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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2 Pt 2
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pubmed:dateCreated |
1994-9-21
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pubmed:abstractText |
In electrically stimulated myocytes loaded with the fluorescent Ca2+ indicator indo 1-acetoxymethyl ester, spermine induced a dose-dependent (100-500 microM) negative inotropic effect, which was associated with a decrease in the magnitude of the cytosolic Ca2+ concentration ([Ca2+]i) transient but not with changes in myofilament responsiveness to Ca2+. Spermidine induced a less pronounced negative inotropic effect, whereas putrescine did not modify myocyte contraction. In the unstimulated state, spermine did not alter resting [Ca2+]i. Superfusion of the cardiac myocytes with 10 mM alpha-difluoromethylornithine, an inhibitor of polyamine synthesis, did not modify cellular responses to isoproterenol (10(-9)-10(-7) M). beta-Adrenergic stimulation did not affect either ornithine decarboxylase activity or intracellular polyamine levels within a 10-s to 15-min period of treatment. In summary, only exogenously administered polyamines were able to influence myocyte contractility. Their negative inotropic effect resulted from changes in [Ca2+]i homeostasis and required cellular depolarization.
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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 |
Aug
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
267
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
H587-92
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:8067415-Animals,
pubmed-meshheading:8067415-Calcium,
pubmed-meshheading:8067415-Cell Separation,
pubmed-meshheading:8067415-Eflornithine,
pubmed-meshheading:8067415-Electric Stimulation,
pubmed-meshheading:8067415-Heart Ventricles,
pubmed-meshheading:8067415-Homeostasis,
pubmed-meshheading:8067415-Intracellular Membranes,
pubmed-meshheading:8067415-Isoproterenol,
pubmed-meshheading:8067415-Male,
pubmed-meshheading:8067415-Myocardial Contraction,
pubmed-meshheading:8067415-Myocardium,
pubmed-meshheading:8067415-Osmolar Concentration,
pubmed-meshheading:8067415-Polyamines,
pubmed-meshheading:8067415-Rats,
pubmed-meshheading:8067415-Rats, Wistar
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pubmed:year |
1994
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pubmed:articleTitle |
Polyamine effects on [Ca2+]i homeostasis and contractility in isolated rat ventricular cardiomyocytes.
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pubmed:affiliation |
Institute of Biochemistry A. Bonsignore, University of Sassari, Italy.
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pubmed:publicationType |
Journal Article
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