitope-Targeting of Tertiary Protein Structure Enables Target-Guided Synthesis of a Potent in Cell Inhibitor of Botulinum Neurotoxin**

OpenAIRE

Farrow, Blake; Wong, Michelle; Malette, Jacquie; Lai, Bert; Deyle, Kaycie M.; Das, Samir; Nag, Arundhati; Agnew, Heather D.; Heath, James R.

2015-01-01

Botulinum neurotoxin (BoNT) serotype A is the most lethal known toxin and has an occluded structure, which prevents direct inhibition of its active site before it enters the cytosol. Target-guided synthesis by in situ click chemistry is combined with synthetic epitope targeting to exploit the tertiary structure of the BoNT protein as a landscape for assembling a competitive inhibitor. A substrate-mimicking peptide macrocycle is used as a direct inhibitor of BoNT. An epitope-targeting in situ ...

Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

Science.gov (United States)

Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

2016-09-01

Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and

The effect of chemical anti-inhibitors on fibrinolytic enzymes and inhibitors

DEFF Research Database (Denmark)

Sidelmann, Johannes Jakobsen; Jespersen, J; Kluft, C

1997-01-01

proteases. We studied the influence of chemical anti-inhibitors (chloramine T, flufenamate, sodium lauryl sulfate, and methylamine) on fibrinolytic serine proteases and fibrinolytic enzyme inhibitors using the physiological substrate fibrin as plasmin substrate. Low concentrations of chloramine T (0.01 mmol......%) and plasminogen activators (apparent recovery > 200%). Sodium lauryl sulfate eliminates the major fibrinolytic enzyme inhibitors, but increases the activity of plasmin (apparent recovery > 200%) and plasminogen activator, urokinase type (apparent recovery 130%). Methylamine affects only plasmin inhibition. We...

Effects of a phospholipase A2 inhibitor on uptake and toxicity of liposomes containing plant phosphatidylinositol

International Nuclear Information System (INIS)

Jett, M.; Alving, C.R.

1986-01-01

Plant phosphatidylinositol (PI) has been shown by us to have a direct cytotoxic effect on cultured tumor cells but not on normal cells. Synthetic PI containing 14 C-linoleic acid in the sn-2 position, also showed the same pattern of selective cytotoxicity. When the metabolic fate of synthetic PI was examined with tumor cells, the radioactivity which no longer occurred as PI, was found as either products of phospholipase A 2 (93%, free fatty acids and phosphatidylcholine) or phospholipase C (7%, diglycerides). Uptake of liposomal PI was directly correlated with cytotoxicity. They tested a variety of inhibitors to see the effect on uptake and/or cytotoxicity of plant PI. General metabolic inhibitors such as metrizamide or sodium azide did not alter cellular uptake of the plant PI liposomes. Inhibitors of lipoxygenase formation, such as indomethacin, also did not alter the uptake or cytotoxicity induced by plant PI. Quinacrine, an inhibitor of phospholipase A 2 , decreased the uptake of the PI containing liposomes to 50% of that seen in the presence or absence of any other inhibitor. Although quinacrine is itself toxic to cells, at low concentrations of quinacrine, plant PI did not show the same degree of cytotoxicity as in the absence of quinacrine. These data are compatible with the hypothesis that plant PI exerts cytotoxicity by serving as a substrate for phospholipase A 2

Potential of a renin inhibitory peptide from the red seaweed Palmaria palmata as a functional food ingredient following confirmation and characterization of a hypotensive effect in spontaneously hypertensive rats.

Science.gov (United States)

Fitzgerald, Ciaran; Aluko, Rotimi E; Hossain, Mohammad; Rai, Dilip K; Hayes, Maria

2014-08-20

This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.

Impact of the clinical use of ROCK inhibitor on the pathogenesis and treatment of glaucoma.

