大鼠急性局灶性脑挫裂伤后血脑屏障的改变研究

Influence of acute regional contusion and laceration of the brain on blood brain barrier in rats

目的研究急性局灶性脑挫裂伤后大鼠血脑屏障的改变及对脑水肿的影响。方法采用Feeney's自由落体撞击法建立急性局灶性脑挫裂伤模型。每组6只测量伤侧脑组织伊文思蓝(evansblue,EB)含量、脑组织含水量。每组3只电镜观察微血管内皮细胞超微结构改变。结果急性局灶性脑挫裂伤后24h脑组织含水量为(79.79±0.83)%,与正常对照组(78.68±0.63)%相比差异有显著性(P<0.01),脑损伤后6h脑组织中EB含量为(362.12±28.16)μg/g,与正常对照组(11.89±2.28)μg/g相比差异有显著性(P<0.01);脑损伤后30min,微血管内皮细胞有轻度受损迹象,伤后3h毛细血管腔内有微绒毛形成,伤后6h微绒毛增多,伤后24～72h毛细血管腔明显狭窄。结论脑含水量的变化与脑组织中EB含量变化不同步,BBB的开放先于脑水肿的形成。BBB的开放与微血管的机械性损伤、内皮细胞吞饮小泡增加、内皮细胞紧密连接中断有关,也与早期缺血、缺氧关系密切。

[Objective] To study the alteration of blood brain barrier （BBB） after brain injury and to look for the influence of it on the brain edema. [Methods] Acute regional brain trauma was applied according to Feeney＇s apparatus. The water content and the Evanse blue （EB） content of the brain tissue were measured at six rats of each group. Three of it were observed on the alteration of altrastructure of micrangium endotheliocyte. [Results] The water content of brain tissue was significantly higher than the normal control groups （79.79±0.83）% versus （78.68± 0.63）% 24 h after brain injury and the EB content of brain tissue was significantly higher than the normal control groups （362.12±28.16） μg/g versus （11.89±2.28） μg/g 6 h after brain injury. The micrangium endoheliocyte was damaged at 30 rain, the microvilli was formed at 3 h and 6 h, the cavum of micrangium was narrowed at 24-72 h. [Conclusion] The water content and EB content in brain tissue changed in different pace and the BBB is disrupted before the formation of brain edema. The disrupted of BBB due to the mechanical injury of microangium and increase of vesicle endothelial cells and the interruption of endothelial cells tight junctions and early ischemia and oxygen deficit of brain.