Gargus J J, Adelberg E A, Slayman C W
J Cell Physiol. 1984 Jul;120(1):83-90. doi: 10.1002/jcp.1041200112.
When grown in medium containing 5 mM potassium and 140 mM sodium, HL-60, a human promyelocytic cell line, maintained a steady-state intracellular K+ concentration of 145 mmol/L cells and a steady-state intracellular Na+ concentration of 30 mmol/L cells. Nearly 90% of the unidirectional 42K+ influx could be inhibited by the cardiac glycoside ouabain with a Ki of 5 X 10(-8) M. This ouabain-sensitive component of influx rose as a saturating function of the extracellular K+ concentration with a K1/2 of 0.85 mM. The component of 42K+ influx resistant to ouabain inhibition was a linear function of the extracellular K+ concentration and was insensitive to inhibition by the diuretic furosemide. Unidirectional K+ efflux followed first order kinetics with a half-time of 55 min. Addition of 1.5% dimethyl sulfoxide (DMSO) to a culture of HL-60 cells allowed two population doublings followed by the cessation of growth without an impairment of cell viability. Beginning 2 to 3 days after DMSO addition, the cells underwent a dramatic reduction in volume (from 925 microns 3 to 500 microns 3) and began to take on the morphological features of mature granulocytes. Throughout this process of differentiation there was no change in the intracellular sodium or potassium concentration. However, immediately following the addition of DMSO to a culture of cells, there began an immediate, coordinated reduction in bidirectional K+ flux. The initial rate of the ouabain-sensitive component of K+ influx fell with a half-time of 11 h to a final rate, at 6 days induction, equal to one ninth that of the uninduced control, and over the same period, the rate constant for K+ efflux fell with a half-time of 14 h to a final value one fourth that of the uninduced control. The rapidity with which these flux changes occur raises the possibility that they play some role in the control of subsequent events in the process of differentiation.
当在含有5 mM钾和140 mM钠的培养基中培养时，人早幼粒细胞系HL - 60维持细胞内K⁺浓度为145 mmol/L细胞的稳态以及细胞内Na⁺浓度为30 mmol/L细胞的稳态。将近90%的单向⁴²K⁺内流可被强心苷哇巴因抑制，其抑制常数Ki为5×10⁻⁸ M。这种哇巴因敏感的内流成分随细胞外K⁺浓度呈饱和函数增加，其半饱和常数K1/2为0.85 mM。对哇巴因抑制有抗性的⁴²K⁺内流成分是细胞外K⁺浓度的线性函数，且对利尿剂呋塞米的抑制不敏感。单向K⁺外流遵循一级动力学，半衰期为55分钟。向HL - 60细胞培养物中添加1.5%的二甲基亚砜（DMSO）可使细胞进行两次群体倍增，随后生长停止，但细胞活力未受损。在添加DMSO后2至3天开始，细胞体积急剧减小（从925立方微米降至500立方微米），并开始呈现成熟粒细胞的形态特征。在整个分化过程中，细胞内钠或钾浓度没有变化。然而，在向细胞培养物中添加DMSO后，双向K⁺通量立即开始协同降低。K⁺内流的哇巴因敏感成分的初始速率以11小时的半衰期下降，在诱导6天时降至最终速率，等于未诱导对照的九分之一，并且在同一时期，K⁺外流的速率常数以14小时的半衰期下降至最终值，为未诱导对照的四分之一。这些通量变化发生的速度表明它们可能在分化过程中后续事件的控制中发挥某种作用。