Science.gov (United States)

Honjo, Megumi; Tanihara, Hidenobu

2018-03-01

Rho-associated protein kinase (ROCK), a ubiquitously expressed signaling messenger and downstream effector of Rho, is activated by several bioactive factors in the aqueous humor (AH). Rho-ROCK signaling regulates a wide spectrum of fundamental cellular events, including cell adhesion, motility, proliferation, differentiation, and apoptosis. Previous studies, including our own, found that ROCK inhibitor lowers intraocular pressure (IOP) via a direct effect on the conventional AH outflow pathway, by regulation of contractile properties, fibrotic activity, and permeability of the trabecular meshwork (TM) and Schlemm's canal (SC) tissues, influencing extracellular matrix (ECM) production. Recently, a novel ROCK inhibitor, ripasudil, has been introduced in Japan. Other ROCK inhibitors are now in clinical trials as new IOP-lowering drugs for glaucoma patients. To date, ripasudil, administered together with other glaucoma medications, has proved safe and efficient in lowering IOP as well as additional effects such as prostaglandin analogs, beta-blockers, and carbonic anhydrase inhibitors, all of which help lower IOP by different mechanisms. In addition, we found that long-term treatment with ripasudil exerted an additional IOP-lowering effect, especially in eyes with high IOP, suggesting that late-onset remodeling of the ECM in glaucomatous eyes may elicit mild and delayed changes in IOP levels. ROCK inhibitors have also shown several additional effects, including increased retinal blood flow, direct protection of neurons against various types of stress, and regulation of wound healing; these benefits may potentially be useful in glaucoma treatment.

Combined effects of EGFR tyrosine kinase inhibitors and vATPase inhibitors in NSCLC cells

Energy Technology Data Exchange (ETDEWEB)

Jin, Hyeon-Ok [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Hong, Sung-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Kim, Chang Soon [Department of Microbiological Engineering, Kon-Kuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143–701 (Korea, Republic of); Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Park, In-Chul, E-mail: parkic@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Lee, Jin Kyung, E-mail: jklee@kirams.re.kr [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of)

2015-08-15

Despite excellent initial clinical responses of non-small cell lung cancer (NSCLC) patients to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), many patients eventually develop resistance. According to a recent report, vacuolar H + ATPase (vATPase) is overexpressed and is associated with chemotherapy drug resistance in NSCLC. We investigated the combined effects of EGFR TKIs and vATPase inhibitors and their underlying mechanisms in the regulation of NSCLC cell death. We found that combined treatment with EGFR TKIs (erlotinib, gefitinib, or lapatinib) and vATPase inhibitors (bafilomycin A1 or concanamycin A) enhanced synergistic cell death compared to treatments with each drug alone. Treatment with bafilomycin A1 or concanamycin A led to the induction of Bnip3 expression in an Hif-1α dependent manner. Knock-down of Hif-1α or Bnip3 by siRNA further enhanced cell death induced by bafilomycin A1, suggesting that Hif-1α/Bnip3 induction promoted resistance to cell death induced by the vATPase inhibitors. EGFR TKIs suppressed Hif-1α and Bnip3 expression induced by the vATPase inhibitors, suggesting that they enhanced the sensitivity of the cells to these inhibitors by decreasing Hif-1α/Bnip3 expression. Taken together, we conclude that EGFR TKIs enhance the sensitivity of NSCLC cells to vATPase inhibitors by decreasing Hif-1α/Bnip3 expression. We suggest that combined treatment with EGFR TKIs and vATPase inhibitors is potentially effective for the treatment of NSCLC. - Highlights: • Co-treatment with EGFR TKIs and vATPase inhibitors induces synergistic cell death • EGFR TKIs enhance cell sensitivity to vATPase inhibitors via Hif-1α downregulation • Co-treatment of these inhibitors is potentially effective for the treatment of NSCLC.

Synergistic apoptosis induction in leukemic cells by the phosphatase inhibitor salubrinal and proteasome inhibitors.

