Elevation of mouse liver glutathione level by low-dose γ-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 γ-ray irradiation and its inhibitory effect on CCl₄-induced liver damage. The liver GSH level increased soon after irradiation with 50 cGy of γ-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 peroxidase also showed the same pattern of change, while the activity of γ-glutamylcysteine synthetase showed a gradual increase up to 24 h. The effect of pre-irradiation on CCl₄-induced liver damage was also investigated. The activities of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase in serum were markedly increased 12 h post-treatment with CCl₄. Both increases were significantly suppressed by a single low-dose pre-irradiation. Malondialdehyde, a marker of lipidperoxidation, was also greatly elevated after CCl₄ treatment, and its increase was suppressed by irradiation. These results suggest low-dose γ-ray irradiation might be effective for the prevention of and/or therapy of various reactive oxygen species-related diseases including cancer.