Studies On Efiect Of Estrogen On PGE₂ And PGF_2α Secretion And Expression Of PGs Receptors In Bovine Oviduct Epithelial Cells

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 (PGF2a) 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 epithelial cells. Detailed research contents are as follows:1. Analysis of PGs receptor on bovine oviduct epithelial cellsQuantitative real-time PCR assays measured types of PGs receptor, fluorescence method detected effect of PGs on Ca2+ concentration, ELISA detected the concentration of cAMP in cells. The results show, EP1, EP2, EP4, DP, FP and TP exit in bovine oviduct epithelial cells, EP2, EP4, DP were founded of high expression, whereas EP1, FP, TP were founded of low expression.2. Effect of E2 on PGE2 and PGF2a secretionQuantitative real-time PCR assays measured the effect of E2 on PGs synthetase and receptor activity, in cell western blot continue to confirm the result of real-time PCR, and ELISA detected the concentrations of the two PGs in extracellular fluid. We observed that E2 caused cyclooxygenase-2 (COX-2) increase in 2h (P<0.01), which stimulated PGE2 and PGF2α secretion (P<0.05), after 8h COX-2 (P<0.01) decreased and cyclooxygenase-1 (COX-1) (P<0.01) increased which produced a high PGE2:PGF2α ratio. mPGES-1 increase in 4h (P<0.01), then decrease; mPGES-2 and cPGES were not influenced by E2; PGFS increased after 8h (P<0.01); CBR1 increased at 8h (P<0.05); EP2 and EP4 increased in 4 or 48h(P<0.05); FP decreased in 4h (P<0.05), and increased after 48h (P<0.05).3. Effect of PGs on its own secretionQuantitative real-time PCR assays measured effect of PGs receptor agonist butaprost and fluprostenol on PGs synthetase and receptor activity. Result shows, butaprost caused COX-2 increase in 2h (P<0.01), and then decreased; COX-1 increased in 24h (P<0.01); mPGES-1 decreased in 8h (P<0.01); mPGES-2 and cPGES were not influenced by butaprost; PGFS increased in 4h (P<0.01); CBRl were not influenced by butaprost; EP2 and EP4 increased in 2 or 48h(P<0.05); FP increased in 8 or 48h(P<0.05),Fluprostenol caused COX-2 increase in 4h (P<0.01), and then decreased; COX-1 were not influenced by fluprostenol; mPGES-1 decreased in 8h (P<0.01); mPGES-2 and cPGES were not influenced by fluprostenol; PGFS increased in 4h (P<0.01); CBR1 were not influenced by fluprostenol; EP2 decreased in 16h (P<0.01); EP4 decreased in 8h (P<0.05); FP decreased in 2h (P<0.01), and increased in 8h (P<0.05).Conclusions:1. EP1, EP2, EP4, DP, FP and TP are exited in bovine oviduct epithelial cells, which mediate the bovine oviduct epithelial cells function.2. E2 caused a short-term increase of PGE2 and PGF2α, and a subsequent high PGE2:PGF2a ratio.3. E2 caused increase of EP2、EP4 and FP.4. PGE2 and PGF2α have a positive feedback regulation mode.