Kitasato H, Sato S, Marunaka Y, Murayama K, Nishio K
Jpn J Physiol. 1980;30(4):603-16. doi: 10.2170/jjphysiol.30.603.
The dependency of Na efflux on intracellular Na concentration was examined on sartorius muscles of Rana catesbeiana. In normal Ringer, the rate coefficient of 22Na efflux is nearly proportional to the internal Na concentration, i.e., Hill's coefficient in the dependency of Na efflux on internal Na concentration was around two. As long as insulin is present in the bathing solution, the rate coefficient of 22Na efflux retains the stimulated level. Insulin caused a leftward shift of the relationship between Na efflux and the logarithm of internal Na concentration, and concomitantly decreased Hill's coefficient. A model of the coupling of Na transport and hydrolysis of ATP was proposed. The theoretical relation derived from this model accounted for these findings quite satisfactorily. According to this model, insulin shifts as a cofactor the equilibrium between dephosphorylated and phosphorylated states of carriers, whose Na binding sites are not occupied by Na, toward the phosphorylated state.
在牛蛙的缝匠肌上研究了钠外流对细胞内钠浓度的依赖性。在正常任氏液中，22Na外流的速率系数几乎与细胞内钠浓度成正比，即钠外流对细胞内钠浓度依赖性的希尔系数约为2。只要浴液中存在胰岛素，22Na外流的速率系数就保持在受刺激的水平。胰岛素使钠外流与细胞内钠浓度对数之间的关系向左移动，并同时降低了希尔系数。提出了钠转运与ATP水解偶联的模型。从该模型推导的理论关系相当令人满意地解释了这些发现。根据该模型，胰岛素作为辅因子使载体的去磷酸化和磷酸化状态之间的平衡（其钠结合位点未被钠占据）向磷酸化状态移动。
