Biochemical changes of enzymatic defense system after phenanthrene exposure in olive flounder, Paralichthys olivaceus

The objective of this study was to investigate the early biological response in the olive flounder exposed to sub-lethal concentrations of waterborne phenanthrene (0.5, 1 or 2 mu M). The fish were exposed for 4 weeks and we analyzed their enzymatic defense system, antioxidant and phase II enzyme activities, to evaluate the chronic exposure toxicity of phenanthrene. Waterborne phenanthrene affected antioxidant enzymes and glutathione-mediated detoxification as an enzyme defense system. Hepatic, gill and kidney glutathione reductase as well as glutathione S-transferase, and catalase activities were markedly elevated after two or four weeks of exposure. These enzyme activities of the olive flounder, Paralichthys olivaceus, seem to be a convenient approach for monitoring pollution in coastal areas against polycyclic aromatic hydrocarbon pollution including phenanthrene.