心肌细胞/胶原复合体移植心梗大鼠梗死周边区的电偶联网络变化

Changes of electric coupling in myocardial infarction in the rat after cardiac muscle cell-porous collagen scaffold complex transplantation

目的应用免疫组化技术和电生理技术记录心肌细胞/胶原复合体对心梗大鼠梗死周边区的有效不应期(ERP)及缝隙连接蛋白43(Cx43)改变,探讨梗死周边区的电偶联网络变化。方法将成年SD大鼠随机分组: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。结果①左室ERP变化:与假手术组相比,心梗组梗死周边区ERP显著延长(P<0.01);移植组梗死周边区ERP延长,但较心梗阻ERP缩短,差异无显著性(P>0.01)。②Cx43免疫组化结果:移植组Cx43阳性蛋白表达高于心梗组。结论移植的心肌细胞/胶原复合体移植可改善大鼠心肌梗死周边区缝隙连接电偶联网络,进而调控心肌细胞/胶原复合体与宿主心肌同步收缩。

Objective To study the changes of effective refractory period （ERP） and expression of connexin 43 （ Cx43 ）, and to explore the changes of electric coupling in the myocardial infarct border zone in rats after cardiac muscle cell- porous collagen scaffold complex transplantation, using electrophysiological techniques and immunohistochemistry. Methods Forty-five SD rats of either sex weighing 220 - 250 g were randomly divided into three groups ： control （ sham operation） group （ n = 15 ）, myocardial infarct （MI） model group （ n = 15 ） and transplantation group （ n = 15 ）. Myocardial tissues were examined by histopathology with HE staining, and expression of connexin 43 （Cx43） protein was examined by immuno- histochemistry. Results （~）Left ventricular ERP： Compared with the control group, ERP of infarction border zone was significantly prolonged in the MI group （ P 〈 0. O1 ）, and shortened in the transplantation group （ P 〈 0. 01 ）. 2. Left ventricular Cx43 expression ： Immunohistochemistry showed that the expression of the left ventricular Cx43 was significantly higher in the transplantation group than that in the MI group （ P 〈 0.01 ）. Conclusions Engineered heart tissue transplantation can improve electrophysiological function in MI rats, improve the electric coupling and myocardial contraction, and regulate the sys- tolic contraction by synchronization of cardiac muscle cell-porous collagen scaffold complex with host myocardium.