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Hannes C A Drexler

Full Text Available Cells adapt to endoplasmic reticulum (ER-stress by arresting global protein synthesis while simultaneously activating specific transcription factors and their downstream targets. These processes are mediated in part by the phosphorylation-dependent inactivation of the translation initiation factor eIF2alpha. Following restoration of homeostasis protein synthesis is resumed when the serine/threonine-protein phosphatase PP1 dephosphorylates and reactivates eIF2alpha. Proteasome inhibitors, used to treat multiple myeloma patients evoke ER-stress and apoptosis by blocking the ER-associated degradation of misfolded proteins (ERAD, however, the role of eIF2alpha phosphorylation in leukemic cells under conditions of proteasome inhibitor-mediated ER stress is currently unclear.Bcr-Abl-positive and negative leukemic cell lines were used to investigate the functional implications of PP1-related phosphatase activities on eIF2alpha phosphorylation in proteasome inhibitor-mediated ER stress and apoptosis. Rather unexpectedly, salubrinal, a recently identified PP1 inhibitor capable to protect against ER stress in various model systems, strongly synergized with proteasome inhibitors to augment apoptotic death of different leukemic cell lines. Salubrinal treatment did not affect the phosphorlyation status of eIF2alpha. Furthermore, the proapoptotic effect of salubrinal occurred independently from the chemical nature of the proteasome inhibitor, was recapitulated by a second unrelated phosphatase inhibitor and was unaffected by overexpression of a dominant negative eIF2alpha S51A variant that can not be phosphorylated. Salubrinal further aggravated ER-stress and proteotoxicity inflicted by the proteasome inhibitors on the leukemic cells since characteristic ER stress responses, such as ATF4 and CHOP synthesis, XBP1 splicing, activation of MAP kinases and eventually apoptosis were efficiently abrogated by the translational inhibitor cycloheximide.Although PP1

Tyrosinase inhibitor screening in traditional Chinese medicines by electrophoretically mediated microanalysis.

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Tang, Lilin; Zhang, Wenpeng; Zhao, Haiyan; Chen, Zilin

2015-08-01

A capillary-electrophoresis-based method for the screening of tyrosinase inhibitors in traditional Chinese medicines was developed. The method integrated electrophoretically mediated microanalysis with sandwich mode injection, partial filling, and rapid polarity switching techniques, and carried out on-column enzyme reaction and the separation of substrate and product. The conditions were optimized including the background electrolyte, mixing voltage, and the incubation time. Finally, the screening of nine standard natural compounds of traditional Chinese medicines was carried out. The inhibitors can be directly identified from the reduced peak area of the product compared to that obtained without any inhibitor. Chlorogenic acid (100 μM) showed inhibitory activity with the inhibitory percentage of 19.8%, while the other compounds showed no inhibitory activity. This method has great application potential in drug discovery from traditional Chinese medicines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Farmácia Popular Program: pharmaceutical market analysis of antihypertensive acting on the renin-angiotensin system medicines

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Rondineli Mendes da Silva

Full Text Available Abstract This paper aims to analyse changes in the retail pharmaceutical market following policy changes in the Farmácia Popular Program (FP, a medicines subsidy program in Brazil. The retrospective longitudinal analyses focus on therapeutic class of agents acting on the renin-angiotensin system. Data obtained from QuintilesIMS (formerly IMS Health included private retail pharmacy sales volume (pharmaceutical units and sales values from 2002 to 2013. Analyses evaluated changes in market share following key FP policy changes. The therapeutic class was selected due to its relevance to hypertension treatment. Market share was analysed by therapeutic sub-classes and by individual company. Losartan as a single product accounted for the highest market share among angiotensin II antagonists. National companies had higher sales volume during the study period, while multinational companies had higher sales value. Changes in pharmaceutical market share coincided with the inclusion of specific products in the list of medicines covered by FP and with increases in or exemption from patient copayment.

