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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1991-3-1
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pubmed:abstractText |
We examined the effects of the vasoconstrictor peptide endothelin-1 in isolated hearts under ischemic and cardioplegic conditions. Isolated isovolumic rat hearts were perfused with Krebs-Henseleit buffer at constant pressure. Cumulative dose-response curves were obtained for endothelin-1 boluses of 0.04-400 pmol in four groups of hearts. Coronary flow decreased with increasing dosages and was almost abolished at 400 pmol in control hearts perfused at a constant pressure of 100 mm Hg. In hearts made ischemic by reducing coronary perfusion pressure to 35 mm Hg, thus reducing coronary flow by 76%, the constrictor effect of endothelin-1 was well preserved. The endothelin-1 dose-response curve was unaltered when hearts were perfused with buffer containing 30 mM KCl to abolish mechanical activity without reducing extracellular Ca2+ concentration. A fourth group of hearts was perfused with Ca2(+)-free buffer, thus eliminating the source of extracellular Ca2+ as well as mechanical activity. In this group, the constrictor response to endothelin-1 was largely, but not completely, abolished, with a maximal constrictor effect of only 19% as opposed to 87% in control hearts. We conclude that in isolated rat heart endothelin-1 is a potent coronary constrictor under ischemic perfusion conditions and that absence of mechanical activity does not affect the action of endothelin-1, for which the presence of extracellular Ca2+ is essential. The small residual constrictor response with Ca2(+)-free perfusion is probably due to release of Ca2+ from intracellular stores.
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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 |
Nov
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pubmed:issn |
0160-2446
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
16
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
804-11
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1703604-Animals,
pubmed-meshheading:1703604-Calcium,
pubmed-meshheading:1703604-Coronary Circulation,
pubmed-meshheading:1703604-Coronary Disease,
pubmed-meshheading:1703604-Dose-Response Relationship, Drug,
pubmed-meshheading:1703604-Endothelins,
pubmed-meshheading:1703604-Heart Arrest, Induced,
pubmed-meshheading:1703604-Male,
pubmed-meshheading:1703604-Nitric Oxide,
pubmed-meshheading:1703604-Perfusion,
pubmed-meshheading:1703604-Rats,
pubmed-meshheading:1703604-Rats, Inbred Strains,
pubmed-meshheading:1703604-Vasodilation
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pubmed:year |
1990
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pubmed:articleTitle |
Effects of endothelin-1 in the isolated heart under ischemic and cardioplegic conditions.
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pubmed:affiliation |
Medizinische Universitätsklinik, Würzburg, F.R.G.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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