Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
J Clin Invest. 1967 Sep;46(9):1433-41. doi: 10.1172/JCI105635.
The effect of some cations on the active potassium transport system of the human red blood cell has been investigated. At low extracellular potassium concentrations, extracellular sodium competitively inhibits the active potassium influx at all sodium concentrations investigated, and tetraethylammonium behaves in a fashion similar to that of sodium. At low extracellular concentrations of potassium, ammonium at low concentrations at first stimulates the active potassium influx, but at higher concentrations inhibits it. Tetramethylammonium at most slightly stimulates the active potassium influx, and calcium is without effect. The behavior is consistent with a model in which potassium is required at more than one site before transport occurs, and the sites are indistinguishable as far as their behavior toward the ions investigated is concerned. The affinity of the alkali metal cations for the sites appears to be explicable in terms of their physical characteristics.
研究了一些阳离子对人红细胞主动钾转运系统的影响。在细胞外钾浓度较低的情况下，细胞外钠离子在所有研究的钠离子浓度下竞争性抑制主动钾内流，四乙铵的行为与钠离子相似。在细胞外钾浓度较低的情况下，低浓度的铵首先刺激主动钾内流，但在较高浓度时抑制它。四甲基铵最多只能轻微刺激主动钾内流，而钙离子则没有影响。这种行为与一种模型一致，即在运输发生之前，钾需要在一个以上的位点，而这些位点在它们对所研究离子的行为方面是无法区分的。碱金属阳离子对这些位点的亲和力可以用它们的物理特性来解释。
