犬三层心室肌细胞的分离和鉴别

Isolation and identification of cells in three different layers of canine ventricular muscle

目的探讨有效分离和鉴别犬三层心室肌细胞的方法。方法用带有左室前降支的犬心肌组织块灌流分离心室肌细胞,得到的心肌细胞先根据解剖部位大致分成三层,再采用膜片钳技术,在电流钳模式下,随机选择各层15个细胞记录动作电位(AP),根据AP的形态、时程、频率依赖性进一步判断是否为相应层的心室肌细胞。结果经左室前降支插管灌流心肌组织块,可以得到数量多、状态好的心肌细胞。在15个心室肌细胞中,能准确判断其层次的有:外层7个、中层5个、内层8个。结论经冠状动脉插管灌流分离犬心室肌细胞是可行的,结合解剖部位和动作电位特点,能有效鉴别不同层的心室肌细胞。

Objective To find an effective way to isolate and identify cells in three different layers of canine ventricular muscle. Methods A portion of the left ventricular wall containing the left anterior descending coronary artery was dissected from the canine heart, cannulated and perfused from this arterial branch. Ventricular myocytes were dissociated from it and classified into three groups by their anatomic position, epicardial myocytes, midmyocardial myocytes, and endocardial myocytes. Then, 15 ventricular myocytes were chosen from each group at random. Their action potentials （APs） were recorded and to be identified later. Results The ventricular myocytes were numerous and rod-shaped with clear striations. According to the characteristics of action potential, 7 epicardial myocytes, 5 midmyocardial myocytes and 8 endocardial myocytes were correctly identified. Conclusion It is feasible to isolate ventricular myocytes by cannulating and perfusing from the branch of coronary artery. It is helpful to identify the types of ventricular myocytes by the characteristics of both anatomic position and action potential.