ATRIAL NATRIURETIC FACTOR INHIBITS THE STIMULATION OF ALDOSTERONE SECRETION BY ANGIOTENSIN II, ACTH AND POTASSIUMIN VITROAND ANGIOTENSIN II-INDUCED STEROIDOGENESISIN VIVO.

Abstract

Since atrial natriuretic factor (ANF) blocks the contractile effect of angiotensin II on vascular strips, we investigated the action of the synthetic 48–73 ANF (previously called 8–33 ANF) on another target tissue of angiotensin II, the adrenal glomerulosa. ANF did not affect basal aldosterone output by isolated rat adrenal glomerulosa cells. ANF inhibited aldosterone secretion stimulated by 10^–8M angiotensin II with an IC₅₀ of 1.3 × 10^–9M. Aldosterone secretion stimulated by 2.9 × 10^–10M ACTH and by 15 mM potassium was similarly inhibited by ANF. In vivo, ANF blocked the effect of angiotensin II infused iv on aldosterone secretion in conscious unrestrained rats. We conclude that ANF is a non-selective inhibitor of stimulated aldosterone output.