Fenvalerate-induced changes in a catfish, Clarias batrachus: metabolic enzymes, RNA and protein.

We studied the effects of a sublethal concentration of pyrethroid insecticide fenvalerate on metabolic enzymes, RNA and protein of brain, liver and skeletal muscle of the freshwater catfish, Clarias batrachus. Exposure to fenvalerate gradually decreased the activity of citrate synthase (CS), glucose 6-phosphate dehydrogenase (G6-PDH) and lactate dehydrogenase (LDH) in brain, liver and skeletal muscle up to 21 days. The maximum decrease in enzyme activity was 23-47%. Withdrawal of fenvalerate from the medium for 21 days restored enzyme activity to their control level in all three tissues. RNA and protein content in brain, liver and skeletal muscle decreased significantly with exposure of fenvalerate up to 21 days. The maximum decrease in RNA and protein was 22-32%. Withdrawal of fenvalerate from the medium for 21 days restored the RNA and protein contents to control levels. The present study suggests that fenvalerate impairs cellular metabolism and its biochemical effects are reversible after withdrawal of fenvalerate.