Aging and Severity of Hypertension Attenuate Endothelium-Dependent Renal Vascular Relaxation in Humans

Endothelial dysfunction may be related to cardiovascular risk factors, such as aging, hypertension, and atherosclerosis. We investigated whether aging and hypertension independently alter endothelial function in the renal circulation in humans in the absence of abnormalities in lipid and glucose metabolism. L-Arginine (500 mg/kg over 30 minutes) was intravenously administered to 33 patients with essential hypertension and 35 normotensive subjects. The L-arginine-induced increases in renal plasma flow (10.1 +/- 0.8% versus 15.8 +/- 0.9%, P