Effect of ischemia and reperfusion on metabolism of eATP (A), eAMP (B) and adenosine (C). After 20 min equilibration, the hearts (n = 5) were subjected to a 30 min-ischemia, followed by reperfusion for 30 min. Each substrate at 10 μM (0.3 ml) was added to the coronary perfusate and subsequent metabolites in the coronary effluents of the first one minute fraction after injection of the substrate were measured by HPLC. Control metabolism was examined in heart after a time-matched control perfusion (80 min, n = 5). Open columns; metabolites from the control hearts, dark columns; metabolites from ischemic heart. Data are shown as percent of total metabolites collected. All values are means ± S.E.M (n = 5). *Significantly different from the control value at P < 0.05 by Student’s t-test.