Endocrine disrupting effects of dichlorodiphenyltrichloroethane analogues on gonadotropin hormones in pituitary gonadotrope cells

It has been shown that exposure to dichlorodiphenyltrichloroethane (DDT) analogues leads to disharmony of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, the effects and mechanisms of DDT analogues on the expression of gonadotropin genes (FSH beta, LH beta and Cg alpha), which is the rate-limiting step of FSH and LH biosynthesis, remain unknown. In this study, we assessed the effects of p,p'-DDT, o,p'-DDT, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and methoxychlor (MXC) on gonadotropin genes expression and hormones synthesis in gonadotrope cells. p,p'-DDT and MXC at test concentrations ranging from 10(-9) to 10(-7) mol/L, stimulated gonadotropin genes expression and hormones synthesis in a dose-dependent manner. The activation of extracellular signal-regulated kinase (ERK) was required for the induction of gonadotropin genes expression and hormones synthesis by p,p'-DDT or MXC exposure. This study showed for the first time that p,p'-DDT and MXC regulated gonadotropin genes expression and hormones synthesis through ERK pathway in gonadotrope cells. (C) 2014 Elsevier B.V. All rights reserved.