Inhibitory Effects of Prior Low - dose X - irradiation Ischemia - reperfusion Iajury in Mouse Paw on Takahiro KATAOKA , Yuko MIZUGUCHI , Masaaki YOSHIMOTO

Edemallschemia-reperfusion iajllrylLow-dose irradiation/Reactive oxygen species/Antioxidation function. We have reported that low-dose, unlike high-dose, irradiation enhanced antioxidation function and reduced oxidative damage. On the other hand, ischemia-reperfusion ajury is induced by reactive oxygen species, In this study, we examined the inhibitory effects of prior Iow-dose X-irradiatien on ischemiareperfUsion iajury in mouse paw. BALBIc mice were irradiated by sham or O,5 Gy of X-ray. At 4 hrs after irradiation, the left hind leg was bound 10 times with a rubber ring for O.5, 1, er 2 hrs and the paw thickness was measured. Results show that the paw swelling thickness by ischemia for O,5 hr was Iower than that for 2 hrs, At 1 hr after reperfUsion from ischemia for 1 hr, superoxide dismutase activity in serum was increased in those mice which received O.5 Gy irradiation and in the case of the ischemia for O.5 or 1 hr, the paw swelling thicknesses were inhibited by O,5 Gy irradiation, I addition, interstitial edema in those mice which received O,5 Gy irradiation was Iess than that in the mice which underwent by sham irradiation. These findings uggest that the ischemia-reperfusion ajury is inhibited by the enhancement of antioxidation function by O.5 Gy irradiation.