犬窦房结细胞起搏电流与乳鼠心肌细胞野生型超极化激活环化核苷酸门控通道电流的比较  

Comparison of the pacemaker current in canine sino-atrial node cells and the wild type mHCN2 pacemaker current in neonatal rat myocardial cells

作　　者：赵欣[1] 李红霞[1] 杨向军[1] 汪小华[1] 程绪杰[1] 许海峰[1] 

机构地区：[1]苏州大学附属第一医院心内科,215006

出　　处：《中华老年医学杂志》2014年第11期1212-1215,共4页Chinese Journal of Geriatrics

基　　金：国家自然科学基金（81170173）,苏州市科技计划资助（SYS201113）

摘　　要：目的 研究犬窦房结细胞起搏电流动力学特点,并与乳鼠心肌细胞表达野生型超极化激活环化核苷酸门控（mHCN2）通道比较. 方法 用含胶原酶、弹性蛋白酶的无钙溶液酶解犬窦房结细胞,分离并记录窦房结细胞起搏电流,并在相同实验条件下与乳鼠心肌细胞表达野生型mHCN2通道电流的激活动力学比较. 结果 犬窦房结细胞的形态为长梭形或多边形,边缘清楚,有自发性搏动,犬窦房结细胞的起搏电流是内向电流,并随着超极化电位的增加,电流增加幅度明显加快,在V=-75 mV,窦房结起搏电流为（-2.1±0.3）pA/pF,犬窦房结细胞起搏电流激活较mHCN2通道电流激活接近,通道激活时间常数分别为（728±137） ms、（530±65） ms,（P＞0.05）. 结论 生理范围内犬窦房结细胞起搏电流和乳鼠心肌细胞过表达野生型mHCN2通道电流有类似激活动力学.Objective To investigate the dynamic characteristics of the pacemaker current of canine sino-atrial node cells and compare them with the wild type mHCN2 pacemaker current overexpressed in neonatal rat myocardial cells.Methods Fresh canine sino-atrial node cells were enzymatically isolated in a calcium-free solution containing collagenase and elastase,and the funny current was recorded and compared with the mHCN2 current overexpressed in cultured neonatal rat myocardial cells under the same experimental conditions.Results The canine sinus node cells were elongated,spindle-shaped or polygonal,with well-defined boundaries,and showed spontaneous beating.The elicited pacemaker current was an inward current and its rise in amplitude quickened as the hyperpolarization potential increased.At V ＝-75 mV,the canine sinus atrial node pacemaker current was （-2.1±0.3） pA/pF and had the same activation kinetics as those of the mHCN2 channel current overexpressed in neonatal rat myocardial cells [τact：（728±137） ms vs.（530±65） ms,P＞0.05].Conclusions Within the physiological range,the pacemaker current in canine sino-atrial node cells and the wild type mHCN2 pacemaker current over expressed in neonatal rat myocardial cells have similar activation kinetics.

关 键 词：窦房结 环核苷酸门控阳离子通道 电生理学技术 心脏 

分 类 号：R542.2[医药卫生—心血管疾病]