氢气对大鼠全脑缺血再灌注损伤海马CA1区神经元的保护作用

摘要

Objective To investigate the effect of high concentration hydrogen gas on neurons in the rat hippocampus CA1 region during global cerebral ischemic/reperfusion injury (GCIR) Methods Four-vessel occlusion was used to establish rat model with GCIR injury. One hundred and five healthy male Sprague-Dawley rats were randomly divided into sham operation group(SH group, n = 15), model group(4-VO group, n = 45) and treatment group(4-VO+H2 group,n = 45). After 72 h and 9 d reperfusion, hippocampal CA1 region pyramidal neurons in every group were detected with Nissle staining , immunohistochemical neuron-specific nuclear protein (NeuN), specific protein antibody microglial cells (Iba1) staining and the relationship of position between neurons and microglia was observed through fluorescence double staining. We used Morris water maze to test the space orientation ability and the learning and memory ability in rats after 9 d reperfusion. Results Compared with those of 4-VO group,the neurons of hippocampus CA1 region were closer to normal in 72 h and 9 d in 4-VO+H2 group and neuron form and the number of neuron survival were increased significantly (P < 0.05);immunohistochemical staining showed that the number of neuron survival in 4-VO+H 2 group was obviously higher than that in 4-VO group (P < 0.05) and the number of microglia in 4-VO group was obviously higher than that in 4-VO+H2 group (P < 0.05). Water maze experiment showed that the swimming time in quadrant Ⅳ in 4-VO+H2 group was longer than that in 4-VO group (P < 0.05). Conclusion Inhalation of high concentration hydrogen gas has prominent protective effect on neurons of rat hippocampal CA1 region during reperfusion. The mechanism may be related with inhibiting the microglia excitation and activation during GCIR.%目的:观察吸入高浓度氢气对大鼠全脑缺血再灌注(I/R)损伤海马CA1区神经元的影响.方法:雄性SD大鼠105只,采用四血管阻断法(4-VO)建立全脑I/R损伤模型.随机数字表法将大鼠分为3组,即假手术组(SH组,n=15),模型组(4-VO组,n=45),治疗组(4-VO+H2组,n=45).检测各组再灌注72 h、9 d尼氏染色海马CA1区锥形神经元、免疫组织化学法神经元特异性核蛋白抗体(NeuN)、小胶质细胞特异性蛋白抗体(Iba1)染色计数以及免疫荧光双标NeuN与Iba1观察神经元与小胶质细胞的位置关系;再灌注9 d后水迷宫实验,检测大鼠的空间定位和学习记忆能力.结果:与4-VO组相比,4-VO+H2组于再灌注72 h及9 d海马CA1区神经元形态更接近正常,神经元存活数量明显增多(P<0.05);免疫组织化学染色结果显示4-VO+H2组神经元存活数量明显高于4-VO组(P<0.05),4-VO组小胶质细胞数量明显高于4-VO+H2组(P<0.05).水迷宫实验结果显示,4-VO+H2组第4象限游泳时间明显长于4-VO组(P<0.05).结论:再灌注同时吸入高浓度氢气对大鼠全脑I/R损伤海马CA1区神经元可产生明确保护作用,其机制可能与氢气抑制I/R后小胶质细胞的激活与活化有关.