The orphan nuclear receptor SF-1 is involved in the effect of PCBs,DDT, and DDE on the secretion of steroid hormones and oxytocin from bovine luteal cells during the estrous cycle in vitro

The orphan receptor steroidogenic factor-1 (SF-1) is involved in the regulation of ovarian steroidogenesis in cows. It is hypothesized that estrogen-like chlorinated compounds might affect SF-1, and thus impair the function of the ovary. Bovine luteal cells from the estrous cycle (Days: 1–5, 6–10, 11–15, and 16–19) were treated for 50 hours with DDT, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene, 3,3′4,4′-tetrachlorobiphenyl or 2′2′4,4′,5,5′-hexachlorobiphenyl (each at a dose of 10 ng/mL). Luteal cells were also treated with 4-(heptyloxy)phenol (1 × 10⁻⁷ M), an SF-1 agonist, and F0160 (1 × 10⁻⁶ M), an SF-1 blocker, jointly or separately. The secretion of progesterone and oxytocin and the expression of oxytocin precursor (NP-I/OT) messenger RNA were increased (P < 0.05) by all studied xenobiotics and 4-(heptyloxy)phenol, although they were inhibited (P < 0.05) by F0160. However, the xenobiotics did not affect (P > 0.05) SF-1 messenger RNA expression. In summary, SF-1 is involved in the adverse effect of chlorinated xenobiotics on the regulation of the bovine CL.