Effects of peripherally and centrally applied ghrelin on the oxidative stress induced by renin angiotensin system in a rat model of renovascular hypertension.

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Boshra, Vivian; Abbas, Amr M

2017-07-26

Renovascular hypertension (RVH) is a result of renal artery stenosis, which is commonly due to astherosclerosis. In this study, we aimed to clarify the central and peripheral effects of ghrelin on the renin-angiotensin system (RAS) in a rat model of RVH. RVH was induced in rats by partial subdiaphragmatic aortic constriction. Experiment A was designed to assess the central effect of ghrelin via the intracerebroventricular (ICV) injection of ghrelin (5 μg/kg) or losartan (0.01 mg/kg) in RVH rats. Experiment B was designed to assess the peripheral effect of ghrelin via the subcutaneous (SC) injection of ghrelin (150 μg/kg) or losartan (10 mg/kg) for 7 consecutive days. Mean arterial blood pressure (MAP), heart rate, plasma renin activity (PRA), and oxidative stress markers were measured in all rats. In addition, angiotensin II receptor type 1 (AT1R) concentration was measured in the hypothalamus of rats in Experiment B. RVH significantly increased brain AT1R, PRA, as well as the brain and plasma oxidative stress. Either SC or ICV ghrelin or losartan caused a significant decrease in MAP with no change in the heart rate. Central ghrelin or losartan caused a significant decrease in brain AT1R with significant alleviation of the brain oxidative stress. Central ghrelin caused a significant decrease in PRA, whereas central losartan caused a significant increase in PRA. SC ghrelin significantly decreased PRA and plasma oxidative stress, whereas SC losartan significantly increased PRA and decreased plasma oxidative stress. The hypotensive effect of ghrelin is mediated through the amelioration of oxidative stress, which is induced by RAS centrally and peripherally.

Structural insights into central hypertension regulation by human aminopeptidase A.

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Yang, Yang; Liu, Chang; Lin, Yi-Lun; Li, Fang

2013-08-30

Hypertension is regulated through both the central and systemic renin-angiotensin systems. In the central renin-angiotensin system, zinc-dependent aminopeptidase A (APA) up-regulates blood pressure by specifically cleaving the N-terminal aspartate, but not the adjacent arginine, from angiotensin II, a process facilitated by calcium. Here, we determined the crystal structures of human APA and its complexes with different ligands and identified a calcium-binding site in the S1 pocket of APA. Without calcium, the S1 pocket can bind both acidic and basic residues through formation of salt bridges with the charged side chains. In the presence of calcium, the binding of acidic residues is enhanced as they ligate the cation, whereas the binding of basic residues is no longer favorable due to charge repulsion. Of the peptidomimetic inhibitors of APA, amastatin has higher potency than bestatin by fitting better in the S1 pocket and interacting additionally with the S3' subsite. These results explain the calcium-modulated substrate specificity of APA in central hypertension regulation and can guide the design and development of brain-targeting antihypertensive APA inhibitors.

Structural Insights into Central Hypertension Regulation by Human Aminopeptidase A*

Science.gov (United States)

Yang, Yang; Liu, Chang; Lin, Yi-Lun; Li, Fang

2013-01-01

Hypertension is regulated through both the central and systemic renin-angiotensin systems. In the central renin-angiotensin system, zinc-dependent aminopeptidase A (APA) up-regulates blood pressure by specifically cleaving the N-terminal aspartate, but not the adjacent arginine, from angiotensin II, a process facilitated by calcium. Here, we determined the crystal structures of human APA and its complexes with different ligands and identified a calcium-binding site in the S1 pocket of APA. Without calcium, the S1 pocket can bind both acidic and basic residues through formation of salt bridges with the charged side chains. In the presence of calcium, the binding of acidic residues is enhanced as they ligate the cation, whereas the binding of basic residues is no longer favorable due to charge repulsion. Of the peptidomimetic inhibitors of APA, amastatin has higher potency than bestatin by fitting better in the S1 pocket and interacting additionally with the S3′ subsite. These results explain the calcium-modulated substrate specificity of APA in central hypertension regulation and can guide the design and development of brain-targeting antihypertensive APA inhibitors. PMID:23888046

