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(41-11) Evidence of oxidative stress responses in fish from polluted sites. Sturve, Joachim*,1, Carney, Bethanie1, Stephensen, Eirikur1, Forlin, Lars1, 1 Department of Zoology, Zoophysiology, Goteborg, Sweden ABSTRACT- Oxidative stress is considered to be one of the major mechanisms of cytotoxicity and can be caused by various xenobiotics present in aquatic environments. Oxidative damage includes the oxidation of lipids, proteins and DNA. In order to identify possible biomarkers for oxidative stress fish were exposed to the model redox cycling compounds, Paraquat and Menadione. Fish were injected with Paraquat (3,3 and 10 mg/Kg) and Menadione (5 and 15 mg/Kg) and sampled after 2 and 5 days. The catalytical activities of DT-diaphorase (DTD), superoxide dismutase (SOD), catalase (CAT) and glutathione related enzymes were measured. We also studied the effects on the more general responses total glutathione levels (totGSh), methaemoglobin reductase and glucose-6-phosphate dehydrogenase (G6PD). Both compounds caused slight but significant increase in glutathione-S transferase and DTD activities while glutathione reductase activity and totGSh levels were strongly increased. In addition paraquat caused an increase in CAT. Menadione caused an increase of G6PD activity in red blood cells. Glutathione reductase and totGSh showed the strongest response to the treatments and can be considered as possible biomarkers for oxidative stress. Results from the lab study was compared with data from two field studies preformed within the EU-BEEP project, one at the Norwegian west coast and one at the Swedish west coast. Corkwing wrasse (Symphodus melops) caught at one copper and one PAH contaminated site in Norway showed no responses of antioxidant enzyme activities compared with reference sites. In the Swedish west coast, eelpout (Zoarces viviparus ) were caught close to a petro-chemical industry area and at a large harbor area. In the industry area, eelpout showed effects on glutathione reductase levels and at the harbor area, effects on the levels of glutathione reductase, totGSh and CAT. These studies was supported in part by EU-BEEP project. Key words: fish, oxidative stress, pollution |
