干细胞移植对犬缺血性二尖瓣关闭不全影响的研究

STUDY OF MITRAL VALVE INCOMPETENCE TREATED WITH AUTOLOGOUS STEM CELLS IMPLANTATION AFTER PERMANENT CORONARY OCCLUSION IN CANINE MODEL

目的 :观察干细胞移植对犬缺血性二尖瓣关闭不全的影响。方法 :取 12只成年犬臀大肌分离干细胞 ,培养、传代、DAPI标记 ,自左冠状动脉前降支结扎点远端灌注入犬急性心肌梗死动物模型缺血心肌中。 2 ,4 ,8周后观察犬二尖瓣瓣下结构及二尖瓣启闭功能改变。结果 :各对照组及 2周实验组室间隔中下部变薄及典型的矛盾运动 ,二尖瓣前组乳头肌明显挛缩 ,二尖瓣中到重度关闭不全 ;4周及 8周实验组 ,室间隔中下部变薄 ,无矛盾运动 ,二尖瓣前组乳头肌无明显挛缩 ,二尖瓣形态正常无反流。结论 :干细胞种植保护了乳头肌的结构与功能免受缺血的损害 ,可有效防止二尖瓣关闭不全的发生。

Objective:This study aimed to compare the transmitral inflow pattern before and after implanting autologous skeletal muscle satem cells into ischemic myocardium.Methods:Satellite cells isolated from the skeletal muscle of adult canines are labeled with 4,6-dimidino-2-phenylindone(DAPI), which bands to DNA and to the protein tubulin to form a fluorescent complex. Aligation of left anterodecendant artery (LAD) was carried out on a canine model to induce a well-delineated transmural lesion or acute myocardial infarction. Thereafter, autologous skeletal muscle cells (experimental) or culture media (control) were infused into ventricular myocardium of isogenic canine through left anterodecendant artery(LAD). Two, four, and eight weeks after cell implantation ,the transmitral inflow pattern were evaluated by three-dimensional (3 D) echocardiography.Results:Echocardiography was performed preoperatively, 2, 4, 8 weeks postoperatively. In all the 3 control groups and experimental group of 2 weeks, mitral valve regurgitation showed no improvement, and the middle and inferior parts of ventricular septum became thin. But mitral regurgitation improved or disappeared gradually after 2 weeks. On the contrary, the middle and inferior parts of ventricular septum showed no significant change. Conclusions:Stem cells implantation into the ischemic myocardium can protect mitral valve structure and function from myocardial ischemia.