ABSTRACT
The present study was conducted on rats exposed to LD50 and sublethal doses of malathion for acute and chronic toxicity in the presence and absence of carbon tetrachloride (CC1(4)) induced liver injury. In acute malathion poisoning either in the presence or absence of CC1(4), erythrocyte cholinesterase (EChE) and plasma cholinesterase (PChE) declined significantly. Correlation between toxic signs and enzyme activities existed in the early phase of exposure (10 min). Acute treatment of CC1(4) and. malathion did not significantly alter aspartate aminotransferase (AST) and alanine aminotIransferase (ALT) activities. In chronic poisoning, the blood cholinesterases (ChE) were significantly lowered with corresponding elevation of AST and ALT which was noticed for 2 wk after the withdrawal of malathion. The findings suggest that the persons with pre-existing liver diseases may exhibit enhanced toxicological responses to pesticides.