LOCALIZED MITOCHONDRIAL DYSFUNCTION IN CANINE MYOCARDIAL-ISCHEMIA

Effects of myocardial ischemia on mitochondrial enzymes and mitochondr ial DNA (mtDNA) were examined using the model of Ameroid constriction of canine cardiac vessels. Endocardium supplied by constricted coronar y arteries was found to have significantly lower citrate synthase and complex IV activities compared to values obtained from either epicardi um supplied by constricted vessels or endocardium supplied by unconstr icted coronary arteries. Neither significant differences in mtDNA copy number nor changes in respiratory complexes I, III and V were detecte d These results suggest that highly localized, specific mitochondrial enzyme changes result from chronic myocardial ischemia.