Abstract

Data are presented to show up to 50-fold potentiation in the acute toxicity of EPN and malathion if they are administered simultaneously to dogs. The potentiation is marked but less for the rat. The potentiation from acute doses to dogs is associated with a marked increase in erythrocyte cholinesterase inhibition. Subacute experiments reveal that feeding of diets containing both EPN and malathion to dogs produces minimum blood cholinesterase inhibition at levels ½ to [unknown] the level required for the individual compounds for similar effect. Subacute studies with rats reveal increased cholinesterase inhibition, but again to a lesser degree than with the dog.