Properties of the Na+-K+ pump in human red cells with increased number of pump sites.
Properties of the Na+-K+ pump in human red cells with increased number of pump sites.
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人红细胞中 Na-K 泵的特性，泵位点数量增加。
DOI：
10.1172/jci113037
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Tosteson,DC
中科院分区：
文献类型：
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作者：
Halperin,JA;Brugnara,C;Kopin,AS;Ingwall,J;Tosteson,DC
我们研究了肥胖人类受试者 (MAJ) 红细胞中的 Na+/K+ 泵，其中泵/细胞的数量比正常人高 10-20 倍。通过测量 Na+/K+ 泵的几种操作模式的动力学特性，我们确定 MAJ 细胞中的泵在动力学上是正常的。在存在足够的代谢底物的情况下，Na+泵送和乳酸产生的最大速率分别饱和于每小时 60 和 12 nmol/1 细胞。在生理条件下，MAJ 细胞和正常细胞中的泵送和“泄漏”Na+ 通量相似。由于 MAJ 中的内部 Na+ 低于正常细胞（Nai+ 分别约为 2 和 8 mmol/1 个细胞），因此我们得出结论，细胞 Na+ 的减少使 MAJ 细胞中的 Na+/K+ 泵能够以最大容量的较低部分运行，并补偿泵数量的增加。
We studied the Na+/K+ pump in red cells from an obese human subject (MAJ) in which the number of pumps/cell was 10-20 times higher than normal. Through measurements of the kinetic properties of several modes of operation of the Na+/K+ pump we determined that the pumps in MAJ cells are kinetically normal. In the presence of adequate metabolic substrate the maximum rates of Na+ pumping and lactate production saturated at 60 and 12 nmol/1 cell per h, respectively. Under physiological conditions pump and "leak" Na+ fluxes were similar in MAJ and normal cells. Since internal Na+ was lower in MAJ than in normal cells (Nai+ approximately 2 and 8 mmol/1 cell, respectively), we conclude that the reduction in cell Na+ allows the Na+/K+ pump in MAJ cells to operate at lower fraction of maximum capacity and to compensate for the increased number of pumps.