| Abstract: | Human ovarian teratocarcinoma cells of line PA 1, (Zeuthen et al., 19791]) used as model for early embryonic cells, were analyzed for their in vitro capacity to convert steroids. The cells were incubated for 20 h with radioactive pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone or estradiol-17 beta, or with non-radioactive progesterone, 6 alpha- or 6 beta-hydroxyprogesterone, 3 beta-hydroxy-5 alpha-pregnan-20-one, dehydroepiandrosterone or estradiol-17 beta. The metabolites were analyzed by thin layer chromatography or studied by gas chromatography-mass spectrometry. The results indicate that PA 1 cells are able to metabolize, although to a restricted amount, a variety of steroids, most markedly progesterone. The metabolites were almost exclusively found in the medium. The main metabolite of progesterone was 3 beta, 6 alpha-dihydroxy-5 alpha-pregnan-20-one. Minor formation of progesterone from pregnenolone could be detected. Human chorionic gonadotropin did not have any effect on pregnenolone metabolism. No formation of estradiol-17 beta or estrone from dehydroepiandrosterone, androstenedione or testosterone could be detected. However, estradiol-17 beta was shown to be converted mainly to estrone. These findings indicate that undifferentiated PA 1 teratocarcinoma cells like certain mouse teratocarcinoma cells, seem not to be steroidogenic but are capable of metabolizing naturally occurring steroid hormones and their precursors. |
