黄芪多糖抗心肌缺血作用与机制

目的研究黄芪多糖抗心肌缺血作用及其机制。方法 40只大鼠随机分为假手术组、模型组、阳性药物组（复方丹参片）及黄芪多糖高、低剂量组,采用冠状动脉结扎的方法建立大鼠心肌缺血模型。TUNEL法观察各组大鼠的心肌细胞凋亡情况,采用Real-time PCR和Western blot检测各组大鼠心肌细胞凋亡相关因子mRNA和蛋白表达相关水平,并探讨它们之间的相互关系。结果与模型组相比,给药组bcl-2mRNA和蛋白表达明显升高（P〈0.05）,caspase-3mRNA和蛋白表达明显降低（P〈0.05）,给药组能明显改善心肌细胞凋亡。结论黄芪多糖对心肌缺血大鼠模型心肌梗死有明显保护作用,其作用机制可能与上调bcl-2及下调caspase-3相关。

The protective effect of astragalus polysaccharides on myocardial ischemia and its mechanisms

Objective To investigate the effect of astragalus polysaccharides against myocardial ischemia.Methods 40 rats were randomly divided into sham-operation group,model group,positive control group and astragalus polysaccharides group.Myocardial apoptosis was detected with terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL).Real-time PCR and Western blot were used to detect apoptosis-related factor such as bcl-2 and caspase-3 and to elucidate their relations.Results Compared with model group,the expression level of bcl-2 mRNA and protein increased significantly in the astragalus polysaccharides group(P<0.05).Whereas,the expression level of caspase-3 were down-regulated.The astragalus polysaccharides have a protective effect on apoptosis.Conclusion Astragalus polysaccharides has obviously protective effects on myocardial infarction in the myocardial ischemia rats,the mechanism may be related with the up-regualtion of bcl-2 and down-regulation of caspase-3.