高压氧对脑缺血再灌注小鼠脑源性神经营养因子及神经细胞结构的影响

Effects of hyperbaric oxygen on brain derived neurotrophic factor and the structure of neurons after the cerebral ischemia-reperfusion in mice

目的探讨高压氧对脑缺血再灌注小鼠脑源性神经营养因子(BDNF)及神经细胞结构的影响。方法昆明小鼠27只,随机分为高压氧组、对照组、假手术组,每组9只。采用无创微动脉夹阻断双侧颈总动脉血流30min后松开动脉夹恢复血流的方法,建立脑缺血再灌注模型。高压氧组在模型完成当天开始高压氧处理,每日1次,共10次;对照组及假手术组不做高压氧处理。在高压氧处理完成后次日,将高压氧组及其他2组小鼠断头处死,取脑后分离额叶皮层和海马,进行HE染色,采用免疫组化技术观察神经细胞结构及BDNF表达情况。结果普通光镜显示3组小鼠额叶皮层及海马有不同程度的神经细胞变性、坏死;高压氧组与对照组异常细胞数比较,差异有统计学意义(P<0.05);同组小鼠的皮质和海马比较,差异无统计学意义(P>0.05)。免疫组织化学检测显示,3组小鼠的皮质与海马均可见BDNF染色阳性细胞,高压氧组阳性细胞较多,与对照组比较,差异有统计学意义(P<0.05);另外,高压氧组和对照组BDNF阳性细胞均比假手术组增多,差异有统计学意义(P<0.05);同组小鼠的皮质和海马BDNF阳性细胞比较差异无统计学意义(P>0.05)。结论高压氧可减轻脑缺血再灌注损伤,增强BDNF在脑神经细胞中的表达;两者的联系及作用机制有待进一步研究。

Objective To explore the effects of hyperbaric oxygen(HBO) on brain derived neurotrophic factor(BDNF) and the changes of neuron structure after cerebral ischemia-reperfusion(CIR) in mice. Methods Twenty-seven mice were randomly and evenly divided into three groups : a HBO group, a control group and a sham-operation group (SO group). CIR models were established by clamping both carotid arteries in mice for 30 min,and then, untying clamps. 0.20 MPa HBO was applied once a day for 10 days after establishment of models in HBO group,but not in the control and SO groups. Following sacrifice after treatment and acquirement of cortex and hippocamal tissues, HE stain and immunohistochemistry technique were used to observe the changes of neuron structure and expression of BDNF. Results The neural degeneration and necrosis in cortex and hippocampus (issues) were observed under light microscope after CIR, and the amount of abnormal cells in the control group was more than that in HBO group (P<0.05). It is shown by the results of immunohistochemistry that the expression of BDNF in cortex and hippocampus tissues was observed in 3 groups,and compared with that in the SO group,the amount of positive cells in the HBO and control groups was increased obviously (P<0.05), so was that in the HBO group with comparison with that in the control group (P<0.05). Conclusion HBO could alleviate brain injury after CIR and improve the expression of BDNF significantly. The relationship between HBO and BDNF and its mechanism should be further studied.