Effect of Low Dose Radiation on Tran: sient Global Cerebral Ischemia in Gerbils

ABSTRACT

PURPOSE: To date, much research has been performed for amelioration of secondary brain damage after cerebral ischemia and reperfusion. We investigated the antioxidative and anti-inflammatory effects of post-ischemic low-dose total-body irradiation (TBI) on transient global cerebral ischemia. METHODS: The gerbils were divided into six groups (8 gerbils in each group) group I and II, sham operation; group III and IV, 10-minutes ischemia without TBI; group V and VI, 10-minutes ischemia with TBI at 10 minutes after reperfusion. The activity of superoxide dismutase (SOD) and the levels of myeloperoxidase (MPO) and malondialdehyde (MDA) in the brains of group I, III, and V at 4 hours after reperfusion were measured. In the brains of group II, IV, and V, the levels of MPO and MDA were measured and the hippocampal areas were stained with hemotoxylineosin (H-E) and TUNEL at 5 days after reperfusion. RESULTS: The activity of Cu/Zn SOD in group V was significantly increased compared to that in group III, but their activities were significantly lower than that of group I. The MPO and MDA levels in groups V and VI were significantly lower than those in group III and IV. The percent dead neurons found in the hippocampal CA1 region by using H-E staining was significantly lower in group VI than in group IV. The number of TUNEL positive cells in the hippocampal CA1 region was significantly lower in group VI and in group IV. CONCLUSION: Anti-oxidative and anti-inflamatory responses induced by post-ischemic low-dose TBI may reduce secondary neuronal damage following 10 minutes of transient global cerebral ischemia.