Enzymes as biomarkers of cypermethrin toxicity: response of Clarias batrachus tissues ATPase and glycogen phosphorylase as a function of exposure and recovery at sublethal level.

The present study was conducted to evaluate the sublethal effects of a synthetic pyrethroid, cypermethrin on ATPase, and glycogen phosphorylase in gill, kidney, liver, and muscle tissue of freshwater fish, Clarias batrachus (Linn) during exposure and cessation of exposure. Thirty-six fish were exposed to 1/3 of LC 50 concentration i, e. 0.07 mg/L cypermethrin for 10 days. After 10 days, 18 fish were transferred to freshwater and 10 days recovery response was observed. Thirty-six fish were kept as a control group. The effect of cypermethrin intoxication was studied on total, Mg(+2), Na(+)-K(+) ATPase, glycogen, and glycogen phosphorylase (a) and (ab) in various physiological tissues at the end of 1, 5, and 10 days of exposure and recovery period. Cypermethrin intoxication resulted in a significant inhibition in the activities of total, Mg(+2), and Na(+)-K(+) ATPase enzyme and glycogen content, whereas it caused a significant induction in the levels of glycogen phosphorylase (a). The activity level of glycogen phosphorylase (ab) showed mixed response. When exposed fish were released into freshwater, they were able to normalize the activities of ATPase enzyme in liver tissue whereas gill, kidney, and muscle tissues showed slight recovery. At the end of 10 days of recovery period, glycogen and glycogen phosphorylase activities in kidneys recover better than muscle. Therefore, the present study clearly suggests that ATPase and glycogen phosphorylase enzymes can be used as biomarkers of exposure to aquatic organisms under cypermethrin intoxication.