大鼠脑局灶性缺血再灌注后的细胞凋亡及bcl-2、bax蛋白表达的改变和银杏叶提取物干预的研究

目的探讨大鼠大脑中动脉重度栓塞再灌注动物的脑细胞凋亡及其相关调控基因bcl鄄2、bax阳性蛋白质表达的变化和银杏叶提取物(EGB)的治疗作用。方法采用插线法制作大鼠大脑中动脉栓塞后再灌注模型。将大鼠随机分为对照组、栓塞3h组、栓塞3h再灌注24h组、栓塞3h再灌注48h组、栓塞3hEGB干预、再灌注24hEGB干预组、再灌注48hEGB干预组。观察脑缺血/再灌注不同时点大鼠脑细胞凋亡(TUNEL法)、凋亡相关基因bcl鄄2、bax(S鄄P免疫组化法)的阳性表达和EGB对其治疗作用。EGB干预方法:术后2min腹腔注射,8h/次。结果大鼠大脑中动脉栓塞3h、栓塞3h/再灌注24、48h时,bcl鄄2、bax表达增强,细胞凋亡逐步加重,损伤加重。EGB干预后,bcl鄄2表达增强、bax表达减弱,细胞凋亡明显减少。结论细胞凋亡与bcl鄄2/bax有关,银杏叶提取物(EGB761)可以明显抑制大鼠脑组织缺血/再灌注后细胞凋亡的发生。

Rat brain cell apoptosis and the expression of bcl-2 bax after focal cereberal ischemia/reperfusion and effects of extract of Ginkgo biloba

Objective To explore the relationship between the number of apopfosis ell and the expression of the bcl-2 and bax, and the effecct of the extrat of Ginkgo biloba(EGB) on all of them after ischemia/reperfusion. Methods The animal model of middle cerebral artery(MCA)ischemia/reperfusion was used. The rats were randomly divided into seven groups: (1)control group; (2)13 h group; (3)ischemia/reperfusion(R) 24 h group; (4)R 48 h group; (5)13 h+EGB group; (6)R 24 h+EGB group; (7)R 48 h+EGB group. We observed the alteration of apoptosis(TUNEL method) and the expression of bcl-2 and bax (immunohistochemistry method) after ischimia 3 h/reperfusion 24 h and 48 h. The usage of EGB:injection by abdominal cavity 2 min after operation, 3 times daily. Results Compared with control group, the number of the expression of bcl-2 was obviously increased (P<0.05 or 0.01)and the number of the apoptosis was obviously increased too (P<0.01) in the groups of ischemia; Compared with the groups of ischemia, the number of the expression of bcl-2 was obviously increased (P<0.01), while the number of the expression of bax was reduced obviously respectively(P<0.01) and the number of the apoptosis was reduced obviously respectively(P<0.01). Conclusion The mechanism of apoptosis may be related to up-regulation of bcl-2 and down-regulation of bax protein expression. EGB can inhibit apoptosis after ischemia/reperfusion, and has a obvious efficacy in focal ischemia/reperfusion.