Vitellogenin as a biomarker for environmental estrogens

Much recent interest has focused on "xenoestrogens" in the environment. The potential for these chemicals to disrupt hormonal function in wildlife has led to the development of techniques to monitor the effects of discharges of these compounds particularly in aquatic environments. Increases in the c oncentration of the egg yolk precursor protein, vitellogenin (Vtg), in the plasma of fish and other vertebrates have been identified as a potentially useful biomarker of exposure to and the effects of chemicals with estrogen like properties. Here, we review the mechanisms underlying Vtg production, methods for the analysis of Vtg, and studies that have measured Vtg product ion in response to chemical or effluent exposure. These studies indicate th at the production of Vtg may be a useful biomarker of exposure to estrogeni c chemicals but that a greater understanding of the mechanism of action of these chemicals is required. In cyprinid fishes reproductive endpoints are more sensitive to exposure to xenoestrogens than Vtg induction. These obser vations indicate that Vtg induction is of more use as a biomarker of exposu re to xenoestrogens rather than a predictor of adverse effects.