Renoprotective effects of angiotensin II receptor blockade in type 1 diabetic patients with diabetic nephropathy

DEFF Research Database (Denmark)

Andersen, S; Tarnow, L; Rossing, P

2000-01-01

BACKGROUND: Angiotensin I-converting enzyme (ACE) inhibitors reduce angiotensin II formation and induce bradykinin accumulation. Animal studies suggest that bradykinin may play a role for the effects of ACE inhibition on blood pressure and kidney function. Therefore, we compared the renal and hem...... inhibition is primarily caused by interference in the renin-angiotensin system. Our study suggest that losartan represents a valuable new drug in the treatment of hypertension and proteinuria in type 1 diabetic patients with diabetic nephropathy....... and hemodynamic effects of specific intervention in the renin-angiotensin system by blockade of the angiotensin II subtype-1 receptor to the effect of ACE inhibition. METHODS: A randomized, double-blind, cross-over trial was performed in 16 type 1 diabetic patients (10 men), age 42 +/- 2 years (mean +/- SEM...

Encoded library technology as a source of hits for the discovery and lead optimization of a potent and selective class of bactericidal direct inhibitors of Mycobacterium tuberculosis InhA.

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Encinas, Lourdes; O'Keefe, Heather; Neu, Margarete; Remuiñán, Modesto J; Patel, Amish M; Guardia, Ana; Davie, Christopher P; Pérez-Macías, Natalia; Yang, Hongfang; Convery, Maire A; Messer, Jeff A; Pérez-Herrán, Esther; Centrella, Paolo A; Alvarez-Gómez, Daniel; Clark, Matthew A; Huss, Sophie; O'Donovan, Gary K; Ortega-Muro, Fátima; McDowell, William; Castañeda, Pablo; Arico-Muendel, Christopher C; Pajk, Stane; Rullás, Joaquín; Angulo-Barturen, Iñigo; Alvarez-Ruíz, Emilio; Mendoza-Losana, Alfonso; Ballell Pages, Lluís; Castro-Pichel, Julia; Evindar, Ghotas

2014-02-27

Tuberculosis (TB) is one of the world's oldest and deadliest diseases, killing a person every 20 s. InhA, the enoyl-ACP reductase from Mycobacterium tuberculosis, is the target of the frontline antitubercular drug isoniazid (INH). Compounds that directly target InhA and do not require activation by mycobacterial catalase peroxidase KatG are promising candidates for treating infections caused by INH resistant strains. The application of the encoded library technology (ELT) to the discovery of direct InhA inhibitors yielded compound 7 endowed with good enzymatic potency but with low antitubercular potency. This work reports the hit identification, the selected strategy for potency optimization, the structure-activity relationships of a hundred analogues synthesized, and the results of the in vivo efficacy studies performed with the lead compound 65.

Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

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Boutin Jean A

2010-10-01

Full Text Available Abstract Background Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. Methods Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours. The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue. Results Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently. Conclusions In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.

The development prospection of HDAC inhibitors as a potential therapeutic direction in Alzheimer?s disease

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Yang, Shuang-shuang; Zhang, Rui; Wang, Gang; Zhang, Yong-fang

2017-01-01

Alzheimer?s disease (AD) is a chronic neurodegenerative disease, which is associated with learning and memory impairment in the elderly. Recent studies have found that treating AD in the way of chromatin remodeling via histone acetylation is a promising therapeutic regimen. In a number of recent studies, inhibitors of histone deacetylase (HDACs) have been found to be a novel promising therapeutic?agents for neurological disorders, particularly for AD and other neurodegenerative diseases. Alth...

