Confinement stress and starvation modulate the induction of EROD activity after dietary exposure to PCB 126 in the Mozambique tilapia (Oreochromis mossambicus)

摘要: Polychlorinated biphenyls (PCBs) are environmental pollutants, accumulating in the food chain and inducing cytochrome P450 1A (CYP 1A) monooxygenase enzymes. This study aimed to investigate influence of dietary PCB 126 exposure on P4501A-associated enzyme activities head kidney, liver, gill intestine unstressed stressed tilapia (Oreochromis mossambicus) before after starvation. Fish were fed diets containing 0 μg (control), 0.5 (low) or 50 (high) PCB126 per kg body weight day for 7 days. After PCB-exposure each treatment group was sampled directly, subsequently exposed confinement stress. Replicate groups remained undisturbed, starved 3 weeks thereafter directly confinement. Catalytic activity CYP P4501A determined as 7-ethoxyresorufin-O-deethylase (EROD) activity. Directly starvation, EROD kidney increased with higher dose. Intestinal not detectable at any sampling point. Confinement, known evoke a stress response livers (only exposure) kidneys (directly starvation) but only fish low PCB-diet. We suggest that stressing induces non-saturating concentrations this effect is more pronounced nourished than fish. These data show toxicants also influenced by non-chemical factors. should be considered when used biomarker monitoring studies.