Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-10-19
pubmed:abstractText
We have recently demonstrated that adenosine, acting via adenosine A2 receptors, inhibits generation of superoxide anions (O2-) by stimulated neutrophils. To determine the mechanism(s) by which adenosine inhibits O2- generation stimulated by the chemoattractant N-formylmethionylleucylphenylalanine (FMLP), we examined cyclic AMP (cAMP) concentrations, stimulated membrane depolarization and Ca2+ movements. Neither adenosine nor 5'-N-ethylcarboxamidoadenosine (NECA), the most potent agonist at adenosine A2 receptors, increases neutrophil cAMP content. However in the presence of the non-methylxanthine phosphodiesterase inhibitor, Ro-20-1724, both adenosine and NECA elicit a reversible increase in intracellular cAMP concentration. The chemoattractant FMLP also elicits an increment in the neutrophil cAMP content. NECA, in the presence of Ro-20-1724, synergistically enhances the increment in cAMP following stimulation by FMLP. However Ro-20-1724 does not potentiate the inhibition of O2- generation by NECA. Unlike other agents which increase neutrophil cAMP concentrations, NECA, even in the presence of a phosphodiesterase inhibitor, only trivially inhibits degranulation. We also found that adenosine markedly inhibits stimulated membrane depolarization but does not affect the stimulated increment in free ionized intracellular calcium. Moreover, inhibition by adenosine of O2- generation does not vary with the concentration of extracellular calcium. These results fulfil the last criterion for the demonstration of an A2 receptor on human neutrophils, and indicate that adenosine occupies an A2 receptor on neutrophils to raise intracellular cAMP in synergy with occupancy of the FMLP receptor. The results reported here also indicate that cAMP is not the second messenger for inhibition of O2- generation by adenosine and its analogues.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-14332482, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-171281, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-228008, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-2411298, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-2989364, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-3019343, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-3024727, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-3928764, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-4004786, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-4125373, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-4179068, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-5656398, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6114369, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6153685, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6245105, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6248853, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6249851, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6311934, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-686171, http://linkedlifedata.com/resource/pubmed/commentcorrection/2844154-6980885
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/4-(3-Butoxy-4-methoxybenzyl)-2-imida..., http://linkedlifedata.com/resource/pubmed/chemical/Adenosine, http://linkedlifedata.com/resource/pubmed/chemical/Adenosine-5'-(N-ethylcarboxamide), http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/N-Formylmethionine..., http://linkedlifedata.com/resource/pubmed/chemical/Oxygen, http://linkedlifedata.com/resource/pubmed/chemical/Phosphodiesterase Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Formyl Peptide, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Immunologic, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Purinergic
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0264-6021
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
709-15
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Occupancy of adenosine receptors raises cyclic AMP alone and in synergy with occupancy of chemoattractant receptors and inhibits membrane depolarization.
pubmed:affiliation
Department of Medicine, New York University Medical Center, NY 10016.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't