The influence of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolite—dichlorodiphenyldichloroethylene (DDE) on mRNA expression for NP-I/OT and PGA, involved in oxytocin synthesis in bovine granulosa and luteal cells

The effect of polychlorinated biphenyls (PCBs) congeners (PCB 77, PCB 126, PCB 153) and their technical mixture—Aroclor (Ar) 1248, as well as dichlorodiphenyltrichloroethane (DDT) and its metabolite—dichlorodiphenyldichloroethylene (DDE; two individual isomers p,p′- and o,p′- or their mixture, 95% and 5%, respectively) at the dose of 10 ng/ml each, on the gene expression of (a) oxytocin (OT) precursor—neurophysin–oxytocin (NP-I/OT) and (b) peptidyl glycine-α-amidating mono-oxygenase (PGA), the terminal enzyme in the pathway of OT synthesis, was studied. Granulosa cells from follicles >1 cm in diameter, collected on days 19–21 of estrous cycle, and luteal cells from corpora lutea (CL) collected on days 8–12 of the estrous cycle were used. The cells were incubated (6 h) with these xenobiotics and the expression of NP-I/OT and PGA genes was determined. All PCBs increased (P < 0.05) NP-I/OT gene expression in granulosa cells. Similarly, all PCBs but PCB 126 increased (P < 0.05) PGA gene expression in these cells. DDT and DDE increased (P < 0.05) gene expression of NP-I/OT in granulosa cells, while gene expression of PGA in these cells was stimulated (P < 0.05) by DDE only. The mRNA expression for NP-I/OT and PGA in luteal cells was increased (P < 0.05) by PCB 77 and PCB 153. Both DDE isomers and mixture also stimulated (P < 0.05) of NP-I/OT mRNA expression, while increase (P < 0.05) of PGA mRNA expression was elicited by incubation of these cells with DDE mixture and Ar 1248.Obtained data suggest that PCBs, DDT and DDE can affect the mRNA expression for NP-I/OT and PGA in bovine granulosa and luteal cells.