Effect Of Direct Renin Inhibition Research Articles

(Pro)renin receptor promotes crescent formation via the ERK1/2 and Wnt/β-catenin pathways in glomerulonephritis.

(Pro)renin receptor [(P)RR] has multiple functions, but its regulation and role in the pathogenesis in glomerulonephritis (GN) are poorly defined. The aims of the present study were to determine the effects of direct renin inhibition (DRI) and demonstrate the role of (P)RR on the progression of crescentic GN. The anti-glomerular basement membrane nephritis rat model developed progressive proteinuria (83.64 ± 10.49 mg/day) and glomerular crescent formation (percent glomerular crescent: 62.1 ± 2.3%) accompanied by increased macrophage infiltration and glomerular expression of monocyte chemoattractant protein (MCP)-1, (P)RR, phospho-extracellular signal-regulated kinase (ERK)1/2, Wnt4, and active β-catenin. Treatment with DRI ameliorated proteinuria (20.33 ± 5.88 mg/day) and markedly reduced glomerular crescent formation (20.9 ± 2.6%), induction of macrophage infiltration, (P)RR, phospho-ERK1/2, Wnt4, and active β-catenin. Furthermore, primary cultured parietal epithelial cells stimulated by recombinant prorenin showed significant increases in cell proliferation. Notably, while the ERK1/2 inhibitor PD98059 or (P)RR-specific siRNA treatment abolished the elevation in cell proliferation, DRI treatment did not abrogate this elevation. Moreover, cultured mesangial cells showed an increase in prorenin-induced MCP-1 expression. Interestingly, (P)RR or Wnt4-specific siRNA treatment or the β-catenin antagonist XAV939 inhibited the elevation of MCP-1 expression, whereas DRI did not. These results suggest that (P)RR regulates glomerular crescent formation via the ERK1/2 signaling and Wnt/β-catenin pathways during the course of anti-glomerular basement membrane nephritis and that DRI mitigates the progression of crescentic GN through the reduction of (P)RR expression but not inhibition of prorenin binding to (P)RR.

Effect of direct renin inhibition on vascular function after long-term treatment with aliskiren in hypertensive and diabetic patients.

We tested the hypothesis that chronic treatment with the direct renin inhibitor aliskiren improves vascular function in resistance and conduit arteries of type two diabetic and hypertensive patients. Sixteen patients with mild essential hypertension and with a previous diagnosis of noninsulin-dependent diabetes mellitus were included in the study. Patients were then randomized to aliskiren (150 mg once daily, n = 9), or ramipril (5 mg once daily, n = 7). Each patient underwent a biopsy of the subcutaneous tissue and small arteries were dissected and mounted on a pressurized micromyograph to evaluate endothelium dependent vasorelaxation in response to acetylcholine ± N omega-nitro-L-arginine methyl ester hydrochloride in vessels precontracted with norepinephrine. Endothelial function has been quantified also in large conduit arteries by flow-mediated dilation. A similar office blood pressure-lowering effect was observed with the two drugs, although changes in DBP were not statistically significant in the ramipril group. Aliskiren significantly improved endothelium-dependent relaxation in subcutaneous resistance arteries, as well as increased flow-mediated dilation in conduit arteries, whereas the effects induced by ramipril did not reach statistical significance. Only aliskiren significantly increased the expression of p1177-endothelial nitric oxide synthase in the endothelium. Both aliskiren and ramipril had a negligible effect on markers of oxidative stress. Aliskiren restored endothelial function and induced a more prompt peripheral vasodilation in hypertensive and diabetic patients possibly through the increased production of nitric oxide via the enhanced expression and function of the active phosphorylated form of endothelial nitric oxide synthase.

