WHOLE-CELL MEMBRANE CURRENTS IN CULTURED PIG ENDOCARDIAL ENDOTHELIAL-CELLS

被引:22
作者
FRANSEN, PF
DEMOLDER, MJM
BRUTSAERT, DL
机构
来源
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY | 1995年 / 268卷 / 05期
关键词
ENDOCARDIAL ENDOTHELIUM; INWARD RECTIFIER; VOLUME ACTIVATION; ANION CHANNEL;
D O I
10.1152/ajpheart.1995.268.5.H2036
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
The whole cell mode of the patch-clamp technique was applied to cultured endocardial endothelial cells from the porcine right ventricle to study their electrophysiological properties. With isotonic pipette and bathing solutions (300-310 mosmol/kgH(2)O), single endocardial endothelial cells had resting membrane potentials ranging from -20 to -90 mV (mean = -55 +/- 20 mV, n = 48). In voltage-clamp experiments, the main membrane current was an inwardly rectifying K+ current with all characteristics described for the inwardly rectifying K+ current in vascular endothelium. Outward currents at positive clamp potentials were small, but when cell swelling was induced by means of a hypertonic pipette or hypotonic bathing solution and ATP (5 mM) was present in the pipette solution, a large outwardly rectifying current developed. This volume-activated current was insensitive to extracellular K+ or Na+ concentration variations but sensitive to changes in extracellular Cl- concentrations. It was inhibited in the presence of 4,4'-diisothiocyanostilbene-2,2 disulfonic acid (100-300 mu M) and flufenamic acid (50-100 mu M). Volume-activated Cl- channels are different from the stretch-activated cationic channels described in vascular endothelium and might be involved in the regulation of cell volume or the response to mechanical stretch.
引用
收藏
页码:H2036 / H2047
页数:12
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