CATION-TRANSPORT AND GROWTH-REGULATION IN NEURO-BLASTOMA CELLS - MODULATIONS OF K+-TRANSPORT AND ELECTRICAL MEMBRANE-PROPERTIES DURING THE CELL-CYCLE
CATION-TRANSPORT AND GROWTH-REGULATION IN NEURO-BLASTOMA CELLS - MODULATIONS OF K+-TRANSPORT AND ELECTRICAL MEMBRANE-PROPERTIES DURING THE CELL-CYCLE
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DOI：
10.1002/jcp.1041070110
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发表时间：
1981-01-01
影响因子：
5.6
通讯作者：
DELAAT, SW
中科院分区：
文献类型：
--
作者：
BOONSTRA, J;MUMMERY, CL;DELAAT, SW
在[小鼠]神经母细胞瘤细胞（克隆Neuro-2A）的细胞周期期间研究了阳离子转运和膜电位，以研究其在生长调节中的作用。通过有丝分裂细胞的选择性分离使细胞同步化。用常规微电极和K+选择性微电极测定细胞膜电位和细胞内K+活性。细胞膜电位和K+活性在有丝分裂期高，在G1期下降到最大值的一半，在S期又上升。用42 K+作为放射性示踪剂，采用单层细胞洗涤法和悬浮液中有丝分裂细胞连续外排法研究了K+跨质膜外排。细胞内K+含量和单向K+流出率在细胞周期中表现出类似于膜电位的调节。利用电扩散理论方程计算了膜对K+和Na+的渗透率。这些渗透性在有丝分裂期较高，在G1期迅速下降，在S期增加，随后在G2期短暂下降。在G2期和下一次有丝分裂之间观察到快速增加。K+电导也有类似的模式。K+电阻的变化在细胞周期中的变化相似的比膜电阻的变化，除了早期细胞周期阶段（有丝分裂和G1）。在细胞周期中被动膜渗透性特性的这些大的调节可以与细胞周期中的物理化学膜变化相关，例如膜流动性和脂质的横向流动性。
Cation transport and membrane potential were studied during the cell cycle of [mouse] neuroblastoma cells (clone Neuro-2A) to investigate their role in growth regulation. The cells were synchronized by selective detachment of mitotic cells. The membrane potential and intracellular K+ activity were measured with conventional and K+-selective microelectrodes. The membrane potential and K+ activity were high in mitosis, decreased to half maximal in G1 phase and rose again during S phase. K+ efflux across the plasma membrane was studied with 42K+ as a radioactive tracer using a washing method for cells grown in monolayer and a continuous efflux method for mitotic cells in suspension. The intracellular K+ content and unidirectional K+ efflux rate showed modulations during the cell cycle similar to those of the membrane potential. Using equations of electrodiffusion theory, the membrane permeabilities to K+ and Na+ were calculated. These permeabilities were high in mitosis, decreased rapidly in G1 phase and increased during S phase, followed by a transient decrease in G2 phase. A rapid increase was observed between G2 phase and the next mitosis. A similar pattern was obtained for the K+ conductance. K+ resistance changes during the cell cycle were similar to changes in the specific membrane resistance except for the early cell cycle phases (mitosis and G1). These large modulations of the passive membrane permeability properties during the cell cycle can be correlated with physicochemical membrane variations during the cell cycle, such as membrane fluidity and lateral mobility of lipids.