Influence of polychlorinated biphenyls (PCBs) and phytoestrogens on prostaglandin F2α and E2secretion from bovine endometrial cells at a postovulatory stage of the estrous cycle

Polychlorinated biphenyls (PCBs) and phytoestrogens were found to affect contractions of bovine uterus. Prostaglandins (PG) F2á and E2 are also involved in the uterine contractility. Hence the aim of these studies was to investigate the effect of PCBs and some phytoestrogens on PG secretion from endometrial cells obtained on days 1-5 of the oestrous cycle. Cells were incubated in aerated atmosphere at 38°C for 24 h, separately with the mixture of PCBs - Aroclor 1248 (10 ng/ml), with individual congeners -77, -126 or -153 (each at the dose 100 g/ml), coumestrol, daidzein or genistein (each at the dose 10-6M) or jointly each PCB with each of the phytoestrogens. Using the TOX1-kit neither Aroclor 1248 (Ar 1248) nor individual congeners were found to affect the viability of cells compared to the control (P > 0.05). All used PCBs markedly increased the metabolite of PGF2á(PGFM) concentrations (P < 0.05) but not PGE2 (P > 0.05). Hence the ratio of PGF2á to PGE2 was also increased by PCBs. However, when these cells were incubated with each of the phytoestrogens, there was a decrease in both PGF2á and PGE2 secretion compared to the control (P < 0.05) but without altering the PGF2á : PGE2 ratio. Moreover, phytoestrogens could clearly reduce the concentrations of PGFM elicited by PCBs, and they reduced PGE2 secretion compared to that evoked by PCB-126 and -153 only. Thus phytoestrogens can restore the proper ratio of PGF2á : PGE2 secreted by the bovine endometrium.