亚低温通过下调分化抑制因子2保护脑缺血再灌注损伤大鼠

目的 探讨亚低温对脑缺血再灌注大鼠的保护作用以及对分化抑制因子2(inhibitor of differentiation 2,Id2)蛋白表达的影响.方法 72只成年雄性大鼠随机分为假手术组、常温组和亚低温组.应用线栓法制备大脑中动脉闭塞模型,亚低温组给予低温处理肛温(33±1)℃,鼓膜温度(31±1)℃].分别在缺血再灌注6、12、24和72 h时采用改良神经功能损伤严重程度评分(modified Neurological Severity Score,mNSS)评价神经功能缺损,氯化三苯基四氮唑检测梗死体积,蛋白质印迹法检测缺血皮质Id2表达水平.结果 缺血再灌注6、12、24和72 h时,亚低温组mNSS评分均显著高于常温组,梗死体积均显著小于常温组(P均<0.001).蛋白质印迹分析显示,亚低温组脑缺血再灌注6、12、24和72 h时缺血皮质Id2蛋白表达水平显著低于常温组(P均<0.05).结论 亚低温能减轻脑缺血再灌注后神经功能缺损和缩小梗死体积,其机制可能与下调Id2蛋白表达水平有关.

Mild hypothermia protects cerebral ischemia-reperfusion injury in rats by downregulating inhibitor of differentiation 2

Objective To investigate the protective effect of mild hypothermia on cerebral ischemia-reperfusion injury in rats and the effect of mild hypothermia on the expression of inhibitor of differentiation 2 (Id2) protein.Methods A total of 72 adult male rats were randomly divided into a sham operation group,a normothermia group,and a mild hypothermia group.A model of middle cerebral artery occlusion was induced by a suture method.The mild hypothermia group was treated with low temperature (anal temperature 33±1 ℃,tympanic membrane temperature 31±1 ℃).Modified Neurological Severity Score (mNSS) was used to evaluate neurological deficits,triphenyltetrazolium chloride staining was used to detect infarct volume,and Western blot was used to detect the Id2 expression in the ischemic cortex at ischemia-reperfusion 6,12,24,and 72 h,respectively.Results The mNSS scores in the mild hypothermia group were significantly lower than those in the normothermia group,the infarct volumes were significantly smaller than those in the normothermia group at ischemia-reperfusion 6,12,24,and 72 h (all P<0.001).Western blot analysis showed that the Id2 expressions in the ischemic cortex in the mild hypothermia group were significantly lower than those in the normothermia group at ischemia-reperfusion 6,12,24,and 72 h (all P<0.05).Conclusion s Mild hypothermia can decrease neurological deficits and reduce infarct volume after cerebral ischemia-reperfusion,its mechanism may be associated with the down-regulation of the Id2 expression.