【摘要】 目的探讨缝隙连接(GJ)在脑缺血再灌注血脑屏障通透性变化中的作用及其可能机制。方法①应用激光共聚焦显微镜技术观察 GJ 蛋白 Cx43在缺血再灌注半暗带区脑毛细血管周终足上含量及分布情况的变化。②将 Wistar 大鼠随机分成假手术组,手术组。线栓法制备大鼠大脑中动脉缺血再灌注模型。通过荧光分光光度定量的方法测定不同时间点脑组织中的伊文蓝含量来观察血脑屏障的通透性的改变。③取伊文蓝漏出最多的时间点,增设辛醇干预组和 DMSO 溶剂对照组,与相同时间点手术对照组比较,观察辛醇对血脑屏障通透性的影响。结果缺血2 h 再灌注3 h 脑组织伊文蓝含量开始增加,再灌注24 h 达高峰。激光共聚焦显微镜发现 GJ 蛋白 Cx43在脑内毛细血管周围的星形胶质细胞终足上分布密集。在缺血2 h 再灌注24 h 半暗带内,终足上的 Cx43分布发生变化,聚集成较大斑块。在缺血2 h 再灌注24 h 组术前给予辛醇干预,脑组织伊文蓝含量[(4.924±0.296)μg/g]低于手术对照组[(5.543±0.506)μg/g],二者差异有统计学意义(P<0.05)。结论GJ 在脑缺血再灌注后半暗带终足上分布变化明显,可能加重了血脑屏障通透性的增加;辛醇阻断 GJ可以降低脑缺血再灌注血脑屏障的通透性,从而起到减轻脑水肿的作用。更多还原

【Abstract】 Objective To investigate the possible mechanism of the gap junctional influence on the change in permeability of the blood-brain barrier(BBB)after reperfusion subsequent to cerebral ischemia.Methods In the test laser scanning confocal microscope(LSCM)was used to investigate the change of Cx43 levels and distribution.The MCAO/R model was induced using intraluminal suture technique first described by Longa with a little modification.A total of 60 Wistar rats were divided into 4 groups:the sham-operation group,control group,octanol-treatment group and DMSO vehicle control group. Control group were further divided into seven subgroups at different time points of reperfusion after middle cerebral artery occlusion.To observe the change in permeability of BBB,Evans blue(EB)in the brain tissue was surveyed by the means of EB fluorescent quantitation.Octanol-treatment group and DMSO vehicle control group were done at the point of the peak of permeability of BBB.Octanol,the specific blocker for gap junctions(GJ)was used in an intervention study.To compare the amount of EB with the same point of groups,the influence of octanol on BBB permeability was investigated.Results At 3 h of reperfusion after cerebral ischemia for 2 h,the permeability of BBB began to increase,reached the peak at 24 h of reperfusion and was still elevated at 72 h.The Cx43 expression formed into bigger plague and remained linear disposition in the penumbra after reperfusion subsequent to cerebral ischemia.Octanol group was done at 24 h of reperfusion after cerebral ischemia.The amount of EB of octanol group((4.924±0.296)μg/g)was significantly lower than that of corresponding operation control group(5.543±0.506)μg/g.Conclusions (1)Cx43 expression is concentrated around vessels in brain.The Cx43 forms into bigger plague and the function maybe strengthens after reperfusion.Gap junction might aggravate the disruption of BBB.(2) Octanol,the specific blocker of gap junctions,could effectively prevent the permeability of BBB from increasing and has a protective effect on BBB.更多还原