Effects of direct renin inhibition versus angiotensin II receptor blockade on angiotensin profiles in non-diabetic chronic kidney disease

Background: Direct renin inhibition (DRI) is clinically inferior to other blockers of the renin–angiotensin system (RAS). Thus far, the underlying molecular causes of this finding remain unknown.Methods: Twenty four patients with non-diabetic chronic kidney disease (CKD) stages III–IV and albuminuria were randomized to DRI or angiotensin receptor blocker (ARB). Employing a novel mass-spectrometry method, the concentrations of renin, aldosterone and plasma angiotensin peptides [Ang I, Ang II, Ang-(1-7), Ang-(1-5), Ang-(2-8), Ang-(3-8)] were quantified before and after an 8-week treatment.Results: While blood pressure, renal function and albuminuria decreased comparably in both groups, profound RAS component differences were observed: DRI led to a massive renin increase, while suppressing both vasoconstrictive (Ang I and Ang II) and vasodilatory RAS metabolites (Ang-(1-7) and Ang-(1-5)). In contrast, ARB led to a four-fold increase of Ang I and Ang II, while Ang-(1-7) and Ang-(1-5) increased moderately but significantly. With ARB treatment, a decreased aldosterone-to-Ang II ratio suggested efficacy in blocking AT1 receptor.Conclusions: DRI therapy abolishes all RAS effector peptides. ARB increases both vasoconstrictive and vasodilative angiotensins, while this is accompanied by efficient blockade of vasoconstrictive effects. These differential molecular regulations should be considered when selecting optimal antihypertensive and disease-modifying therapy in CKD patients.Key messagesDirect renin inhibition leads to a complete and lasting abolition of both classical and alternative RAS components.Angiotensin receptor blockade leads to effective receptor blockade and up-regulation of alternative RAS components.Differential molecular regulations of the RAS should be considered when selecting optimal antihypertensive and disease-modifying therapy in CKD patients.

Renoprotective Effects of Direct Renin Inhibition in Glomerulonephritis

The development of glomerulonephritis causes glomerular injury and renal dysfunction and is thought to increase renin release, thus activating the renin-angiotensin system (RAS). The aims of this study were to demonstrate activation of the intrarenal RAs and determine the effects of direct renin inhibition (DRi) on the progression of glomerulonephritis. Rats were treated with anti-Thy1.1 antibody with or without DRI, aliskiren (30 mg/kg/d). In the glomerulonephritic rats, protein, microalbumin excretion levels, urinary angiotensinogen excretion, glomerular expansion score and intrarenal transforming growth factor-β and plasminogen activator inhibitor-1 mRNA levels were augmented compared with control rats; however, hypertension was not observed in the glomerulonephritic rats, and aliskiren treatment did not modify their blood pressure. The increases in urinary protein (94.7 ± 13.0 mg/d) and microalbumin (7.52 ± 2.6 mg/d) excretion were reduced by aliskiren (43.6 ± 4.5 mg/d of protein and 2.57 ± 0.7 mg/d of microalbumin). Furthermore, the progression of glomerular expansion and elevation of intrarenal transforming growth factor-β and plasminogen activator inhibitor-1 levels were prevented by aliskiren. Importantly, aliskiren suppressed the augmentation of urinary angiotensinogen levels, the increased angiotensinogen expression in the kidneys and the increases in Ang II levels in renal medulla induced by the anti-Thy1.1 antibody. These results suggest that DRI with aliskiren prevents intrarenal RAS activation leading to mitigation of the development of glomerulonephritis. In addition, the renoprotective effects of DRI on glomerulonephritis occur in a blood pressure-independent manner. Accordingly, treatment with aliskiren may be an effective approach to treat glomerulonephritis and other intrarenal RAS-associated kidney diseases.

