SUBMICROSCOPIC CA2+ DIFFUSION MEDIATES INHIBITORY COUPLING BETWEEN INDIVIDUAL CA2+ CHANNELS
SUBMICROSCOPIC CA2+ DIFFUSION MEDIATES INHIBITORY COUPLING BETWEEN INDIVIDUAL CA2+ CHANNELS
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DOI：
10.1016/0896-6273(92)90159-b
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发表时间：
1992-08-01
期刊：
影响因子：
16.2
通讯作者：
YUE, DT
中科院分区：
文献类型：
--
作者：
IMREDY, JP;YUE, DT
心脏中二氢吡啶敏感的Ca2+通道表现出重要的负反馈特性：它们关闭或失活，以响应先前的Ca2+进入。我们现在发现，通过一个通道的Ca2+内流可以选择性地促进另一个相邻通道的失活，而不会引起细胞内大量Ca2+浓度的普遍升高。Ca2+螯合剂BAPTA的细胞内应用极大地减少了Ca2+通道对内的这种负相互作用。这些发现表明Ca2+电流不仅受固有通道特性的控制，还受邻近通道之间局部扩散相互作用的控制。这种通道间的抑制性偶联提供了局域Ca2+信号的具体例子，长期存在于理论计算的基础上。
Dihydropyridine-sensitive Ca2+ channels in heart demonstrate an important negative feedback property: they close, or inactivate, in response to prior Ca2+ entry. We now find that Ca2+ influx through one channel can selectively contribute to the inactivation of another adjacent channel, without a generalized elevation of bulk intracellular Ca2+ concentration. Intracellular application of the Ca2+ chelator BAPTA greatly diminishes such negative interactions within Ca2+ channel pairs. These findings demonstrate that Ca2+ currents are controlled not only by intrinsic channel properties, but also by local diffusive interactions among neighboring channels. Such inhibitory coupling among channels provides a concrete example of localized Ca2+ signaling, long proposed to exist on the basis of theoretical calculations.