Gonadal influences on the pituitary-adrenal axis

Abstract

Quartered adrenals from male and female rats produce the same quantity of corticoids when incubated for 2 hr. Castration reduces steroid production sharply and equally in the two sexes. Addition to the adrenals of fluid in which pituitary glands have been incubated causes a 37% greater production of steroids by male than by female adrenals; castration depresses this response in both sexes but much more so in the male adrenals so that the sex difference is no longer apparent. ACTH produces almost identical results, and castration again abolishes the sex difference. 3′,5′-AMP increases the steroid output from adrenals of both sexes; the increase is 31% greater in the male than in the female adrenal. Addition of G-6-P plus TPN increases steroid output and, unlike the situation with pituitary, ACTH, and 3′, 5′-AMP stimulation, there is either no sex difference or a female preponderance, depending on the concentration of the reactants. Castration of the male rat produces a slight increase in adrenal response to G-6-P plus TPN, but adrenal sensitivity to these compounds is not changed by castration of the female. Pretreatment of female rats with testosterone does not modify adrenal steroid production in the presence or absence of pituitary stimulation. Adrenals from estradiol-pretreated males exhibit a profound decrease in steroid production under both conditions.