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Background nonselective cationic current and the resting membrane potential in rabbit aorta endothelial cells

Title
Background nonselective cationic current and the resting membrane potential in rabbit aorta endothelial cells
Authors
Park, SJKim, YCSuh, SHRhim, HSim, JHKim, SJSo, IKim, KW
Ewha Authors
서석효
SCOPUS Author ID
서석효scopus
Issue Date
2000
Journal Title
JAPANESE JOURNAL OF PHYSIOLOGY
ISSN
0021-521XJCR Link
Citation
vol. 50, no. 6, pp. 635 - 643
Keywords
rabbit aorta endothelial cellbackground nonselective cationic currentresting membrane potentialrelative permeability
Publisher
CENTER ACADEMIC PUBL JAPAN
Indexed
SCIE WOS
Abstract
The ion channel conductances that regulate the membrane potential was investigated by using a perforated patch-clamp technique in rabbit aorta endothelial cells (RAECs). The whole-cell current/voltage (I-V) relation showed a slight outward rectification under physiological ionic conditions. The resting membrane potential was -23.3+/- 1.1 mV (mean+/-SEM, n=19). The slope conductances at the potentials of -80 and 50mV were 31.0+/-4.0 and 62.8+/-7.1 pS pF(-1), respectively (n=15). Changes in the extracellular and intracellular Cl- concentrations did not affect the reversal potential on I-V curves. The background nonselective cationic (NSC) current was isolated after the K+ current was suppressed. The relative permeabilities calculated from the changes in reversal potentials using the constant-field theory were P-K: P-Cs: P-Na: P-Li = 1:0.87:0.40:0.27 and P-Cs: P-Ca = 1:0.21. Increases in the external Ca2+ decreased the background NSC current in a dose-dependent manner. The concentration for half block by Ca2+ was 1.1+/-0.3 mM (n=7). Through the continuous recording of the membrane potential in a current-clamp mode, it was found that the background NSC conductance is the major determinant of resting membrane potential. Taken together, it could be concluded that the background NSC channels function as the major determinant for the resting membrane potential and can be responsible for the background Ca2+ entry pathway in freshly isolated RAECs.
DOI
10.2170/jjphysiol.50.635
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의학전문대학원 > 의학과 > Journal papers
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