Single delayed rectifier channels in the membrane of rabbit ventricular myocytes.
Single delayed rectifier channels in the membrane of rabbit ventricular myocytes.
复制标题
兔心室肌细胞膜上的单个延迟整流通道。
DOI：
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发表时间：
1993
影响因子：
20.1
通讯作者：
Lennart N. Bouman
中科院分区：
文献类型：
--
作者：
M. Veldkamp;G. AntoniC.;van;Ginneken;Lennart N. Bouman
In rabbit ventricular cells, the delayed rectifier current (IK) has not been extensively studied, and properties of single IK channels still need to be determined. In this study, we present data on a voltage-dependent channel in rabbit ventricular cells; the properties indicate that it is an IK channel. Patch-clamp experiments were carried out on cell-attached and inside-out patches of rabbit ventricular cells. Single-channel currents were recorded at negative potentials as inward currents with 150 mM K+ in the pipette. Voltage-dependent channel activity was only present after the return from a depolarizing test pulse, indicating activation on depolarization. Single-channel conductance calculated from the current-voltage relation was 13.1 pS (pooled data, n = 8). The shift in reversal potential of the unitary currents, determined at 150 and 300 mM K+ at the intracellular side of the membrane, showed that the channels were highly permeable to potassium ions. Increase of the duration or the amplitude of the depolarizing test pulse increased channel activity. The time constant for activation at +30 mV was 187 msec (pooled data, n = 4). Half-activation potential was -4.9 +/- 3.8 mV (mean +/- SD), and the slope factor was 7.2 +/- 3.7 mV (mean +/- SD). Current tails, reconstructed from averaged single-channel currents, revealed that the time course of deactivation decreased from 694 +/- 73 msec at -80 mV to 136 +/- 39 msec at -110 mV. Additional evidence that the channel was indeed an IK channel was provided by the observation that the channel was blocked by 10(-7) M E-4031, a class III antiarrhythmic agent that has been shown to block a component of the macroscopic IK in guinea pig heart.
氯非铵及其三级类似物阻断心脏钾通道：药物结构与阻断通道类型之间的关系。
影响因子：
3.6
作者：
Arena,JP;Kass,RS
通讯作者：
Kass,RS
青蛙心房细胞中的单个延迟整流通道。
影响因子：
3.4
作者：
Duchatelle-Gourdon,I;Hartzell,HC
通讯作者：
Hartzell,HC