Influence of polychlorinated biphenyls on the secretion of oxytocin from bovine luteal cells and from granulosa cells obtained from the follicles of different size.
Effect of polychlorinated biphenyles (PCBs) on viability and secretory function of luteal and granulosa cells from mature cows was studied. Luteal cells from corpora lutea of different developmental stages and granulosa cells from follicles of >1 cm< in diameter were used. Neither individual congeners (PCB-126, -77, -153) nor mixture of PCBs Aroclor Ar) 1248 at the dose of 1, 10 or 100 ng/ml affected the viability of cells (P>0.05) compared to control after 72 h of incubation. PCBs markedly increased (P<0.05-0.001) oxytocin (OT) secretion from granulosa cells. This effect was the most evident when granulosa cells from follicles <1 cm diameter was treated with PCB-77 which is assumed to stimulate both arylhydrocarbon receptor (AhR) and estradiol (E2) receptor. Even the lowest dose of this compound (1 ng/ml) outranged the effect produced by cortisol (10(-5)M) used as positive control. There was marked effect (P<0.05-0.001) of PCBs on luteal cells from days 6-15 of the estrous cycle. However, influence of PCBs on OT secretion from luteal cells on day 1-5 and 16-18 of the estrous cycle was less evident. Again, PCB-77 was the most efficient stimulator of OT secretion. While the lowest effect was found after treatment of cells with PCB-126 which has dioxin-like properties. It can be assumed that diverse effect of PCBs on female reproduction largely results from the influence of these compounds on ovarian OT secretion. Since both synthesis and secretion of ovarian OT in bovine do not markedly depend on estradiol, some alternative cellular pathways of PCBs on ovary function are suggested.
Młynarczuk
J
J
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima, Poland.
Kotwica
J
J
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism; D008184:Luteal Cells / Q000187:drug effects* / Q000378:metabolism; D010121:Oxytocin / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000494:pharmacology*
D010121:Oxytocin; D011078:Polychlorinated Biphenyls