[Feminization of embryonic chicken testicle by diethylstilbestrol and antagonistic action of tamoxifen].

The question was asked whether the feminization of the chick embryo testis by diethylstilboestrol involves oestrogen secretion. The left gonads of male embryos treated with diethylstilboestrol at the stage of 5 days of incubation were removed at the stage of 17 days and cultured in vitro in the presence of radiolabelled androstenedione, dehydroepiandrosterone, progesterone or sodium acetate. Radiochromatography and repeated crystallizations to constant specific activity were used to demonstrate the formation of oestrone and oestradiol. The results show that oestrogen synthesis takes place from any of the 4 precursors. The normal testis does not produce oestrogens or produces them only in small amounts. Thus, it can be concluded that diethylstilboestrol induces oestrogen synthesis in the chick embryo testis. In a second part of the work, it is shown that tamoxifen antagonizes the feminizing action of diethylstilboestrol on the testes, both at the morphological and biochemical levels.