The Impact Of DETA-NONOate On NADPH Oxidase-derived Oxidative Stress In Rats After Stroke

Objective:To determine the effect of NO donor DETA-NONOate on stroke rats after experimental MCAO and reperfusion injury, especially focus on the mechanisms concerning NADPH oxidase. Methods:A total of approximately 65 male Sprague-Dawley rats were used in this study. The animals were freely divided into three groups:(i) sham-operated group; (ii) control group:ischemia (60min) and reperfusion group (4h or 24h); (iii) ischemia (60min) and reperfusion (4h or 24h) with DETA-NONOate-treated group. Right MCA was occluded with a 4.0 monofilament nylon suture for an hour and then the nylon monofilament was withdrawn at the end of ischemic period for the beginning of reperfusion. DETA-NONOate-treated animals were treated with effective doses (0.4mg/kg) of NO donors DETA-NONOate in 250μl saline. The solution was slowly infused by tail vein at the time of reperfusion in 10-15 min. We evaluated the neuroprotective effect and antioxidant property of DETA-NONOate in rats after MCAO/reperfusion by ischemic infarct volume, neurological function score, MDA level, NO level, NADPH oxidase activities and the expressions of NADPH oxidase subunits (p22phox, p47phox, gp91phox, Nox4 and Rac-1). Results:1) DETA-NONOate improved neurological function by decreasing brain infarction volume and neurological function score in 60min MCAO/24h reperfusion rats compared to control group (P<0.05);2) The NO level of DETA-NONOate treated group was higher than control in 60min MCAO/4h reperfusion rats (P<0.05); 3) DETA-NONOate depressed MDA formation in brains of rats after 60min MACO and 4h reperfusion compared to control group (P <0.05); 4) NADPH oxidase activity and the expressions of NADPH oxidase subunit p22phox, p47phox, and Rac-1 in brains of 60min MCAO/4h reperfusion rats were significantly reduced by DETA-NONOate treatment compared to control (P<0.05). Conclusion:NO donor DETA-NONOate depressed the level of oxidative stress in the brains of MCAO/reperfusion rats by reducing the activity of NADPH oxidase, and thus played a protective role in ischemic stroke.