RELATING THE SODIUM CURRENT AND CONDUCTANCE TO THE SHAPE OF TRANSMEMBRANE AND EXTRACELLULAR POTENTIALS BY SIMULATION - EFFECTS OF PROPAGATION BOUNDARIES
RELATING THE SODIUM CURRENT AND CONDUCTANCE TO THE SHAPE OF TRANSMEMBRANE AND EXTRACELLULAR POTENTIALS BY SIMULATION - EFFECTS OF PROPAGATION BOUNDARIES
复制标题
DOI：
10.1109/tbme.1985.325489
复制
发表时间：
1985-01-01
影响因子：
4.6
通讯作者：
KOOTSEY, JM
中科院分区：
文献类型：
--
作者：
SPACH, MS;KOOTSEY, JM
本文的目的是描述跨膜和细胞外电位波形及其导数之间的相互关系，以及与传播心脏动作电位的钠电流和电导的关系。结果表明，跨膜电位的形状以及钠电流和电导的动力学在很大程度上取决于脉冲传导开始处和碰撞或解剖末端的边界效应。这些传播不均匀导致了Vmax与内膜变量GNA和INA之间的关系，而这与经典的Vmax与钠电流大小之间的关系正好相反。例如，在这些情况下，峰值INA和GNA曲线下的面积都随着Vmax的增加而减小。此外，Vmax与GNA和INA的最大上升速率在时间上一致。所有波形的细胞外波形的最大负斜率与跨膜电位的Vmax在时间上一致。因此，细胞外波形的最大负斜率或动作电位的Vmax为相同的潜在去极化事件提供了时间标记，即去极化电流及其电导的最大增长率。
The purpose of this paper is to describe how the transmembrane and extracellular potential waveforms, and their derivatives, are related to each other and to the sodium current and conductance in propagating cardiac action potentials. The results show that the shape of the transmembrane potential and the kinetics of the sodium current and conductance are highly determined by boundary effects at sites where impulse conduction begins and where it ends at a collision or an anatomical end. These propagation nonuniformities produced a relationship between Vmax and the internal membrane variables gNa and INa that is just the opposite of the classical relation between Vmax and the magnitude of the sodium current. For example, in these cases, both peak INa and the area under the gNa curve decreased when Vmax increased. In addition, Vmax, was shown to coincide in time with the maximum rate of increase of gNa and INa. The maximum negative slope of the extracellular waveform coincided in time with Vmax of the transmembrane potential for all shapes of the waveforms. Therefore, either the maximum negative slope of the extracellular waveform or Vmax of the action potential provides a time marker for the same underlying depolarizing event, i.e., the maximum rate of increase of the depolarizing current and its conductance.