Source:http://linkedlifedata.com/resource/pubmed/id/11113003
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
12
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pubmed:dateCreated |
2001-1-16
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pubmed:abstractText |
Volume-regulated chloride channels have recently been proposed to be end-effectors in ischemic preconditioning. The present study attempted to confirm this hypothesis by looking both at cardioprotection and channel activity. In isolated rabbit cardiomyocytes, hypo-osmotic stress (167 mosm/l) induced a current with a magnitude of 2-5 pA/pF at 60 mV. That current could be blocked by the selective chloride channel blockers 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) or indanyloxyacetic acid 94 (IAA-94), but only at 100 microM and 1 m M respectively. Lower concentrations were not effective. Because the channel-blocking concentrations were toxic in isolated perfused rabbit hearts, as evidenced by cessation of cardiac contraction and massive infarction, neither agent could be tested against preconditioning's anti-infarct effect. NPPB and IAA-94 at 1 microM and 10 microM, respectively (the doses used in a previous report), did not affect coronary flow, heart rate and developed pressure, and also did not prevent the infarct size reduction of ischemic preconditioning with 5 min global ischemia/10 min reperfusion preceding 30 min of regional ischemia and 120 min of reperfusion [11. 4(+/-3.6) and (11.1(+/-3.7)% infarction of risk area, respectively]. The volume-regulated chloride and organic osmolyte channel blocker 4, 4;-diisothiocyanostilbene-2,2;-disulfonic acid (DIDS) at 100 microM blocked the hypo-osmotically induced current in myocytes, but again could not be used, since it induced total cessation of cardiac contraction and reduced infarct size in non-preconditioned hearts. Our data do not confirm a prior study on a causal role for volume-regulated chloride channels in the protection of ischemic preconditioning. This hypothesis remains to be adequately tested.
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pubmed:commentsCorrections | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0022-2828
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pubmed:author | |
pubmed:copyrightInfo |
Copyright 2000 Academic Press.
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pubmed:issnType |
Print
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pubmed:volume |
32
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2279-85
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:11113003-Animals,
pubmed-meshheading:11113003-Cells, Cultured,
pubmed-meshheading:11113003-Chloride Channels,
pubmed-meshheading:11113003-Electrophysiology,
pubmed-meshheading:11113003-Heart Ventricles,
pubmed-meshheading:11113003-Hemodynamics,
pubmed-meshheading:11113003-Ischemic Preconditioning,
pubmed-meshheading:11113003-Myocardial Infarction,
pubmed-meshheading:11113003-Myocardium,
pubmed-meshheading:11113003-Rabbits
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pubmed:year |
2000
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pubmed:articleTitle |
No confirmation for a causal role of volume-regulated chloride channels in ischemic preconditioning in rabbits.
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pubmed:affiliation |
Department of Physiology, University of South Alabama College of Medicine, Mobile, AL 36688, USA.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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