Amphibians as a model to study endocrine disruptors: II. Estrogenic activity of environmental chemicals in vitro and in vivo

摘要: Abstract Several environmental chemicals are known to have estrogenic activity by interacting with development and functions of endocrine systems in nearly all classes vertebrates. In order get a better insight potential effects on amphibians caused pollution this study aims develop model for investigating disruptors using the amphibian Xenopus laevis . that is determined at several levels investigation: (I) binding liver estrogen receptor; (II) estrogenicity vitro inducing vitellogenin synthesis primary cultured hepatocytes; (III) vivo sexual development. Here we deal establishing methods assay vivo. used semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique determine mRNA-induction biomarker hepatocytes male Time courses vitellogenin-mRNA presence absence 10 −6 M 17β-estradiol (E2) resulted marked loss mRNA from controls after 2 days while E2 treatment kept relatively stable level. After 36 h incubation activities E2, 4-nonylphenol (NP), 2,2-bis-(4-hydroxyphenyl)-propan (bisphenol A) concentrations ranging −10 −5 were assayed RT-PCR showed following ranking dose-dependent potency: E2>NP>bisphenol A. These results confirmed further experiments determining differentiation exposure during larval Concentrations −7 −8 as well NP or bisphenol A significant higher number female phenotypes compared indicating similar potencies vitro. addition, butylhydroxyanisol octylphenol, both feminization octylphenol was also effective M. summary these demonstrate first time use screening assaying induction The combination newly developed method classical necessary determination biological significance chemicals.