Role of prostaglandin F2alpha in modulation of LH-stimulated steroidogenesis in vitro in different types of rat and ewe corpora lutea.

An inhibitory effect of PGF2alpha at a dose of 7 X 10(-7) M on LH stimulated synthesis of progesterone was observed in vitro after incubation of pseudopregnant rat ovaries for a period of 2 hours. A similar effect was seen with cyclic and gestant ewe corpora lutea at the same dose of PGF2alpha. This effect was observed both in the secretion of progesterone and on the amount of progesterone present in the tissue. This inhibitory effect of PGF2alpha on LH stimulated progesterone synthesis may explain the modification in the time course for gonadotropin action in luteal tissue at high and low doses.