蛛网膜下腔出血后血脑屏障通透性的实验研究

目的观察蛛网膜下腔出血后脑血管痉挛后血管通透性改变以及探讨其发生机制。方法将36只新西兰大白兔随机平分为6组,各手术组通过枕大池注血建立兔蛛网膜下腔出血后脑血管痉挛的模型,假手术组枕大池注入生理盐水。假手术1组和手术1组用于通过免疫组化方法检测血管内皮细胞的caspase-3表达情况,作为细胞凋亡的标志;假手术2组和手术2组用于检测注血后3d处死动物,比较手术组与对照组脑含水量。假手术3组和手术3组用于通过Evan's蓝荧光染色方法检测手术组和非手术组血脑屏障的通透性。结果手术1组的基底血管内皮细胞caspase-3高度表达,与假手术1组相比有显著统计学差异,反映了蛛网膜下腔出血后基底血管内皮细胞发生了细胞凋亡;手术2组与假手术2组脑含水量相比增加,有显著统计学差异;手术3组脑组织Evan,s蓝含量明显增加,与假手术3组相比有显著统计学差异,反映了蛛网膜下腔出血后血脑屏障的通透性也发生了明显改变。结论血管内皮细胞凋亡可能是蛛网膜下腔出血后脑血管痉挛引发血脑屏障损伤的重要原因。

Study of the permeability of blood-brain barrier (BBB)after subarachnoid hemorrhage model in rabbit

Objective To examined the relationships between apoptosis and the disruption of blood-brain barrier(BBB)and brain edema in SAH model in rabbit.Methods Thirty-six New Zealand White rabbits were randomized to six experimental groups.The SAH model was produced in anesthetized rabbits by injecting 1.5ml/kg autologous fresh arterial blood into the cisterna magna.Control animals underwent sham operations.At 72h after SAH,expression of caspase-3 was examined as marker for apoptosis in operation group-1 and sham-operation group-1.Brain water content were observed in operation group-2 and sham-operation group-2.The amount of extravasated Evans blue dye in the brain was determined by spectrofluorophotometry in operation group-3 and sham- operation group-3.Results Significant increase(P<0.05)in water content and BBB permeability were detected in SAH rabbits after 72 hours after SAH when compared with sham-operated rabbits.Apoptosis occurred mostly in endothelial cells of rabbits.Conclusions Apoptosis could be main cause of early brain injury after SAH.