The Effect of Angiotensin II on the Blood Pressure in Humans with Hypertensive Disease*

Abstract

The sensitivity to the pressor action of intravenously administered synthetic angiotensin was measured in humans under a variety of experimental and pathological conditions where the levels of endogenous angiotensin were either shown or are presumed to be altered. The studies demonstrate that subjects with presumably low levels of endogenous angiotensin (primary aldosteronism, after saline infusion) are more sensitive to the pressor effect of exgneous angiotensin; subjects with presumably high levels (cirrhosis with ascites, salt depletion) are less sensitive. The changes in sensitivity to angiotensin are greater than to L-norepinephrine. Patients with malignant or renovascular hypertension are less sensitive to the pressor effect of angiotensin than are patients with essential hypertension, hypertension associated with chronic renal parenchymal disease, or primary aldosteronism. This simple procedure may have clinical usefulness in the differential diagnosis of renovascular hypertension.