Paraquat induces different pulmonary biochemical responses in Wistar rats and Swiss mice

The paper presents results showing differential response to paraquat toxici ty in Wistar rats and Swiss strain of mice. Paraquat-induced pulmonary bioc hemical responses in the two animal species were studied at different time point after giving a single intraperitoneal injection of the respective LD1 0 doses of the herbicide paraquat to rats and mice. Paraquat induced differ ent biochemical responses including different protective responses in the t wo animal species. As a protective response, NADPH-specific quinone reducta se is induced in rats, while catalase is induced in mice. It is implied tha t an early induction of catalase in mice as opposed to rats may account for the resistance of Swiss mice to paraquat toxicity. Xanthine oxidase, which was induced in rats, remains unaffected in mice indicating that the enzyme contributes to paraquat toxicity only in Wistar rats. Time-course studies were also conducted to compare the differential responses of antioxidant en zymes and lipid peroxidation between the two species. The results of the st udy led us to suggest that the manifestation of paraquat toxicity involve d istinct differences in early pulmonary biochemical responses in Wistar rats and Swiss mice. (C) 2000 Published by Elsevier Science Ireland Ltd. All ri ghts reserved.