Study of Cholinesterase Activity in Adult Ewes Treated by the Anthelmintic Drug Levamisole

The aim of this study was to examine the toxic effects of levamisole in adult ewes, using a modified electrometric method to measure the cholinesterase ( ChE ) activity in whole blood, plasma and erythrocyte. The normal mean ChE activity ( pH / 30 min) was the highest in the erythrocyte (0.64) , followed by the whole blood (0.36) and then in plasma (0.08). In Vitro, levamisole at concentrations (0,25,50,100,200,300) m/L caused significant inhibition of erythrocyte ChE by (0%, 13%, 15%, 19%, 36% and 54%) respectively. Adult ewes were divided into three groups each group contained 40 animal. The animals were treated with levamisole by doses of (0, 7.5, 15mg/Kg B.W ) by mouth and after zero ( 1,2,3)h blood sample(erythrocyte) was drawn to measure cholinesterase (ChE) activity. The activity was significantly decrease (%19.4) compared to the control. in activity of cholinesterase in the group that was treated by levamisole 15 mg/kg B.W and these results indicate the ability of levamisole to inhibit ChE activity.