Biphasic effect of extracellular ATP on the membrane potential of mouse thymocytes.
Biphasic effect of extracellular ATP on the membrane potential of mouse thymocytes.
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细胞外 ATP 对小鼠胸腺细胞膜电位的双相效应。
DOI：
10.1006/bbrc.1993.1228
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发表时间：
1993
影响因子：
3.1
通讯作者：
S. Damjanovich
中科院分区：
文献类型：
--
作者：
J. Matkó;P. Nagy;G. Panyi;G. Vereb;L. Bene;L. Mátyus;S. Damjanovich
分析了细胞外ATP诱导BALB/c小鼠胸腺细胞膜电位的变化。当浓度低于0.1 mM时，ATP在Ca（2+）信号发生的时间尺度上使细胞膜发生超极化。经过较长时间的超极化转变为去极化。当ATP浓度高于0.5 mM时，会导致快速去极化，而不会产生超极化。维拉帕米，奎宁或缺乏细胞外Ca2+阻断了ATP的超极化。在无Na（+）介质中，去极化幅度减小。我们的数据表明，Ca（2+）激活的K+通道对低浓度ATP的超极化效应有贡献。膜电位变化的方向可能是由atp受体介导的Ca(2+)-和Na(+)-内流以及Ca（2+）激活的K（+）通道活性的敏感平衡决定的。
Extracellular ATP induced changes in the membrane potential of thymocytes from BALB/c mice were analyzed. At concentrations below 0.1 mM, ATP hyperpolarizes the cell membrane on the time scale of development of the Ca(2+)-signal. After a longer time hyperpolarization turns to depolarization. ATP concentrations higher than 0.5 mM caused rapid depolarization without previous hyperpolarization. Verapamil, quinine or the absence of extracellular Ca2+ blocked the hyperpolarization by ATP. In Na(+)-free medium the magnitude of depolarization decreased. Our data suggest a contribution of Ca(2+)-activated K+ channels to the hyperpolarizing effect of ATP at lower concentrations. The direction of membrane potential changes is determined presumably by a sensitive balance of ATP-receptor mediated Ca(2+)- and Na(+)-influx and the Ca(2+)-activated K(+)-channel activity.