The effects of vesicular volume on secretion through the fusion pore in exocytotic release from PC12 cells
The effects of vesicular volume on secretion through the fusion pore in exocytotic release from PC12 cells
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DOI：
10.1523/jneurosci.1119-03.2004
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发表时间：
2004-01-14
影响因子：
5.3
通讯作者：
Ewing, AG
中科院分区：
文献类型：
--
作者：
Sombers, LA;Hanchar, HJ;Ewing, AG
许多峰电流记录的胞吐事件最初表现出prespike功能，或脚，这代表了一个稳定的融合孔跨越囊泡和质膜和连接囊泡腔细胞外液的神经递质的稳态流量。在这里，我们提出的第一个证据表明，分泌前囊泡体积与安培足事件的特征密切相关。L-3，4-二羟基苯丙氨酸和利血平已分别用于增加和减少单个嗜铬细胞瘤细胞囊泡的体积。电流测定法和透射电子显微镜已被用来确定，作为囊泡的大小减少的频率与脚事件被观察到的增加，在事件的脚部分释放的神经递质的量和持续时间减少，和囊泡释放更大的百分比，其总内容物在事件的脚部分。这种以前未确定的相关性提供了新的见解如何囊泡体积可以调节胞吐融合孔的活性。
Many spikes in amperometric records of exocytosis events initially exhibit a prespike feature, or foot, which represents a steady-state flux of neurotransmitter through a stable fusion pore spanning both the vesicle and plasma membranes and connecting the vesicle lumen to the extracellular fluid. Here, we present the first evidence indicating that vesicular volume before secretion is strongly correlated with the characteristics of amperometric foot events. L-3,4-Dihydroxyphenylalanine and reserpine have been used to increase and decrease, respectively, the volume of single pheochromocytoma cell vesicles. Amperometry and transmission electron microscopy have been used to determine that as vesicle size is decreased the frequency with which foot events are observed increases, the amount and duration of neurotransmitter released in the foot portion of the event decreases, and vesicles release a greater percentage of their total contents in the foot portion of the event. This previously unidentified correlation provides new insight into how vesicle volume can modulate the activity of the exocytotic fusion pore.