[Effects of endocrine disruptors on preimplantation embryo development]

Endocrine disruptors such as dioxins and bisphenol A(BPA) were detected in the human follicular fluids indicating that the reproductive organs have been exposed to these substances. To study possible effects of these chemicals on the germ cells and early embryos, we employed mouse preimplantation embryo development models. Dioxin(TCDD) and BPA both have positive and negative effects on embryo development in mice. The developmental rates were significantly decreased by exposure to concentrations of TCDD between 1 and 5 pM as compared with the control group. On the other hand, stimulatory effects of BPA were observed in the blastocyst formation rate at concentrations of 1 nM and 3 nM. The present study demonstrated that low concentration of both TCDD and BPA, not dose dependent manner, exert stimulatory or inhibitory effects on preimplantation embryo development. These alterations in low doses may be mediated by AhR or ER alpha and ER beta, present in mouse preimplantation embryos.