Steroidogenic Effect of Stimulators of Aldosterone Biosynthesis upon Separate Zones of the Rat Adrenal Cortex*,** Influence of Sodium and Potassium Deficiency

Capsular and decapsulated adrenal glands of rats kept on different diets were separately incubated with and without stimulators of aldosterone biosynthesis. The steroidogenic effect of serotonin, potassium ions and angiotensin II was limited to the capsular portion (zona glomerulosa), whereas ACTH and cyclic AMP acted on both the capsular and the decapsulated portion (zona fasciculata‐reticularis) of the adrenal cortex. In capsular adrenal glands of normal and sodium‐deficient rats all these agents stimulated aldosterone production severalfold and had a smaller effect on corticosterone output. Sodium deficiency led to a decreased response in corticosterone and deoxycorticosterone output. In capsular glands of potassium‐deficient rats the stimulators did not enhance aldosterone production but actsd mainly on deoxycorticosterone output. ACTH enhanced corticosteron e and deoxycorticosterone output to a similar extent in decapsulated glands of all groups of experimental animals. These results indicate a zone specificity of certain stimulators and confirm that they act at an early stage in the corticosteroid biosynthetic pathway preceding the formation of deoxycorticosterone. On the other hand, changes in sodium and potassium balance induce alterations in the activity of the enzymes involved in the conversion of deoxycorticosterone to aldosterone and thus influence the steroidogenic response of the zona glomerulosa to stimulating agents.