Linked Life Data

10991956

Source:http://linkedlifedata.com/resource/pubmed/id/10991956

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-11-3
pubmed:abstractText
The purpose of this study was to investigate whether the extracellular cAMP-adenosine pathway (i.e., transport of cAMP out of cells followed by extracellular conversion of cAMP to adenosine) exists in preglomerular microvessels (PGMVs). Incubation of PGMVs for 1 h with 30 microM cAMP increased the amount of extracellular adenosine from 163 +/- 18.6 (n = 18) to 9810 +/- 604 (n = 12) pmol/mg of protein (P < 10(-6)). The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX; 1 mM; n = 6) and the ecto-phosphodiesterase inhibitor 1, 3-dipropyl-8-p-sulfophenylxanthine (DPSPX; 1 mM; n = 6) significantly (P < 10(-6) and P < 10(-5), respectively) reduced the cAMP-induced increase in extracellular adenosine. Incubation of PGMVs for 1 h with isoproterenol (beta-adrenoceptor agonist; 1 microM) + IBMX (0.1 mM) increased the amount of extracellular cAMP from 0.800 +/- 0.047 to 22.3 +/- 2.20 pmol/mg of protein (P < 10(-6); n = 41). In PGMVs incubated with isoproterenol (1 microM) + IBMX (0.1 mM) for 1 h, there was a significant (P < 10(-4)) linear (r(2) = 0.6) relationship between intracellular and extracellular cAMP levels. Incubation of PGMVs for 1 h with 1 microM isoproterenol increased the amount of extracellular adenosine from 163 +/- 18.6 (n = 18) to 297 +/- 38.3 (n = 12) pmol/mg of protein (P =.002). Propranolol (beta-adrenoceptor antagonist; 1 microM; n = 7), IBMX (1 mM; n = 14), and DPSPX (1 mM; n = 12) blocked (P =.037, P =.015, and P =.026, respectively) isoproterenol-induced increases in extracellular adenosine. CONCLUSIONS: PGMVs transport endogenous cAMP to the extracellular compartment and metabolize extracellular cAMP to adenosine. This pathway can increase extracellular levels of adenosine during beta-adrenoceptor activation of adenylyl cyclase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
295
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Preglomerular microcirculation expresses the cAMP-adenosine pathway.
pubmed:affiliation
Center for Clinical Pharmacology, Departments of Pharmacology and Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA. edj+@pitt.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't