Valsartan and retinal endothelial function in elderly hypertensive patients.

Background: The aim of this study was to investigate the impact of short-term treatment with the angiotensin II receptor blocker (ARB) valsartan on retinal endothelial function in elderly patients with mild to moderate essential hypertension.

Methods: In an open-labeled study, 20 elderly, male patients with arterial hypertension (WHO I-II) were treated with the ARB valsartan (80-160 mg once daily) over 8 days. Central retinal artery perfusion at rest and during flicker light stimulation was measured before and after treatment using pulsed wave Doppler sonography.

Effects of nitric oxide synthase inhibition and L-arginine on renal haemodynamics in young patients at high cardiovascular risk.

Background: Aging and a variety of cardiovascular risk factors are associated with oxidative stress and impaired endothelial function. Whether such an association is already evident in the renal vascular bed in young patients at high cardiovascular risk has not yet been determined.

Methods: We compared renal haemodynamics in 23 young (age 30+/-5 years) male patients at high cardiovascular risk with impaired lipid metabolism and elevated blood pressure with 23 matched, healthy control subjects (age 28+/-3 years) without cardiovascular risk factors at baseline and following infusions of the nitric oxide (NO) synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA: 4.

Effect of nos inhibition on retinal arterial and capillary circulation in early arterial hypertension.

Background: Arterial hypertension is involved in the pathogenesis of end organ damage by influencing the ability of the vascular endothelium to produce nitric oxide (NO). This study analyzes changes of retinal and systemic NO-dependent circulation parameters by inhibiting nitric oxide synthase (NOS) in both hypertensive and normotensive individuals.

Methods: In a double-blind crossover trial, 19 hypertensive patients (H, age 28.

Superoxide scavenging effects of N-acetylcysteine and vitamin C in subjects with essential hypertension.

Background: It is not known whether the beneficial effects of N-acetylcysteine (NAC) in conditions associated with increased oxidative stress are caused by direct superoxide scavenging. We therefore compared the acute superoxide scavenging efficacy of NAC against vitamin C (VITC) on impaired endothelium-dependent vasodilation in subjects with essential hypertension.

Methods: In a cross-over randomized study, the effects of intra-arterial administration of either NAC (48 mg/min) or VITC (18 mg/min) were examined in 15 subjects with essential hypertension and in 15 normotensive control subjects.

Increased response of renal perfusion to the antioxidant vitamin C in type 2 diabetes.

Background: Reactive oxygen species play a major role in the development of endothelial dysfunction. It is as yet unspecified whether increased oxidative stress contributes to endothelial dysfunction of the renal vasculature in patients with type 2 diabetes.

Methods: Renal haemodynamics were studied in 20 patients with type 2 diabetes and arterial hypertension (age 62 +/- 5 years) and 20 non-diabetic hypertensive patients at baseline and following infusions of the nitric oxide synthase inhibitor, N(G)-monomethyl-L-arginine (L-NMMA; 4.

Impaired endothelial function of the retinal vasculature in hypertensive patients.

Background And Purpose: Arterial hypertension constitutes a central factor in the pathogenesis of stroke. We examined endothelial function of the retinal vasculature as a model of the cerebral circulation.

Methods: Thirty-eight young subjects (19 hypertensive and 19 normotensive) were treated with the AT1-receptor blocker candesartan cilexetil and placebo, each over 7 days.

Rapid nongenomic effects of aldosterone on human forearm vasculature.

The impact of aldosterone in cardiovascular disease and hypertension has recently gained new interest. Aldosterone is now suggested to be a more common cause of hypertension than previously believed and has been linked to myocardial fibrosis, independent of its hypertensive effects. Finally, rapid nongenomic aldosterone effects have been proposed to be important in hypertension, in addition to its genomic effects.

L-arginine-induced vasodilation of the renal vasculature is not altered in hypertensive patients with type 2 diabetes.

Objective: Diabetes, arterial hypertension, hypercholesterolemia, and aging are associated with endothelial dysfunction in various vasculatures. Endothelium-dependent vasodilation of the renal vasculature cannot be easily assessed, but infusion of L-arginine, the substrate of endothelial nitric oxide synthase, leads to an increase in renal plasma flow (RPF) in humans. We have examined the effect of L-arginine infusion on renal hemodynamics in hypertensive patients with type 2 diabetes.

The C242T p22phox polymorphism and endothelium-dependent vasodilation in subjects with hypercholesterolaemia.

Oxidative stress plays a major pathogenetic role in cardiovascular disease. The C242T variant of the CYBA gene encoding the p22phox subunit of the NAD(P)H oxidase, a major source of superoxide production, has been shown to be associated with coronary artery disease and with vascular superoxide production in human veins ex vivo. Since superoxide degrades nitric oxide (NO), we hypothesized that the C242T variant influences endothelium-dependent vasodilation of the human forearm vasculature in vivo.

Functional relevance of aldosterone for the determination of left ventricular mass.

In experimental studies, the importance of aldosterone for the development of left ventricular (LV) hypertrophy has been demonstrated. In 120 healthy Caucasian men (aged 25 +/- 3 years; blood pressure, 134 +/- 15/86 +/- 12 mm Hg), we determined LV mass (2-dimensionally guided M-mode echocardiography), urinary aldosterone concentration, and the response of aldosterone to angiotensin II infusion (3.0 ng/kg/min).

Hypercholesterolaemia and treatment with statins do not alter L-arginine-induced changes of renal haemodynamics.

Background: Hypercholesterolaemia has been found to impair endothelial function in the systemic and coronary circulations and lipid-lowering therapy with statins has been shown to improve this abnormality.

Methods: We examined the impact of hypercholesterolaemia on L-arginine-induced renal vascular relaxation by a cross-sectional study, and the effects of lipid-lowering therapy by a double-blind, randomized, placebo-controlled study. Using constant infusion input clearance technique (PAH and inulin respectively), changes of renal plasma flow (RPF) and glomerular filtration rate (GFR) in response to intravenous infusions of L-arginine (100 mg/kg/30 min and 500 mg/kg/30 min) were studied in 21 hypercholesterolaemic humans (age 57+/-9 years, LDL-cholesterol 211+/-35 mg/dl) and in 20 young healthy (age 26+/-2 years, LDL-cholesterol 90+/-27 mg/dl) and 20 older healthy age-matched control individuals (age 50+/-8 years, LDL-cholesterol 106+/-20 mg/dl).