Decreased nuclear encoded subunits of cytochrome c oxidase and increased copper, zinc–superoxide dismutase activity are found in cardiomyopathic human hearts

Mineral concentrations, copper, zinc–superoxide dismutase and cytochrome c oxidase subunits in human cardiomyopathic heart explants were compared with noncardiomyopathic hearts from autopsy subjects. Iron was reduced in cardiomyopathic hearts, but the zinc:iron ratio was higher in cardiomyopathic hearts. Copper, zinc–superoxide dismutase activity was increased in cardiomyopathic human hearts compared to the noncardiomyopathic hearts. In a subsample of specimens analyzed, the nuclear encoded subunits of cytochrome c oxidase were diminished in the cardiomyopathic hearts. The decreases have been observed in rodents fed copper-deficient diets. However, in this study heart copper levels did not differ by disease status.