EFFECT OF CADMIUM ON ENZYMATIC PARAMETERS OF FRESHWATER CATFISH, HETEROPNEUSTES FOSSILIS

Quantitative assessment of enzymes is a reliable indicator of stress imposed on the organism by environmental pollutants such as heavy metals. The activities of Acetylcholinesterase (AChE), alkaline phosphatase (ALP) and acid phoshatase (ACP) enzymes in liver, brain, gill and serum are used as stress indicators. The significant changes in activities of these enzymes in blood plasma indicate tissue impairment caused by stress. In the present study, significant changes were observed in AChE, ALP and ACP activities in liver, brain, gill and serum of Heteropneustes fossilis fish exposed to cadmium when compared to the control group. In this study, the AChE activity was inhibited moderately by sub-lethal concentration of cadmium. During 21 days treatment among the tissues tested, the gill AChE was more inhibited than any other tissue AChE. Alkaline phosphatase activities of cadmium treated fish under various sub-lethal concentrations were significantly decreased in liver and increased in brain, gill and serum. Acid phosphatase activities of cadmium treated fish under various sub-lethal concentrations were significantly increased in liver, brain, gills and serum