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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
11
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pubmed:dateCreated |
1990-3-15
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pubmed:abstractText |
1. The effects of adenosine antagonism (8-phenyltheophylline) and beta-blockade (1-propranolol) were examined during low-flow ischaemia (0.5 mL/min per g for 20 min) in rat heart. 2. Myocardial adenosine release, heart rate, and left ventricular developed pressure were monitored to determine whether endogenous adenosine affected ischaemic function directly, and/or via interaction with endogenous catecholamines. 3. Adenosine release increased more than 10-fold during low-flow ischaemia. Release displayed a phasic pattern, with maximal release occurring at 10 min. Ischaemia produced bradycardia (-180 beats/min) which was reduced by 8-phenyltheophylline infusion (P less than 0.001, n = 10). Adenosine antagonism also significantly increased left ventricular developed pressure in the initial 5 min of ischaemia (P less than 0.001, n = 10). 4. beta-blockade alone was without effect in ischaemic hearts, however, beta-blockade significantly reduced the initial increases in heart rate and developed pressure observed during infusion of 8-phenyltheophylline (P less than 0.001, n = 10). The effect of beta-blockade was transient, occurring in the initial 5-6 min of ischaemia. 5. The data indicate that endogenous adenosine directly mediates greater than 30% of the bradycardia associated with low-flow ischaemia, and that endogenous adenosine inhibits the release and/or the effects of endogenous catecholamines produced during the initial 5-6 min of ischaemia.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/8-phenyltheophylline,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine,
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic beta-Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Catecholamines,
http://linkedlifedata.com/resource/pubmed/chemical/Theophylline
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0305-1870
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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 |
885-91
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2575475-Adenosine,
pubmed-meshheading:2575475-Adrenergic beta-Antagonists,
pubmed-meshheading:2575475-Animals,
pubmed-meshheading:2575475-Blood Pressure,
pubmed-meshheading:2575475-Catecholamines,
pubmed-meshheading:2575475-Coronary Disease,
pubmed-meshheading:2575475-Heart Rate,
pubmed-meshheading:2575475-Male,
pubmed-meshheading:2575475-Rats,
pubmed-meshheading:2575475-Rats, Inbred Strains,
pubmed-meshheading:2575475-Theophylline
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pubmed:year |
1989
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pubmed:articleTitle |
Effects of adenosine antagonism and beta-blockade during low-flow ischaemia in rat heart.
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pubmed:affiliation |
Division of Science and Technology, Griffith University, Nathan, Queensland, Australia.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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