脑脉泰胶囊对大鼠局灶性脑缺血再灌注损伤血脑屏障和 脑水肿 的影响

 目的 研究脑脉泰胶囊对大鼠局灶性脑缺血再灌注损伤血脑屏障和脑水肿的影响。 方法 大脑中动脉线拴法（ MCAO ）制作大鼠局灶性脑缺血再灌注模型：雄性 SD 大鼠随机分为假手术组（ sham ）、脑缺血再灌注模型组（ MCAO ）、脑脉泰大、中、小剂量组（ MCAO+ 脑脉泰 2.2 ， 1.1 ， 0.6 g ·kg^-1 ）和尼莫地平组（ MCAO+ 尼莫地平 1 × 10 ^-2 g ·kg^-1 ），每组 10 只大鼠。大鼠大脑中动脉阻断 1.5 h ，再灌注 24 h 。伊文思兰（ EB ）法测定血脑屏障的损伤程度；用 TUNEL 法和免疫组化染色法分别检测缺血半暗带凋亡细胞和水通道蛋白（ AQP4 ）的表达；电镜观察脑组织超微结构。 结果 脑脉泰大、中 2 个剂量能显著减少大鼠实验性局灶性脑缺血的 EB 含量、降低脑含水量，脑缺血半暗带的凋亡细胞显著减少， AQP4 表达减少，与 MCAO 模型组比较，有显著性差异（ P <0.05 ）。电镜显示 MCAO 模型组神经细胞胞质水肿，神经元核不规则，核膜断续，线粒体肿胀、嵴断裂或空泡化，粗面内质网扩张。与 MCAO 模型组比较，脑脉泰组大鼠神经细胞水肿和线粒体损伤明显减轻。 结论 脑脉泰对脑缺血 / 再灌注损伤的保护作用和减轻脑水肿的机制，可能与抑制神经细胞凋亡，降低 AQP4 蛋白的表达，减少线粒体和血脑屏障的损伤有关。

Effect of Naomaitai Capsules on Rat Blood-Brain Barrier and Cerebral Edema Induced by Cerebral Ischemic Reperfusion Injury

ABSTRACTOBJECTIVE To investigate the effect of Naomaitai capsule on blood-brain barrier and cerebral edema in cerebral ischemic reperfusion injury rats. Methods A reversible middle cerebral artery occlusion model (MCAO) was built in this study. Male Sprague-dawley rats were randomly divided into six groups(n=10) sham-operated group，MCAO group，MCAO+ Naomaitai (2.2, 1.1, 0.6g·kg-1) group and MCAO combined nimodipine (1×10-2g·kg-1) group. 24 hours after reperfusion, the permeability of the blood brain barrier was evaluated by measurement of the Evans Blue (EB) content in the brain with spectrophotometer. The brain tissue was obtained for TUNEL staining that was used for the determination of neuronal apoptosis. AQP4 protein expression of the neurons was detected with immunohistochemistry. Electron microscope was used to observe the ultrastructures of neuron and mitochondria. Results The Naomaitai (2.2, 1.1g·kg-1) reduced the permeability of blood brain barrier and brain water content. Apoptotic cells and AQP4 protein expression were significantly decreased compared with the MCAO group (P<0.01). Electron microscope revealed that neuronal cytoplasm was swollen and denaturalization, the nucleus of neuron were irregular, and nuclear membrane was not successive or broken．The mitochondria were swelling and the semicrista of mitochondria were broken．Rough endoplasmic reticulum expanded, the mitochondria changed like-bubbles．In Naomaitai group，the cellular swelling and mitochondrial damage were less lightened．Conclusion The mechanism of brain protection and cerebral edema alleviation with Naomaitai may relate to inhibit the apoptosis of neural cells, decrease the expression of AQP4，and relieve the damages of mitochondria and blood brain barrier in rats suffered from local cerebral ischemic reperfusion injury.