Effect of Dietary Methionine on Chlorobenzene-Induced Variation in Hepatic Glutathione and Lipid Peroxide Leveis in Rats

Abstract

Effects of dietary methionine on hepatic glutathione synthesis and lipid peroxidation in rats injected with chlorobenzene were investigated. After being fed for 4 weeks on a 10% casein-based diet (basal diet) or the basal diet supplemented with 0.3% DL-methionine, rats were intraperitoneally injected with chlorobenzene at a level of 0, 0.2, 0.5, or 2.0mmol/kg body weight. In the rats fed the basal diet, a mortality of four-sixths was brought within 48 hours by the 2.0mmol/kg of chlorobenzene, and TBA value, an index of lipid peroxidation, was significantly increased by the 0.5mmol/kg of chlorobenzene. Supplementation with methionine to the basal diet made all the rats survive, and caused a lowered TBA value and a significant increase of liver wet weight in the rats in jected with the 0.5 or 2.0mmol/kg of chlorobenzene. while a significantly higher hepatic glutathione synthesis activity was observed, hepatic total glutathione level was significantly lower in the rats fed the basal diet. Chlorobenzene-induced increases in the glutathione level and its synthesis activity were observed 48 hours after the injection in the rats fed the methionine-supplemented diet but not in the rats fed the basal diet. These results indicate that chlorobenzene exposure may cause a critical impairment due to lipid peraxidation in rats fed a diet marginal in sulfur-containing amino acids.