Delay between fusion pore opening and peptide release from large dense-core vesicles in neuroendocrine cells
Delay between fusion pore opening and peptide release from large dense-core vesicles in neuroendocrine cells
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DOI：
10.1016/s0896-6273(02)00563-9
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发表时间：
2002-01-17
期刊：
影响因子：
16.2
通讯作者：
Rorsman, P
中科院分区：
文献类型：
--
作者：
Barg, S;Olofsson, CS;Rorsman, P
与经典神经递质介导的相比，肽能神经传递缓慢。我们已经研究了胞吐膜融合和货物释放的同时电容测量和共聚焦成像的单个分泌囊泡在神经内分泌细胞。易释放池（RRP）的消耗与10%-20%的停靠囊泡的胞吐作用相关。一些剩余的囊泡在RRP恢复后变得可释放。融合孔的扩张，表现为管腔pH的增加，在大约0.3秒后发生，肽的释放被延迟另外1-10秒。我们的结论是：（1）RRP再填充涉及已经到位的囊泡的化学修饰，（2）通过融合孔释放的大神经肽是可以忽略的，只有在完全融合后才能进行，（3）缓慢的肽能传递反映了囊泡排空的时间过程。
Peptidergic neurotransmission is slow compared to that mediated by classical neurotransmitters. We have studied exocytotic membrane fusion and cargo release by simultaneous capacitance measurements and confocal imaging of single secretory vesicles in neuroendocrine cells. Depletion of the readily releasable pool (RRP) correlated with exocytosis of 10%-20% of the docked vesicles. Some remaining vesicles became releasable after recovery of RRP. Expansion of the fusion pore, seen as an increase in luminal pH, occurred after similar to0.3 s, and peptide release was delayed by another 1-10 s. We conclude that (1) RRP refilling involves chemical modification of vesicles already in place, (2) the release of large neuropeptides via the fusion pore is negligible and only proceeds after complete fusion, and (3) sluggish peptidergic transmission reflects the time course of vesicle emptying.