Slow current systems in the A-V node of the rabbit heart
Slow current systems in the A-V node of the rabbit heart
复制标题
兔心脏 A-V 结中的慢电流系统
作者：
A. Noma;H. Irisawa;S. Kokobun;H. Kotake;M. Nishimura;Y. Watanabe
如果心脏要像一个有效的泵一样工作，心房收缩和心室收缩之间必须有足够的时间延迟。这种延迟的主要部分是由跨房室（A-V）结的兴奋传导时间提供的，房室（A-V）结将心室与心房电连接。当窦房结（S-A）中的主起搏器无法控制心律时，由于自律性降低或传导受损，A-V结可以成为心脏的起搏器1。尽管房室结具有这些基本的生理功能，但房室结组织中传导和自律性的精确离子基础仍然不清楚。本文用双微电极电压钳技术观察了房室结的慢内向钾电流和延迟钾电流。
If the heart is to function as an efficient pump, there must be an adequate time delay between the contraction of the atria and that of the ventricles. A major part of this delay is provided by the time of conduction of excitation across the atrioventricular (A-V) node, which electrically links the ventricles with the atria. When the primary pacemaker in the sinoatrial (S-A) node fails to control the cardiac rhythm, as the result of either a depressed automaticity or an impaired conduction, the A-V node can become the pacemaker of the heart1. In spite of these essential physiological functions of the A-V node, the precise ionic bases of conduction and the automaticity in the A-V node tissue remain unclear. Here we demonstrate the slow inward current as well as the delayed potassium current in the A-V node using the two-microelectrode voltage-clamp technique.