Effects of Direct Renin Inhibition on Atherosclerotic Biomarkers in Patients With Stable Coronary Artery Disease and Type 2 Diabetes Mellitus

To evaluate whether the direct renin inhibitor, aliskiren, has a more favorable effect compared to amlodipine on atherosclerotic biomarkers in patients with stable coronary artery disease and diabetes currently receiving standard secondary prevention therapy. A total of 38 patients were randomly assigned initially to either aliskiren (150 mg daily) or amlodipine (5 mg daily) for 2 weeks after which the dose of either medication was increased to its maximum daily dose for 4 additional weeks. Baseline and 6-week blood samples were analyzed for changes from baseline and between treatment groups for vascular and intracellular cell adhesion molecule, C-reactive protein, nitric oxide, plasminogen activator inhibitor 1, 8-isoprostane, and thiobarbituric acid reactive substances. Thirty-one patients completed the study. More of the dropouts occurred in patients receiving aliskiren. Systolic blood pressure decreased in both treatment arms with no differences between the groups being noted. Plasminogen activator inhibitor 1, nitric oxide, and C-reactive protein concentrations increased in both groups from baseline but changes from baseline or between groups were not significant. Vascular and intracellular cell adhesion molecule, thiobarbituric acid reactive substances, and isoprostane concentrations decreased in each treatment arm from baseline, but these changes were not significant and no differences were noted between the groups. Treatment with either aliskiren or amlodipine did not significantly alter surrogate biomarkers of atherosclerosis in patients with both diabetes and established cardiovascular disease already receiving appropriate secondary cardiovascular prevention therapy. The study is limited in its size and duration to see an effect.

The Safety and Short-Term Efficacy of Aliskiren in the Treatment of Immunoglobulin A Nephropathy – A Randomized Cross-Over Study

BackgroundLaboratory research and previous study suggest that aliskiren, a direct renin inhibitor, has anti-proteinuric effects. We conducted a randomized crossover study to evaluate the anti-proteinuric effect of aliskiren in patients with immunoglobulin A (IgA) nephropathy.MethodsWe studied 22 patients with biopsy-proven IgA nephropathy and persistent proteinuria despite angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). Patients were randomized to either oral aliskiren 300 mg/day or placebo for 16 weeks and then crossed over to the other treatment arm after a washout period. Proteinuria, estimated glomerular filtration rate (eGFR), blood pressure, and serum potassium were monitored.ResultsAfter aliskiren treatment, there was a significant reduction in proteinuria in 4 weeks (1.76±0.95 to 1.03±0.69 g:g-Cr, p<0.0001), which remained at a low level throughout the treatment period. There was a significant difference in proteinuria between the aliskiren and placebo groups from 4 to 16 weeks after treatment (p<0.01 for all comparisons). After aliskiren treatment, there were modest but statistically significant reductions in eGFR (57.2±29.1 to 54.8±29.3 ml/min/1.73 m2, p = 0.013) and diastolic blood pressure (72.6±12.3 to 66.2±11.2 mmHg, p<0.0001). None of the patient developed severe hyperkalemia (serum potassium ≥6.0 mmol/l) during the study period.ConclusionsAliskiren has anti-proteinuric effect in patients with IgA nephropathy and persistent proteinuria despite ACE inhibitor or ARB. Further studies are needed to confirm the renal protecting effect of direct renin inhibition in chronic proteinuric kidney diseases.Trial Registration ClinicalTrials.gov NCT00870493

The Effect of Direct Renin Inhibition Alone and in Combination With ACE Inhibition on Endothelial Function, Arterial Stiffness, and Renal Function in Type 1 Diabetes

