Suppression of atopic dermatitis and tumor metastasis in mice by small amounts of radon.

We examined the effect of radon in two experimental disease models in mice by administering radon dissolved in water at 68-203 Bq/liter. Administration of radon in drinking water to NC/Nga mice significantly delayed the progression of atopic dermatitis-like skin lesions induced by picrylchloride when administered prior to the induction of disease signs. The number of pulmonary metastatic foci in C57BL/6 mice inoculated with B16 melanoma cells was also reduced significantly by administration of radon in drinking water when the number of tumor cells was small and the radon treatment was started prior to tumor inoculation.

Involvement of mitochondrial peroxynitrite in nitric oxide-induced glutathione synthesis.

Cells respond to oxidative stress including nitric oxide (NO) by increasing cellular glutathione concentration, as a part of adaptive response against oxidative injury. To elucidate the mechanism by which NO induces glutathione we investigated the reactive oxygen species (ROS) generated in the cell. Treatment of RAW264.

Elevation of glutathione induced by low-dose gamma rays and its involvement in increased natural killer activity.

We examined the relationship between the induction of an increase in the level of glutathione and the elevation of natural killer (NK) activity in mouse splenocytes by a low dose of gamma rays. The glutathione levels in mouse splenocytes increased significantly between 2 h and 6 h after whole-body gamma irradiation at 0.5 Gy, peaked at 4 h, and then decreased almost to the level before irradiation by 12 h postirradiation.