目的　探讨黄芪对扩张型心肌病(DCM)大鼠心肌缝隙连接蛋白43(Cx43)表达的影响。方法　应用多柔比星腹腔注射建立DCM大鼠模型；模型组大鼠按照不同的给药方法随机分为黄芪组和模型对照组，黄芪组应用黄芪颗粒加双蒸馏水灌胃，模型对照组和正常对照组用定量的双蒸馏水灌胃，三组均1次/d灌胃4周。12周末超声测量各组大鼠心脏左心室射血分数(LVEF)，逆转录聚合酶链反应法检测Cx43 mRNA，采用免疫组化方法观察Cx43分布。结果　与模型对照组比较，黄芪组大鼠心肌Cx43mRNA、Cx43平均灰度值、LVEF均增高，差异均有统计学意义(P均<0.05)；黄芪组较模型对照组心肌Cx43的分布紊乱有改善。结论　黄芪能改善DCM大鼠心肌Cx43表达和分布，并能改善其心功能。

　Objective　To observe the effect of Radix astragali (RA) on myocardial connexin-43 in rats with dilated cardiomyopathy (DCM). Methods The dilated cardiomyopathy model in rat was established through intraperitoneal injection with adriamycin. The rats in the model group were randomly divided into RA group and the model control group according to different methods of administration. Rats in RA group were gavaged with Astragalus particles and double-distilled water, and rats in model control group and normal control group were gavaged with an equal amount of double-distilled water daily for four weeks. At the end of 12 weeks, the left ventricular ejection fraction (LVEF) was measured with echocardiogram. The Cx43 mRNA level was tested by reverse transcriptase polymerase chain reaction (RT-PCR). Immunohistochemical method was used to observe myocardial Cx43 expression and distribution. Results Compared with the model control group, the Cx43 mRNA and protein expressions and LVEF were increased significantly in RA group (P<0.05). The disorders in distribution of myocardial Cx43 improved in RA group in contrast to the model control group. Conclusions Radix astragali can improve myocardial Cx43 expression and distribution in DCM rats, and can further improve the cardiac function.