Changes in the mRNA expression of structural proteins, hormone synthesis and secretion from bovine placentome sections after DDT and DDE treatment

Disorders in the barrier function and secretory activity of the placenta can be caused by xenobiotics (XB) present in the environment and their accumulation in tissues of living organisms. Thus, the aim of this study was to investigate the effect of 1,1,1-trichloro-2,2,-bis-4-chlorophenyl-ethane (DDT) and its metabolite 1,1-dichloro-2,2-bis-4-chlorophenyl-ethene (DDE) (for 24 or 48 h) at doses of 1, 10 or 100 ng/ml on the function of cow placentome sections in the second trimester of pregnancy. DDT and DDE affected neither (P > 0.05) the viability nor hypoxia inducible factor 1 (HIF1α) mRNA expression of the sections. XB decreased (P < 0.05) connexin (Cx) 26, 32, 43 and placenta-specific 1 (PLAC-1) mRNA expression but did not affect (P > 0.05) keratin 8 (KRT8) mRNA expression. DDT and DDE also reduced (P < 0.05) prostaglandin F2α (PGF2α) synthase (PGFS) mRNA expression, while DDT increased (P < 0.05) prostaglandin E2 (PGE2) synthase (PGES) mRNA expression. Neither cyclooxygenase 2 (COX-2) mRNA expression nor PGF2α and PGE2 secretion were affected. Both DDT and DDE increased (P < 0.05) neurophysin I/oxytocin (NP1/OT) mRNA expression and oxytocin (OT), oestradiol (E2) and progesterone (P4) secretion while DDT stimulated only 3β-hydroxysteroid dehydrogenase (3βHSD) and cholesterol side-chain cleavage enzyme (CYP11A1) mRNA expression (P < 0.05). In summary, DDT and DDE impaired the barrier function and secretory activity of the placenta. Thus, these compounds can disrupt trophoblast invasion, myometrium contractility and gas/nutrient exchange throughout pregnancy in cows.