Siep E
J Math Biol. 1978 Mar 3;5(2):143-68. doi: 10.1007/BF00275896.
A molecular and biochemically plausible model for the excitation process of the sodium pore is suggested. From basic arguments it is concluded that the sodium pore exists in at least three states: the resting state, the sodium conducting state, and the refractory state. They are connected to form a cyclic process. A specification of the different states is given. It is suggested that inactivation of the sodium pore results from a conformational change, which is caused by the transport of a calcium ion through the membrane. The transport carrier is the sodium pore. This assumption can explain the observed calcium influx during stimulation, and the effect of Ca on the rate of inactivation and on the rate, at which sodium conductance shuts off upon repolarization. It cannot give a quantitative explanation for the effect of Ca on the rate of rise, peak sodium conductance, and steady state inactivation. These asects are successfully described by the surface potential hypothesis, which has been published recently. It is concluded, that a combination of both theories gives a rather complete description of the sodium pore. The Ca transport model is discussed quantitatively and in great detail.
提出了一种关于钠通道兴奋过程的分子和生物化学上合理的模型。基于基本论点得出，钠通道至少存在三种状态：静息状态、钠传导状态和不应期状态。它们相互连接形成一个循环过程。给出了不同状态的具体说明。有人提出，钠通道的失活是由构象变化引起的，而这种构象变化是由钙离子通过膜的转运所导致的。转运载体就是钠通道。这一假设能够解释刺激过程中观察到的钙内流，以及钙对失活速率和复极化时钠电导关闭速率的影响。它无法对钙对上升速率、钠电导峰值和稳态失活的影响给出定量解释。这些方面最近发表的表面电位假说已成功进行了描述。得出的结论是，两种理论相结合能对钠通道给出相当完整的描述。对钙转运模型进行了详细的定量讨论。
