Alterations in cardiac cytochrome C oxidase, but not in laminin and fibronectin, are observed within three weeks of copper restriction in rats: Implications for cardiac hypertrophy

Abstract

Weekly cardiac laminin, fibronectin, and cytochrome c oxidase (CCO) levels and cardiac hypertrophy were assessed over a period of five weeks in male Long Evans rats fed copper restricted (< 15.8 μmol/kg diet, n = 15) or copper adequate diets (94.5 μmol/kg diet, n = 15). Copper restricted rats displayed significantly lower liver copper and ceruloplasmin activity by the first week and lower hematocrit by the third week of dietary treatment. Cardiac hypertrophy was observed after three weeks of copper restriction as evidenced by greater heart:body weigh ratiot. SDS-PAGE analysis of cardiac laminin and fibronectin did not reveal any changes between copper restricted and copper adequate rats at any time period during this study. Western blots of cardiac CCO from copper restricted rats displayed significantly lower amounts of nuclear encoded peptide subunits after three weeks of dietary treatment than control rats. The decrease in the nuclear encoded subunits of CCO coincided with the appearance of cardiac hypertrophy and other signs of copper deficiency.