EFFECTS OF FENTHION, ISOXATHION, DICHLORVOS AND PROPAPHOS ON THE SERUM-CHOLINESTERASE ISOENZYME PATTERNS OF DOGS

The serum cholinesterase (ChE) isoenzyme patterns consist of 5 bands f or normal beagle dogs. We examined the ChE isoenzyme patterns and ChE activities of 4 groups, each of which consisted of 4 dogs, given the o rganophosphate (OF) compounds fenthion (P=S type), isoxathion (P=S typ e), dichlorvos (P=O type) or propaphos (P=O type) po at 220, 75, 120 o r 90 mg/kg respectively. Blood samples were collected for 30 d after t he OP administrations. ChE isoenzyme bands 4 and 5 were inhibited 12 h after fenthion and isoxathion administration; dichlorvos and propapho s produced suppression of main bands 4 and 5 20 min after administrati on. This change was effective to differentiate the type of OP administ ered (P=S and P=O), while the main ChE isoenzyme bands of dog serum re flected inhibition of serum ChE activity.