Vitellogenesis as a biomarker of reproductive disruption by xenobiotics

There is increasing evidence that many xenobiotic chemicals can reduce the reproductive capacity of fish through disruption of the endocrine system. H epatic stimulation of vitellogenesis in male and juvenile fish provides a s ensitive indication of exposure to environmental oestrogens and oestrogenic chemicals. Moreover, perturbations of female vitellogenin levels can provi de a useful marker of dysfunction caused by endocrine disruption at many si tes in the reproductive axis. Vitellogenesis can therefore provide a useful indicator of endocrine disruption by xenobiotics. Both inhibition and stim ulation of vitellogenesis can have direct repercussions on the reproductive capacity of fish. An important caveat in interpreting the results of such studies is that they must be related to other components in the reproductiv e system which may be more sensitive to disruption and have greater consequ ences for reproductive success. (C) 1999 Elsevier Science B.V. All rights r eserved.