Direct inhibitory effects of natural and synthetic oestrogens on testosterone release from human testicular tissue in vitro.

Human testicular slices were incubated in vitro in order to examine the direct effects of natural and synthetic oestrogens on testosterone secretion. In the presence of human chorionic gonadotrophin (10 IU per ml), oestradiol-17 beta (1 or 10 micrograms per ml) and ethinyl oestradiol (0.1, 1 or 10 micrograms per ml) inhibited testosterone release into the media in a dose dependent manner. The addition of estramustine phosphate, estromustine, diethylstilboestrol or diethylstilboestrol diphosphate in comparable concentrations produced no significant effects on testosterone release.