实验性大鼠蛛网膜下腔出血后病理观察

Pathological changes in rats with experimental subarachnoid hemorrhage

在既往研究大鼠蛛网膜下腔出血（SAH）后局部脑血流量（rCBF）变化的基础之上，进一步观察SAH后颅底血管痉挛状态和结构变化、血脑屏障（BBB）开放及脑水肿过程．发现SAH后颅底动脉出现间期为72h的痉挛过程，rCBF变化与之有显著的相关性（r＝0．93，P＜0.01）；SAH后早期血管壁呈现强烈的收缩，无血管壁结构变化，晚期在血管壁扩张过程中有部分内皮细胞脱落，弹力膜断裂和平滑肌细胞退性变；SAH后早中期出现轻度BBB通透性增加和脑水肿，二者之间有显著的相关性（r＝0．92，P＜0．01）；BBB通透性改变与血管痉挛有显著的负相关关系（r＝－0．84，p＜005）．这些结果提示：SAH后rCBF变化是反映脑血管痉挛（CVS）状态的较好功能指标；SAH后CVS主要是由脑血管收缩功能改变所致而非血管壁结构改变所致；SAH后出现轻度的BBB开放和血管源性脑水肿，主要是由于CVS引起，但也可能间接部分地影响CVS过程。

On the basis of changes of regional cerebral blood flow(rCBF) in rats after subarachnoid hemorrhage, we studied further the changes of spasm and structure basicranial arteries, blood-brain barrier (BBB) permeability and brain edema. The results were as follows. The basicranial arteries showed a spasm of 72-hour duration which correlated well with the changes of rCBF (r = 0. 93,P<0. 01 ). The arterial wall constricted strongly without structural changes in the early stage after SAH, and in the late stage there were vasodi1atation and detachment of some endothelial cells,breakup of elastic lamina and degeneration of smooth muscles. There were slight increase of BBB permeability and brain edema in the early and middle stage after SAH and correlation well with each other (r= 0. 92,P<0.01). The changes of BBB permeability also correlated with arterial spasm (r= - 0. 84,P<0.05 ). These results suggested that changes of rCBF can reflect the true state of cerebral vasospasm (CVS) following SAH;CVS is mainly due to functional changes of constriction rather than structural change of cerebral arteries; there are slight increase of BBB permeabilitly and vasogenic brain edema,which are induced mainly by CVS and may also affect the course of CVS partially and indirectly.