病变侧亚低温对大鼠局脑缺血再灌注后Akt、Survivin表达的影响

Effect of mild hypothermia at focal side on changes of apoptosis Akt and survivin in rats after focal cerebral ischemia and reperfusion

目的 通过检测Akt及Survivin蛋白的表达,探讨亚低温对局脑缺血再灌注后神经元存活的影响.方法 用线拴法制作大鼠大脑中动脉闭塞（MCAO）局脑缺血再灌注模型,将44只SD大鼠随机分成假手术组、常温缺血组和亚低温缺血组,缺血组分别缺血2,6 h再灌注4,24,72 h,1周,2周后处死,亚低温组于缺血后13～14 min实施病灶侧亚低温持续4 h.免疫组织化学法检测Akt、Survivin 蛋白的表达.结果 相同缺血再灌注时间点,亚低温组比常温组缺血侧Akt、Survivin、表达水平显著增高（P＜0.05）.结论 病灶侧亚低温通过促进缺血半暗带脑组织Akt、Survivin表达的核内移,从而抑制神经元凋亡,促进脑缺血后神经功能恢复.

Objective To explore the effect of local mild hypothermia on expression of Akt and Survivin to and neuron survival in rats after focal cerebral ischemia and reperfusion injury. Methods The focal cerebral ischemia and reperfusion model of rats was achieved by intraluminal middle cerebral artery occlusion （MCAO）. The adult rats were randomly divided into sham-operation group, normothermia ischemia and reperfusion group and hypothermia ischemia and reperfusion group. The ischemic groups were further subdivided into 2hr and 6hr ischemia and then all reperfused for 4h,24h,72h,lwk,and 2wk group （n=4 per time point）. Brain mild hypothermia was achieved 13-14 minutes after ischemia and reperfusion for 4h. The expression of Akt and Survivin were assayed by immunohistochemistry. Results Compared with the normothermia group, focal mild hypothermia greatly increased the expression of Akt and Survivin in penumbra （P 〈 0.05 or P 〈 0.01）. Conclusions The focal mild hypothermia can accelerate the recovery of the neurological outcome. The neuroprotective effect of mild hypothermia may be related to enhancing Akt and Survivin expression in penumbra.