title: In vitro effects of estradiol, testosterone or progesterone on luteal steroidogenesis in the pregnant rat.
abstract: In order to assess the direct luteotropic effects of steroids, dispersed luteal cells from rats on day 8 or 16 of pregnancy were incubated for 2 h with various concentrations of estradiol (1-1000 ng/ml), testosterone (1-100 ng/ml) or progesterone (1-100 ng/ml). Estradiol, at any concentration, did not cause significant changes in the in vitro accumulation of progesterone, 20 alpha-dihydroprogesterone (20 alpha-OHP) or testosterone by dispersed luteal cells on both days 8 and 16. Addition of testosterone (1-100 ng/ml) increased the accumulation of estradiol on day 8 with estrone synthesized at half to one third the rate of estradiol. On day 16, accumulation of estradiol by dispersed luteal cells was more sensitive to 1 ng/ml testosterone than on day 8 with a concomitant drop in estrone synthesis. Although luteal secretion of estradiol was readily stimulated by testosterone, there were no corresponding changes in the production of progesterone or 20 alpha-OHP. Although the addition of a small amount of progesterone did not cause the anticipated increase in accumulation of 20 alpha-OHP, 100 ng/ml progesterone elicited a slight but significant increase in accumulation of 20 alpha-OHP on day 8. Thus, none of 3 steroids added was found to exert any direct in vitro luteotropic action in the pregnant rat, in acute experiments.
mesh_terms: D000818:Animals; D003338:Corpus Luteum / Q000187:drug effects* / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology*; D004970:Estrone / Q000378:metabolism; D005260:Female; D006908:Hydroxyprogesterones / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D013739:Testosterone / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D006908:Hydroxyprogesterones; D004970:Estrone; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol