黄芪注射液对脑缺血再灌注大鼠海马神经元形态学和Apaf-1表达的影响

The Effects of Astragalus Injection on the Morphology and Expression of Apaf-1 in Hippocampal Neurons after Cerebral Ischemia Reperfusion in Rats

目的观察黄芪注射液对脑缺血再灌注大鼠海马神经元形态学和Apaf-1表达的影响。方法SD大鼠随机分为假手术组、脑缺血再灌注组(再灌注组)和黄芪注射液处理组(实验组)。采用Pulsinelli四血管阻断法建立大鼠脑缺血再灌注模型,实验组于术前30 min腹腔注射黄芪注射液6 mL/kg,每24 h注射1次,各组于再灌注后24h断头取脑。采用HE染色,光镜下观察海马组织病理学改变;透射电镜下观察海马神经元超微结构变化;免疫组织化学法和Western blot法检测大鼠海马组织凋亡蛋白酶激活因子-1(Apaf-1)蛋白表达的变化。结果与假手术组比较,再灌注组大鼠海马神经元出现胞核及线粒体损伤,并且Apaf-1蛋白的表达明显升高(免疫组化:0.024±0.001 vs 0.109±0.011;Western blot法:0.270±0.018 vs 0.894±0.072,均P<0.01),与再灌注组比较,实验组大鼠海马神经元胞核及线粒体损伤明显减轻,而Apaf-1蛋白的表达明显降低(免疫组化:0.048±0.005;Western blot法:0.392±0.046,均P<0.01)。结论黄芪注射液可减轻脑缺血再灌注大鼠海马神经元的损伤,其作用机制可能与抑制Apaf-1蛋白表达有关。

Objective To investigate the effects of astragalus injection on the morphology and expression of Apaf-1 in hippocampal neurons after cerebral ischemia reperfusion in rats. Methods The male SD rats were randomly divided into 3 groups, sham-operated group, cerebral ischemia-reperfusion group （reperfusion group） and astragalus injection interven-tion group （experiment group）. The global cerebral ischemia-reperfusion rat model was established by Pulsinelli four-vessel occlusion method. The astragalus injection group was intraperitoneally injected with astragalus 6 mL/kg, 30 mins before sur-gery and repeated every 24 h. Rat brains were removed 24 h after reperfusion in each group. HE staining was used to observe the pathological changes of the hippocampal neurons under the light microscope. The ultrastructural changes of hippocam-pal neurons were observed by transmission electron microscopy. Immunohistochemistry and Western blot methods were used to measure the expression of apoptotic protease activating factor-1（Apaf-1） protein. Results Compared with sham-operat-ed group, nuclear and mitochondrial damage was found in reperfusion group, and the expression of Apaf-1 protein increased obviously in hippocampus（Immunohistochemistry result：0.024 ± 0.001 vs 0.109 ± 0.011;Western blot result：0.270 ± 0.018 vs 0.894±0.072, P〈0.01）. Compared with reperfusion group, the damage in nuclear and mitochondria was relieved obviously in experiment group, and the expression of Apaf-1 protein in hippocampus was significantly decreased （Immunohistochemistry result：0.048±0.005;Western blot result：0.392±0.046, P〈0.01）. Conclusion Astragalus injection can reduce pathological damage of hippocampal neurons after cerebral ischemia and reperfusion in rats, and the mechanism is related with inhibiting of Apaf-1 protein.