The proportion of pyruvate dehydrogenase complex in the active, dephosphorylated form was decreased (compared with lean controls) in heart muscle in gold thioglucose-treated obese hyperinsulinaemic mice, and the extent of enzyme inactivation was significantly linearly correlated with both body weight and body fat content. A single oral dose (25 mg/kg body wt.) of the beta-oxidation inhibitor 2-tetradecylglycidic acid to obese animals restored pyruvate dehydrogenase complex activity to that of lean controls. It is suggested that increased fatty acid oxidation may be a major factor in mediating the phosphorylation and inactivation of pyruvate dehydrogenase complex in mouse heart muscle in obesity, and this may represent an important mechanism in the development and/or expression of insulin resistance in respect of abnormalities of cellular glucose homoeostasis in these animals.
- © 1984 London: The Biochemical Society