Increased Plasma Paraquat Levels in Intoxicated Mice Following Antiparaquat F(ab′)₂ Treatment

Abstract

Death most often results from human acute poisonings due to paraquat, a widely used herbicide. It causes a quick and insidious accumulation in lungs. It was proposed to study the effects of the administration of antiparaquat F(ab′)₂ fragments in mice intoxicated with paraquat. Antisera against a paraquat acid derivative coupled to bovine serum albumin were prepared in rabbits, then purified using immunoaffinity chromatography columns and fragmented by pepsin. Antiparaquat F(ab′)₂ antibodies obtained were preventively injected to mice. After intravenous paraquat injection of 8 mg/kg, plasma paraquat levels were measured from 0.25 to 48 hours. Plasma from antiparaquat F(ab′)₂ pretreated mice as compared with non-specific immunoglobulin pretreated control mice showed a significant increase (p < 0.001) of the paraquat concentrations from the 4th (1.17 ± 0.06 versus 0.20 ± 0.01 μg/ml) to the 48th hour (0.47 ± 0.08 versus 0.02 ± 0.01 μg/ml). Although pulmonary paraquat concentrations presented no modification, it could be considered that these preliminary results would have to be studied thoroughly with a view to finding an efficient treatment in human acute poisonings with paraquat.