Effects Of Estradiol On The Synthesis Of PGE₂ And PGF_2α And Expression Of Their Receptor In Bovine Oviduct Smooth Muscle

Prostaglandins (PGs) are local hormones performing a wide range of functions in mammals, they are mediating the main process of reproduction, including:ovulation, implantation, parturition, and luteolysis, prostaglandins E2 (PGE2) and prostaglandins F2a (PGF2α) are abundant in the bovine oviduct, which have important meaning in oviduct contents transport, sperm and ovum combination, and development of primary embryo. In this study, we investigate the time effect relationship of estrogen (E2) on PGE2 and PGF2a secretion in bovine oviduct smooth muscle. Detailed research contents are as follows:1. Regulation of PGE2 and PGF2a synthetase in the bovine oviductal smooth muscleBovine oviductal smooth muscle was cultured in vivo,messenger RNA expression of PGE2 and PGF2a synthetase was investigated using real-time RT-PCR. Protein expression was investigated using Western blot analysis. The results indicated that the mRNA and protein expression levels of COX-1,COX-2,mPGES-1 and PGFS in bovine oviductal smooth muscle tissue were increased by estradiol in a concentration-and time-dependent manner. The mRNA and protein expression levels of mPGES-2 and cPGES were not increased by estradiol. The mRNA and protein expression levels of COX-1,COX-2,mPGES-1 and PGFS were decreased by fulvestrant and tamoxifen (selective antagonists of E2 receptor) compared to treated with estradiol.2. Regulation of PGE2 and PGF2α receptors in bovine oviductal smooth muscleBovine oviductal smooth muscle was cultured in vivo,messenger RNA expression of PGE2 and PGF2α, receptors was investigated using real-time RT-PCR. Protein expression was investigated using Western blot analysis. The results indicated that the mRNA and protein expression levels of EP2,EP4 and FP receptor in bovine oviductal smooth muscle tissue were increased by estradiol in a concentration-and time-dependent manner. The mRNA and protein expression levels of EP2, EP4 and FP receptor were decreased by fulvestrant and tamoxifen (selective antagonists of E2 receptor) compared to treated with estradiol.3. Regulation of the contraction on bovine oviductal smooth muscleTo evaluate cultured smooth muscle tissue contraction or relaxation, the peristalsis of oviduct smooth muscle tissue was tested by to determine its contractile activity of the smooth muscle. The results indicated that the relaxation by PGE2 and contraction by PGF2a were more sensitive by estradiol.Conclusions:1. The mRNA and protein expression levels of COX-1,COX-2,mPGES-1 and PGFS in bovine oviductal smooth muscle tissue were increased by estradiol in a concentration-and time-dependent manner.2. EP2,EP4 and FP receptor are exited in bovine oviductal smooth muscle.Estradiol up-regulated the mRNA and protein expression levels of EP2.EP4 and FP receptor in the oviductal smooth muscle of bovines in a specific manner.3. The relaxation by PGE2 and contraction by PGF2a were more sensitive by estradiol.