[Oxidation of fatty acids in heart mitochondria of the ischemic myocardium].

Oxidation of acetate, palmitoyl carnitine and palmitoyl-CoA was studied in isolated rabbit heart mitochondria. The highest rate of respiration was found if acetate was used as a substrate, the other substances studied were less effective. Oxidation of these substrates was gradually decreased after permanent coronary artery occlusion within 1, 4 and 24 hrs; the extent of the oxidation decrease was similar for all the substrates used. Incomplete oxidation of palmitoyl carnitine was observed in mitochondria from ischemic heart. Consumption of acetate in the mitochondria of control and ischemic animals exceeded distinctly its production in total respiration and in beta-oxidation of palmitoyl carnitine. The data obtained suggest that the decrease in coupled respiration, observed in mitochondria under conditions of ischemia, caused rather by lowering in respiratory capacity than by impairment of adenine nucleotides transport.