Objective To investigate the effects of astragus injection on blood-brain barrier and expressions of occludin and zonula occludens protein-1 (ZO-1) after cerebral ischemia and reperfusion (I/R) and its mechanism in rats. Methods Fifty-four SD rats were divided randomly into three groups; sham-operated group, normal saline control group and treatment group with astragus injection. The model was performed by the occlusion of middle cerebral artery, and the sham operation was made by isolation of the artery without occlusion. After the establishment of model, 2 ml/kg of astragus injection was injected into the abdominal cavity immediately. Water content, Evans Blue (EB) leakage and expressions of occludin and ZO-1 protein were respectively detected by dry-wet weight assay, spectrophotometry and immunohistochemistry. Results Compared with the sham operation group, the water content in brain tissue C(83. 12±0. 28)% vs. (78. 14± ,0.26)%] and EB leakage (μg/g: 419.3±19.4 vs. 85.4±12.7) were increased markedly, the numbers of blood vessels with expressions of occludin and ZO-1 protein were decreased obviously in the model group (Occludins 28. 5±4. 2 vs. 90. 3±4. 7, ZO-1.. 34. 8±6. 2 vs. 118. 5±8. 9, both P<0. 01). Compared with the model group, the water content in brain tissue C(81. 06±0. 42)% vs. (83.12± 0. 28)%3 and EB leakage C(205. 9±17. 0) vs. (419. 3±19. 4) ng/gD were decreased, the expressions of occludin (62. 7±3. 5) and ZO-1 (98. 6±5. 3) protein increased significantly in astragus treatment group (all P<0. 05). Conclusion Astragus injection has protective effects on blood-brain barrier after cerebral ischemia and reperfusion. Its mechanism may be associated with the up-regulation of expressions of occludin and ZO-1 protein.%目的 探讨黄芪注射液对大鼠脑缺血/再灌注(I/R)后血脑屏障的保护作用及其机制.方法 SD大鼠54只,按随机数字表法分为3组,每组18只.采用大脑中动脉闭塞法复制脑I/R损伤模型;假手术组只分离不结扎;黄芪治疗组在制模后即刻经腹腔注射黄芪注射液2ml/kg.采用干湿重法、分光光度计法及免疫组化法分别检测各组大鼠脑组织含水量、伊文思蓝(EB)含量及咬合蛋白(Occludin)、闭锁小带蛋白(ZO-1)蛋白的表达.结果 与假手术组相比,模型组大鼠脑组织含水量[(83.12±0.28)%比(78.14±0.26)%)],EB含量(μg/g:419.3±19.4比85.4±12.7)明显增多,Occludin和ZO-1的阳性血管数(个)明显减少(Occludin:28.5±4.2比90.3±4.7,ZO-1:34.8±6.2比118.5±8.9,均P<0.01),与模型组相比,黄芪治疗组大鼠脑组织含水量[(81.06±0.42)%比(83.12±0.28)%],EB含量(205.9±17.0比419.3±19.4)显著减少,Occludin阳性血管数(62.7±3.5)和ZO-1的阳性血管数(98.6±5.3)显著增加(均P<0.05).结论 黄芪注射液对脑1/R后血脑屏障具有保护作用,这可能与黄芪注射液上调Occludin,ZO-1的表达有关.
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