Dual modulation of swelling-activated chloride current by NO and NO donors in rabbit portal vein myocytes
The effects of authentic NO and the NO donor S- nitroso- N- acetylpenicillamine (SNAP) on swelling-activated chloride currents ( I swell ) were investigated in freshly dispersed rabbit portal vein smooth muscle cells. I swell was recorded with the perforated patch configuration of the whole-cell pat...
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Published in | The Journal of physiology Vol. 528; no. 1; pp. 15 - 24 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
The Physiological Society
01.10.2000
Blackwell Publishing Ltd Blackwell Science Inc |
Subjects | |
Online Access | Get full text |
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Summary: | The effects of authentic NO and the NO donor S- nitroso- N- acetylpenicillamine (SNAP) on swelling-activated chloride currents ( I swell ) were investigated in freshly dispersed rabbit portal vein smooth muscle cells. I swell was recorded with the perforated patch configuration of the whole-cell patch clamp technique.
In approximately 50 % of cells NO and SNAP inhibited the amplitude of I swell by about 45 % in a voltage-independent manner. I swell was also inhibited by an inhibitor of NO-sensitive guanylate cyclase (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and
by KT5823, an inhibitor of cGMP-dependent protein kinase.
In other cells both NO and SNAP enhanced I swell by about 40 % in a voltage-independent manner. A similar increase was produced by application of the cell-permeable cGMP
analogue 8-bromo-guanosine 3â²,5â²-cyclic monophosphate (8-Br-cGMP). However, 8-Br-cGMP had no effect on current amplitude in
cells pre-treated with KT5823. In contrast 8-Br-cGMP increased the amplitude of I swell in cells which had been pre-treated with ODQ.
SNAP also modulated I swell recorded in the conventional whole-cell configuration with internal solutions containing 10 m m EGTA to rule out any contribution from Ca 2+ -activated Cl â currents.
These data suggest that the amplitude of I swell can be enhanced by NO via a cGMP-dependent phosphorylation and inhibited by NO in a cGMP-independent manner. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1111/j.1469-7793.2000.00015.x |