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目的探讨脑淋巴引流途径的生理意义和在缺血性脑神经元损伤中的作用。方法应用摘除颈部浅、深淋巴结并结扎其输入和输出淋巴管的方法建立脑淋巴引流阻滞(CLB)大鼠模型 ,大脑中动脉线栓法制作局部脑梗塞(MCAO)大鼠模型。将动物分为假手术对照(SO)组、CLB组、MCAO组和CLB +MCAO组。应用多种技术手段 ,检测动物不同时间点脑微区血流量(激光多普勒法)、皮层诱发电位 ,测定脑组织一氧化氮合酶(NOS)活性 ,丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性 ,干湿重比较法观察脑组织含水率 ,原子吸收分光光度法测定脑组织电解质含量 ,TUNEL法观察神经元凋亡 ,电子显微镜观察细胞损伤等指标。结果在术后观察7d内 ,与SO组大鼠比较 ,CLB组不同脑皮层部位微区血流量显著下降 ,体感诱发电位潜伏期明显延长(波幅未见明显变化) ,脑组织NOS活性逐渐升高 ,MDA含量增加SOD显著活性下降。脑组织水、Na +含量增加 ,伴有K +丢失和Ca2 +积聚 ,在大脑新皮层和海马区可见TUNEL染色阳性的凋亡神经元。与MCAO组比较 ,CLB +MCAO组大鼠神经功能损伤更为严重 ,同时脑微区血流量降低和MDA含量增加更显著 ,SOD活性明显下降 ,脑组织水、Na+含量增加、K+丢失和Ca2 +积聚更为明显 ,神经元细胞器损伤更加严重。结论脑淋巴引流是维持脑组织内环境稳
Objective To investigate the physiological significance of brain lymphatic drainage and its role in ischemic neuronal injury. Methods Cerebral lymphatic drainage block (CLB) rat model was established by removing the superficial and deep cervical lymph nodes and ligating the lymphatic vessels into and out of the lymphatic vessels. The rat model of local cerebral infarction (MCAO) was established by middle cerebral artery occlusion. Animals were divided into sham-operated control (SO) group, CLB group, MCAO group and CLB + MCAO group. A variety of techniques were used to detect cerebral micro-area blood flow (laser Doppler) and cortical evoked potentials at different time points. The activity of nitric oxide synthase (NOS), malondialdehyde (MDA) The activity of SOD, the moisture content of brain tissue were measured by wet and dry weight comparison. The content of electrolytes in brain tissues was determined by atomic absorption spectrophotometry. The apoptosis of neurons was observed by TUNEL method and the cell damage was observed by electron microscopy. Results Compared with the SO group, the cerebral blood flow in different cerebral cortex areas of CLB group decreased significantly (P <0.05), and the incubation period of somatosensory evoked potentials significantly prolonged (the amplitude did not change obviously). The NOS activity of brain tissue gradually increased, Increased MDA content significantly decreased the significant activity of SOD. Brain water, Na + content increased, accompanied by K + loss and accumulation of Ca2 +, visible in the neocortex and hippocampus TUNEL staining of apoptotic neurons. Compared with the MCAO group, the neurological impairment was more serious in the CLB + MCAO group. At the same time, the blood flow decreased and the content of MDA increased significantly in the CLB + MCAO group. The SOD activity decreased obviously. The content of water and Na + increased, K + loss and Ca2 + Accumulation is more obvious, neuron cell organelle damage more serious. Conclusion Brain lymphatic drainage is to maintain the stability of brain tissue environment