Heien Michael L, Ewing Andrew G
Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
Methods Mol Biol. 2009;544:153-62. doi: 10.1007/978-1-59745-483-4_11.
Exocytosis, the fusion of intracellular vesicles with the membrane and subsequent release of vesicular contents, is important in intercellular communication. The release event is a rapid process (milliseconds), hence detection of released chemicals requires a detection scheme that is both sensitive and has rapid temporal dynamics. Electrochemistry at carbon-fiber microelectrodes allows time-resolved exocytosis of electroactive catecholamines to be observed at very low levels. When coupled with constant-potential amperometry, the number of molecules released and the kinetics of quantal release can be determined. The rapid response time (milliseconds) of microelectrodes makes them well suited for monitoring the dynamic process of exocytosis.
胞吐作用，即细胞内囊泡与细胞膜融合并随后释放囊泡内容物的过程，在细胞间通讯中很重要。释放事件是一个快速过程（毫秒级），因此检测释放的化学物质需要一种既灵敏又具有快速时间动态的检测方案。碳纤维微电极上的电化学方法能够在极低水平下观察到电活性儿茶酚胺的时间分辨胞吐作用。当与恒电位安培法结合使用时，可以确定释放的分子数量和量子释放的动力学。微电极的快速响应时间（毫秒级）使其非常适合监测胞吐作用的动态过程。
