Antioxidant enzyme activity and tissue residue of GIFT tilapia after copper exposure

ObjectiveThe present study was conducted to investigate copper accumulation in GIFT tilapia , analyzed the damages caused by copper in fish body based on enzyme activity variation and its regulation , in order to provide refer-ence for healthy culture of GIFT tilapia. MethodThe experiment set different waters of 0 (CK),1.0, 2.0, 4.0 and 6.0 mg/L copper concentrations. After the fishes were cultured in corresponding waters for 40 days , copper ion contents and antioxidant enzyme activities of gill , liver , kidney , muscle and intestine were measured . ResultLiver and body weight ratio of GIFT tilapia in copper exposure treatments were significantly higher than that in control (P<0.05, the same below). In the same copper concentration exposure, accumulation ability of copper ions in different tissues were ranked as follows:liver>intestine>kidney>gill>muscle. As copper exposure concentration increased , SOD activity in liver reduced and then increased, whereas SOD activity in kidney increased first and then decreased. Among all tissues, CAT activity in kidney was the highest, and went through an up-down variation as copper exposure concentration increased. CAT activity in kidney reached maximum in 2.0 mg/L concentration. Variation regulations of MDA in liver and kidney were as the same as those of SOD activity, but the turning point was 4.0 mg/L concentration. ConclusionCopper exposure leads to copper accumulation in different tissues in GIFT tilapia. Accumulation content in liver is the highest , whereas accumulation in muscle is low, which means it has insignificant influence on edible part of GIFT tilapia. Copper exposure causes damages in liver and kidney, and metabolic disorder.