Superoxide generation and DNA oxidation increased in the ischemia—reperfusion brain.

<p>(a) Representative photomicrograph of Nissl staining showing infarct region in ischemia—reperfusion brain for at 6 h, 1 d, 1w, and 2 w. Scale bars = 1 mm. White solid line and white colored boxes indicate the peri-infarct region in the cortex showing DHE staining. (b) Representative photomicrograph of NeuN (green) and DHE (red) staining showing superoxide levels in neurons of ischemia—reperfusion brain for 6 h, 1 d, 1 w, and 2 w. Superoxide in neurons is demonstrated as yellow staining after merging green (NeuN) and red (DHE) images. Scale bars = 20 μm. (c) DHE-stained cells of the NeuN-stained cells were counted in the peri-infarct region. Results are presented as the mean ± SEM, n = 4/4. *p<0.05, **p<0.01 vs control. (d) Representative photomicrograph of 8-oxo-2dG immunostaining showing DNA oxidation levels in ischemia—reperfusion brain at 2 weeks. Left panel is contralateral region in the cortex. Right panel is cortical peri-infarct region. Black arrows indicate 8-oxo-2dG-staining in the nucleus. Scale bars = 30 μm. (e) 8-oxo-2dG-stained cells were counted in the ischemia—reperfusion brain. Results are presented as the mean ± SEM, n = 4/4. **p<0.01 vs the contralateral region. Contra: contralateral; Ipsi: ipsilateral.