RATE OF GLYCOLYSIS DURING ISCHEMIA DETERMINES EXTENT OF ISCHEMIC-INJURY AND FUNCTIONAL RECOVERY AFTER REPERFUSION

The efficacy of increasing glycolysis during ischemia for enhancing th e salutary effects of reperfusion was evaluated in isolated perfused r abbit hearts subjected to low-flow ischemia followed by reperfusion. C ontrol hearts were perfused with buffer containing 0.4 mM palmitate, 5 mM glucose, and 70 mU/l insulin. Additional groups of hearts were per fused with double glucose/insulin and 1 mM dichloroacetate or were sub jected to substrate priming to increase preischemic glycogen content. Ischemic contracture was completely prevented in hearts perfused with high glucose/insulin and was delayed markedly by either dichloroacetat e or enhanced preischemic glycogen [45 +/- 14 and 31 +/- 20 min, respe ctively; P < 0.01 each vs. control (11 +/- 10 min)] and inversely rela ted to the rate of lactate production. With reperfusion, recovery of d eveloped pressure was 56 +/- 23% of baseline in control hearts, 90 +/- 8% in hearts receiving high glucose/insulin, 92 +/- 5% in hearts rece iving dichloroacetate, and 79 +/- 19% in hearts with increased glycoge n (P < 0.05 each vs. control hearts). Creatine kinase release was redu ced by > 55% in treated hearts. Thus enhancement of glycolysis by dive rse mechanisms during ischemia decreased ischemic damage and improved the recovery of contractile function with reperfusion.