• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.194-198
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• 2001

The study was conducted to investigate the changes of hepatic cytochrome P450 monooxygenase system induced by dietary administration of polychlorinated biphenyls (PCBs) in the tilapia, Oreochromis niloticus. Tilapia were fed pellet with PCBs (Aroclor 1254) 0.05, 0.25 and 0.50 mg/kg body weight/day for 30 days. The dietary administration of PCBs (0.05 mg/kg) induced a significantly increased the concentration of cytochrome P450 and the activity of 7-ethoxyresorufin-O-deethylase (EROD) in the hepatopancreas at 30 days, while the augmentation of both responses was found at 20 days with a higher administration of PCBs-diet (0.25 mg/kg). However, hepatic 7-penthoxyresorufin-O-dealkylase (PROD) activity did not show any noticeable changes with the PCBs-diet 0.05-0.5 mg/kg range compared to control group during the experimental periods of 30 days in the tilapia. These results indicate that tilapia fed PCBs at the concentration of more than 0.05 mg/kg for 30 days are affected by PCBs in terms of cytochrome P450 concentration and EROD activity in the hepatopancreas.