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

Direct renin inhibition improves parasympathetic function in diabetes

The renin-angiotensin-aldosterone system (RAAS) and autonomic nervous system regulate the cardiovascular system. Blockade of the RAAS may slow the progression of end-organ damage. Direct renin inhibition offers a means for blocking the RAAS. The objective of this study was to examine the effect of direct renin inhibition on cardiovascular autonomic function. In this double-blind, placebo-controlled trial, 60 individuals with diabetes were randomly assigned to 300 mg of aliskiren or placebo once daily for 6 weeks. The primary end point was a change in tests of cardiovascular autonomic function. Autonomic function was assessed by power spectral analysis and RR-variation during deep breathing [i.e. mean circular resultant (MCR), expiration/inspiration (E/I) ratio]. The MCR and E/I ratio assess parasympathetic function. Secondary measures included change in biochemical parameters [e.g. plasma renin activity, leptin and interleukin-6]. Change in cardiovascular autonomic function and blood analytes were analysed by a mixed effects model for repeated measures. Baseline characteristics were similar between treatment groups. In response to aliskiren compared with placebo, blood pressure was reduced as well as plasma renin activity [from 2.4 ± 3.8 (mean ± standard deviation) to 0.5 ± 0.4 µg/l/h, p < 0.001]. There was a significant interaction (aliskiren × visit) for MCR (p = 0.003) and E/I ratio (p = 0.003) indicating improvement in MCR and E/I ratio for those on aliskiren. MCR means, baseline vs. follow-up, were 41.8 ± 19.7 vs. 50.8 ± 26.1 (aliskiren) and 38.2 ± 23.6 vs. 37.5 ± 24.1 (placebo). Parasympathetic function (i.e. MCR and E/I ratio) was enhanced by downregulation of the RAAS.

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

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 of albuminuria with aliskiren or placebo added to losartan in the Aliskiren in the EValuation of PrOteinuria In Diabetes (AVOID) study. In AVOID, 599 patients with type 2 diabetes, hypertension and nephropathy received 6 months' aliskiren or placebo added to losartan 100 mg and optimal antihypertensive therapy. Changes in urinary albumin creatinine ratio at end of study were assessed by tertiles of baseline HbA(1c) levels. Patients were divided into tertiles of HbA(1c) (<7.1%, 7.1 to <8.4% and ≥8.4%). There were no differences between tertiles, except patients in the highest tertile group more frequently used insulin. The antiproteinuric effect of aliskiren was consistent across tertiles, with the largest effect in the highest tertile (HbA(1c) ≥8.4%). This post-hoc analysis of the AVOID study suggests that renin inhibition with aliskiren 300 mg once daily added to losartan 100 mg once daily plus optimal antihypertensive therapy provides reductions in urinary albumin creatinine ratio that are efficacious in all, but particularly in poorly controlled, diabetic patients.

Left ventricular systolic and diastolic function, remodelling, and clinical outcomes among patients with diabetes following myocardial infarction and the influence of direct renin inhibition with aliskiren

We assessed the relationship between diabetes and cardiac structure and function following myocardial infarction (MI) and whether diabetes influences the effect of direct renin inhibition on change in left ventricular (LV) size. The ASPIRE trial enrolled 820 patients 2-8 weeks after MI with ejection fraction ≤ 45% and randomized them to the direct renin inhibitor aliskiren (n= 423) or placebo (n = 397) added to standard medical therapy. Echocardiography was performed at baseline and after 36 weeks in 672 patients with evaluable paired studies. Compared with non-diabetic patients, diabetic patients (n = 214) were at higher risk for a composite of cardiovascular (CV) death, heart failure hospitalization, recurrent MI, stroke, or aborted sudden death (14 vs. 7%; adjusted hazard ratio 1.63, 95% confidence interval 1.01-2.64, P= 0.045), despite similar left ventricular ejection fraction (37.9 ± 5.3 vs. 37.6 ± 5.2%, P= 0.48) and end-systolic volume (ESV) (84 ± 25 vs. 82 ± 28 mL, P= 0.46). Diabetic patients demonstrated greater concentric remodelling (relative wall thickness 0.38 ± 0.07 vs. 0.36 ± 0.07, P= 0.0002) and evidence of higher LV filling pressure (E/E' 11.1 ± 5.3 vs. 9.1 ± 4.3, P= 0.0011). At 36 weeks, diabetic patients experienced similar per cent reduction in ESV overall (-4.9 ± 17.9 vs. -5.5 ± 16.9, P= 0.67) but tended to experience greater reduction in ESV than non-diabetic patients when treated with aliskiren (interaction P = 0.08). Compared with non-diabetic patients, diabetic patients are at increased risk of CV events post-MI despite no greater LV enlargement or reduction in systolic function. Diabetic patients demonstrate greater concentric remodelling and evidence of higher LV filling pressure, suggesting diastolic dysfunction as a potential mechanism for the higher risk observed among these patients.

