大鼠蛛网膜下腔出血后血脑屏障通透性变化

Changes of blood brain barrier permeability after experimental subarachnoid hemorrhage

目的探讨大鼠蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后血脑屏障(blood brain barrier,BBB)通透性变化。方法雌性SD大鼠80只,分为生理盐水对照组(NS组)和SAH组。采用经额叶底面蛛网膜下腔插管至Willis环注血法建立SAH模型,在SAH后6、12、24、36、48、60、72h等不同时间点,应用荧光分光光度计和荧光显微镜方法分别检测大脑皮质BBB对伊文思蓝(Evans Blue,EB)的通透性,同时利用透射电镜观察BBB超微结构变化。结果与NS组比较,大脑皮质EB含量和漏出量的最大值均出现在SAH后36h时(P<0.05),于60h时恢复至正常水平(P>0.05)。BBB超微结构改变在SAH后36h时最明显。结论BBB通透性改变发生在SAH急性期,是由多种因素共同所致,而且SAH后BBB具有自我修复特性。

Objective To explore the dynamic changes of blood brain barrier （BBB） permeability after experimental subarachnoid hemorrhage （SAH） in rats. Methods Eighty female SD rats were divided into normal saline control group （n = 10） and SAH group （n =70）. The SAH model was induced by injecting 300μl of autologous arterial blood into the subarachnoid space near the circle of Willis via a cannula in an artificial hole between the olfactory bulb and frontal lobe. BBB permeability in cerebral cortex of SAH and normal saline rats was assessed at 6, 12, 24, 36, 48, 60, and 72 h after SAH establishment by fluorescence spectrophotometer and fluorescence microscopy for Evans Blue （EB） extravasation. The ultrastructural changes in BBB were observed with transmission electron microscope. Results Compared with the control group, the changes of Evans Blue content and extravasation in cerebral cortex of SAH group peaked at 36 h （P 〈 0. 05 ）, and down to the normal level at 60 h after SAH （P 〉 0. 05 ）. The severe ultrastructural abnormality was found at 36 h after SAH. Conclusion The changes of BBB permeability develop at the acute stage of SAH, resulting from multipie factors together. The BBB after SAH possesses a self-repairable property.