蓝布正对大鼠梗死灶周围大脑皮质神经元凋亡和蛋白表达的影响

Effects of Gei Herba on Neuronal Apoptosis and Protein Expression in Peri-infarct Cortex of Rats with Permenant Middle Cerebral Artery Occlusion

目的:观察蓝布正对局灶脑缺血大鼠梗死灶周围大脑皮质神经元凋亡及蛋白表达的影响,探讨其促脑卒中后神经功能恢复作用及机制。方法:72只SD大鼠采用线栓法建立脑缺血损伤模型(p MCAO),随机分成假手术组,模型组,蓝布正高、中、低剂量组(7.00,3.50,1.75 g·kg-1),银杏叶片组(0.007 g·kg-1),连续ig给药3 d。进行神经功能评分,四氮唑红(TTC)染色观察大鼠的脑梗死范围,苏木素-伊红(HE)染色观察梗死灶周围大脑皮质的病理形态学改变,原位细胞凋亡检测(TUNEL)梗死灶周围大脑皮质神经元凋亡,免疫组化检测梗死灶周围大脑皮质中B细胞淋巴瘤/白血病-2(Bcl-2)和Bcl-2相关X蛋白(Bax)蛋白表达的情况。结果:模型组一侧大脑中动脉永久性栓塞3 d大鼠神经功能评分增加,脑梗死范围增多,梗死灶周围大脑皮质部分神经元变性,Bcl-2蛋白表达下降,Bax蛋白水平升高,与假手术组比较,差异具有统计学意义(P<0.01);与模型组比较,蓝布正高、中、低剂量组均能不同程度减少神经功能评分,缩小脑梗死范围,改善梗死灶周围大脑皮质的病理形态学改变;抑制梗死灶周围大脑皮质神经元凋亡,促进抗凋亡蛋白Bcl-2的表达,抑制促凋亡蛋白Bax表达(P<0.05)。结论:蓝布正对大鼠脑缺血性损伤具有一定的保护作用,机制可能与其促进梗死灶周围大脑皮质Bcl-2水平增加,抑制Bax活性,提高脑组织抗缺血损伤的能力和抑制神经细胞凋亡有关。

Objective： To observe the effect of Gei Herba on neuronal apoptosis and protein expressions in the peri-infarct cortex of rats with permenant middle cerebral artery occlusion,and investigate its possible mechanism. Method： Totally 72 SD rats were used to establish the models of permenant middle cerebral artery occlusion（ p MCAO） by suture-occluded method,and they were randomly divided into sham-operation group,model group,Gei Herba high,middle and low dose groups（ 7. 00,3. 50,1. 75 g·kg^-1） and positive control group（ Yinxingye tablet,0. 007 g·kg^-1）. The rats were administered with appropriate drugs intragastrically for 3consecutive days. The nerve function scores were detected; extent of cerebral infarction was observed by 2,3,5-triphenyltetrazolium chloride（ TTC） staining; the pathological changes in peri-infarct cortex were observed by htoxylin eosin（ HE） staining; neuronal apoptosis was detected by TUNEL staining; Bcl-2 and Bax protein expression levels were detected by immunohistochemical assay. Result： The nerve function scores and the extent of cerebral infarction were significantly increased; and the neurons were degenerated; the levels of Bax protein expression were increased and Bcl-2 protein expression were decreased of the peri-infarct cortex in p MCAO rats after cerebral ischemia for 3 d,with statistically significant differences as compared with the sham operation group（ P〈0. 01）. As compared with the model group,Gei Herba high,middle and low dose groups showed reduction in the nerve function scores and the cerebral infarction extent,improved the pathological changes in peri-infarct cortex,inhibited the neuronal apoptosis,promoted the protein expression of apoptin Bcl-2,and inhibited the protein expression of apoptin Bax（ P〈0. 05）. Conclusion： Gei Herba has certain protective effect on the cerebral ischemia injury in rats,and its mechanism may be related to increasing Bcl-2 level,inhibiting Bax activities in peri-infarct cortex,promoting anti-ischemia brain injury capacity and inhibiting apoptosis of nerve cells.