组织工程化心肌片层移植心肌梗死大鼠的心功能及电生理变化

Cardiac function and electrophysiological characteristics in myocardial infarction rats after tissue engineered cardiac patch transplantation

背景:组织工程化心肌组织在组成结构上类似于心脏组织的三维电偶联网络和肌肉横纹,而且具有心肌组织样收缩功能,为病损心肌提供了修复的可能性。目的:观察心肌细胞/胶原复合体移植后心肌梗死大鼠心室肌的心功能及电生理变化。方法:将成年SD大鼠分为假手术组、模型组、移植组,后2组制作心肌梗死动物模型,假手术组仅开胸,不结扎冠状动脉。移植组移植心肌细胞与胶原材料复合组织,其他2组不进行移植。结果与结论:①左室心功能:与假手术组相比,模型组左室舒张末期内径、左室收缩末期内径均显著增大(P<0.01),左室射血分数和左室短轴缩短率显著降低(P<0.01);移植组左室舒张末期内径、左室收缩末期内径、左室射血分数和左室短轴缩短率均未见明显增大或降低(P>0.01)。②左室有效不应期变化:与假手术组相比,模型组梗死周边区有效不应期显著缩短(P<0.01);移植组梗死周边区有效不应期较模型组延长,差异有显著性意义(P<0.01)。③Cx43免疫荧光结果:假手术组、模型组和移植组大鼠缝隙连接蛋白43阳性表达依次呈现阳性,弱阳性,弱阳性。但移植组缝隙连接蛋白43阳性表达高于模型组。结果可见移植的心肌细胞/胶原复合体在组织和结构上形成电偶联网络和收缩偶联,能改善心肌梗死大鼠心室肌的收缩功能及电生理特性。

BACKGROUND： The structure of tissue engineered cardiac muscle tissue is similar to heart tissue three-dimensional electric coupling network and muscle striations, and has myocardial tissue-like systolic functions, and it can be used to repair the injured cardiac tissue.OBJECTIVE： To observe the cardiac functions and electrophysiological characteristics in myocardial infarction rats after myocardial cells/collagen complex transplantation. METHODS： Adult Sprague-Dawley rats were randomly divided into three groups： sham surgery group, model group and transplantation group. Myocardial infarction models were developed in the model group and transplantation group, while sham surgery group was only subjected to thoracotomy with no ligation of coronary artery. Transplantation group was given myocardial cells/collagen complex transplantation, while sham surgery group and model group received no transplantation. RESULTS AND CONCLUSION： （1） Left ventricular heart function： Compared with the sham surgery group, the left ventricular internal diameter at end-diastole and left ventricular internal diameter at end-systole were significantly increased （P 〈 0.01）, while left ventricular ejection fraction and shortening fraction were decreased in the model group （P 〈 0.01）. The above indexes were not changed in transplantation group （P 〉 0.01）. （2） Left ventricular effective refractory period： Compared with the sham surgery group, effective refractory period at the infarct border zone was significantly shortened in the model group （P 〈 0.01 ）; compared with the model group, effective refractory period at the infarct border zone was significantly prolonged in transplantation group （P 〈 0.01 ） （3） Connexin 43 immunofluorescence results： Connexin 43 expression was positive in sham surgery group, weakly positive in the model group and transplantation group. However, the positive expression in the transplantation group was higher than that in model group. Myocardial cells/collagen complex transplantation can improve ventricular myocardium systolic function and electrophysiological properties of myocardial infarction rats, through electric coupling network and contraction coupling in tissue and structure.