Abstract
We have morphologically reported that low-dose irradiation inhibited ischemia-reperfusion injury. In this study, we histologically examined the changes of mouse paw after ischemia-reperfusion by prior low-dose X-irradiation. BALB/c mice were irradiated by sham or 0.5 Gy of X-ray. At 4 hrs after irradiation, the left hind leg was bound 10 times with a rubber ring at just above articulation for 0.5, 1, or 2 hrs. The left hind leg was excised, and divided into small blocks. These legs were stained conventionally with hematoxylin-eosin (HE). In addition, the interstitial fluid in interstitial edema is increased by ischemia-reperfusion and interstitial edema is increased. Therefore we calculated the percentage of interstitial edema (ration of cells spacing). Results show that in case of the ischemia for 0.5 or 1 hr, 0.5 Gy irradiation significantly inhibited the paw swelling thicknesses more than sham irradiation. In case of the ischemia for 0.5 or 1 hr, 0.5 Gy irradiation significantly decreased interstitial edema more than sham irradiation. In case of the ischemia for 1 hr, 0.5 Gy irradiation significantly decreased interstitial edema after 0.5, 2, or 24 hrs reperfusion more than sham irradiation. Moreover 0.5 Gy irradiation significantly increased superoxide dismutase (SOD) activity in serum after 1 hr reperfusion from 1 hr ischemia. These findings suggest that 0.5 Gy irradiation activated the antioxidant function in mouse paw, therefore low-dose irradiation alleviates ischemia-reperfusion injury.
