Effects of various doses of copper sulphate on peroxidase activity in the liver, gills, kidney and brain of Cirrhina mrigala

Metal ion pollution of water generates addition of metals in the fish organs that leads towards redox reactions, making free radicals, particularly reactive oxygen species (ROS). All organisms have a strong antioxidant defense system to defend their tissues from injurious effects of ROS produced by metallic ions toxicity. During this study, effects of various doses of copper sulphate (CuSO4) on peroxidase activity in the liver, gills, kidney and brain of Cirrhina mrigala were measured. One year old C. mrigala were subjected to 96-hr LC50, 2/3rd, 1/4th and 1/5th of LC50 of CuSO4, discretely, for period of the 30 days in glass aquariums with three replications for each treatment. The control group of the fish did not receive any metal stress. After 30-day exposure of CuSO4, the fish from all treated groups were sacrificed and their liver, gills, kidney and brain is separated for peroxidase enzyme assay. Peroxidase enzyme activity in the CuSO4 treated fish were compared amongst several treatments and with the control fish. Activity of peroxidase enzyme in all organs of the fish increased significantly (p<0.05) after exposure of CuSO4 as compared to the control fish. Peroxidase activities in the liver, gills, kidney and brain tissues of metal stressed fish were measured as 0.891±0.002, 0.824±0.004, 0.767±0.004 and 0.334±0.004UmL-1, respectively.