1979 Volume 75 Issue 1 Pages 1-7
Conversion in vitro of pregnenolone to progesterone by the ovaries from immature rats after treatment of PMS and HCG was inhibited by addition of PGE2 (1.4×10-7M) or PGF2α (1.4×10-7M). Result of conversion in vitro of pregnenolone to progesterone and estradiol-17β by ovary of adult rat in estrus showed that the progesterone biosynthesis in the ovary was inhibited by PGF2α (1.4×10-7M) but the releasing rate of progesterone from the ovary into the medium increased by about 1.25 fold. Progesterone in the medium decreased dramatically following incubation. Estradiol-17β in the ovarian tissue and in the medium did not differ from the control rate with addition of PGF2α. When the effect of PGF2α (1.4×10-7M) in vitro on the conversion of testosterone to estrone and estradiol-17β by the ovary from adult rat in estrus was studied, we found that the releasing rate of estrone from the ovary into the medium was increased by addition of PGF2α; the rate was significantly different from control level after addition of PGF2α 30 min of incubation (p<0.01). Thus a minute amount of PGE2 and PGF2α influences steroid biosynthesis in the rat ovary.