ACTION POTENTIAL-INDUCED QUANTAL SECRETION OF CATECHOLAMINES FROM RAT ADRENAL CHROMAFFIN CELLS

被引:123
作者
ZHOU, Z
MISLER, S
机构
[1] WASHINGTON UNIV, JEWISH HOSP ST LOUIS, SCH MED, DEPT MED, DIV RENAL, ST LOUIS, MO 63110 USA
[2] WASHINGTON UNIV, SCH MED, DEPT CELL BIOL PHYSIOL, ST LOUIS, MO 63110 USA
关键词
D O I
10.1074/jbc.270.8.3498
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Using single rat adrenal chromaffin cells, we examined the coupling of action potential activity to quantal release of catecholamines by combining perforated patch current-clamp recording with electrochemical microcarbon fiber amperometry. Chromaffin cells display steeper dependence of quantal release on action potential frequency than many nerve terminals, as well as more desynchronized release following an action potential. Also in contrast to neurons, in chromaffin cells, a major chemical secretagogue (acetylcholine) triggers potent quantal release even in the absence of electrical activity. These findings are consistent with an hypothesis that a major component of exocytosis from chromaffin cells involves diffusion of Ca2+ to secretion sites which are less well co-localized with Ca2+ channels than those in nerve terminals.
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页码:3498 / 3505
页数:8
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