右美托咪定改善大鼠脑缺血再灌注后认知功能障碍

Neuroprotective Effects of Dexmedetomidineto on Cognitive Dysfunction after Cerebral Ischemia-reperfusion Injury in Rats

目的:观察右美托咪定(Dex)对大鼠脑缺血再灌注后认知功能障碍的影响。方法:64只SD大鼠随机分为MCAO组、假手术组、Dex组、对照组,每组16只。建立脑缺血模型,MCAO组大脑中动脉阻塞60 min后再灌注,假手术组仅分离血管,Dex组术前腹腔注射Dex 100μg/kg,其他组经腹腔注射相同体积生理盐水,对照组仅接受全麻20 min,不予手术处理。24 h后ELISA法测定各组大鼠额叶皮质IL-1β、IL-6、TNF-α的表达。术后第7天开始Barnes迷宫测试观察大鼠空间学习记忆功能。结果:MCAO组IL-1β、IL-6、TNF-α的表达比假手术组、对照组和Dex组均增高(均P<0.05),Dex组的炎性因子表达与对照组相比差异无统计学意义(P>0.05);MCAO组大鼠在Barnes迷宫进入目标洞时间比假手术组、对照组和Dex组均延长(均P<0.05),Dex组与对照组相比差异无统计学意义(P>0.05)。结论:Dex能降低大鼠脑缺血术后中枢神经炎性因子的表达,改善其术后认知功能障碍。

Objective：To investigate the effect of dexmedetomidine（Dex） on cognitive dysfunction after cerebral ischemia-reperfusion injury in rats. Methods： Forty-eight SD rats were randomly divided into groups of control, surgery and Dex, with 16 rats in each group. The surgery and Dex groups were subjected to middle cerebral artery occlusion（MCAO）. The Dex group received Dex via intraperitoneal injection at a dose of 100 μg/kg before MCAO operation. The groups of surgery and control were given normal saline of same volume. The control group received 20 min＇s anesthesia without surgery. The IL-1β, IL-6 and TNF-α levels in cerebral cortex were determined with enzyme-linked immunosorbent assay（ELISA） at 24 hours after surgery. On day 7 after surgery, rats were assessed by Barnes maze test. Results： The IL-1β, IL-6 and TNF-α levels in the surgery group were significantly higher than those in the Dex and control groups（all P〈0.05）. The latency to find the target box in the surgery group was much longer than that in the Dex treatment and control groups（all P〈0.05）. Conclusion： Dex may decrease the expression of neuroinflammatory factors after cerebral ischemia in rats, and improve the cognitive function.