Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3290, USA.
INTEGRARE, Généthon, Inserm, Univ Evry, Université Paris-Saclay, 91002, Evry, France.
Pflugers Arch. 2018 Jan;470(1):135-141. doi: 10.1007/s00424-017-2035-6. Epub 2017 Aug 4.
Large dense core vesicles and chromaffin granules accumulate solutes at large concentrations (for instance, catecholamines, 0.5-1 M; ATP, 120-300 mM; or Ca, 40 mM (12)). Solutes seem to aggregate to a condensed protein matrix, which is mainly composed of chromogranins, to elude osmotic lysis. This association is also responsible for the delayed release of catecholamines during exocytosis. Here, we compile experimental evidence, obtained since the inception of single-cell amperometry, demonstrating how the alteration of intravesicular composition promotes changes in the quantum characteristics of exocytosis. As chromaffin cells are large and their vesicles contain a high concentration of electrochemically detectable species, most experimental data comes from this cell model.
大而致密的核心囊泡和嗜铬颗粒会在高浓度下积累溶质（例如，儿茶酚胺，0.5-1 M；ATP，120-300 mM；或 Ca，40 mM（12））。溶质似乎聚集到一种浓缩的蛋白质基质中，该基质主要由嗜铬粒蛋白组成，以避免渗透裂解。这种结合也负责在胞吐作用期间延迟儿茶酚胺的释放。在这里，我们汇编了单细胞安培法开始以来获得的实验证据，证明了囊泡内组成的改变如何促进胞吐作用的量子特征的变化。由于嗜铬细胞较大，其囊泡中含有高浓度的电化学可检测物质，因此大多数实验数据来自这种细胞模型。
