实验性脑星形细胞水肿的CT灌注成像及其病理学研究  

Experimental study of astrocytic swelling in rats and evaluation with CT perfusion imaging and histopathology

作　　者：梁晨阳[1] 高培毅[1] 袁芳[1] 徐立新[1] 胡凌[1] 

机构地区：[1]北京市神经外科研究所神经影像中心

出　　处：《中华放射学杂志》2003年第10期872-876,共5页Chinese Journal of Radiology

基　　金：国家自然科学基金资助项目 (3 0 0 70 2 3 4);北京市自然科学基金资助项目 (70 0 2 0 11)

摘　　要：目的　评价星形细胞水肿对局部脑血流量的影响。方法　随机选取体重在 2 80g至36 0 g之间的雄性Wistar大鼠 16只 ,分为实验组和对照组 ,分别将反式 1 氨基环戊基 1,3 二羧酸(tACPD)溶液或生理盐水 (NS)通过微量注射器注入右侧尾状核。脑水含量通过干湿称重法测定 ;动态CT灌注成像通过微机辅助CT脑灌注成像软件完成 ;Evan蓝是否外渗入脑作为检测血脑屏障(BBB)和内皮细胞受损的指示剂 ;组织病理学检查包括光学显微镜和超微电子显微镜 ,均在尾状核注射操作完成后 6h进行。结果　注射tACPD 6h后的脑组织水含量与对照组及实验组对侧尾状核比较差异有显著性意义 (t值分别为 11 2 15和 10 4 37,P值均 <0 0 5 )。组织病理学检查可以显示星形细胞水肿状况及其与微循环的关系 ,组间差异亦存在显著性。Evan蓝外渗试验未见脑组织蓝染 ,提示tACPD的注入并未使血脑屏障的通透性增加。CT灌注成像中 ,实验组和对照组中局部脑血流量(rCBF)、平均通过时间 (MTT)和最大峰值时间 (TTP)测值组间差异有显著性意义 (t值分别为15 6 90、- 7 916和 - 5 2 34,P值均 <0 0 5 ) ,rCBV组间差异无显著性意义 (t=1 815 ,P >0 0 5 )。结论　星形细胞水肿可以诱发或加重局部脑血流量的减低。有效缓解初期星形细胞水肿 ,可以为脑缺血?Objective To evaluate the influence of astrocytic swelling on regional cerebral blood flow. Methods Sixteen male Wistar rats weighing from 280 g to 360 g were used. 1-aminocyclopentane-trans-1, 3-dicarboxylic acid (tACPD) was microinjected into the right caudatum. Brain water content was determined by a wet weight/dry weight technique. Dynamic CT perfusion imaging was achieved from personal computer aided mapping. Extravasation of Evan′s blue (EB) into the brain was determined as an indicator of disturbance in the blood-brain barrier (BBB) and endothelial cells. Histopathologic examination by both light and electron microscopy was performed in 6 hours after injection surgery. Results Brain edema was induced after tACPD injection and astrocytic swelling was showed in histopathologic examination. EB extravasation showed no blue stain, indicating no increase in BBB permeability induced by tACPD-injection. Electron microscope study confirmed this finding and revealed remarkable swelling of astrocytes, especially endfoot processes of astrocytes around capillaries at 6 h after tACPD-injection. The abnormal extent on CT perfusion images matched with abnormal extent on histopathologic examination. There were statistical significant differences between operated group and control group (P<0.05). Conclusion Astrocytic swelling can induce or deteriorate the decrease of regional cerebral blood flow. The effectually remission of primary astrocytic swelling may provide new clues for the therapeutic intervention.

关 键 词：实验 脑星形细胞水肿 CT灌注成像 病理学 局部脑血流量 

分 类 号：R816.1[医药卫生—放射医学]