Linked Life Data

2750940

Source:http://linkedlifedata.com/resource/pubmed/id/2750940

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 2
pubmed:dateCreated
1989-8-16
pubmed:abstractText
We have recently reported that coronary microembolization sustains myocardial ischemia with hyperemic response of coronary blood flow (CBF) induced by massive release of adenosine from the ischemic myocardium. In this study, we tested the hypothesis that this hyperemic flow caused by released adenosine improves myocardial ischemia. In eight dogs (control), microspheres (5.0 X 10(4)/ml of base-line CBF) were repetitively injected until CBF decreased toward zero, and the changes in CBF, fractional shortening, lactate extraction ratio (LER), and adenosine release were studied. In 15 other dogs, an identical procedure was done with an intracoronary infusion of prazosin (4 micrograms.kg-1.min-1, n = 8) or theophylline (0.1 mg.kg-1.min, n = 7) to elucidate the effect of adenosine, since prazosin inhibits release of adenosine from ischemic myocardium and theophylline blocks adenosine receptors. In 16 other dogs, hemodynamic and metabolic parameters were examined with and without these drugs after a single injection of microspheres (1.0 X 10(5)/ml of base-line CBF). In the control group, CBF increased to 170 +/- (SE) 14% of the base-line CBF at 16-30% of maximal embolization. In contrast, intracoronary infusion of prazosin markedly attenuated adenosine release and hyperemic response and significantly deteriorated both fractional shortening and LER. Theophylline also significantly attenuated the hyperemic response and tended to decrease both fractional shortening and LER. A salutary effect of adenosine release was further confirmed by the improvement of ischemic changes in the same dog after withdrawal of prazosin and theophylline associated with an increase in CBF. Thus we conclude that adenosine released from ischemic myocardium improves ischemia in microembolization through the hyperemic response.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
257
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H244-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Adenosine-induced hyperemia attenuates myocardial ischemia in coronary microembolization in dogs.
pubmed:affiliation
First Department of Medicine, Osaka University School of Medicine, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't