Renal Response to l-Arginine in Salt-Sensitive Patients With Essential Hypertension

Abstract This study examined whether disturbances in nitric oxide formation contribute to renal dysfunction in salt-sensitive essential hypertensive patients. We evaluated the effects of intravenous administration of l-arginine (500 mg/kg given over 30 minutes) on systemic and renal hemodynamics in 23 patients with mild essential hypertension during 1 week of a low NaCl diet (50 mmol/d) followed by 1 week of a high NaCl diet (340 mmol/d). Patients were classified as salt sensitive (n=10) or salt resistant (n=13) based on salt-induced changes in their blood pressures. Salt loading increased renal vascular resistance but not renal plasma flow in salt-sensitive patients. The l-arginine–induced renovascular relaxation was significantly reduced by a high NaCl diet (renal vascular resistance: low NaCl −12.4±2.3% versus high NaCl −7.1±1.8%, P P