Effect of L-cystine on toxicity of paraquat in mice.
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.
Kojima
S
S
Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Kumamoto University, Japan.
Miyazaki
Y
Y
Honda
T
T
Kiyozumi
M
M
Shimada
H
H
Funakoshi
T
T
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
D003553:Cystine; D013482:Superoxide Dismutase; D005978:Glutathione; D003545:Cysteine; D010269:Paraquat