目的和方法：本文通过ＤＯＣＡ硅胶管皮下埋入法建立大鼠心力衰竭模型，比较正常与心衰大鼠心肌收缩力的变化。采用ＲＮＡｓｌｏｔｂｌｏｔ杂交从基因转录水平检测正常与心衰大鼠心肌组织中心肌收缩蛋白分子基因αｃａｒｄｉａｃａｃｔｉｎ与αＭＨＣ表达的变化。结果：（１）心衰大鼠心肌收缩力较正常大鼠明显降低；（２）心衰大鼠与正常大鼠相比，心肌收缩蛋白分子基因αｃａｒｄｉａｃａｃｔｉｎ表达水平未见有统计学意义的变化，而αＭＨＣ表达水平呈显著降低（下降２１．３０％，Ｐ＜０．０５）；（３）αＭＨＣｍＲＮＡ的含量与心肌收缩力的大小存在线性正相关（ｒ＝０．４１４３，ｎ＝４３，Ｐ＜０．０５）。结论：αＭＨＣ基因表达水平的下降是心衰时心肌收缩力减退的主要分子基础之一，且与心肌收缩力的大小存在线性正相关 PURPOSE AND METHODS: The model of heart failure was established by subcutaneous burial of DOCA silicone tube, and the changes of myocardial contractility were compared between normal and heart failure rats. RNAslotblot hybridization was used to detect the changes of αcardiacactin and αMHC expression in the myocardial contractile protein in normal and heart failure rats at gene transcription level. Results: (1) Myocardial contractile force of heart failure rats was significantly lower than that of normal rats; (2) Compared with normal rats, α -cardiacactin expression of myocardial contractile protein molecules in heart failure rats showed no statistical significance (P <0.05); (3) There was a linear positive correlation between the content of α-MHC mRNA and the myocardial contractility (r = 0.4143, n = 43, P <0.05). Conclusion: The decline of αMHC gene expression is one of the main molecular basis of myocardial contractility in heart failure, and there is a linear positive correlation with myocardial contractility