Impact of aliskiren treatment on urinary aldosterone levels in patients with type 2 diabetes and nephropathy: an AVOID substudy

Aldosterone blockade reduces albuminuria in diabetic patients with chronic kidney disease (CKD), and improves prognosis in chronic heart failure. This study assessed the effects of direct renin inhibition with aliskiren in combination with losartan and optimal antihypertensive therapy on urinary aldosterone, plasma renin activity (PRA) and plasma renin concentration (PRC). In the AVOID study, 599 patients with type 2 diabetes, hypertension and nephropathy received 6 months aliskiren (150 mg force titrated to 300 mg once daily after 3 months) or placebo added to losartan 100 mg and optimal antihypertensive therapy. Urinary aldosterone excretion, PRA and PRC were measured at baseline and after 24 weeks in a prespecified subset of 133 patients. Aliskiren added to losartan provided reductions from baseline in urinary aldosterone compared with adding placebo (-24% vs. -4%, p = 0.017) at week 24. There was no significant difference between the aliskiren and placebo groups in the proportion of patients with aldosterone breakthrough (aliskiren 35%, placebo 46%, p = 0.199). Aliskiren treatment reduced PRA by 90% at 24 weeks and increased PRC by 328%. Adding aliskiren to recommended renoprotective treatment with losartan and optimal antihypertensive therapy provided significant reductions in urinary aldosterone excretion which may attenuate decline in kidney function.

Comparative effect of direct renin inhibition and AT1R blockade on glomerular filtration barrier injury in the transgenic Ren2 rat

Renin-angiotensin system (RAS) activation contributes to kidney injury through oxidative stress. Renin is the rate-limiting step in angiotensin (ANG II) generation. Recent work suggests renin inhibition improves proteinuria comparable to ANG type 1 receptor (AT1R) blockade (ARB). Thereby, we investigated the relative impact of treatment with a renin inhibitor vs. an ARB on renal oxidative stress and associated glomerular structural and functional changes in the transgenic Ren2 rat, which manifests hypertension, albuminuria, and increased tissue RAS activity. Young Ren2 and age-matched Sprague-Dawley (SD) controls (age 6-9 wk) were treated with a renin inhibitor (aliskiren), an ARB (irbesartan), or vehicle for 21 days. Ren2 rats exhibited increases in systolic pressure (SBP), albuminuria, and renal 3-nitrotyrosine content as well as ultrastructural podocyte foot-process effacement and diminution of the podocyte-specific protein nephrin. Structural and functional alterations were accompanied by increased renal cortical ANG II, AT1R, as well as NADPH oxidase subunit (Nox2) expression compared with SD controls. Abnormalities were attenuated to a similar extent with both aliskiren and irbesartan treatment. Despite the fact the dose of irbesartan used caused a greater reduction in SBP than aliskerin treatment (P < 0.05), the effects on proteinuria, nephrin, and oxidative stress were similar between the two treatments. Our results highlight both the importance of pressor-related reductions on podocyte integrity and albuminuria as well as RAS-mediated oxidant stress largely comparable between ARB and renin inhibition treatment.

Renal and cardio-protective effects of direct renin inhibition: a systematic literature review

