Linked Life Data

9743598

Source:http://linkedlifedata.com/resource/pubmed/id/9743598

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-10-27
pubmed:abstractText
The effects of the selective adenosine (ADO) A3 receptor agonist IB-MECA (N6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide) on cultured newborn rat cardiomyocytes were examined in comparison with ADO, the ADO A1 receptor-selective agonist R-PIA (N6-R-phenylisopropyladenosine), or the ADO A3 selective antagonist MRS 1191 (3-ethyl-5-benzyl-2-methyl-6-phenyl-4-phenylethynyl-1, 4-(+/-)-dihydropyridine-3,5 dicarboxylate), using digital image analysis of Feulgen-stained nuclei. At high concentration, IB-MECA (>/=10 microM ) and ADO (200 microM) induced apoptosis; however, R-PIA or MRS 1191 did not have any detectable effects on cardiac cells. In addition, DNA breaks in cardiomyocytes undergoing apoptosis following treatment by IB-MECA were identified in situ using the nick end labeling of DNA ("TUNEL"-like) assay. In the presence of >/=10 microM IB-MECA, disorder in the contraction waves appeared, and a decrease in the frequency of beats was observed. Analysis with light microscopy revealed that the number of contracting cells decreased in a concentration-dependent manner. The A3 receptor agonist IB-MECA caused an increase in intracellular free calcium concentration ([Ca2+]i). The drug produced a rapid rise followed by a sustained increase in [Ca2+]i, which lasted for 40-60 s. Finally, cessation of beating and Ca2+ transients were observed. Full recovery of contractile activity and rhythmical Ca2+ transients were observed 15-20 min after IB-MECA treatment. The induction of apoptosis in the cardiocytes by IB-MECA led to the appearance of features of apoptotic nuclei: the onset of condensation, compacting, and margination of nuclear chromatin. These effects were accompanied by the disintegration of the structural framework of the nucleus and nuclear breakdown. The results suggest that activation of the A3 adenosine receptor may participate in the process of apoptosis in cardiomyocytes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-4827
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Academic Press.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
243
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
383-97
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Induction of apoptosis in cardiac myocytes by an A3 adenosine receptor agonist.
pubmed:affiliation
Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't