Sub-lethal effect of chlorpyrifos on protein metabolism of the food fish Clarias batrachus and monitoring of recovery

The effect of sub-lethal concentrations of chlorpyrifos on protein metabolism in physiological important tissues, namely gills, kidney, liver, and muscle of the freshwater fish, Clarias batrachus, was studied. Fish were exposed to 1/20th and 1/10th of 96 h LC50 concentrations for 7, 14, 21, and 28 days. After 28 days of exposure, fish were released into fresh water and kept in the same for 21 days in order to study the recovery. Fish were sacrificed at the stipulated periods and gills, kidney, liver, and muscle tissues were used for the estimation of total protein, amino acids, ammonia, urea, glutamine, protease, transaminases, and phosphatases. Total protein, amino acid, and ammonia contents were decreased in all tissues for 28 days and recovery was observed during the recovery period. Urea and glutamine levels were elevated, except in kidneys, and recovered at the end of the recovery period. The activities of protease, alanine, and aspartate aminotransferases, and acid and alkaline phosphatases were elevated in the tissues for 28 days exposure at both concentrations. Recovery of these enzymes activities was noticed during depuration.