Lack of effect of ageing on acetate oxidation in rat skeletal muscle during starvation: A C-13 NMR study

Acetate oxidation was examined by C-13 nuclear magnetic resonance in skelet al muscle from adult and old rats. Rats fasted for 5 days were perfused wit h [2-C-13]acetate over 2h, and muscle extracts were analyzed for [C-13]glut amate isotopomers. This study shows that approximately 80 % of acetyl-coenz yme A entering the tricarboxylic cycle was derived from substrate infusion in both adult and old rats, and that the flux through anaplerotic pathways was approximately 21 % of the flux through citrate synthase. These data dem onstrate that skeletal muscle from adult and old rats oxidizes the same pro portion of exogenous acetate.