Sodium channel permeation in squid axons. II: Non‐independence and current‐voltage relations.
Sodium channel permeation in squid axons. II: Non‐independence and current‐voltage relations.
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鱿鱼轴突中的钠通道渗透II：非独立性和电流-电压关系。
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
M. Cahalan
中科院分区：
文献类型：
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作者：
T. Begenisich;M. Cahalan
1.研究了鱿鱼巨轴突钠通道电流的浓度和电压依赖性。使用渗透阳离子Na、K和铵。2.在固定电压下，Na通道电流随着内渗透离子浓度的增加而饱和。发现50 mV下Na、NH 4和K的半饱和活性分别为623、268和161 mM。Na和K的这些Km值似乎是电压依赖性的。3.瞬时电流-电压关系用两种不同的内部Na浓度和Na外部和K内部来确定。4.此处显示了先前用于描述Na通道逆转电位的三屏障双位点离子渗透模型，以解释Na通道电流。
1. The concentration and voltage dependence of current through the Na channels of squid giant axons was studied. The permeant cations Na, K and ammonium were used. 2. The Na channel current at a fixed voltage saturates as the internal permeant ion concentration is increased. The half‐saturation activities at 50 mV were found to be 623, 268, 161 mM for Na, NH4, and K, respectively. These Km values for Na and K appear to be voltage‐dependent. 3. Instantaneous current‐voltage relations were determined with two different internal Na concentrations and with Na outside and K inside. 4. A three‐barrier, two‐site ion permeation model previously used in describing Na channel reversal potentials is shown here to account for the Na channel currents as well.