Whole body exposure to low-dose gamma radiation promotes kidney antioxidant status in Balb/c mice

Antioxidant status/Kidney/Low-dose gamma-irradiation/Radiation hormesis. We examined the effect of whole body low-dose gamma- irradiation on the status of the antioxidant defense system in the rodent kidneys at different time intervals. Young male Balb/c mice were exposed to whole body radiation from a Co-60 source at doses of 10, 25 and 50 cGy (48.78 cGy/min). Antioxidant status and lipid peroxidation were estimated in the kidneys at 4, 12 and 24 h after irradiation. Lipid peroxidation increased between 33% and 49% and reduced glutathione between 12% and 47% at 12 h at different radiation doses. Reduced glutathione level remained significantly (p<0.05) elevated even at 24 h after irradiation to 25 cGy. Superoxide dismutase activity also increased by 37% at 12 h on exposure of animals to all the doses up to 50 cGy. Catalase activity increased significantly at 12 h on exposure to 10 cGy and 50 cGy. Interestingly, glutathione peroxidase activity increased by 31% at 4 h and subsequently returned to control levels at 24 h after exposure to 50 cGy. Glutathione reductase activity increased by 10-12% at 12 h after exposure to 25 cGy and 50 cGy. The results suggest that the whole body exposure of animals to gamma radiation stimulates the antioxidant defense system in the kidneys within 4 to 24 h after irradiation, at doses of 25 cGy and 50 cGy.