Hypothalamic and pituitary regulation of adrenocortical function in the hamster: effects of gonadectomy and gonadal hormone replacement.

Abstract

Prepuberal gonadectomy in the hamster resulted in greater pituitary content of ACTH in adult castrates than in intact controls. Testosterone or estradiol replacement did not restore pituitary ACTH content to intact levels. Daily administration of ACTH for 2 weeks resulted in adrenal enlargement in all groups, abolished or reversed the diminutions in adrenal weight, plasma steroids, and adrenal slice steroid output observed after orchiectomy, and abolished the diminution in adrenal weight observed after ovariectomy. Pituitary content of ACTH was markedly diminished after ACTH injections in intact males and females in comparison with saline-injected controls. Pituitary release of ACTH in vitro was similarly reduced in ACTHtreated males. Testosterone replacement stimulated adrenal weight and hepatic metabolism of the side-chain of cortisol in vitro in hypophysectomized, castrated males but failed to alter adrenal slice steroid output or hepatic metabolism of ring A. Estradiol had no effect on adrenal weight,...