外源性钠、钾和锂激活的哇巴因敏感的人红细胞钠外流对ATP的依赖性。

The ATP dependence of a ouabain-sensitive sodium efflux activated by external sodium, potassium and lithium in human red cells.

作者信息

Beaugé L A, Del Campillo E

出版信息

Biochim Biophys Acta. 1976 May 21;433(3):547-54. doi: 10.1016/0005-2736(76)90280-7.

Abstract

The stimulation of ouabain-sensitive Na+ efflux by external Na+, K+ and Li+ was studied in control and ATP-depleted human red cells. In the presence of 5 mM Na+, with control and depleted cells, Li+ stimulated with a lower apparent affinity than K+, and gave a smaller maximal activation than K+. The ability of Na+, K+ and Li+ to activate Na+ efflux was a function of the ATP content of the cells. Relative to K+ both Na+ and Li+ became more effective activators when the ATP was reduced to about one tenth of the control values. At this low ATP concentration Na+ was absolutely more effective than K+.

摘要

在对照和ATP耗竭的人红细胞中研究了细胞外Na⁺、K⁺和Li⁺对哇巴因敏感的Na⁺外流的刺激作用。在存在5 mM Na⁺的情况下，对照细胞和ATP耗竭的细胞中，Li⁺刺激的表观亲和力低于K⁺，且最大激活程度小于K⁺。Na⁺、K⁺和Li⁺激活Na⁺外流的能力是细胞ATP含量的函数。相对于K⁺，当ATP降低至对照值的约十分之一时，Na⁺和Li⁺均成为更有效的激活剂。在这种低ATP浓度下，Na⁺绝对比K⁺更有效。