文章摘要

文章信息/Info

Title:: Contribution of three major pacemaker currents to spontaneous depolarization of rabbit sinus node cells

作者:: 李慈珍; 李沪生; 刘远谋; 上海交通大学医学院生理学教研室，上海 200025

Author(s):: LI Ci-zhen; LI Hu-sheng; LIU Yuan-mou; Department of Physiology, Shanghai Jiaotong University Medical School, Shanghai 200025, China

关键词:: 窦房结; 动作电位; 起搏离子流

Keywords:: sinus node; action potential; pacemaker currents

分类号:: Q463;R331.38

DOI:: -

文献标识码:: A

摘要:: 目的应用不同的起搏离子流通道阻断剂，观察If、IK和ICa·T在自律性活动中的作用，以比较它们作用的大小。方法细胞内微电极技术记录兔心窦房结细胞自律性动作电位，研究它们对自律性活动的影响。结果用E4031（1 μmol/L）阻断钾通道，窦房结自律活动减慢45.4%；Cs (2 mmol/L) 阻断If通道后，心率减少26.8%；Ni (100 μmol/L) 阻断T型钙通道后，自律活动减少14.3%。联合运用2种通道阻断剂，留下所观察的通道，得出类似的结果。结论对窦房结细胞起搏作用大小的次序为IK、超极化激活的起搏离子流If和T型钙通道电流ICa·T。

Abstract:: AIM To compare the contributions of delayed rectifier potassium current (Ik), hyperpolarizedactivated current(If) and Ttype calcium current (ICa·T) to the spontaneous depolarization during phase 4 in sinus node cells. METHODS The specific channel blockers were used in the perfused Tyrode′s solution. Conventional microelectrode technique was used to record the spontaneous action potential of rabbit sinus node cells. RESULTS E-4031 1 μmol/L (Ik blocker), CsCl 2 mmol/L(If blocker) and NiCl2 100 μmol/L (ICa·T block) decreased the heart rate by 45.3%, 26.8% and 14.3% respectively. The use of twoblockermethod showed the same results. CONCLUSION The contributions of three major pacemaker currents to the spontaneous depolarization of SN cells are in the order of: Ik, If and ICa ·T.

参考文献/References

［1］Di Francesco D. The contribution of the ‘pacemaker’ current (If ) to generation of spontaneous activity in rabbit sinoatrial node myocytes［J］.J Physiol,1991,434: 23-40.

［2］ Hangang Y, Ira S. Pacemaker current exists in ventricular myocytes［J］. Circ Res,1993,72: 232-236.

［3］ Rae J, Cooper K, Gates P, et al. Low access resistance perforated patch recordings using amphotericin B［J］. J Neurosci Methods, 1991,37(1):15-26.

［4］李慈珍,刘远谋,杨智昉,等. CS对兔窦房结细胞起搏离子流If和Ik及自律活动的影响［J］. 生理学报,1998,50（4）:409-415.

［5］ Ono K, Shibata S, Iijima T. Properties of the delayed rectifier potassium current in porcine sinoatrial node cells［J］. J Physiol,2000, 524(1): 51-62.

［6］ PerezReyes E. Molecular physiology of lowvoltageactivated Ttype calcium channels［J］. Physiol Rev,2003, 83:117-161.

我们的网站为什么显示成这样？

兔窦房结细胞三种主要起搏离子流的作用(PDF)

《心脏杂志》[ISSN:1009-7236/CN:61-1268/R]

文章信息/Info

参考文献/References

备注/Memo

常用功能

导航/Navigate

工具/Tools

统计/Statistics