Antineutrophil and myocardial protecting actions of a novel nitric oxide donor after acute myocardial ischemia and reperfusion of dogs.

BACKGROUNDIt has recently been demonstrated that myocardial ischemia and reperfusion results in a marked decrease in the release of nitric oxide (NO) by the coronary endothelium. NO may possess cardioprotective properties, possibly related to inhibition of neutrophil-related activities. We tested the hypothesis that a cysteine-containing nitric oxide donor compound, SPM-5185, would reduce infarct size and inhibit neutrophil-related activities (adherence to coronary vascular endothelium, accumulation).METHODS AND RESULTSThe effects of intracoronary infusion of SPM-5185 were investigated in a 5.5-hour model of myocardial ischemia (1 hour) and reperfusion (4.5 hours) (MI-R) in anesthetized, open-chest dogs. SPM-5185 (500 nmol/L) or saline vehicle was infused for 4.5 hours into the left anterior descending coronary artery (LAD) at the time of reperfusion after 1 hour of LAD occlusion. MI-R in dogs receiving saline vehicle resulted in severe myocardial injury characterized by dyskinesis, a profound elevation o...