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(T/EH001) OXIDATIVE STRESS IN FISH EXPOSED TO CADMIUM. Almeida, Jeane1, Diniz, Yeda1, Marques, Silvio1, Novelli, Ethel1,2, Ribas, Bartolome1, 1 2 ABSTRACT- The presence of toxic substances in the aquatic environment requires systematic evalutionof exposure. As a nondegradable cumulative pollutant, cadmium can alter trophic levels for centuries. Because fish are an important food resource and a major ecosystem component, it is important to assess the biochemical and physiological effects of cadmium on fish, determine acceptable levels of Cd in aquatic environment and develop new methods for determining deleterious effects of cadmium in early stage. The aim of this study was to assess changes in several biochemical parameters in fish exposed to cadmium chloride for 60 days. This report also investigate whether reactive oxygen species (ROS) play a role in cadmium toxicity. Juveniles Oreochromis niloticus(Nile tilapia), 50 animals were exposed during 60 days,to 0.35mg/L, 0.75mg/L, 1.5mg/L, 3.0mg/L of cadmium chloride. A control group was not exposed to Cd.No significant changes were observed in superoxide dismutase and glutathione peroxidase activities of liver and red muscle of fish at different cadmium exposure. On the other hand, glycogen was increased and lactate dehydrogenase and creatine kinase activities were decreased in white muscle of fish at different cadmium concentration exposure, indicating a decreased metabolic degradation of carbohydrate in these tissues. Since no alterations were observed in lipoperoxide concentration, while superoxide dismutase and glutathione peroxidase activities were increased in white muscle, we can conclude that these antioxidant enzymes were important in the protection to cadmium damage in white muscle, inhibiting the lipoperoxide formation in fish exposed to different cadmium concentration Key words: cadmium, fish, oxidative stress, enzymes |
