Adenine nucleotide content and regional function during ischemia and reperfusion in canine ventricular myocardium

We have compared in open-chest dogs the evolution of adenine nucleotides and creatine phosphate to that of regional mechanical function during ischemia and reperfusion. Reperfusion restored normal value of creatine phosphate whereas adenine nucleotide level remained depressed. The percentage of systolic shortening, which after occlusion has a zero or negative value, increased to about 20% of control, after reperfusion similarly the pressure-length loop areas decreased to 14.9% of control during ischemia and increased to 39.3% of control during the early phase of the reperfusion period. No individual correlation was found between the ATP content and segmental function during ischemia or reperfusion, suggesting that a low level of ATP did not prevent some restoration of mechanical function. However, the ATP content measured at the end of the ischemic period was correlated with mechanical function measured 75 min after reperfusion, and thus ATP depletion could appear as an indicator of the severity of ischemic damage.