ACTION-POTENTIAL WAVE-FORM VOLTAGE-CLAMP COMMANDS REVEAL STRIKING DIFFERENCES IN CALCIUM ENTRY VIA LOW AND HIGH-VOLTAGE ACTIVATED CALCIUM CHANNELS
ACTION-POTENTIAL WAVE-FORM VOLTAGE-CLAMP COMMANDS REVEAL STRIKING DIFFERENCES IN CALCIUM ENTRY VIA LOW AND HIGH-VOLTAGE ACTIVATED CALCIUM CHANNELS
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DOI：
10.1016/0896-6273(91)90080-j
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发表时间：
1991-07-01
期刊：
影响因子：
16.2
通讯作者：
BEAM, KG
中科院分区：
文献类型：
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作者：
MCCOBB, DP;BEAM, KG
钙通道将自然电压瞬变，如动作电位，转化为功能上重要的细胞内钙瞬变。 我们已经使用数字构建的波形，模拟自然动作电位作为电压钳命令，研究通道功能的转导。 研究了几种动作电位波形（APW）引起的全细胞钙电流。 电流被细分为T（或低压激活）和高压激活成分。 钙通过T通道进入构成了一个不成比例的大部分，在正常的，短暂的APW。 通过高电压激活的通道进入更响应APW，增加更显着的APW持续时间增加。 因此，结果表明，这两种通道类别的选通特性的差异联合收割机结合起来赋予它们显著不同的换能器特性。
Calcium channels transduce natural voltage transients, like action potentials, into functionally important intracellular calcium transients. We have used digitally constructed waveforms that simulate natural action potentials as voltage-clamp commands to study channel function in transduction. Whole-cell calcium currents elicited by several action potential waveforms (APWs) were studied. The currents were subdivided into T (or low voltage-activated) and high voltage-activated components. Calcium entry through T channels constituted a disproportionately large fraction of the total during normal, brief APWs. Entry through high voltage-activated channels was much more responsive to APW, increasing more significantly as APW duration increased. Thus the results indicate that differences in the gating properties of these two channel classes combine to endow them with strikingly different transducer properties.