The role of glucose in the survival and ‘recovery’ of the anoxic isolated perfused rat heart

Studies with the isolated perfused working rat heart were carried out to investigate factors that may enable the heart to recover after periods of anoxia. It was found that the presence of glucose in the perfusion fluid during anoxia was essential for complete post-anoxic recovery and the presence of a high concentration of K⁺ increased not only the rate of recovery but also the final extent of recovery. In an attempt to clarify the roles played by glucose and K⁺ in aiding the survival and recovery of the anoxic myocardium the concentrations of parameters associated with energy liberation and anaerobic glycolysis (ATP, ADP, AMP, P_i, creatine phosphate, glycogen and lactate) were measured in the presence and absence of glucose during the anoxic phase. Determinations of these parameters were carried out during the working aerobic control period, the anoxic period (K⁺ arrest) and the recovery period. The results demonstrated that glucose acted as an energy source during anoxia and thus maintained myocardial concentrations of high-energy phosphates, particularly ATP. These studies have also shown a direct relationship between the ability of the heart to recover and the concentration of myocardial ATP at the time of reoxygenation.