FURTHER OBSERVATIONS ON THE FUNCTIONAL ZONATION OF THE ADRENAL CORTEX

Abstract

In the isolated zona glomerulosa of beef adrenal cortex, progesterone, 11β-hydroxyprogesterone, 11-desoxycorticosterone, and corticosterone are precursors of aldosterone. 18-Hydroxylation is probably a rate-limiting step in the biosynthesis of aldosterone. At low concentration Metopirone selectively inhibits 18-hydroxylase activity. The sequence of hydroxylation of the steroid molecule proceeds effectively in the order 11, 17, 21. The main action of ACTH is to increase cortisol production by the fasciculate–reticularis. In the present in vitro system, the production of aldosterone by the glomerulosa is not affected by either ACTH or angiotensin.