大鼠局灶性脑缺血再灌注后神经细胞凋亡和Bcl-2蛋白表达的改变及银杏叶提取物的保护作用(英文)

Effects of Ginkgo biloba extract on apoptosis and expression of Bcl-2 in rats following focal cerebral ischemia and reperfusion

目的 研究大鼠局灶性脑缺血再灌注后神经细胞凋亡和Bcl-2蛋白表达的变化及银杏叶提取物对其表达的影响。方法 制造大鼠大脑中动脉缺血再灌注模型。40只Wistar雄性大鼠被随机分为A假手术组、B缺血组、C小剂量治疗组和D大剂量治疗组。于术前30min及术后1h分别给予银杏叶提取物20mg/kg和40mg/kg腹腔内注射。应用TTC染色及HE染色观察梗死体积及缺血坏死程度,应用免疫组化染色及POD法检测Bcl-2蛋白表达及凋亡细胞数。结果 C、D两组梗死体积明显小于B组(P<0.01),D组梗死体积小于C组(P<0.05);C、D两组凋亡细胞数明显少于B组(P<0.01),D组凋亡细胞数少于C组(P<0.05);C、D两组Bcl-2蛋白表达明显高于B组(P<0.01),D组Bcl-2蛋白表达高于C组(P<0.05)。结论 银杏叶提取物可通过上调Bcl-2蛋白表达,减少神经细胞凋亡,对脑缺血再灌注损伤起保护作用,疗效与剂量有关。

Objective: To study the effects of Ginkgo biloba extract (GBE) on apoptosis and the expression of Bcl-2 following focal cerebral ischemia and reperfusion. Methods:The model of middle cerebral artery occlusion (MCAO) and reperfusion was set up. Forty Wistar male rats were randomly divided into 4 groups : A (sham-operated group), B (ischemic group), C (small-dose GBE treatment group) and D (high-dose GBE treatment group). GBE of 20 mg/kg and 40 mg/kg was respectively intraperitoneally injected to rats 0.5 h before and 1 h after focal cerebral ischemia. The brain sections were used for POD staining and Bcl-2 immunohistochemical staining. Meanwhile, the sections were stained by TTC and HE for surveying the infarct volume and the degree of ischemia.Results:The infarct volumes and apoptotic cells of groups C and D were significantly less than group B ( P <0.01), Received date:Oct. 20, 2003 those of group D were less than group C( P <0.05). The expression of Bcl-2 positive cells in groups C and D was significantly higher than in group B ( P <0.01), that in group D was higher than that in group C ( P <0.05).Conclusions: GBE can decrease the number of apoptotic cells after ischemia and reperfusion by up-regulating Bcl-2. The effect of GBE is correlated with dose.