Mitochondrial functional aberrations in a mouse model of non-ischemic heart failure

We characterized the metabolic and cardiac mitochondrial function in a mouse model of non-ischemic HF. Inhibition of nitric oxide synthesis and hypertension, which often present together, are two important risk factors in human non-ischemic HF. Compared with L-NAME L-NG-Nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis or Angiotensin II (AngII), a hypertensive agent treatment alone, L-NAME+AngII induced the most severe HF phenotype characterized by edema, hypertrophy, fibrosis, increased blood pressure and reduced ejection fractions. L-NAME+AngII treated mice had robust deterioration of cardiac mitochondrial function we observed. Microarray analyses revealed majority of the gene changes attributed to the combination of L-NAME+AngII. Pathway analyses indicated significant changes in metabolic pathways such as mitochondrial oxidative phosphorylation, fatty acid metabolism and tricarboxylic acid pathways etc.in L-NAME+AngII hearts. We conclude that combination of L-NAME+AngII exacerbates cardiac contractile and mitochondrial functional de-regulation compared with L-NAME and AngII alone, resulting in non-ischemic HF. This model of heart failure may be highly valuable in studying mechanisms and treatments for non-ischemic heart failure. Twelve week-old C57BL6 male mice were randomly assigned to 4 groups: 1. Control, 2. L-NAME treatment, 3. AngII treatment, 4. L-NAME+AngII treatment.L-NAME (0.3 mg/ml with 1% NaCl) was administered in drinking water. AngII (0.7 mg/kg/day) was administered via subcutaneous micro-osmotic pumps. L-NAME and AngII were administered to mice for 5 weeks and 4 weeks in combination to induce HF or alone to study the effects of the individual agents.