ANGIOTENSIN INFUSION TEST AND PERIPHERAL VENOUS RENIN ACTIVITY

Abstract

Forty hypertensive patients were studied to examine the assumption that the angiotensin pressor dose reflects endogenous renin activity. Peripheral renin activity was assayed by the method of Boucher et al. Sensitivity to the infusion of synthetic angiotensin n was determined as suggested by Kaplan and Silah. Sixteen patients with essential hypertension with normal renal angiography required 3.8 ng. angiotensin/kg./min. to raise the diastolic pressure 20 mm. Hg. All but 1 were sensitive to angiotensin infusion of less than 5 ng./kg./min. Renin activity was normal in all except in 1 sensitive subject. Angiotensin infusion response and mean renin activity in 13 patients with essential hypertension with abnormal renal angiography were similar to that of the 1st group. The pressor dose in 11 renovascular hypertensives was 9.8 ng./kg^nin. All but 3 had elevated plasma renin activity. Our results suggest that: the angiotensin infusion test is suitable for differentiating patients with true renovascular hypertension from those with essential hypertension with or without associated renal artery disease; the angiotensin pressor dose correlates with the level of peripheral venous renin activity (p<0.01).