运动预处理对大鼠脑缺血再灌注损伤后血脑屏障通透性的影响

Effects of Exercise Preconditioning on Blood-brain Barrier Permeability in Rats after Cerebral Ischemia-reperfusion Injury

目的观察运动预处理对大鼠脑缺血再灌注损伤后血脑屏障通透性,以及连接蛋白43 (Cx43)和泛连接蛋白1(Panx1)的影响。方法 54只雄性Sprague-Dawley大鼠随机分为假手术组、模型组和运动预处理组,每组18只。造模前,运动预处理组行跑台训练3周。采用改良Koizumi线栓法闭塞对模型组和运动预处理组大脑中动脉,再灌注24 h后,采用改良神经功能缺损评分(mNSS)评估神经功能;伊文思蓝渗透法观察血脑屏障通透性;Western blotting和免疫组化检测缺血侧脑组织Cx43和Panx1蛋白表达。结果与模型组比较,运动预处理组mNSS评分降低(P <0.05),伊文思蓝含量以及Cx43和Panx1蛋白表达量下降(P <0.05),Cx43和Panx1阳性面积率降低(P <0.05)。结论运功预处理可改善脑缺血再灌注大鼠血脑屏障通透性,下调Cx43蛋白和Panx1蛋白表达,具有脑保护作用。

Objective To observe the effects of exercise preconditioning on blood-brain barrier (BBB) permeability, and connexin 43 (Cx43) and pannexin 1 (Panx1) protein after cerebral ischemia-reperfusion injury in rats. Methods Fifty-four male Sprague-Dawley rats were randomly divided into sham group (n = 18), model group (n = 18) and exercise preconditioning group (n = 18). The exercise preconditioning group was trained with treadmill for three weeks before modeling. The middle cerebral arteries were occluded in the model group and the exercise pre-conditioning group using the modified Koizumi suture. After reperfusion of 24 hours, the rats were assessed with modified Neurological Severity Score (mNSS). The permeability of BBB was observed with Evans blue (EB). The expression of Cx43 and Panx1 was detected with Western blotting and immunohistochemistry in the ischemic tissues. Results Compared with the model group, the mNSS score decreased in the exercise preconditioning group (P < 0.05), while the Evans blue content and the expression of Cx43 and Panx1 decreased (P < 0.05), as well as the the positive areas of Cx43 and Panx1 (P < 0.05). Conclusion Exercise preconditioning can improve the permeability of BBB in cerebral ischemia-reperfusion rats, which may associate with down-regulation of Cx43 and Panx1, to protect brain from injury.