title: Effect of L-cystine on toxicity of paraquat in mice.
abstract: The protective effect of L-cystine on the toxicity of paraquat (PQ) in mice was studied. Lipid peroxidation in the lung significantly increased after oral administration of PQ (200 mg/kg) and the increase in lipid peroxidation was prevented by L-cystine treatment (300 mg/kg). PQ administration produced an increase in superoxide dismutase (SOD) activity and a decrease in glutathione peroxidase (GSH-Px) activity in the lung at 24 h after PQ. L-Cystine treatment significantly prevented the changes in SOD and GSH-Px activity in the lung after PQ. L-Cystine treatment prevented the decrease in non-protein sulfhydryl (NP-SH) content in the lung after PQ administration. The tissue distribution and excretion of PQ after PQ administration were not changed by L-cystine treatment. Plasma aspartate aminotransferase activity did not change after PQ administration. These results suggest that L-cystine protects against the toxicity of PQ by maintaining reduced glutathione levels in the cells.
authors.affiliation: Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Kumamoto University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kojima
authors.forename: Y
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: T
authors.initials: T
authors.lastname: Honda
authors.forename: M
authors.initials: M
authors.lastname: Kiyozumi
authors.forename: H
authors.initials: H
authors.lastname: Shimada
authors.forename: T
authors.initials: T
authors.lastname: Funakoshi
mesh_terms: D000818:Animals; D003545:Cysteine / Q000502:physiology; D003553:Cystine / Q000378:metabolism / Q000494:pharmacology*; D005978:Glutathione / Q000032:analysis; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D051379:Mice; D010269:Paraquat / Q000378:metabolism / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000032:analysis
chemical_list: D003553:Cystine; D013482:Superoxide Dismutase; D005978:Glutathione; D003545:Cysteine; D010269:Paraquat