EFFECT OF HYDROGEN GAS ON THE SURVIVAL RATE OF MICE FOLLOWING GLOBAL CEREBRAL ISCHEMIA

Global cerebral ischemia and reperfusion (I/R) often result in high mortality. Free radicals have been reported to play an important role in global cerebral I/R, and therefore, reduction of these might improve the outcome. Here, we investigated the effect of hydrogen gas (H-2) (a strong free radical scavenger) on the survival rate of mice following global cerebral I/R. We further examined the histopathological outcome and also the brain water content (as a possible determinant of mortality). Male C57BL/6J mice were subjected to global cerebral I/R by means of 45-min bilateral common carotid artery occlusion (BCCAO). A total of 160 mice were divided into three groups: sham surgery (sham group), BCCAO without H-2 (BCCAO group), and BCCAO treated with 1.3% H-2 (BCCAO + H-2 group). We observed that H-2 treatment significantly (P = 0.0232) improved the 7-day survival rate of mice, from 8.3% (BCCAO group, n = 12) to 50% (BCCAO + H-2 group, n = 10). Histopathological analysis revealed that H-2 treatment significantly attenuated neuronal injury and autophagy in the hippocampal cornu ammonis 1 sector and also brain edema, after 24 h of reperfusion. The beneficial effects of H-2 treatment on brain injury were associated with significantly lower levels of oxidative stress markers (8-hydroxy-2'-deoxyguanosine and malondialdehyde) in the brain tissue. Thus, we believe that H-2 may be an effective treatment for global cerebral I/R.