Skip Navigation

Cardiovascular Research 1997 36(1):52-59; doi:10.1016/S0008-6363(97)00160-0
© 1997 by European Society of Cardiology
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Carr, C. S
Right arrow Articles by Yellon, D. M
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carr, C. S
Right arrow Articles by Yellon, D. M
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1997, European Society of Cardiology

Evidence for a role for both the adenosine A1 and A3 receptors in protection of isolated human atrial muscle against simulated ischaemia

Cornelia S Carra, Roger J Hillb, Hiroko Masamuneb, Scott P Kennedyc, Delvin R Knightb, W.Ross Traceyb and Derek M Yellona,*

aThe Hatter Institute, Department of Academic and Clinical Cardiology, University College London Hospitals, Grafton Way, London WC1E 6DB, UK
bDepartments of Cardiovascular and Metabolic Diseases, University College London Hospitals, London, UK
cMolecular Sciences, Pfizer Inc., Groton, CT, USA

* Corresponding author. Tel.: +44 171 380 9888; Fax: +44 171 388 5095; E-mail: s.bush-cavell@ucl.ac.uk

Objective: Adenosine receptor activation has been implicated in the mechanism of ischaemic preconditioning protection. Evidence suggests adenosine A1 receptor involvement, and possibly A3 receptor involvement in the rabbit. This study investigated the roles of these receptors in human preconditioning. Human A1- and A3-selective compounds were chosen based on Ki values for inhibition of N6-(4-amino-3-[125I]iodobenzyl)adenosine (125I-ABA) binding to stably expressed recombinant human A1 and A3 receptors. Cyclopentyladenosine (CPA), a 194-fold selective A1 agonist, and iodobenzylmethylcarboxamidoadenosine (IBMECA), a 10-fold selective A3 agonist were used alone and in combination with dipropylcyclopentylxanthine (DPCPX) a 62-fold selective A1 antagonist. Methods: Human atrial trabeculae were superfused with oxygenated Tyrode's solution. After stabilisation, muscles underwent one of 8 protocols (n = 6 per group), followed by 90 min of simulated ischaemia and 120 min of reoxygenation. The experimental endpoint was recovery of contractile function, presented as percentage baseline function. Results: 5 nM CPA (52.2±3.1%), 30 nM IBMECA (49.7±3.8%) and preconditioning (55.3±2.5%) produced similar functional recoveries at 120 min of reoxygenation; significantly different to controls (27.7±1.0%; P<0.05, ANOVA). When DPCPX (200 nM) was added prior to 5 nM CPA, protection was lost (31.8±0.9%), but when added prior to 30 nM IBMECA, muscles continued to be significantly protected (41.5±2.3%). Conclusions: In human atrium both A1 and A3 receptor stimulation appears to mimic ischaemic preconditioning. This may represent the first evidence for A3 receptor involvement in ‘pharmacological’ preconditioning of human myocardium.

KEYWORDS Adenosine A1 receptor; Adenosine A3 receptor; Ischemic preconditioning; Human atrium


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.