title: Environmental (anti-)androgenic chemicals affect germinal vesicle breakdown (GVBD) of Xenopus laevis oocytes in vitro.
abstract: Progesterone-induced germinal vesicle breakdown (GVBD) of Xenopus oocytes in vitro was used to study endocrine disrupting activity of chemicals in previous studies. In this study, we investigated for the first time effects of environmental androgens on oocyte maturation and effects of anti-androgens on androgen-induced oocyte maturation, using Xenopus GVBD in vitro. Trenbolone and nandrolone, two environmental androgens, were found to induce Xenopus GVBD at low concentrations. The potential of trenbolone to induce GVBD was approximately 100-fold lower than that of testosterone, while nandrolone had a several-fold lower potential than testosterone. Our findings have aroused new concerns for effects of environmental androgens on amphibian oocyte maturation at environmentally relevant concentrations, and suggested that Xenopus GVBD can be used to test androgenic activity of suspicious environmental androgens. Androgen receptor (AR) antagonist flutamide at 10 μM only exhibited a weakly inhibitory effect on androgen-induced GVBD, while another known AR antagonist vinclozolin had no effect even at high concentrations. The results show that Xenopus GVBD is not sensitive to AR-mediated environmental anti-androgens. In contrast to flutamide and vinclozolin, methoxychlor (a weaker AR antagonist) inhibited dramatically androgen-induced GVBD, suggesting that androgen-induced Xenopus GVBD can be used to study non-AR-mediated effects of chemicals on oocyte maturation.
authors.affiliation: Nanjing University of Technology, Nanjing 210009, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Cao
authors.affiliation: Nanjing University of Technology, Nanjing 210009, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Qin-Qin
authors.initials: QQ
authors.lastname: Lou
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Yin-Feng
authors.initials: YF
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Ya-Xian
authors.initials: YX
authors.lastname: Zhao
authors.affiliation: Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Wu-Ji
authors.initials: WJ
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: qinzhanfen@rcees.ac.cn.
authors.forename: Zhan-Fen
authors.initials: ZF
authors.lastname: Qin
mesh_terms: D000726:Androgen Antagonists / Q000494:pharmacology*; D000728:Androgens / Q000008:administration & dosage / Q000633:toxicity; D000818:Animals; D052244:Endocrine Disruptors / Q000008:administration & dosage / Q000633:toxicity*; D005485:Flutamide / Q000494:pharmacology; D008731:Methoxychlor / Q000494:pharmacology; D009277:Nandrolone / Q000008:administration & dosage / Q000633:toxicity*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D010080:Oxazoles / Q000494:pharmacology; D011944:Receptors, Androgen / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology; D014204:Trenbolone Acetate / Q000008:administration & dosage / Q000633:toxicity*; D014982:Xenopus laevis
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D052244:Endocrine Disruptors; D010080:Oxazoles; D011944:Receptors, Androgen; D013739:Testosterone; D009277:Nandrolone; D005485:Flutamide; C025643:vinclozolin; D008731:Methoxychlor; D014204:Trenbolone Acetate
keywords: Androgen receptor antagonist; Germinal vesicle breakdown; Nandrolone; Testosterone; Trenbolone; Xenopus laevis