Adenosine and myocardial protection

A DENOSINE (ADO, MW = 267.24) is an endogenous nucleoside (Fig I), which is the end-product of highenergy adenosine triphosphatc (ATP) catabolism during reduced oxygen (02) supply/demand states resulting from hypoxia and ischemia.’ In regard to the cardiovascular system, ADO may be considered a self-protective hormone or autocoid, because it is secreted by myocardial cells during ischemiaihypoxia while having many beneficial effects against arrhythmias, myocardial ischemia. and reperfusion ischemia.‘-a Leung et al” have published the first preliminary evidence that 5aminoimidazole-4-carboxamide riboside (AICAR) infusion reduces the frequency of perioperative myocardial infarctions (PMI) during coronary artery bypass graft (CABG) by increasing endogenous ADO in ischemic myocardium. The following is a critical review of published Englishlanguage articles regarding residual myocardial injury and potential metabolic therapy with either ADO or AICAR during CABG surgery.