RELEASABLE POOLS AND THE KINETICS OF EXOCYTOSIS IN ADRENAL CHROMAFFIN CELLS
RELEASABLE POOLS AND THE KINETICS OF EXOCYTOSIS IN ADRENAL CHROMAFFIN CELLS
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DOI：
10.1016/0896-6273(94)90050-7
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发表时间：
1994-11-01
期刊：
影响因子：
16.2
通讯作者：
BOOKMAN, RJ
中科院分区：
文献类型：
--
作者：
HORRIGAN, FT;BOOKMAN, RJ
使用高分辨率电容（C-m）测量技术，我们绘制了短暂（5-100 ms）去极化激活大鼠肾上腺嗜铬细胞电压依赖性Ca 2+通道诱发的胞吐动力学。校正后的C-M信号的贡献Na+通道门控电荷运动，胞吐的初始动力学是一致的去极化触发释放最初发生的立即释放池仅类似于17个分泌囊泡。相比之下，重复应用较长的去极化诱发释放从一个独特的，更大的容易释放池类似于170囊泡。我们的研究结果表明，嗜铬细胞的分泌反应的动作电位是有限的立即释放池的大小，而不是由一个融合机制，是stower比在突触。
Using high resolution capacitance (C-m) measurement techniques, we mapped the kinetics of exocytosis evoked by brief (5-100 ms) depolarizations that activate voltage-dependent Ca2+ channels in rat adrenal chromaffin cells. After correcting the C-m signal for contributions from Na+ channel-gating charge movements, the initial kinetics of exocytosis were consistent with depolarization-triggered release occurring initially from an immediately releasable pool of only similar to 17 secretory vesicles. In contrast, repetitive application of longer depolarizations evoked release from a distinct, larger readily releasable pool of similar to 170 vesicles. Our results suggest that the secretory response of a chromaffin cell to an action potential is limited by the size of the immediately releasable pool rather than by a fusion mechanism that is stower than that at synapses.