A MAJOR ROLE FOR CALCIUM-DEPENDENT POTASSIUM CURRENT IN ACTION-POTENTIAL REPOLARIZATION IN ADRENAL CHROMAFFIN CELLS

被引:6
作者
PANCRAZIO, JJ [1 ]
JOHNSON, PA [1 ]
LYNCH, C [1 ]
机构
[1] UNIV VIRGINIA,HLTH SCI CTR,DEPT BIOMED ENGN,CHARLOTTESVILLE,VA 22908
关键词
ACTION POTENTIAL; CALCIUM-DEPENDENT POTASSIUM CURRENT; CHROMAFFIN; NEUROENDOCRINE; REPOLARIZATION; WHOLE-CELL VOLTAGE-CLAMP;
D O I
10.1016/0006-8993(94)90531-2
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
To determine the extent which Ca dependent K current (I-KCa) contributes during an action potential (AP), bovine chromaffin cells were voltage-clamped using a pre-recorded AP as the command voltage waveform. Based on (1) differential sensitivity of I-KCa and Ca-independent K current (I-K) to tetraethylammonium; (2) measurements of AP currents under conditions where Ca activation of I-KCa had been abolished; and (3) blockade by charybdotoxin, I-KCa comprised 70-90% of the outward K current during AP repolarization. In addition, observations are made concerning the form of AP-evoked Ca current.
引用
收藏
页码:246 / 251
页数:6
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