Membrane currents following activity in canine cardiac Purkinje fibers.
Membrane currents following activity in canine cardiac Purkinje fibers.
复制标题
犬心脏浦肯野纤维活动后的膜电流。
DOI：
10.1016/s0006-3495(81)84890-4
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发表时间：
1981
影响因子：
3.4
通讯作者：
Kline,R
中科院分区：
文献类型：
--
作者：
Cohen,I;Falk,R;Kline,R
最近对犬Pukinje纤维的实验(Gadsby和Cranefield，1979)表明，在无K+溶液中一段时间的钠负荷后，观察到缓慢衰减的外向电流。这一电流归因于生电Na+-K+交换泵的活动。在本文中，我们发现，在动作电位或短暂的去极化电压钳脉冲的长时间过驱动后，也可以观察到类似的缓慢衰减的外向电流。报告了延长的外向电流与前一过驱期的持续时间和频率以及过驱后的电位的关系。我们的结果还表明，这种电流的很大一部分可以由通过快内向通道的相位Na+负载所诱导。
Recent experiments in canine Pukinje fibers (Gadsby and Cranefield, 1979) have shown that following a period of sodium loading in K+-free solution a slowly decaying outward current is observed. This current has been attributed to the activity of the electrogenic Na+-K+ exchange pump. In the present paper we show that similar slowly decaying outward currents are observed following prolonged periods of overdrive with action potentials or with brief depolarizing voltage clamp pulses. The dependent of the prolonged outward current on the duration and frequency of the preceding period of overdrive and on the potential following overdrive is reported. We also present results which indicate that a large portion of this current can be induced by phasic Na+ loading through the fast-inward channel.