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(061) Comparative study on the in vitro/in vivo estrogenic potencies of estradiol, estrone and ethynylestradiol. Van den Belt, Kris1.2, Vangenechten, Clea1, Berckmans, Pascale1, Verheyen, Rudy2, Witters, Hilda1, 1 2 ABSTRACT- The occurence of elevated levels of xeno-estrogenic compounds in waste and surface waters has increased international concern for the impact of these hormonal active compounds on aquatic wildlife and drinking water resources. Numerous short term assays (in vitro receptor tests, biomarker studies) are often used to screen for the estrogenic activity of both individual compounds and field samples. However, the predictive value of these assays for in vivo potency or effects remains uncertain. In this study, the potency of 3 environmental estrogens: the synthetic estrogen 17 Key words: endocrine disruption, in vitro/in vivo estrogenic potencies, zebrafish |
-ethynylestradiol (EE2), the natural 17MISSING CHARACTER ENTITY: Beta-estradiol (E2) and estrone (E1), which are likely to occur in effluents of waste water treatment plants, was assessed by two in vitro cellular tests, a fish biomarker test and an in vivo reproduction-related effect. The Yeast Estrogen Screen and the MVLN-screen (human breast cancer cell line), 2 well established in vitro recombinant screening assays for receptor binding were used. An in vivo model with the zebrafish (Danio rerio) was used in order to assess plasma vitellogenin levels and gonadosomatical index, which is related to reproductive success. Dose-response curves were generated from in vitro screening assays and after a 3-week exposure of female zebrafish to a 1:2 dilution serie of individual estrogenic compounds in the concentration range of 0.007 up to 1.84 nM. Relative potency for estrogenic compounds and in vitro versus in vivo response will be compared and discussed in relation to both previous results and literature data.