Johnson M A, Weber M J
J Cell Physiol. 1980 May;103(2):363-70. doi: 10.1002/jcp.1041030222.
Growth-contingent alterations in potassium and sodium fluxes, ouabain binding, and potassium ion content were examined following serum stimulation of quiescent, density-inhibited chicken embryo fibroblasts. Serum stimulation resulted in very rapid 1.5- to 1.8-fold increases in ouabain-sensitive potassium influx and lesser 1.4- to 1.5-fold increases in potassium efflux and sodium influx. Potassium influx stimulation was maximal after addition of 5-20% calf serum and was unaffected by cycloheximide inhibition of protein synthesis. Reflecting the slightly greater stimulation of potassium influx versus potassium efflux, potassium ion levels were 10-15% higher in serum-stimulated compared to unstimulated cells. Specific ouabain binding levels in stimulated and unstimulated control cells were initially similar, however, by four hours after stimulation a 40-50% increase in specific ouabain binding was observed. Incubation with ouabain was found also to inhibit later serum-stimulated hexose uptake and thymidine incorporation; this blockage may be consequence of subnormal potassium levels rather than ouabain inhibition of the serum-stimulated potassium influx.
在用血清刺激静止的、密度抑制的鸡胚成纤维细胞后，检测了生长相关的钾离子和钠离子通量、哇巴因结合以及钾离子含量的变化。血清刺激导致哇巴因敏感的钾离子内流迅速增加1.5至1.8倍，钾离子外流和钠离子内流增加幅度较小，为1.4至1.5倍。添加5 - 20%小牛血清后，钾离子内流刺激达到最大值，且不受环己酰亚胺对蛋白质合成的抑制影响。与钾离子外流相比，钾离子内流受到的刺激略大，这反映在血清刺激的细胞中钾离子水平比未刺激的细胞高10 - 15%。刺激组和未刺激的对照组细胞最初的特异性哇巴因结合水平相似，然而，刺激后4小时，观察到特异性哇巴因结合增加了40 - 50%。还发现用哇巴因孵育会抑制随后血清刺激的己糖摄取和胸苷掺入；这种阻断可能是钾离子水平低于正常的结果，而不是哇巴因对血清刺激的钾离子内流的抑制。
