In vivo effects of angiotensin antagonists on plasma aldosterone in the dog.

Abstract The effects of infusions of equimolar doses of Sar 1 -Ile 8 -angiotensin II and of Sar 1 -Ala 8 -angiotensin II on plasma aldosterone, plasma renin activity and arterial blood pressure were compared in normal dogs. Plasma aldosterone increased significantly after Sar 1 -Ile 8 -angiotensin II whereas it was unaffected by Sar 1 -Ala 8 -angiotensin II. Changes in blood pressure and renin activity were small without marked differences between both groups of animals. The experiments demonstrate a clear steriodogenic potency of Sar 1 -Ile 8 -angiotensin II. Therefore, Sar 1 -Ala 8 -angiotensin II should be preferred as antagonist of the action of angiotensin II in the adrenal gland.