Single-cell measurements of quantal secretion induced by alpha-latrotoxin from rat adrenal chromaffin cells: dependence on extracellular Ca2+.
Single-cell measurements of quantal secretion induced by alpha-latrotoxin from rat adrenal chromaffin cells: dependence on extracellular Ca2+.
复制标题
大鼠肾上腺嗜铬细胞 α-蛇毒素诱导的量子分泌的单细胞测量：对细胞外 Ca2+ 的依赖性。
DOI：
10.1007/s004240050232
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Misler,S
中科院分区：
文献类型：
--
作者：
Barnett,DW;Liu,J;Misler,S
α-Latrotoxin (α-LT), from black widow spider venom, is a potent enhancer of the spontaneous quantal release of neurotransmitter from a variety of nerve terminals and clonal neurosecretory cells. Using electrochemical amperometry and estimation of membrane impedance by phase detection, we present evidence that α-LT induces exocytosis of catecholamines from rat adrenal chromaffin cells beginning as rapidly as 30 s after close application of the toxin. This release is largely dependent on adequate levels of extracellular Ca2+([Ca2+]o). Lowering [Ca2+]ofrom 2 mM to ≤ 10–20 μM reduces the α-LT-induced rise in membrane capacitance by at least sixfold, on average, and nearly abolishes α-LT-induced quantal amperometric events, while still permitting insertion of non-selective cation channels. Based on these experiments, we argue that the rapid onset of α-LT action in promoting massive quantal release from chromaffin cells is primarily due to an increase in the Ca2+permeability of the plasma membrane through non-selective cation channels.
