Développement et validation d'une méthode ELISA de détection immunochimique de l'induction de la vitellogénine chez la truite juvénile après exposition au Nonylphenol

[Departement_IRSTEA]GMA [TR1_IRSTEA]12 - MILEAU / EXPERThere is increasing concern about man-made chemicals in the aquatic environment that mimic the action of the steroid hormone, 17b-oestradiol. One of the most sensitive responses to the xenobiotics oestrogens in fish is the induction of the egg-yolk precursor vitellogenin which is normally synthetised by female under oestrogen stimulation. In immature or male fish, vitellogenin may thus serve as a reliable biomarker for xenobiotic oestrogen. In this study, a competitive enzyme linked immunosorbent assay (ELISA) using anti-salmon vitellogenin antibodies (Biosense Laboratories) was developed for the quantification of plasma vitellogenin in rainbow trout. Cross-reactivity and specificity of the antibodies with rainbow trout Vitellogenin was assessed by western blotting and ELISA and no cross-reactivity was observed with juvenile plasma. Vitellogenin was purified from plasma of oestradiol-treated juvenile fish by anion exchange chromatography followed by gel filtration. Purity was confirmed by silver staining Native PAGE, and hence the purified vitellogenin was used as standard in the ELISA. The sensitivity range of the ELISA was 16-175 ng/ml and the detection limit was 7,5 ng/ml. The repetability and the reproductibility were 5-9,5% andChez des poissons juveniles ou des mâles on peut utiliser la mesure de la vitellogenine comme biomarqueur aux xénobiotiques oestrogenes. Nous avons developpé une méthode immunochimique de type ELISA avec un anticorps anti-saumon (laboratoire Biosense). Cet essai a permis d'estimer les effets de la durée d'exposition et de la dose sur l'induction par le 17b oestradiol et le 4 nonylphenol. Les différences observées pour les deux composés sont certainement dues à la métabolisation. Le 4nonylphenol semble beaucoup moins capable d'effet oestrogénique que le 17 beta oestradiol