Interactions of Chlorinated Hydrocarbon Pesticides with the 8S Estrogen-binding Protein in Rat Testes

The effect of certain DDT analogs on the binding of 3H-estradiol to the 8--9S estrogen binding protein of rat testicular cytosol was studied by sucrose sedimentation analysis. The binding of 3H-estradiol to testicular cytosol was inhibited by o,p'DDT, a DDT analog which is estrogenic in the intact female, but not by p,p'DDE which is a nonestrogen in the female. The pesticide methoxychlor, which is estrogenic in vivo in the female, failed to inhibit 3H-estradiol binding, presumably requiring metabolic activation for binding to the testicular cytosol. In fact, its di-demethylated metabolite 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE), also estrogenic in vivo, caused marked suppression of 3H-estradiol binding.