Selective adenosine A3 receptor stimulation reduces ischemic myocardial injury in the rabbit heart.
Cardiovasc Res
; 33(2): 410-5, 1997 Feb.
Article
en En
| MEDLINE
| ID: mdl-9074706
ABSTRACT
OBJECTIVE:
The aim of this study was to determine whether selective activation of the adenosine A3 receptor reduces infarct size in a Langendorff model of myocardial ischemia-reperfusion injury.METHODS:
Buffer-perfused rabbit hearts were exposed to 30 min regional ischemia and 120 min of reperfusion. Infarct size was measured by tetrazolium staining and normalized for area-at-risk (IA/AAR).RESULTS:
Preconditioning by 5 min global ischemia and 10 min reperfusion reduced infarct size (IA/AAR) to 19 +/- 4% (controls 67 +/- 5%). Replacing global ischemia with 5 min perfusion of the rabbit A3-selective agonist, IB-MECA (A3 Ki 2 nM; A1 Ki 30 nM) elicited a concentration-dependent reduction in infarct size; 50 nM IB-MECA reduced IA/AAR to 24 +/- 4%. The A1-selective agonist, R-PIA (25 nM) reduced IA/AAR to a similar extent (21 +/- 6%). However, while the cardioprotective effect of R-PIA was significantly inhibited (54 +/- 7% IA/AAR) by the rabbit A1-selective antagonist, BWA1433 (50 nM), the IB-MECA-dependent cardioprotection was unaffected (28 +/- 6% IA/AAR). A non-selective (A1 vs. A3) concentration of BWA1433 (5 microM) significantly attenuated the IB-MECA-dependent cardioprotection (61 +/- 7% IA/AAR).CONCLUSIONS:
These data clearly demonstrate that selective A3 receptor activation provides cardioprotection from ischemia-reperfusion injury in the rabbit heart. Furthermore, the degree of A3-dependent cardioprotection is similar to that provided by A1 receptor stimulation or ischemic preconditioning.
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Banco de datos:
MEDLINE
Asunto principal:
Fenilisopropiladenosina
/
Adenosina
/
Receptores Purinérgicos
/
Isquemia Miocárdica
Límite:
Animals
Idioma:
En
Revista:
Cardiovasc Res
Año:
1997
Tipo del documento:
Article
País de afiliación:
Estados Unidos