Effects of bisphenol A, diethylhexyl phthalate and pentabrominated diphenyl ether 99 on steroid synthesis in cultured bovine luteal cells

Bisphenol A (BPA), diethylhexyl phthalate (DEHP) and pentabrominated diphenyl ether 99 (PBDE 99) are environmental toxicants belonging to the endocrine disrupting compounds (EDCs). They exert adverse effects on the various physiological systems, especially the reproductive system of humans and animals. The aim of this study was to investigate the effects of BPA, DEHP and PBDE 99 on progesterone (P4) synthesis in cultured bovine luteal cells. The bovine luteal cells isolated from the mid-luteal corpora lutea were exposed to different concentrations of BPA (1, 3, 10 and 30 mu M), DEHP (1, 3, 10 and 30 mu M) and PBDE 99 (0.1, 0.3, 1 and 3 mu M) in a serum-free culture media for 48 and 96 hr. At 48 hr, the P4 level in the luteal cells decreased after treatment with all concentrations of BPA; 3, 10 and 30 mu M of DEHP; and 3 mu M of PBDE 99 compared to the control (p < .05). Treatment of cells with 3-30 mu M of BPA, 1-30 mu M of DEHP and 1-3 mu M of PBDE 99 for 96 hr resulted in reduction in P4 synthesis (p < .05). However, lower concentrations of PBDE 99 (0.1 and 0.3 mu M) increased P4 levels at 48 and 96 hr. Synthesis of P4 was lower at 96 hr compared to the 48 hr in the groups treated with BPA (30 mu M), DEHP (1-30 mu M), PBDE 99 (0.3-3 mu M) and control group. Our results showed that BPA, DEHP and PBDE 99 are able to alter luteal steroidogenesis in bovine cells and can disrupt hormonal balance in the ovary. However, it is necessary to evaluate the exact mechanism underlying these effects in future studies.