脑缺血再灌注损伤后大脑皮质和海马区脑红蛋白的表达变化

Changes in neuroglobin expression in cerebral cortex and hippocampus after cerebral ischemia-reperfusion injury

目的研究脑缺血再灌注损伤后脑红蛋白（NGB）在大脑皮质和海马区的表达变化。方法采用双侧颈总动脉夹闭法制备沙鼠全脑缺血再灌注损伤模型，在缺血20min后分别再灌注2、8、16、24、48、72h，处死动物并取脑，采用免疫组化染色结合阳性细胞计数的方法，检测脑缺血再灌注损伤后大脑皮质和海马区NGB的表达变化。结果沙鼠脑缺血再灌注损伤后，大脑皮质的NGB蛋白表达于损伤后16～48h上调，而海马区NGB表达则呈持续减少的趋势。病理学检测显示海马区神经细胞损伤程度较大脑皮质区严重。结论不同脑区对缺血性损伤的耐受性差异可能与NGB表达水平有关。NGB表达上调可能对脑缺血再灌注损伤具有保护作用。

Objective To observe the dynamic changes in neuroglobin （NGB） expression in cerebral cortex and hippocampus alter cerebral ischemia-reperfusion injury in gerbils. Methods The global cerebral ischemia of gerbils was induced by clamping bilateral carotid arteries for 20 minutes, then they were released to allow reperfusion for 2h, 8h, 16h, 24h, 48h and 72h. The NGB expression in cerebral cortex and hippocampus was measured with immunohistochemical methods coupled with computer-assisted image analysis. Results The changes in NGB expression were different in cerebral cortex and in the hippocampus. NGB protein was up-regulated from 16h to 48h after ischemia-reperfusion insult to cerebral cortex, whereas it was down-regulated hippocampus. Conclusion The different expressions of NGB in cerebral cortex and hippocampus are suggestive of compensatory and repair mechanisms in ischemia-damaged neurons after transient global cerebral ischemia. The increased expression of endogenous NGB in the brain after ischemia-reperfusion may be associated with the protective response to ischemic damage.