Abnormally elevated VTG concentrations in flounder (Platichthys flesus) from the Mersey estuary (UK)--a continuing problem.

Vitellogenin (VTG) plasma concentrations were measured in flounder (Platicthys flesus L.) caught in two neighbouring UK estuaries between autumn 1997 and summer 2000. As found in previous studies, male and immature female flounder that were caught in the Mersey, but not in the Dee, had abnormally elevated concentrations of VTG in their plasma-evidence of the presence of natural and synthetic estrogens and/or xenoestrogens in the Mersey.

General condition biomarkers in relation to contaminant burden in European flounder (Platichthys flesus).

In respect to the differences found for vitellogenin (VTG) expression in male and immature flounder, general biological aspects and a set of chemical residues in the liver were compared between flounder from the Mersey and Dee estuaries (UK). Except for alpha-HCH, all pollutant chemicals analysed in flounder liver differed highly significantly between Mersey and Dee fish. Overall, the higher liver contaminant concentrations were found in VTG-induced Mersey flounder.

A biomarker approach to endocrine disruption in flounder--estrogen receptors, hepatocyte proliferation, and sperm motility.

Three different physiological parameters were assessed to determine their potential for serving as biomarkers to predict abnormally elevated vitellogenin (VTG) production in male and immature flounder. Whereas abnormally elevated mean VTG plasma concentrations clearly distinguished the Mersey and Dee flounder studied, the results showed no significant differences in estrogen receptor binding capacity or binding affinity between the two groups. Hepatocyte proliferation was not found to be a "biomarker of effect" that could specifically be used to assess an increase in VTG-related proliferation.