[Evaluation of endocrine disruptors in environmental water using yeast two-hybrid system]

Estrogenicity of concentrates from waters of lake, river, tap water and effluent of sewage treatment plant by XAD-2 resin column concentration method was detected by the yeast two-hybrid system. Estrogenicity was detected in all environmental waters. From dose-response curve on estrogenic activity of concentrates from the Yodo river water by the two-hybrid system with and without S9mix, 17 beta-estradiol equivalent values in the river water were very similar to analytical values of 17 beta-estradiol reported by the Ministry of Constraction's survey(1999). Estrogenic activities of these concentrates were enhanced by metabolic activation. On the other hand, the tests on effect of these concentrates against estrogenic activity of 17 beta-estradiol (6 x 10(-10) M) revealed that the river water may contain not only inhibitors to estrogenicity but also precursors of estrogenic substances formed by metabolic activation.