Effects of gradual reperfusion on postischemic metabolism and functional recovery of isolated guinea pig heart.

Gradual reperfusion improves recovery of the pump function of isolated guinea pig heart subjected to total ischemia. This effect is associated with the restoration of higher myocardial contents of ATP, adenine nucleotides, total Cr, and lactate level close to preischemic one, and reduced losses of tissue Cr, glutamate, and aspartate. Positive correlations between energy and functional indices in reperfused hearts indicate that resumption of aerobic energy production may be a crucial factor for postischemic functional recovery. The importance of metabolism of glutamate and aspartate for recovery of cardiac function is confirmed by good correlations between the pools of these amino acids and of ATP, adenine nucleotides, and the total Cr. The results suggest that a decrease in energy demand during the early phase of reperfusion promotes achievement of a better metabolic and functional status in the postischemic heart.