Hormonal regulation of prostaglandin f 2 [alpha] receptor gene expression in mouse ovary . Sugatani, Junko, Yasuo Masu, Mikio Nishizawa, Kazuichi Sakamoto_, Takeshi Houtani, Tetsuo Sugimoto, and Seiji Ito. Departments of Medical Chemistry and Anatomy, Kansai Medical University, 10-15 Fumizonocho, Moriguchi, Osaka 570, Japan and Department of Cell Biology, Osaka Bioscience Institute, Suita 565, Japan
APStracts 3:0119E, 1996.
In this study we examined regulation by pituitary gonadotropins of the prostaglandin F2[alpha] (PGF2[alpha]) receptor gene expression in 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 6-fold 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 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 the expression of the PGF2[alpha] receptor may be functionally associated with the decrease in serum progesterone level.

Received 6 January 1996; accepted in final form 5 June 1996.
APS Manuscript Number E7-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96