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ATP and nitric oxide modulate a Ca2+-activated non-selective cation current in macrovascular endothelial cells

Title
ATP and nitric oxide modulate a Ca2+-activated non-selective cation current in macrovascular endothelial cells
Authors
Suh S.H.Watanabe H.Droogmans G.Nilius B.
Ewha Authors
서석효
SCOPUS Author ID
서석효scopus
Issue Date
2002
Journal Title
Pflugers Archiv European Journal of Physiology
ISSN
0031-6768JCR Link
Citation
vol. 444, no. 3, pp. 438 - 445
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
We have studied the properties of a non-selective cation current (NSCCa) in macrovascular endothelial cells derived from human umbilical vein (EA cells) that is activated by an increase of intracellular Ca2+ concentration, [Ca2+]i. Current-voltage relationships are linear and the kinetics of the current is time-independent. Current-[Ca2+]i relationships were fitted to a Ca2+ binding site model with a concentration for half-maximal activation of 417±76 nM, a Hill coefficient of 2.3±0.8 and a maximum current of -23.9±2.7 pA/pF at -50 mV. The Ca2+-activated channel is more permeable to Na+ than for Cs+ (PCs/PNa=0.58, n=7), but virtually impermeable to Ca2+. Current activation was transient if ATP was omitted from the pipette solution. The maximal currents at 300 and 500 nM [Ca2+]i were smaller than in the absence of ATP, but were not significantly different at 2 μM. The intracellular Ca2+ concentration for half-maximal activation of the Ca2+-activated current was shifted to 811±12 nM in the absence of ATP. Substitution of ATP by the non-hydrolysable ATP analogue adenylylim-idodiphosphate (AMP-PNP) did not affect current activation. Sodium nitroprusside (SNP) decreased NSCCa in a concentration-dependent manner. The nitric oxide (NO) donors S-nitroso-N-acetylpenicillamine (SNAP) and 3-morpholinosydnonimine (SIN-1) also inhibited NSCCa. In contrast, nitro-L-arginine (NLA), which inhibits all NO-synthases, potentiated NSCCa, whereas superoxide dismutase (SOD), which inhibits the breakdown of NO, inhibited NSCCa. It is concluded that the Ca2+-activated non-selective action channel in EA cells is modulated by the metabolic state of the cell and by NO.
DOI
10.1007/s00424-002-0825-x
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의학전문대학원 > 의학과 > Journal papers
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