间歇性低压缺氧预处理对大鼠全脑缺血/再灌注海马CA1区Ngb和Bcl-2蛋白表达的影响

Effect of intermittent hypobaric hypoxia preconditioning on expression of Ngb and Bcl-2 in hippocampal CA1 region in rats with global cerebral ischemia-reperfusion

目的:探讨间歇性低压缺氧预处理对大鼠全脑缺血/再灌注海马CA1区脑红蛋白(Ngb)和Bcl-2蛋白表达的影响。方法:将Wistar大鼠随机分为假手术组、低压缺氧预处理对照组、全脑缺血/再灌注组、低压缺氧预处理+全脑缺血/再灌注组4组,将间歇暴露于低压缺氧环境的大鼠作为低压缺氧预处理对照组。采用Pulsinelli四血管闭塞法复制大鼠全脑缺血/再灌注模型,夹闭颈总动脉造成全脑缺血8 min后再灌注。用硫堇染色法和免疫组织化学方法分别观察大鼠海马组织学改变和海马组织Ngb、Bcl-2蛋白表达变化。结果:低压缺氧预处理+全脑缺血/再灌注组大鼠海马CA1区存活细胞数较全脑缺血/再灌注组明显增加,其海马组织Ngb和Bcl-2蛋白表达量较全脑缺血/再灌注组显著升高。结论:间歇性低压缺氧预处理可能通过上调海马组织Ngb和Bcl-2蛋白的表达,减少全脑缺血再灌注后海马神经元的死亡而发挥神经保护作用。

AIM： To study the effect of intermittent hypobaric hypoxia preconditioning （IHHP） on the expres- sion of neuroglobin （Ngb） and Bcl-2 in hippocampal CA1 region in the rats with global cerebral ischemia-reperfusion. METHODS ： The Wistar rats were randomly divided into sham group, IHHP control group, global cerebral iscbemia-reper- fusion group （ I/R group）, and IHHP ＋ I/R group. The 4-vessel occlusion rat model of Pulsinelli was performed in the rats in I/R group and IHHP ＋ I/R group, in which the common carotid artery was occluded for 8 min before reperfusion. Thio- nine staining and immunohistochemical staining were used to observe the histological changes of the hippcampus and the ex- pression of Ngb and Bcl-2 in the hippocampal CA1 region. RESULTS： A significant increase in the quantity of surviving cells in the hippocampal CA1 region was observed in IHHP ＋ I/R group as compared with I/R group. There was a signifi- cant increase in the expression of Ngb and Bcl-2 in the hippocampal CA1 region in IHHP ＋ I/R group as compared with IZ R group. CONCLUSION： Through the up-regulation of hippocampal Ngb and Bcl-2 expression, intermittent hypobaric hypoxia preconditioning may play a role in neuroprotection by reducing hippocampal neuronal apoptosis from ischemia- reperfusion.