The effect of NBO on NADPH oxidase subunit gp91phoxin the cortex penumbra at 22.5 h reperfusion after 90 min ischemia. A) Representative western blotting shows the expression of gp91phox. B) Histogram represents the relative amount of NADPH oxidase subunit gp91phox normalized to the level of sham-operation contralateral. Values are expressed as mean ± SD, n = 5 each group. *P < 0.05 and **P < 0.01 vs. sham; # P < 0.05 and ## P < 0.01 vs. normoxia group.