Cholinergic stimulation of the Na+/K+ adenosine triphosphatase as revealed by microphysiometry.
Cholinergic stimulation of the Na+/K+ adenosine triphosphatase as revealed by microphysiometry.
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DOI：
10.1016/s0006-3495(93)81442-5
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发表时间：
1993-03
影响因子：
3.4
通讯作者：
D. Miller;J. Olson;J. W. Parce;J. Owicki
中科院分区：
文献类型：
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作者：
D. Miller;J. Olson;J. W. Parce;J. Owicki
广泛的细胞受体的激活已经被检测到以前使用一种新的仪器，微生理计。本研究采用微生理测量法监测人横纹肌肉瘤TE671细胞系Na+/K+腺苷三磷酸酶（ATPase）的基础活性和胆碱能刺激的活性。用瓦巴因或去除细胞外K+对Na+/K+ atp酶活性的操纵表明，通过监测酸代谢物的产生，这种离子泵负责细胞总能量利用的8.8 +/- 0.7%。经过一段时间的抑制后，泵的激活使酸化速率短暂地高于基线，这与泵关闭时细胞内[Na+] （[Na+]i）的增加相对应。这一瞬态的振幅是在没有泵活性的情况下[Na+]i总偏移的函数，这反过来又取决于泵抑制的持续时间和Na+内流速率。通过改变碳底物和使用代谢抑制剂来操纵这些细胞的能量代谢模式表明，与研究的其他细胞不同，TE671细胞中的Na+/K+ atp酶不依赖于任何一种代谢模式来获取三磷酸腺苷来源。用乙醇刺激这些细胞中的胆碱能受体通过增加[Na+]i而不是直接激活atp酶来激活Na+/K+ atp酶。
The activation of a wide range of cellular receptors has been detected previously using a novel instrument, the microphysiometer. In this study microphysiometry was used to monitor the basal and cholinergic-stimulated activity of the Na+/K+ adenosine triphosphatase (ATPase) (the Na+/K+ pump) in the human rhabdomyosarcoma cell line TE671. Manipulations of Na+/K+ ATPase activity with ouabain or removal of extracellular K+ revealed that this ion pump was responsible for 8.8 +/- 0.7% of the total cellular energy utilization by those cells as monitored by the production of acid metabolites. Activation of the pump after a period of inhibition transiently increased the acidification rate above baseline, corresponding to increases in intracellular [Na+] ([Na+]i) occurring while the pump was off. The amplitude of this transient was a function of the total [Na+]i excursion in the absence of pump activity, which in turn depended on the duration of pump inhibition and the Na+ influx rate. Manipulations of the mode of energy metabolism in these cells by changes of the carbon substrate and use of metabolic inhibitors revealed that, unlike some other cells studied, the Na+/K+ ATPase in TE671 cells does not depend on any one mode of metabolism for its adenosine triphosphate source. Stimulation of cholinergic receptors in these cells with carbachol activated the Na+/K+ ATPase via an increase in [Na+]i rather than a direct activation of the ATPase.