In vitro inhibitory effects of selected anticholinesterase insecticides on human plasma and erythrocyte cholinesterases and their thermal reactivation

The inhibitory effect of a number of locally used organophosphorus and carbamate insecticides on human plasmaand erythrocyte were examined in vitro by using the modified electrometric method for determination ofcholinesterase (ChE) activity. The negative logarithum of inhibitor concentration required for 50% inhibition(pIC50) was estimated to range between -12.6 to 2.4 and between - 8.5 to - 0.77 for plasma and erythrocyte ChE,respectively. Plasma ChE was more susceptible than erythrocyte ChE to effects of the insecticides. Thermalreactivation technique was applied on plasma and erythrocyte ChE to identify and differentiate betweenorganophosphorus and carbamate insecticides