Hormonal regulation of prostaglandin F2 alpha receptor gene expression in mouse ovary

In this study we examined regulation by pituitary gonadotropins of the prostaglandin F2 alpha (PGF2 alpha) receptor gene expression in the mouse ovary. Administration of pregnant mare serum gonadotropin (PMSG) to 35-day-old mice in the diestrus phase stimulated the ovary and enhanced the production of progesterone at 1 h PMSG also increased the ovarian PGF2 alpha receptor mRNA level in a time-dependent manner, reaching a sixfold maximum at 1 h. These actions of PMSG were mimicked by human chorionic gonadotropin (hCG), follicle-stimulating hormone (FSH), and cholera toxin, all of which elevate intracellular adenosine 3',5'-cyclic monophosphate (cAMP). In situ hybridization revealed that PGF2 alpha receptor mRNA was localized to the corpus luteum, but the intensity of staining varied among corpora lutea in the same ovary. Exogenous PGF2 alpha inhibited the PMSG-stimulated progesterone production. These results demonstrate that gonadotropins may induce the expression of the PGF2 alpha receptor gene in luteal cells of the corpus luteum, probably by acting through a cAMP-mediated pathway, and that expression of the PGF2 alpha receptor may be functionally associated with the decrease in serum progesterone level.