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

Acetate oxidation was examined by ¹³C nuclear magnetic resonance in skeletal muscle from adult and old rats. Rats fasted for 5 days were perfused with [2-¹³C]acetate over 2 h, and muscle extracts were analyzed for [¹³C]glutamate isotopomers. This study shows that approximately 80 % of acetyl-coenzyme 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 demonstrate that skeletal muscle from adult and old rats oxidizes the same proportion of exogenous acetate.