Linked Life Data

10699369

Source:http://linkedlifedata.com/resource/pubmed/id/10699369

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-5-3
pubmed:abstractText
Adenosine administration has been reported to lower blood pressure by activating specific membrane receptors. The rat and human heart and aorta have been previously found to express both A2-type adenosine receptors, which activate adenylyl cyclase, and A3 adenosine receptors (A3AR), which inhibit adenylyl cyclase. In the current study, we used A3 adenosine receptor (A3AR) knock-out mice to examine the hypothesis that the relative levels of the A2-type adenosine receptors and A3AR determine the steady-state levels of cAMP in the cells and may affect blood pressure. We found that the A3AR knock-out mice express normal levels of the A1- and A2-type adenosine receptors. In situ hybridization demonstrated that the level of A3AR is high in the vascular smooth muscle layer of aortas derived from wild-type mice, but is not detectable in the knock-out mice. The steady-state level of cAMP is elevated in the aorta and heart of knock-out mice, as compared to wild-type mice, but is not altered in platelets, where A3AR is not expressed naturally. A3AR knock-out mice possess a blood pressure comparable to this in wild-type mice. However, when challenged with adenosine, the knock-out mice display a further increase in cAMP levels in the heart and vascular smooth muscle and a significant decrease in blood pressure, as compared to wild-type mice. In contrast, the effect of adenosine on ADP-induced platelet aggregation is similar in both types of mice. These studies indicate that the A3AR affects the steady-state level of cAMP in the tissues where it is naturally expressed, and that it influences the blood pressure in response to adenosine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
1500
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
280-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
A role for the A3 adenosine receptor in determining tissue levels of cAMP and blood pressure: studies in knock-out mice.
pubmed:affiliation
Department of Biochemistry and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't