Alteration in the activities of three peptidases and lipase in the digestive system of the fish Channa punctatus exposed to lead nitrate.

The effect of exposure of Channa punctatus to LC(50) (6.8 mg/L) and sublethal concentration (2.8 mg/L) of lead nitrate on the activities of amino tripeptidase, glycylglycine, leucyl-l-glycine dipeptidases and lipase has been investigated. An inhibition in the activities of all the enzymes is noted after 96 hr, 15 and 30 days of treatment period. The inhibition in lipase activity is statistically insignificant in both the acute and chronic treatment cases. The experiments indicate that lead induced toxicity is more severe in chronic treatment as compared to acute treatment.