【摘要】 目的探讨亚低温对大鼠局灶性脑缺血再灌注后不同脑区诱导型一氧化氮合酶(iNOS)表达的影响。方法雄性SD大鼠,随机分为假手术组、常温缺血组和亚低温组。采用线栓法制作大脑中动脉闭塞再灌注模型,于缺血后48h,观察不同组间组织形态学变化,检测不同脑区iNOS蛋白表达、iNOS活性和产物NO含量。结果常温缺血后48h,纹状体和皮质均检测到iNOS活性升高和免疫阳性反应,且皮质缺血半暗带区iNOS免疫反应明显强于纹状体和皮质缺血核心区。亚低温明显缩小梗死面积,抑制皮质和纹状体iNOS活性,明显下调半暗带区iNOS蛋白表达,减少NO产生。结论亚低温可能通过减少半暗带区iNOS蛋白表达,抑制iNOS活性,减少NO产生而起到脑保护作用。更多还原

【Abstract】 Objective To investigate the effect of mild hypothermia on inducible nitric oxide synthase (iNOS) expression in different brain regions following focal cerebral ischemia-reperfusion in rats. Methods The Male Sprague-Dawley rats were randomly assigned to sham-operated group,normthermic group and intraischemic hypothermia group. The middle cerebral artery of rat was occluded by using the intraluminal suture method and then recirculated. At 48h postischemia,The histological morphological damage were investigated and iNOS proteins,iNOS activity,nitric oxide (NO) concent were measured in the different brain regions. Results The increase of iNOS activity and iNOS immunoreactivity were detected in striatum and cortex at 48h postischemia in normthermic group. iNOS immunoreactivity in cortical penumbra was significantly higher than that in the striatum and the cortical core. Mild hypothermia significantly reduced the infarct area. Furthermore,Mild hypothermia reduced iNOS protein expression in the different brain regions,especially in the cortical penumbra,as well as suppressed iNOS activity and NO generation in the cortex and striatum. Conclusion It is assumed that the decrease of iNOS protein expression in the ischemic penumbra and the inhibition of iNOS activity,resulting in reduction of NO production,may be one of the mechanisms of hypothermic neuroprotection.更多还原