Post R L, Albright C D, Dayani K
J Gen Physiol. 1967 May;50(5):1201-20. doi: 10.1085/jgp.50.5.1201.
Further support for the pump-leak concept was obtained. Net transport was resolved into pump and leak components with the cardiac glycoside, ouabain. The specificity of ouabain as a pump inhibitor was demonstrated by its ineffectiveness when the pump was already inhibited by lack of one of the three pump substrates, sodium ion, potassium ion, or adenosine triphosphate. In the presence of ouabain the rates of passive transport of sodium and potassium ions changed almost in proportion to changes in their extracellular concentrations when one ion was exchanged for the other. In the presence of ouabain and at the extracellular concentrations which produced zero net transport, the ratio of potassium ions to sodium ions was 1.2-fold higher inside the cells than outside. This finding was attributed to a residual pump activity of less than 2% of capacity. The permeability to potassium ions was 10% greater than the permeability to sodium ions. A test was made of the independence of pump and leak. Conditions were chosen to change the rate through each pathway separately or in combination. When both pathways were active, net transport was the sum of the rates observed when each acted separately. A ratio of three sodium ions pumped outward per two potassium ions pumped inward was confirmed.
获得了对泵 - 漏概念的进一步支持。通过强心苷哇巴因将净转运分解为泵和漏成分。当泵因缺乏三种泵底物之一（钠离子、钾离子或三磷酸腺苷）而被抑制时，哇巴因作为泵抑制剂无效，这证明了哇巴因的特异性。在存在哇巴因的情况下，当一种离子与另一种离子交换时，钠离子和钾离子的被动转运速率几乎与它们细胞外浓度的变化成比例变化。在存在哇巴因且细胞外浓度产生零净转运的情况下，细胞内钾离子与钠离子的比率比细胞外高1.2倍。这一发现归因于容量小于2%的残余泵活性。钾离子的通透性比钠离子的通透性大10%。对泵和漏的独立性进行了测试。选择条件分别或联合改变通过每条途径的速率。当两条途径都活跃时，净转运是每条途径单独作用时观察到的速率之和。证实了每向内泵入两个钾离子就向外泵出三个钠离子的比率。
