脑缺血—再灌注后BDNF和bFGF表达与神经元凋亡的关系及脑脉康的干预作用

目的:观察脑缺血-再灌注损伤后脑源性神经营养因子(BDNF)、碱性成纤维细胞生长因子(bFGF)蛋白表达与神经元凋亡的关系,探讨脑脉康的干预作用及机制.方法:建立大鼠脑缺血-再灌注损伤模型,应用脑脉康进行干预.采用免疫组化方法和凋亡原位末端标记技术(TUNEL),观察脑缺血3 h及再灌注7、24、96和168 h的BDNF、bFGF蛋白分布、表达的动态变化与凋亡细胞分布与时相关系以及脑脉康的干预作用.结果:模型组大鼠缺血3 h、再灌注7 h半暗区皮质及新纹状体区BDNF、bFGF表达即明显升高,再灌注24 h达到高峰;缺血侧海马CA1～CA3区及丘脑则于再灌注96 h达到高峰.缺血侧半暗区神经元凋亡于24～96 h达到高峰;海马CA1～CA3区及丘脑、纹状体区于再灌注168 h仍有相当数量的凋亡细胞.与对照组比较,中药组于再灌注24～168 h BDNF、bFGF表达显著升高(P<0.05或P<0.01),凋亡细胞数则明显减少(P<0.05或P<0.01).结论:脑缺血-再灌注损伤后BDNF、bFGF的表达升高,在一定程度上可抑制神经元凋亡,促进神经功能状态的恢复,对脑缺血损伤有重要的保护作用.脑脉康可能通过促进脑缺血-再灌注损伤后BDNF、bFGF表达,激活内源性神经保护机制,发挥其抗凋亡作用.

Study on the relation of brain-derived neurotrophic factor,basic fibroblast growth factor expression and apoptosis of neuron in rats following focal cerebral ischemia/reperfusion and effect of Naomaikang(脑脉康)on it

Objective: To observe the relationship of brainderived neurotrophic factor(BDNF ), basic fibroblast growt h factor (bFGF) expression and apoptosis of neuron, and investigate the effect o f Naomaikang(NMK)on it. Methods: The rat model of cerebral ischemia/reperfusion injury was established, a nd the effects of NMK on it was observed. By the methods of immunohistochemistry and terminal deoxynucleotidyltransferase mediated dUTP biotin nick end labelin g, the expression and distribution of BDNF and bFGF at 3 hour of ischemia an d 7, 24, 96 and 168 hours after reperfusion were observ ed as well as the relation to the distribution of apoptosis cells and time. Results: BDNF and bFGF expressions increased in peuma cortex and new striaturn at 3 hour s of ischemia a nd 7 hours after reperfusion in model rats, peaking at 24 hours after reperfusio n, and those of CA1CA3 regions in hippocampus of ischemia and thalam us were p eaking at 9 6 hours. Nevertheless, the number of apoptosis neurons of peuma of ischemia reac hed peak a t 2496 hours after reperfusion, and those of CA1CA3 regi ons in hippocampus, thalamus and striaturn, were more at 168 hours after reperfu sion. The expressions of BDNF and bFGF i n NMK treated animals were increased and the apoptosis cells were decreased at 24168 hours compared to the controls(P<005 or P<001). Conclusion: Upregulation of BDNF and bFGF are induced by focal cerebral ischemia/reperf usion in penumbra region in rat brain, which inhibit apoptosis o f neurons. NMK plays a neuroprotective role by improving expression of BDNF and bFGF as well as activating internal neuroprotective effects after cerebral ischemia/reperfusion.