Blockade of the renin-angiotensin-aldosterone system (RAAS) at its rate-limiting step by means of renin inhibition has led to the development of direct renin inhibitors (DRIs). Given the renal and cardioprotective effects of RAAS blockade by angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, DRIs may increase the armamentarium for further organ protection. Over the last two decades the effects of DRIs on biomarkers for renal and cardiovascular disease have been investigated. This systematic review aims to delineate the effects of DRIs on surrogate markers of renal and cardiovascular function. MEDLINE and previous systematic reviews were searched for articles reported between 1980 and 2008. A standardized dataset was extracted from articles describing the effects of DRIs on markers of renal and cardiac damage and hard outcomes. Fifty-two articles were included. Blood pressure reductions were generally insufficient using early generation DRIs. However, recent DRIs have greater blood pressure-lowering effects. Preclinical and clinical studies showed profound effects of DRIs on markers of renal function, including clear increases in renal plasma flow and reductions in albuminuria. These effects were observed either alone or in combination with other RAAS inhibitors and suggest potential large renal protective benefit. DRIs improved hemodynamic cardiovascular parameters, such as total peripheral resistance, arterial pressure and left ventricular mass index, to a similar extent as those observed with other RAAS inhibitors. Furthermore, addition of DRIs to optimal heart failure treatment resulted in further reductions in B-type natriuretic peptide. Evidence from preclinical and clinical studies suggests that DRIs may have renal and cardiovascular effects beyond their ability to lower blood pressure. Results of ongoing hard outcome trials are awaited to definitively assess the renal and cardio-protective effects of these agents.

Effect of Direct Renin Inhibition on Renal Hemodynamic Function, Arterial Stiffness, and Endothelial Function in Humans With Uncomplicated Type 1 Diabetes

OBJECTIVEBlockade of the renin-angiotensin system (RAS) plays an important role in preventing end-organ injury associated with diabetes. The recent development of direct renin inhibitors (DRIs) provides a new approach to block the RAS, but the effects of DRIs on renal and systemic vascular function in uncomplicated type 1 diabetes have not been elucidated.RESEARCH DESIGN AND METHODSRenal hemodynamic function (inulin and paraaminohippurate clearance), augmentation index and pulse wave velocity, endothelial dependent vasodilatation (flow-mediated dilation [FMD]), and endothelial independent vasodilatation (response to sublingual nitroglycerin) were evaluated before and after administration of aliskiren (300 mg daily for 30 days) in 10 adult subjects with uncomplicated type 1 diabetes during clamped euglycemia (4–6 mmol/l) and hyperglycemia (9–11 mmol/l).RESULTSIn response to the DRI, plasma renin activity decreased (from 0.40 to 0.13 ng · ml−1 · h−1, P < 0.05) and plasma renin increased (from 5.2 to 75.0 ng/l, P < 0.05). Peripheral and central blood pressures decreased, and effective renal plasma flow and glomerular filtration rate increased during clamped euglycemia and hyperglycemia (P < 0.05). The carotid augmentation index during clamped euglycemia decreased (from 26 ± 6 to 20 ± 5%, P < 0.05) as did pulse wave velocity during clamped hyperglycemia (from 7.8 ± 0.6 to 6.8 ± 0.5 m/s, P < 0.05). In response to the DRI, FMD increased during both clamped euglycemia (from 1.92 ± 1.13 to 5.55 ± 0.81%) and hyperglycemia (from 1.86 ± 0.98 to 5.63 ± 0.62) as did the vasodilatory response to sublingual nitroglycerin.CONCLUSIONSDRIs exert a renal vasodilatory effect and improve parameters of systemic vascular function, suggesting that blockade of the RAS with this new class of agents has important functional effects in subjects with uncomplicated type 1 diabetes.

An Issue of Dependence: Implications From the Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) Trial

The direct renin inhibitor aliskiren is a new antihypertensive agent that appears to be equivalent to other agents in blood pressure reduction. It is well tolerated, has a long half-life, and has a sustained duration of action. At present, aliskiren as monotherapy is not widely used despite these potential benefits. There are many other available options for the treatment of hypertension with demonstrated morbidity and mortality outcomes and economic advantages. The role of aliskiren as part of combination therapy is, however, evolving. Two- or three-drug therapy is necessary for many hypertensive patients, and rational combinations to maximize blood pressure control and influence comorbid conditions should continue to be identified. The characteristics of aliskiren and the broader application of this new class of medications will require further assessment and demonstration of long-term effects, particularly before treatment practices will change. The recently published Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) study evaluated the potential renoprotective effect of direct renin inhibition in patients with hypertension, type 2 diabetes, and proteinuria. Aliskiren, titrated to maximum doses over 6 months, or placebo were added to full-dose angiotensin II receptor blocker (ARB) (losartan) and antihypertensive therapy with other agents in 599 patients. The primary outcome was reduction in the urinary albumin-to-creatinine ratio. 1 Parving and colleagues 1 concluded that aliskiren may

