Linked Life Data

1443197

Source:http://linkedlifedata.com/resource/pubmed/id/1443197

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 2
pubmed:dateCreated
1992-12-22
pubmed:abstractText
Responses to luminal and adventitial adenosine were compared in perfused rabbit central ear arteries. Perfused arteries precontracted with 0.5 microM norepinephrine relaxed dose dependently but asymmetrically to luminal and adventitial adenosine. Arteries were more responsive to luminal adenosine in the 0.1- to 1.0-microM range, but they were more responsive to adventitial adenosine at doses > 10 microM. Alternatively, 2-chloroadenosine, a metabolically stable and poorly transported analogue, was equipotent when applied luminally or adventitially. Endothelial damage reduced sensitivity and response asymmetry to luminal and adventitial adenosine. This was consistent with reduced responses to adenosine in luminally rubbed arterial ring segments. Transport inhibition (10 microM dipyridamole) enhanced arterial reactivity to luminal and adventitial adenosine and reduced response asymmetry but was without effect on responses to 2-chloroadenosine. A comparison of the inhibitory effectiveness of adventitial and luminal 8-phenyltheophylline revealed that adventitial antagonist was approximately threefold more effective in inhibiting responses to adventitial adenosine than luminal antagonist (P < 0.05). This "side-dependent" difference was reduced by prolonged antagonist incubation or endothelial removal. The data indicate that adenosine relaxes ear arteries by activation of smooth muscle [half-maximum effective concentration (ED50) approximately 11 microM] and endothelial (ED50 approximately 2 microM) receptors. Nevertheless, a sensitive endothelial-dependent response does not consistently enhance responses to luminal adenosine in perfused arteries. This appears to be attributable to relative differences in the smooth muscle and endothelium-dependent components of the dilator response and transvascular concentration gradients for luminally and adventitially applied adenosine. A transendothelial diffusion barrier also reduces the ability of luminally applied antagonists to inhibit responses to adventitial adenosine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1437-46
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Relative responses to luminal and adventitial adenosine in perfused arteries.
pubmed:affiliation
Department of Physiology, University of Virginia Health Sciences Center, Charlottesville 22908.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't