益气活血药对心肌梗死大鼠心脏结构和Cx43表达的影响

目的 探讨益气活血药对心肌梗死（myocardial infarction,MI）大鼠心脏结构及心肌电偶联的关键结构缝隙连接蛋白43（connexin 43,Cx43）表达的影响.方法 结扎雄性SD大鼠冠状动脉前降支建立MI模型,将30只MI大鼠随机分为模型组、益气活血组（参芍片0.25 g/kg联合复方丹参片0.75 g/kg）和倍他乐克组（12 mg/kg）,每组10只,于造模成功后24 h开始灌胃,1次/日,连续4周.另设假手术组10只,给予等量去离子水灌胃.4周后取材进行苏木素-伊红染色观察心肌组织病理,图像分析测量左室内径和心肌梗死百分比,免疫组织化学法检测心肌Cx43的表达.结果 与假手术组比较,术后4周模型组大鼠左室内径明显增大,心肌Cx43表达的平均光密度值（average optical density,AOD）、阳性表达面积（Area）和积分光密度（integral optical density,IOD）明显降低（P〈0.01）.与模型组比较,益气活血组和倍他乐克组的左室内径和心肌梗死百分比均明显减少（P〈0.05或P〈0.01）,在心肌Cx43的表达上,仅益气活血组心肌Cx43表达的AOD和IOD明显增加（P〈0.05或P〈0.01）.结论 益气活血治疗能减少MI大鼠左室内径和心肌梗死百分比,增加心肌Cx43表达强度和部分好转Cx43弥散表达状态,对MI后缺血心肌有保护作用,可能是稳定MI后心肌细胞间电偶联的机制之一.

Effects of Supplementing Qi and Promoting Blood Circulation Therapies on Heart Structure and Expression of Connexin 43 in Rats with Myocardial Infarction

Objective To explore effects of supplementing qi and promoting blood circulation therapies on heart structure and expression of connexin 43（Cx43） in rats with myocardial infarction.Methods The myocardial infarction models of male Sprague-Dawley（SD） rats were established by ligating left anterior descending coronary artery and were randomly divided into three groups（10 rats in each group）：Model group,observed group administered intragastrically with Shenshao tablets 0.25 g/kg and compound Danshen tablets 0.75 g/kg,and betaloc group administered intragastrically with betaloc 12 mg/kg.The rats in sham group were given the deionized water by gastric gavage.The pathologic changes in myocardium were observed by hematoxylin-eosin staining.The left ventricular internal diameter and the percentage of myocardial infarction were measured by image analysis 4 weeks later.The expressions of Cx43 in myocardium were measured by immunohistochemical methods.Results Compared with the sham group,the left ventricular internal diameter of rats in model group were increased significantly.The average optical density,positive express area and integral optical density of expressions of Cx43 in myocardium were decreased significantly（P0.05 or P0.01）.Compared with the model group,the left ventricular internal diameter and the percentage of myocardial infarction of rats in the observed group and betaloc group were decreased significantly（P0.05 or P0.01）.The average optical density and integral optical density of expressions of Cx43 in myocardium increased significantly in the observed group（P0.05 or P0.01）.Conclusion Supplementing qi and promoting blood circulation therapies were beneficial on rats with myocardial infarction to decrease left ventricular internal diameter and the percentage of myocardial infarction,enhance expressions of Cx43,ameliorate the diffusion and confusion of Cx43,and protect ischemic myocardium after myocardial infarction.