Effect of protease inhibitors on thermal gelation of squid (Illex argentinus. mantle paste

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Maria Elida Paredi

2014-04-01

Full Text Available The characteristics of the thermal gelation of squid mantle paste and the effect of protease inhibitors on them were investigated. Pastes in the absence and presence the protease inhibitors, ethylendiaminetetracetic acid (EDTA and phenylmethylsulfonyl fluoride (PMSF, were formulated. Pastes were made by the respective one or two step thermal treatments: direct heating at 85°C for 20 min and preincubation at 27 or 40 °C for 3 or 2 hours, followed by heating at 85 °C for 20 min. The gel strength, water holding capacity (WHC and whiteness of gelled pastes were analyzed. The tricloroacetic acid (TCA soluble peptides in homogenate of the muscle were determined. Gel strength decreased when heating was made in two steps. EDTA and PMSF were effective in avoiding that decrease when pre-incubation was made at 40 °C. Maximum gel strength was observed for the gels in presence of EDTA, giving values of 255 and 219 g x cm for the samples made by direct heating and pre-incubated at 40 °C  respectively. TCA soluble peptides increased between 20 and 60 °C, with maximum values reached at 30 and 60 °C. No significant differences (p>0.05 were observed in gel whiteness, neither with the thermal treatment nor with the inhibitors. The WHC was higher (p<0.05 in the gelated paste formulated with EDTA. These results show a good gelation capacity of I argentinus pastes and improvements with protease inhibitors. 

Synthesis of the proteinase inhibitor LEKTI domain 6 by the fragment condensation method and regioselective disulfide bond formation.

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Vasileiou, Zoe; Barlos, Kostas K; Gatos, Dimitrios; Adermann, Knut; Deraison, Celine; Barlos, Kleomenis

2010-01-01

Proteinase inhibitors are of high pharmaceutical interest and are drug candidates for a variety of indications. Specific kallikrein inhibitors are important for their antitumor activity and their potential application to the treatment of skin diseases. In this study we describe the synthesis of domain 6 of the kallikrein inhibitor Lympho-Epithilial Kazal-Type Inhibitor (LEKTI) by the fragment condensation method and site-directed cystine bridge formation. To obtain the linear LEKTI precursor, the condensation was best performed in solution, coupling the protected fragment 1-22 to 23-68. This method yielded LEKTI domain 6 of high purity and equipotent to the recombinantly produced peptide. (c) 2010 Wiley Periodicals, Inc.

Direct-acting antivirals and host-targeting strategies to combat enterovirus infections.

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Bauer, Lisa; Lyoo, Heyrhyoung; van der Schaar, Hilde M; Strating, Jeroen Rpm; van Kuppeveld, Frank Jm

2017-06-01

Enteroviruses (e.g., poliovirus, enterovirus-A71, coxsackievirus, enterovirus-D68, rhinovirus) include many human pathogens causative of various mild and more severe diseases, especially in young children. Unfortunately, antiviral drugs to treat enterovirus infections have not been approved yet. Over the past decades, several direct-acting inhibitors have been developed, including capsid binders, which block virus entry, and inhibitors of viral enzymes required for genome replication. Capsid binders and protease inhibitors have been clinically evaluated, but failed due to limited efficacy or toxicity issues. As an alternative approach, host-targeting inhibitors with potential broad-spectrum activity have been identified. Furthermore, drug repurposing screens have recently uncovered promising new inhibitors with disparate viral and host targets. Together, these findings raise hope for the development of (broad-range) anti-enteroviral drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Palmitoylethanolamide treatment reduces blood pressure in spontaneously hypertensive rats: involvement of cytochrome p450-derived eicosanoids and renin angiotensin system.