Effect of renin inhibition on an experimental glomerulonephritis - a preliminary report

Purpose : We performed this study in order to investigate the effect of direct renin inhibition on an experimental animal model with nephrotoxic serum nephritis and tried to give useful information for clinical research and renin inhibitor treatment. Methods : Thirty BALB/c 6-week-old male mice were divided into 4 groups: control group (CO, n=5), control-treatment group with aliskiren (CT, n=5), disease group (DO, n=10), and disease treatment group with aliskiren (DT, n=10). Nephritis was induced by an intravenous injection of 0.25 mg/g weight of rabbit anti-GBM immunoglobulin G. Model 2002 Alzet mini-osmotic pumps (Durect Corp.) for aliskiren infusion were implanted into CT and DT. Each group strain was sacrificed serially one at a time on day 14. We estimated the protein-creatinine ratio in 12-hour-collected urine (UP/Cr) and measured the mesangial matrix score in the PAS-stained kidney of each strain. Results : One strain at CT and DT died on day 6 and 7, respectively. Each group strain was sacrificed serially at a time on day 10 because DO were seriously ill. The UP/Cr of each group is as follows: CO, 31.246.54 mg/mg, CT, 23.3813.60 mg/ mg, DO, 112.7210.97 mg/mg, DT 114.0732.30 mg/mg. There was no significant difference between DO and DT. The mesangial matrix score of each group was CO, 0.230.10; CT, 0.130.03; DO, 1.900.48; and DT, 1.280.41, respectively, and there was a significant difference between DO and DT in the extent of mesangial matrix expansion (P=0.008). Conclusion : We found that renin inhibition was able to suppress the mesangial matrix expansion in experimental mice with acute nephritis, although there were no significant differences in UP/Cr.

Time course of the antiproteinuric and antihypertensive effects of direct renin inhibition in type 2 diabetes

Inhibition of renin with an active site inhibitor, aliskiren, lowers blood pressure (BP) in diabetic patients. Here, we studied the time course of the antihypertensive and antiproteinuric effect of renin inhibition in 15 patients with type 2 diabetes and elevated urinary albumin/creatinine ratios (UACRs) to check whether aliskiren can decrease proteinuria. After a 4-week washout of previous medications, patients received aliskiren and furosemide daily for 28 days followed by a 4-week withdrawal period. Twenty-four-hour BPs were measured at baseline throughout treatment and withdrawal periods. The UACR was significantly reduced after 2-4 days of treatment with another significant reduction after 28 days. Systolic blood pressure (SBP) was significantly lower after 7 days with no further reduction after 28 days. The BP returned toward baseline 3 days after withdrawal, whereas the UACR was still significantly reduced compared with baseline 12 days after withdrawal. Our study shows that aliskiren reduced 24 h SBP, and this was associated with a reduction in albuminuria in type 2 diabetic patients.

The Direct Renin inhibitor, Aliskiren Improves Diastolic Dysfunction And Adverse Remodelling in Diabetic Ren-2 Transgenic Rats.

Background: Heart failure is a common cause of morbidity and mortality in diateticpatienRthatfrNuently manifests in the absence of impaired left ventricular systolic function. In contrast to the strong evidence base for the treatment of systolic heart failure with ACE inhibitors and ARBs, their benefit in the treatment of heart failure with preserved left ventricular function (HFPEF) is unclear. In the setting of recent studies demonstrating the effects of direct renin inhibition in human and experimental diabetes, we sought to determine the effectiveness of this strategy in diabetes-induced HFPEF.