A simple method for evaluation of Rb+ transport and Na(+)-K+ pump stoichiometry in adherent cells.
A simple method for evaluation of Rb+ transport and Na(+)-K+ pump stoichiometry in adherent cells.
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一种评估贴壁细胞中 Rb 转运和 Na()-K 泵化学计量的简单方法。
DOI：
10.1152/ajpcell.1991.260.6.c1341
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Elsas,LJ
中科院分区：
文献类型：
--
作者：
Longo,N;Griffin,LD;Elsas,LJ
本文描述了一种基于火焰光度法评价贴壁细胞中Rb+跨膜运输和Na(+)-K+泵化学计量的方法。在培养成纤维细胞的单层中，86Rb+（一种在转运研究中广泛用作K+同族的同位素）和非放射性Rb+内流的速率在没有和存在转运抑制剂瓦巴因和布美他尼的情况下是相等的。两种方法对瓦巴因和布美他尼敏感的Rb+通量也相同。火焰光度法允许在测量Rb的同一样品中同时测定细胞内[Na+]。人成纤维细胞与乌阿巴因孵育5分钟后，胞内[Na+]显著增加。在适当的实验条件下，瓦阿因促进细胞内[Na+]的增加速率与瓦阿因敏感的Rb+内流速率之比为1.4，接近于从细胞中挤出3个Na+以换取2个K+的Na(+)-K+泵化学计量所对应的理论值1.5。
This report describes a method based on flame photometry for the evaluation of transmembrane Rb+ transport and Na(+)-K+ pump stoichiometry in adherent cells. In monolayers of cultured fibroblasts, the rates of 86Rb+, an isotope widely used as a K+ congener in transport studies, and nonradioactive Rb+ influx were equivalent when measured in the absence and presence of the transport inhibitors ouabain and bumetanide. Ouabain- and bumetanide-sensitive Rb+ fluxes were also equal with the two methods. Flame photometry allowed the simultaneous determination of intracellular [Na+] in the same sample in which Rb was measured. The incubation of human fibroblasts with ouabain for 5 min promoted a significant increase in intracellular [Na+]. Under appropriate experimental conditions, the ratio between the rate of ouabain-promoted increase in intracellular [Na+] and ouabain-sensitive Rb+ influx was 1.4, close to the theoretical value of 1.5 corresponding to a Na(+)-K+ pump stoichiometry of 3 Na+ extruded from the cell in exchange for 2 K+.