Brodie C, Sampson S R
Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
Int J Dev Neurosci. 1986;4(4):327-37. doi: 10.1016/0736-5748(86)90050-x.
The effects of different growth factors and growth conditions were studied on the development of resting membrane potential and its electrogenic--ouabain-sensitive--pump component in cultured rat myotubes. Resting potential and its electrogenic pump component were dependent on the initial plating density of the myotubes, both values increasing with increasing density. Medium from cells plated at high density, when used to replace the medium of low density cells, increased both the resting potential and its electrogenic pump component of low density myotubes. Treatment of myotubes with cytosine-arabinoside delayed the appearance of [3H]ouabain binding sites and electrogenic pump component of resting potential, but by 8 days in culture there was no difference between treated and control cells. Similarly, cells plated initially in 5% horse serum developed resting potential and its electrogenic pump component more slowly than those in 15% horse serum, but by 8-10 days in vitro, the differences were no longer apparent. Chick embryo extract was found to have little, if any, influence on development of resting potential and its electrogenic pump component. We conclude that the different growth conditions and factors to the extent that they influence membrane potential, do so by altering the time of appearance of Na-K ATPase, the activity of which contributes a considerable component to resting potential.
研究了不同生长因子和生长条件对培养的大鼠肌管静息膜电位及其电生性（哇巴因敏感）泵成分发育的影响。静息电位及其电生性泵成分取决于肌管的初始接种密度，这两个值均随密度增加而升高。高密度接种细胞的培养基用于替换低密度细胞的培养基时，会增加低密度肌管的静息电位及其电生性泵成分。用阿糖胞苷处理肌管会延迟[3H]哇巴因结合位点和静息电位电生性泵成分的出现，但培养8天后，处理组和对照组细胞之间没有差异。同样，最初接种于5%马血清中的细胞比接种于15%马血清中的细胞静息电位及其电生性泵成分的发育更慢，但在体外培养8 - 10天后，差异不再明显。发现鸡胚提取物对静息电位及其电生性泵成分的发育几乎没有影响。我们得出结论，不同的生长条件和因子在影响膜电位的程度上，是通过改变钠钾ATP酶出现的时间来实现的，其活性对静息电位有相当大的贡献。
