ELEVATION OF MOUSE-LIVER GLUTATHIONE LEVEL BY LOW-DOSE GAMMA-RAY IRRADIATION AND ITS EFFECT ON CCL4-INDUCED LIVER-DAMAGE

We examined the elevation of glutathione (GSH) levels in the liver of C57BL/6 female mice after low-dose r-ray irradiation and its inhibitor y effect on CCl4-induced liver damage. The liver GSH level increased s oon after irradiation with 50 cGy of gamma-rays, reached a maximum at around 12 post-treatment, and returned almost to the control level by 24 h. The activities of glutathione reductase, and glutathione peroxid ase also showed the same pattern of change, while the activity of gamm a-glutamylcysteine synthetase showed a gradual increase up to 24 h. Th e effect of pre-irradiation on CCl4-induced liver damage was also inve stigated. The activities of glutamic oxaloacetic transaminase and glut amic pyruvic transaminase in serum were markedly increased 12 h post-t reatment with CCl4. Both increases were significantly suppressed by a single low-dose pre-irradiation. Malondialdehyde, a marker of lipidper oxidation, was also greatly elevated after CCl4 treatment, and its inc rease was suppressed by irradiation. These results suggest low-dose ga mma-ray irradiation might be effective for the prevention of and/or th erapy of various reactive oxygen species-related diseases including ca ncer.