Modification of response to adrenocorticotrophic hormone by the simultaneous administration of gonadotrophic hormones or oestrogen.

Abstract

SUMMARY 1. The urinary excretion of 17-ketosteroids (KS) and 17-ketogenic steroids (KG) has been used as a measure of response to administered adrenocorticotrophic hormone (ACTH). 2. In intact female guinea-pigs the excretion of KG was less when pregnant mares' serum gonadotrophin (PMS) and chorionic gonadotrophin (CG) were administered simultaneously with ACTH, as compared with ACTH alone. The ovaries were essential for this effect. The KS response was not affected by gonadotrophin administration. These observations were reproduced in intact female and ovariectomized guinea-pigs by the administration of oestradiol, but not of progesterone, with ACTH. It is suggested that there is probably a direct inhibition of adrenocortical hormone production by the adrenal glands as a result of treatment with oestrogen, or secretion of oestrogen by ovaries stimulated by administered gonadotrophins. 3. No modification of response to ACTH was obtained by the simultaneous administration of PMS + CG or oestradiol to male guinea-pigs.