Influence of adenosine 3',5'-monophosphate on corticoid production by rat adrenal glands.

It has been shown that adrenocorticotropic hormone will increase the phosphorylase activity of beef adrenal cortical slices in vitro (1). On the basis of this and other observations the hypothesis was proposed that the ACTHl effect on corticoid biosynthesis is mediated by the increased levels of TPNH which result from dehydrogenation of glucose 6-phosphate arising at an accelerated rate from glycogen. TPNH is known to be involved in several steps of steroid biosynthesis (2-4) and to give rise to large increases in corticosteroids in rat adrenal glands in vitro (5). The findings of Sutherland and Rall (6) that the effects of glucagon and epinephrine on hepatic phosphorylase are mediated via 3’) 5’-AMP led to a further study where it was found (7) that additions of 3’) 5’-AMP to adrenal cortical tissue brought about an activation of adrenal phosphorylase. In addition, evidence was presented which showed that ACTH elicits an accumulation of 3’,5’-AMP in adrenal tissue. Thus, these findings are in harmony with the concept that 3’, 5’-AMP serves as an intermediate agent in the ACTH-induced stimulation of phosphorylase. These findings indicated that 3’, 5’-AMP should have the same effect as ACTH in stimulating the production of steroid hormones by the adrenal cortex. The data reported here show that rat adrenal sections which respond to ACTH will also respond to 3’, 5’-AMP with an increase in corticoid output.