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Giuseppina Mattace Raso

Full Text Available Palmitoylethanolamide (PEA, a peroxisome proliferator-activated receptor-α agonist, has been demonstrated to reduce blood pressure and kidney damage secondary to hypertension in spontaneously hypertensive rat (SHR. Currently, no information is available concerning the putative effect of PEA on modulating vascular tone. Here, we investigate the mechanisms underpinning PEA blood pressure lowering effect, exploring the contribution of epoxyeicosatrienoic acids, CYP-dependent arachidonic acid metabolites, as endothelium-derived hyperpolarizing factors (EDHF, and renin angiotensin system (RAS modulation. To achieve this aim SHR and Wistar-Kyoto rats were treated with PEA (30 mg/kg/day for five weeks. Functional evaluations on mesenteric bed were performed to analyze EDHF-mediated vasodilation. Moreover, mesenteric bed and carotid were harvested to measure CYP2C23 and CYP2J2, the key isoenzymes in the formation of epoxyeicosatrienoic acids, and the soluble epoxide hydrolase, which is responsible for their degradation in the corresponding diols. Effect of PEA on RAS modulation was investigated by analyzing angiotensin converting enzyme and angiotensin receptor 1 expression. Here, we showed that EDHF-mediated dilation in response to acetylcholine was increased in mesenteric beds of PEA-treated SHR. Western blot analysis revealed that the increase in CYP2C23 and CYP2J2 observed in SHR was significantly attenuated in mesenteric beds of PEA-treated SHR, but unchanged in the carotids. Interestingly, in both vascular tissues, PEA significantly decreased the soluble epoxide hydrolase protein level, accompanied by a reduced serum concentration of its metabolite 14-15 dihydroxyeicosatrienoic acid, implying a reduction in epoxyeicosatrienoic acid hydrolisis. Moreover, PEA treatment down-regulated angiotensin receptor 1 and angiotensin converting enzyme expression, indicating a reduction in angiotensin II-mediated effects. Consistently, a damping of the

Discovery of DNA repair inhibitors by combinatorial library profiling

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Moeller, Benjamin J.; Sidman, Richard L.; Pasqualini, Renata; Arap, Wadih

2011-01-01

Small molecule inhibitors of DNA repair are emerging as potent and selective anti-cancer therapies, but the sheer magnitude of the protein networks involved in DNA repair processes poses obstacles to discovery of effective candidate drugs. To address this challenge, we used a subtractive combinatorial selection approach to identify a panel of peptide ligands that bind DNA repair complexes. Supporting the concept that these ligands have therapeutic potential, we show that one selected peptide specifically binds and non-competitively inactivates DNA-PKcs, a protein kinase critical in double-strand DNA break repair. In doing so, this ligand sensitizes BRCA-deficient tumor cells to genotoxic therapy. Our findings establish a platform for large-scale parallel screening for ligand-directed DNA repair inhibitors, with immediate applicability to cancer therapy. PMID:21343400

Dengue Virus NS2B/NS3 Protease Inhibitors Exploiting the Prime Side.

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Lin, Kuan-Hung; Ali, Akbar; Rusere, Linah; Soumana, Djade I; Kurt Yilmaz, Nese; Schiffer, Celia A

2017-05-15

The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a small protein with high affinity for DENV protease. In this study, we designed a series of cyclic peptides interacting with both sides of the active site as inhibitors of dengue virus protease. The design was based on two aprotinin loops and aimed to leverage both key specific interactions of substrate sequences and the entropic advantage driving aprotinin's high affinity. By optimizing the cyclization linker, length, and amino acid sequence, the tightest cyclic peptide achieved a K i value of 2.9 μM against DENV3 wild-type (WT) protease. These inhibitors provide proof of concept that both sides of DENV protease active site can be exploited to potentially achieve specificity and lower hydrophilicity in the design of inhibitors targeting DENV. IMPORTANCE Viruses of the flaviviral family, including DENV and Zika virus transmitted by Aedes aegypti , continue to be a threat to global health by causing major outbreaks in tropical and subtropical regions, with no available direct-acting antivirals for treatment. A better understanding of the molecular requirements for the design of potent and specific inhibitors against flaviviral proteins will contribute to the development of targeted therapies for infections by these viruses. The cyclic peptides reported here as DENV protease inhibitors

