Effect of Drug-metabolizing Enzyme Activity Induced by PCB on the Residence Time of Oxolinic Acid, Piromidic Acid and Nalidixic Acid in Carp

A study was made of the effect of drug-metabolizing enzyme activity induced by polychlorinated biphenyl (PCB) on the residence time of quinoline antibacterial agents in carp Cyprinus carpio. Carp were fed with a diet containing PCB (1 mg PCB/kg body weight/day) for 2 weeks to induce drug-metabolizing enzymes. After pretreatment, three kinds of quinoline antibacterial agents (oxolinic acid, piromidic acid and nalidixic acid) were individually administered in feed to PCB-treated or nontreated (as control) fish as a single dose of 20 mg/kg body weight. The peak concentrations of oxolinic acid in the blood, liver and muscle of PCB-treated fish were lower than half of those in the control. The concentrations of piromidic acid in the liver, muscle and kidney of PCB-treated fish were undetectable throughout the experiment (2 to 98 h post dosing), except in the blood. However, the residence time and concentration of nalidixic acid in the tissues of PCB-treated fish showed no significant difference compared with those in the control.