Extracellular Caper se inhibits quantal size of catecholamine release in adrenal slice chromaffin cells |
| |
Authors: | Shujiang Shang Changhe Wang Bin Liu Qihui WuQuanfeng Zhang Wei LiuLianghong Zheng Huadong XuXinjiang Kang Xiaoyu ZhangYeshi Wang Hui ZhengShirong Wang Wei Xiong Tao Liu Zhuan Zhou |
| |
Affiliation: | State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China |
| |
Abstract: | Classic calcium hypothesis states that depolarization-induced increase in intracellular Ca2+ concentration ([Ca2+]i) triggers vesicle exocytosis by increasing vesicle release probability in neurons and neuroendocrine cells. The extracellular Ca2+, in this calcium hypothesis, serves as a reservoir of Ca2+ source. Recently we find that extracellular Ca2+per se inhibits the [Ca2+]i dependent vesicle exocytosis, but it remains unclear whether quantal size is regulated by extracellular, or intracellular Ca2+ or both [1]. In this work we showed that, in physiological condition, extracellular Ca2+per se specifically inhibited the quantal size of single vesicle release in rat adrenal slice chromaffin cells. The extracellular Ca2+ in physiological concentration (2.5 mM) directly regulated fusion pore kinetics of spontaneous quantal release of catecholamine. In addition, removal of extracellular Ca2+ directly triggered vesicle exocytosis without eliciting intracellular Ca2+. We propose that intracellular Ca2+ and extracellular Ca2+per se cooperately regulate single vesicle exocytosis. The vesicle release probability was jointly modulated by both intracellular and extracellular Ca2+, while the vesicle quantal size was mainly determined by extracellular Ca2+ in chromaffin cells physiologically. |
| |
Keywords: | Catecholamine Chromaffin cell Extracellular Ca2+ Quantal release Amperometry |
本文献已被 ScienceDirect 等数据库收录! |
|