EFFECTS OF INTERNAL POTASSIUM AND SODIUM ON THE ANOMALOUS RECTIFICATION OF THE STARFISH EGG AS EXAMINED BY INTERNAL PERFUSION
EFFECTS OF INTERNAL POTASSIUM AND SODIUM ON THE ANOMALOUS RECTIFICATION OF THE STARFISH EGG AS EXAMINED BY INTERNAL PERFUSION
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DOI：
10.1113/jphysiol.1979.sp012849
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发表时间：
1979-01-01
影响因子：
5.5
通讯作者：
YOSHII, M
中科院分区：
文献类型：
--
作者：
HAGIWARA, S;YOSHII, M
研究了细胞内离子组成的变化对海星M. aequalis，研究了使用细胞内灌注技术结合分析的膜电流与电压钳技术。当K平衡电位VK通过改变内部K+浓度而改变时，K电导的内向整流仅取决于膜电位V，而当VK通过改变外部K+浓度而改变时，K电导的内向整流取决于V-VK。内向整流钾通道的门控依赖于V和外部K+浓度。当在固定的外部K+浓度下改变[K+]i时，在给定电压下K通道的电导与[K+]i的平方根大致成比例。由于电导率与[K+]o的平方根成比例，当在固定的内部K+浓度下改变时，该电导率与外部和内部K+浓度的几何平均值成比例。细胞内的Na+离子是必要的激活内向整流; K电导急剧增加与内部Na+浓度，达到饱和在200 mM。一个类似的增强效应被发现为Li+，虽然它是较弱的。Rb+、Cs+和有机阳离子，精氨酸没有这种作用。
The effects of alterations of the intracellular ionic composition on the properties of anomalous (or inward) rectification of the egg membrane of the starfish, M. aequalis, were studied using an intracellular perfusion technique combined with analysis of the membrane current with the voltage-clamp technique. The inward rectification of the K conductance depends only on the membrane potential, V, when the K equilibrium potential, VK, is altered by changing the internal K+ concentration at a fixed external K+ concentration, while it depends on V - VK when VK is altered by changing the external K+ at a fixed internal K+ concentration. The gating of the K channel of the inward rectification depends on V and the external K+ concentration. The conductance of the K channel at a given voltage is roughly proportional to the square root of [K+]i when the latter is altered at a fixed external K+ concentration. Since the conductance is proportional to the square root of [K+]o when this is altered at a fixed internal K+ concentration, this conductance is proportional to the geometrical mean of the external and internal K+ concentrations. Intracellular Na+ ions are necessary for the activation of inward rectification; the K conductance increases sharply with internal Na+ concentration, reaching saturation at 200 mM. A similar potentiating effect is found for Li+, although it is weaker. Rb+, Cs+ and organic cations e.g., arginine, do not have this effect.