Administration of dihydrotestosterone to rhesus monkeys inhibits gonadotropin-stimulated ovarian steroidogenesis.

Abstract

Androgens, in addition to serving as a substrate for estrogen biosynthesis, exert autocrine/paracrine actions on ovarian function. However, much of the information regarding the actions of androgens on the ovary has been obtained using rodents, and the extent to which these results can be extrapolated to higher primates is uncertain. The current study was initiated to determine the effects of dihydrotestosterone (DHT) and testosterone (T) on the responsiveness of the rhesus monkey ovary to exogenous FSH and LH in vivo. Rhesus monkeys whose spontaneous gonadotropin secretion was interrupted with a GnRH antagonist received s. . implants of either DHT or T for 5 d before and continuing throughout a 15-d i.v. infusion of human FSH and LH. Neither T nor DHT treatment synergized with FSH/LH to stimulate estrogen production or increases in ovarian weight. Rather, administration of DHT significantly reduced estrogen secretion and the augmentation of ovarian weight in response to exogenously administered FSH and LH. These results indicate that high concentrations of DHT are antagonistic to gonadotropin-stimulated ovarian function in primates.