title: A novel highly selective adenosine A1 receptor agonist VCP28 reduces ischemia injury in a cardiac cell line and ischemia-reperfusion injury in isolated rat hearts at concentrations that do not affect heart rate.
abstract: The cardioprotective effects of a novel adenosine A1 receptor agonist N6-(2,2,5,5-tetramethylpyrrolidin-1-yloxyl-3-ylmethyl) adenosine (VCP28) were compared with the selective adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) in a H9c2(2-1) cardiac cell line-simulated ischemia (SI) model (12 hours) and a global ischemia (30 minutes) and reperfusion (60 minutes) model in isolated rat heart model. H9c2(2-1) cells were treated with CPA and VCP28 at the start of ischemia for entire ischemic duration, whereas isolated rat hearts were treated at the onset of reperfusion for 15 minutes. In the H9c2(2-1) cells SI model, CPA and VCP28 (100 nM) significantly (P < 0.05, n = 5-6) reduced the proportion of nonviable cells (30.88% +/- 2.49% and 16.17% +/- 3.77% of SI group, respectively) and lactate dehydrogenase efflux. In isolated rat hearts, CPA and VCP28 significantly (n = 6-8, P < 0.05) improved post-ischemic contractility (dP/dt(max), 81.69% +/- 10.96%, 91.07% +/- 19.87% of baseline, respectively), left ventricular developed pressure, and end diastolic pressure and reduced infarct size. The adenosine A1 receptor antagonist abolished the cardioprotective effects of CPA and VCP28 in SI model and isolated rat hearts. In conclusion, the adenosine A1 receptor agonist VCP28 has equal cardioprotective effects to the prototype A1 agonist CPA at concentrations that have no effect on heart rate.
authors.affiliation: Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
authors.forename: Vijay B
authors.initials: VB
authors.lastname: Urmaliya
authors.forename: Colin W
authors.initials: CW
authors.lastname: Pouton
authors.forename: Shane M
authors.initials: SM
authors.lastname: Devine
authors.forename: John M
authors.initials: JM
authors.lastname: Haynes
authors.forename: Lyndon
authors.initials: L
authors.lastname: Warfe
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Scammells
authors.forename: Paul J
authors.initials: PJ
authors.lastname: White
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D058907:Adenosine A1 Receptor Agonists / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
chemical_list: D058907:Adenosine A1 Receptor Agonists; C524327:N(6)-(2,2,5,5-tetramethylpyrrolidin-1-yloxyl-3-ylmethyl)adenosine; D011759:Pyrrolidines; C048599:N(6)-cyclopentyladenosine; D000241:Adenosine