Immunohistochemical detection of vitellogenin in male brown trout from Swiss rivers

The detection of vitellogenin, a yolk precursor protein, may serve as a bio marker for exposure to environmental oestrogens as its induction by xenobio tic oestrogens in the immature and male fish has been reported repeatedly. In the present work, juvenile brown trout were injected with oestradiol (5 mu g g(-1) body weight oestradiol benzoate) in order to assess the inductio n and organ distribution of vitellogenin by means of immunohistochemistry. In addition, brown trout collected from Swiss rivers were analysed. Vitello genin Mras detected in the oestradiol-injected juvenile trout but not in un injected controls. The presence of vitellogenin was also demonstrated in a male and an immature feral brown trout from one of two locations downstream of three sewage treatment plants. In contrast, no positive staining was fo und in livers of trout upstream of the respective plants. The results demon strate the suitability of immunohistochemistry for monitoring feral fish fo r the presence of vitellogenin production. (C) 1998 Chapman & Hall.The dete ction of vitellogenin, a yolk precursor protein, may serve as a biomarker f or exposure to environmental oestrogens as its induction by xenobiotic oest rogens in the immature and male fish has been reported repeatedly. In the p resent work, juvenile brown trout were injected with oestradiol (5 mu g g(- 1) body weight oestradiol benzoate) in order to assess the induction and or gan distribution of vitellogenin by means of immunohistochemistry. In addit ion, brown trout collected from Swiss rivers were analysed. Vitellogenin Mr as detected in the oestradiol-injected juvenile trout but not in uninjected controls. The presence of vitellogenin was also demonstrated in a male and an immature feral brown trout from one of two locations downstream of thre e sewage treatment plants. In contrast, no positive staining was found in l ivers of trout upstream of the respective plants. The results demonstrate t he suitability of immunohistochemistry for monitoring feral fish for the pr esence of vitellogenin production. (C) 1998 Chapman & Hall.