犬左右心室肌细胞L型钙电流不均一性的研究  

Study of Electrical Heterogeneity of L-type Calcium Current in the Canine Ventricular Myocytes

作　　者：高颖[1] 杨新春[2] 周鹏[2] 刘秀兰[2] 

机构地区：[1]首都医科大学附属北京同仁医院心血管诊疗中心 [2]首都医科大学附属北京朝阳医院心脏中心

出　　处：《首都医科大学学报》2007年第1期81-84,共4页Journal of Capital Medical University

摘　　要：目的测定犬左、右心室3层心肌细胞上参与离子流平衡的内向电流L型钙电流(ICa.L)的特性。方法经酶解分离获得犬左、右心室外膜下细胞、M细胞和内膜下细胞,应用全细胞膜片钳技术,记录并比较不同部位心肌细胞的ICa.L,分析电流-电压曲线。结果ICa.L的峰值电流密度(pA/pF)在右心室外膜下细胞、M细胞和内膜下细胞分别为:-4.896±1.907(n=31),-3.406±0.904(n=37)和-2.788±0.756(n=33),心外膜下心肌细胞与M细胞比较,差异有统计学意义(P<0.05);在左心室分别为:-3.824±1.201(n=18),-4.854±1.485(n=20)和-2.988±1.082(n=17),3者之间两两比较,差异有统计学意义(P<0.05)。ICa.L的峰值电流密度在右心室心外膜下心肌细胞大于左心室(P<0.05),而右心室M细胞小于左心室(P<0.01),心内膜下心肌细胞左、右心室之间差异无统计学意义(P>0.05)。结论ICa.L在犬左、右心室肌的不同细胞(外膜下心肌细胞、M细胞、内膜下心肌细胞)存在不均一性,导致右心室跨室壁的电不均一性较左心室明显。Objective To determine the characteristics of L-type calcium current （ICa.L ） in epicardial （ Epi ）, midmyocardial （M）, and endocardial （Endo） canine ventricular myocytes. Methods Using whole-cell patch clamp techniques to compare the electrophysiological characteristics of ICa.L of myocytes enzymatically dissociated from right and left canine ventricular epi, mid and endomyocardium. Results The peak density of ICa.L （pA/pF） was - 4.896 ± 1. 907 （ n = 31 ）, - 3. 406 ± 0.904 （ n = 37 ）, - 2.788 ± 0.756 （ n = 33 ）, respectively in right ventricular （ RV ） epicardial, midmyocardial, and endocardial myocytes （ P 〈 0.01 ）. The peak density of ICa.L （pAVpF） was - 3. 824 ± 1. 201 （ n = 18 ）, - 4. 854 ± 1. 485 （ n = 20 ）, - 2. 988 ± 1. 082 （ n = 17 ）, respectively in left ventricular（LV） （P 〈0.01 ）. In epicardial myocytes, the average peak ICa.L densities was significantly smaller in RV than in LV（ P 〈 0.05 ）. In midmyocardial myocytes, the average peak ICa.L densities was significantly larger in RV than in LV（ P 〈 0.01 ）. In endocardial myocytes, the average peak ICa.L densities wasn＇ t significantly different （ P 〉 0.05 ）. Conclusion L-type calcium current on different ventricular myocytes of canine present with different characteristics.

关 键 词：电不均一性 L型钙电流 全细胞膜片钳 

分 类 号：R331.38[医药卫生—人体生理学]