骨髓间充质干细胞改进心衰大鼠心肌细胞的收缩性

背景：骨髓间充质干细胞治疗心肌梗死已被证明能明显改善心功能。目的：观察骨髓间充质干细胞对心肌梗死后心力衰竭大鼠心肌细胞收缩舒张功能的影响。方法：开胸结扎10只SD大鼠左前降支冠状动脉，制备心肌缺血模型，随机抽签法分为2组，实验组造模4周后在梗死心肌内注射荧光标记的5×10¹⁰ L^-1骨髓间充质干细胞，对照组单纯注射PBS。结果与结论：与左前降支冠状动脉结扎前相比，造模4周后两组大鼠心功能明显下降(P < 0.01)；经骨髓间充质干细胞治疗后实验组的心功能得到明显改善(P < 0.05)。实验组心肌细胞收缩幅度较对照组显著增加，收缩速度显著增快(P < 0.01)。且荧光显微镜发现有经骨髓间充质干细胞分化而来具有收缩功能的心肌细胞。提示经骨髓间充质干细胞治疗后的大鼠心肌细胞其收缩舒张功能显著增强，是骨髓间充质干细胞治疗心衰大鼠导致心功能改善的主要机制之一。

Bone marrow mesenchymal stem cells improve cardiomyocyte contractility in rats with heart failure

BACKGROUND:Bone marrow mesenchymal stem cells (BMSCs) transplantation can significantly improve cardiac function. OBJECTIVE:To investigate the effect of BMSCs on cardiomyocytes contractility and dilatation in rats with heart failure after myocardial infarction. METHODS:Left anterior descending coronary arteries of 10 Sprague Dawley rats were ligated in order to establish the myocardial ischemia model. The model rats were randomly divided into two groups: the experimental group and the control group. Four weeks later, 5×106/L PKH26 labeled BMSCs were injected into the infracted myocardium in the experimental group and in the control group, only injected with PBS.   RESULTS AND CONCLUSION:Compared with ligation, the cardiac function in two groups after modeling for 4 weeks was improved significantly (P < 0.01). After treated with BMSCs administration, the cardiac function in experimental group was improved significantly (P < 0.05). The amplitude of shortening/relengthening and contractile velocity of cardiomyocytes in experimental group was significantly increased (P < 0.01). The cardiomyocytes with contractility differentiated from BMSCs could be seen under fluorescence microscope. The injection of BMSCs could significantly increase the shortening/relengthening function of rat cardiomyocytes and was one of the important mechanisms in BMSCs improved of heart failure rats.