Abstract
The secretion of androgens by the adrenal cortex was studied in intact, castrated and hypophysectomized dogs. The secretory activity was determined by measuring total 17-oxosteroids in adrenal venous blood. Under sodium pentobarbital anesthesia, a, marked increase in the secretion of adrenal 17-oxosteroids was induced in intact and castrated dogs by an intravenous injection of adrenocorticotrophin (ACTH, 2iu/kg), the increase being sustained over a 2-hour period of observation. The secretory response to ACTH in castrated dogs seemed to be somewhat larger than that in intact ones. An intravenous injection of human chorionic gonadotrophin (HCG, 20iu/kg) to intact dogs failed to elicite notable secretion of the adrenal 17-oxosteroids. In other experiments, a treatment with methylenedianiline (15mg or 30mg/kg), an inhibitor of steroidogenesis. after injection of ACTH produced aa rapid diminution in adrenal 17-oxosteroid secretion in response to ACTH, the inhibition being observed within 15 minutes after the treatment. Furthermore, an intravenous injection of ACTH (2iu/kg) after pre-treatment with methylenedianiline (30mg/kg) to intact dogs failed to produce the increase of secretion. It is thus suggested that ACTH primarily produces an increase in secretion of the adrenal 17-oxosteroids and this effect is inhibited by a treatment with inethylenedianiline.
