EFFECT OF PREGNANT MARE SERUM GONADOTROPIN AND ESTRADIOL ON THE FORMATION OF 13, 14-DIHYDROPROSTAGLANDIN F_2α IN RAT OVARY

Abstract

Effects of pregnant mare serum gonadotropin (PMS) and estradiol on the formation of 13, 14-dihydroprostaglandin F_2α (13, 14H₂-PGF_2α) from prostaglandin F_2α (PGF_2α) and 13, 14-dihydro-15-ketoprostaglandin F_2α (15KD-PGF_2α) in the ovarian homogenate of rats were examined. PMS and estradiol were given to the rats (s.c.) on the first day of diestrus, and the ovaries were removed 24 hours after treatment with each hormone. PMS stimulated the formation of 13, 14H₂-PGF_2α from PGF_2α and 15KD-PGF_2α, and estradiol markedly inhibited the formation of 13, 14H₂-PGF_2α from PGF_2α and 15KD-PGF_2α. However, the formation of 15KD-PGF_2α from PGF_2α did not change with PMS and estradiol. These results indicate that 13, 14H₂-PGF_2α formed in rat ovary may play some important role in ovarian function and may be regulated by gonadotropins and ovarian steroids.