Host: The Japan Radiation Research Society
We reported antioxidant capacities in various tissues of mice were enhanced by low dose-rate irradiation. We furthermore found Type II diabetes model mouse (DB mouse) consecutively for low dose-rate gamma ray (0.63 mGy/hr) irradiation changed biological effects, such as urine glucose level decreased to normal level, and lifespan prolonged. These phenomena might be thought increase antioxidative capacities by the irradiation was protected oxidative damages in pancreas of the mice, and insulin secretion function contributed. We used female DB mouse as elucidation of the action that low dose-rate irradiation gave to suppressive effect of pancreatic oxidation, and measured change of plasma glucose and insulin concentration, urinary glucose concentration and pancreatic antioxidant activities. Gamma ray source is 137-Cs (314 GBq). We started radiation from 10 wks old to 82 wks old with at a dose-rate of 0.30, 0.63 or 1.2 mGy/hr consecutively.
The irradiated groups were increased antioxidative capacities in the pancreas; in particular Mn-SOD activity and glutathione concentration of the 1.2 mGy/hr-irradiated group was clearly enhanced. Lipid peroxide concentration was significantly decreased in the 0.63 mGy/hr-irradiated group. In the irradiated groups, plasma glucose concentrations slightly decreased. On the other hand, plasma insulin concentrations in the irradiated groups were not significantly changed. Urinary glucose concentrations were not also different from with or without irradiation. There were not differences between the irradiated groups.
These results indicated that the antioxidative capacities in the pancreas protected from oxidative damage by continuous low dose-rate irradiation, and then to kept the insulin secretion function.
