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Adenosine and the Stunned Heart
Author(s) -
Randhawa Mohinder P.S.,
Lasley Robert D.,
Mentzer Robert M.
Publication year - 1993
Publication title -
journal of cardiac surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 58
eISSN - 1540-8191
pISSN - 0886-0440
DOI - 10.1111/j.1540-8191.1993.tb01335.x
Subject(s) - medicine , adenosine , cardiology
A bstract Adenosine is one agent under investigation as a therapeutic intervention of myocardial stunning. Adenosine caused numerous effects on the cardiovascular system through its interaction with A 1 and A 2 receptors. We investigated adenosine A 1 receptor mediated mechanisms of cardiac protection in the stunned rat myocardium. Previous studies showed that both adenosine and R‐phenylisopropyladenosine (PIA), an A 1 receptor agonist, prolonged the time to onset of ischemic contracture in ischemic isolated rat hearts. Phenylaminoadenosine, an A 2 receptor agonist, did not have any effect, while receptor antagonists blocked adenosine and PIA action. Direct attenuation of the effects of myocardial stunning was observed by altering levels of interstitial fluid adenosine. Our laboratory has shown that administration of erthro‐9(2‐hydroxy‐3‐nonyl) adenine (EHNA; an adenosine deaminase inhibitor) to dogs subjected to left anterior descending coronary artery (LAD) occlusion followed by reperfusion results in dramatic increases in ischemic levels of interstitial fluid adenosine and postischemic myocardial function. Using a similar model in dogs, we have shown that exogenous intracoronary adenosine (50 μg/kg per min) augmented postischemic recovery of function, as assessed by significant enhancement (p < 0.01) of systolic wall thickness (7.0 ± 3.0 pretreatment vs −5.7 ± 1.7 controls). These data support the role for an adenosine A 1 receptor mediated mechanism for protection against myocardial stunning.