Effect of Variations of Plasma Sodium Concentration on the Adrenal Response to Angiotensin II

Abstract

The secretion rate of aldosterone was increased by infusion of valine-5-angiotensin II into the adrenal arterial blood supply of sheep. The dimensions of the increase in aldosterone output were inversely related to the control plasma concentration. This high aldosterone secretion was reduced substantially by concurrent adrenal infusion of concentrated NaCl solution which increased plasma sodium concentration by approximately 10 meq/liter. The reduction of aldosterone secretion occurred within 20 minutes. Angiotensin II infusion did not increase the secretion rates of cortisol or corticosterone. The significance of the finding that environmental sodium concentration has different effects on the aldosterone-stimulating action and the pressor action of angiotensin II is discussed.