An assessment of nitrification inhibitors to reduce nitrous oxide emissions from UK agriculture

International Nuclear Information System (INIS)

Misselbrook, T H; Cardenas, L M; Camp, V; Thorman, R E; Williams, J R; Rollett, A J; Chambers, B J

2014-01-01

A trial was conducted consisting of 14 experiments across sites in England of contrasting soil type and annual rainfall to assess the effectiveness of nitrification inhibitors (predominantly dicyandiamide (DCD) but limited assessment also of 3, 4-dimethylpyrazole phosphate (DMPP) and a commercial product containing two pyrazole derivatives) in reducing direct nitrous oxide (N 2 O) emissions from fertilizer nitrogen (N), cattle urine and cattle slurry applications to land. Measurements were also made of the impact on ammonia (NH 3 ) volatilization, nitrate (NO 3 − ) leaching, crop yield and crop N offtake. DCD proved to be very effective in reducing direct N 2 O emissions following fertilizer and cattle urine applications, with mean reduction efficiencies of 39, 69 and 70% for ammonium nitrate, urea and cattle urine, respectively. When included with cattle slurry a mean, non-significant reduction of 56% was observed. There were no N 2 O emission reductions observed from the limited assessments of the other nitrification inhibitors. Generally, there were no impacts of the nitrification inhibitors on NH 3 volatilization, NO 3 − leaching, crop yield or crop N offtake. Use of DCD could give up to 20% reduction in N 2 O emissions from UK agriculture, but cost-effective delivery mechanisms are required to encourage adoption by the sector. Direct N 2 O emissions from the studied sources were substantially lower than IPCC default values and development of UK country-specific emission factors for use in inventory compilation is warranted. (paper)

PD-1/PD-L1 Inhibitors for Immuno-oncology: From Antibodies to Small Molecules.

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Geng, Qiaohong; Jiao, Peifu; Jin, Peng; Su, Gaoxing; Dong, Jinlong; Yan, Bing

2018-02-12

The recent regulatory approvals of immune checkpoint protein inhibitors, such as ipilimumab, pembrolizumab, nivolumab, atezolizumab, durvalumab, and avelumab ushered a new era in cancer therapy. These inhibitors do not attack tumor cells directly but instead mobilize the immune system to re-recognize and eradicate tumors, which endows them with unique advantages including durable clinical responses and substantial clinical benefits. PD-1/PD-L1 inhibitors, a pillar of immune checkpoint protein inhibitors, have demonstrated unprecedented clinical efficacy in more than 20 cancer types. Besides monoclonal antibodies, diverse PD- 1/PD-L1 inhibiting candidates, such as peptides, small molecules have formed a powerful collection of weapons to fight cancer. The goal of this review is to summarize and discuss the current PD-1/PD-L1 inhibitors including candidates under clinical development, their molecular interactions with PD-1 or PD-L1, the disclosed structureactivity relationships of peptides and small molecules as inhibitors. Current PD-1/PD-L1 inhibitors under clinical development are exclusively dominated by antibodies. The molecular interactions of therapeutic antibodies with PD-1 or PD-L1 have been gradually elucidated for the design of novel inhibitors. Various peptides and traditional small molecules have been investigated in preclinical model to discover novel PD-1/PD-L1 inhibitors. Peptides and small molecules may play an important role in immuno-oncology because they may bind to multiple immune checkpoint proteins via rational design, opening opportunity for a new generation of novel PD-1/PD-L1 inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Outcome of Venom Bradykinin Potentiating Factor on Renin Angiotensin System in Irradiated Rats

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