Renal Tubular Effect of Val5-ngiotensin II Amide in Rats

Abstract

Summary In unanesthetized restrained male rats infused with 0.15 M NaCl solution at 0.8–1.0 ml kg · min, infusions of angiotengin had a strong diuretic and natriuretic effect. The log dose-response relation was linear for doses of angiotensin from 0.008–0.2 μg/kg · min. The diuretic potency of angiotensin per Mol was approximately 17,000–35,000 times greater than that of hydrochlorothiazide. GFR (C₁₈) did not increase with angiotensin diuresis. Tubular rejection fractions for sodium ions and for water were increased to the same extent by angiotensin. Subpressor doses of angiotensin II also were diuretic. Both diuretic and pressor effects tended to decrease after 1–1 1/2 hours though the infusion was continued. There was a large decrease in C_PAH during angiotensin diuresis which may reflect a depression of PAH secretion and/or a decrease in renal blood flow.