ALTERATIONS IN CARDIAC CYTOCHROME-C-OXIDASE, BUT NOT IN LAMININ AND FIBRONECTIN, ARE OBSERVED WITHIN 3 WEEKS OF COPPER RESTRICTION IN RATS - IMPLICATIONS FOR CARDIAC-HYPERTROPHY

Weekly cardiac laminin, fibronectin, and cytochrome c oxidase (CCO) le vels and cardiac hypertrophy were assessed over a period of five weeks in male Long Evans rats fed copper restricted (<15.8 mu mol/kg diet, n=15) or copper adequate diets (94.5 mu mol/kg diet, n=15). Copper res tricted rats displayed significantly lower liver copper and ceruloplas min activity by the first week and lower hematocrit by the third week of dietary treatment. Cardiac hypertrophy was observed after three wee ks of copper restriction as evidenced by greater heart:body weigh rati ot. SDS-PAGE analysis of cardiac laminin and fibronectin did not revea l any changes between copper restricted and copper adequate rats at an y time period during this study. Western blots of cardiac CCO from cop per restricted rats displayed significantly lower amounts of nuclear e ncoded peptide subunits after three weeks of dietary treatment than co ntrol rats. The decrease in the nuclear encoded subunits of CCO coinci ded with the appearance of cardiac hypertrophy and other signs of copp er deficiency. Copyright (C) 1997 Elsevier Science Inc.