Steroid conversions by the 19-day old foetal rat ovary in organ culture.

The ovaries from 19-day old foetal rats were cultured in vitro on Wolff and Haffen's semi-solid medium with radioactive progesterone, dehydroepiandrosterone, testosterone or androstenedione added as precursors, and in the presence or absence of lutropin, follitropin and human chorion gonadotropin. After a 24-h culture period, the media were analysed for the presence of testosterone, androstenedione, oestrone and oestradiol, which were measured by specific activity determination after isotopic dilution.