INFLUENCE OF THE PITUITARY AND THE RENIN-ANGIOTENSIN SYSTEM ON THE SECRETION OF ALDOSTERONE, CORTISOL, AND CORTICOSTERONE

Abstract

Experiments were per-formed to measure the effects on the rate of aldosterone, corticosterone, and cortisol secretion of (1) hypophysectomy in sodium-deprived dogs and (2) intravenous infusions of crude kidney extracts of renin concentrates, of valine-5 asparaginyl angiotensin II, and commercial ACHT in hypophysectomized, nephrectomized dogs. In conscious, unstressed dogs, hypophysectomy did not change the rate of aldosterone secretion when measured not less than 18 hours later. Crude kidney extracts from hypophysectomized, sodium-deprived dogs stimulated the rate of cortisol and aldosterone secretion and increased the arterial blood pressure; those from Na-loaded dogs were inactive. Angiotensin stimulated aldosterone, corticosterone and cortisol secretion to comparable degrees even from levels produced by ACTH infusion in conscious unstressed dogs. Renin produced comparable changes. As compared to ACTH, angiotensin produces a greater increase in aldosterone for a given increase in cortisol secretion. The results suggest that the aldosterone-stimulating factor in kidney extracts is renin and that the renin-angiotensin stimulates aldosterone, corticosterone, and cortisol to a comparable extent.