Biochemical responses in freshwater fish Carassius auratus to Benzo(k)fluoranthene

Freshwater fish Carassius auratus were chosen as experimental animals. The fish were exposed to five different concentrations of benzo(k)fluoranthene (BkF) for 15 days and then hepatic tissues were separated for determination. As shown from the results, 15 days afterwards, the activities of catalase (CAT) were inhibited significantly on the whole compared with control group; glutathione peroxidase (GPx) responded to BkF were induced significantly at only 7.41 mg/kg. Besides, good dose-effect relations, which cover most of the exposure concentration range, were found between BkF level and CAT activity. In conclusion, CAT and GPx may be potential early biomarkers of BkF contamination in aquatic ecosystems, and further studies will be necessary.