Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6 Pt 2
|
| pubmed:dateCreated |
1991-1-31
|
| pubmed:abstractText |
Effects of maturation on the responses of isolated perfused hearts and aortic rings to adenosine were examined. Dose-response relationships for adenosine were obtained in aortic rings and hearts isolated from immature (5 days) and mature (1-2 mo) guinea pigs. Immature and mature hearts were perfused at constant flows of 9.9 +/- 0.3 and 9.5 +/- 0.4 ml.min-1.g-1, respectively, and displayed basal resistances of 4.8 +/- 0.1 and 6.7 +/- 0.2 mmHg.ml-1.min.g. Immature hearts were more sensitive to exogenous adenosine, displaying a significantly lower 50% effective concentration (EC50, 2.5 x 10(-8) M) than mature hearts (1.1 x 10(-7) M, P less than 0.05). Adenosine induced dilation at a lower threshold dose in immature hearts (3 x 10(-9) M, 6.0 +/- 0.3% relaxation) than in mature hearts (10(-8) M, 3.1 +/- 1.3% relaxation). The time required to elicit 50% of the observed dilation was similar in immature and mature hearts, yet the time required for basal tone to recover by 50% was approximately 100% greater in immature hearts (P less than 0.05). Immature aortic rings, stretched to their optimal resting tensions and contracted with EC85 doses of prostaglandin F2 alpha, displayed a significantly lower EC50 (7.7 x 10(-5) M) than mature rings (1.1 x 10(-4) M, P less than 0.05). The maximum percent response to adenosine was greater in immature vessels (64 +/- 1 vs. 54 +/- 0.4%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0002-9513
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
259
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
H1637-42
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:2260690-Adenosine,
pubmed-meshheading:2260690-Aging,
pubmed-meshheading:2260690-Animals,
pubmed-meshheading:2260690-Aorta,
pubmed-meshheading:2260690-Dose-Response Relationship, Drug,
pubmed-meshheading:2260690-Guinea Pigs,
pubmed-meshheading:2260690-Heart,
pubmed-meshheading:2260690-Osmolar Concentration,
pubmed-meshheading:2260690-Perfusion
|
| pubmed:year |
1990
|
| pubmed:articleTitle |
Ontogeny of adenosine response in guinea pig heart and aorta.
|
| pubmed:affiliation |
Department of Physiology, University of Virginia, Charlottesville 22908.
|
| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|