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2C - Biomarkers (TUP/80) G6PDH Activity and Enzyme Altered Foci as Diagnostic Tools for Toxic Liver Injury and Carcinogenesis in Wrasse. Koehler, Angela1, Kaiser, Wiebke1, 1 Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany ABSTRACT- Wrasse (Symphodus melops L.) were sampled at differently contaminated fjord sites around Stavanger (Norway). Livers were analysed for toxipathic alterations by histochemistry of the key enzyme of the pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PDH) and by histopathology. G6PDH is the major source of reducing power NADPH needed for biosynthesis, during biotransformation, oxyradical scavenging and elimination of xenobiotics and in production of nucleotides in proliferating cells. Upregulation of G6PDH activity in (pre)cancerous lesion has been evidenced to be a highly valuable prognostic biomarker for carcinogenesis in mammals as well as in flounder and dab. During macroscopic inspection of the wrasse livers no evidence of nodular or tumorous lesions could be diagnosed. No sex-specific differences in basic G6PDH activity were determined except at the reference site in Foerlandsfjorden (p < 0.05). In male individuals increased maximal G6PDH activity at "polluted sites" (PAHs, organics, metals) compared to the reference Foerlandsfjorden was detected whereas no site-specific alterations in basic G6PDH activity were found in females. Interestingly, frequencies of enzyme altered foci were significantly higher in livers of female wrasse at the PAH- and copper/iron-contaminated sites and equally high (83%) in both gender at the organic polluted site of a kelp factory. These results imply that female wrasse are more susceptible to carcinogens exposured by endogenous factors, such as estradiol upregulation as has been already found in flounder (Platichthys flesus L.). Key words: G6PDH, wrasse, enzyme altered foci, prognostic biomarker |
