Recovery of ventricular function in reperfused ischemic rat hearts exposed to fatty acids

The relationship between tissue levels of fatty acid metabolites in ischemic and reperfused hearts and recovery of mechanical function of these hearts on reperfusion was studied. Isolated rat hearts were exposed to global ischemia for periods up to 60 min under various conditions of coronary flow, O2 supply, and fatty acid concentrations and were then reperfused for either 15 or 30 min under aerobic conditions both with and without fatty acids present. Tissue levels of ATP, creatine phosphate, long-chain acyl CoA, and long-chain acyl carnitine were determined at the end of the ischemic and reperfusion periods. In some experiments K+ arrest during ischemia was used to prevent adenine nucleotide depletion both in the absence and presence of high fatty acids. Although the ability of these hearts to recover their preischemic mechanical function varied from 8 to 90% and tissue levels of acyl CoA and acyl carnitine during ischemia varied from 3- to 10-fold depending on the condition, no correlation was found between the recovery of function during reperfusion and either the presence of fatty acid or high levels of tissue long-chain acyl CoA and carnitine esters during ischemia.