A single oral administration of conjugated linoleic acid enhanced energy metabolism in mice

We investigated the effect of a single oral administration of conjugated li noleic acid (CLA) on energy metabolism in mice. Male Std ddY mice were oral ly administered CLA (5 mL/kg weight) or linoleic acid (5 mL/kg weight) (bot h solutions at concentrations of 73.5%) as a control. Oxygen consumption wa s significantly greater in the CLA-administered mice than in the control mi ce. Respiratory quotient was slightly lower in the CLA-administered mice th an in the control mice. We calculated fat and carbohydrate oxidation from o xygen consumption and respiratory quotient. Fat oxidation in the CLA-admini stered mice was significantly higher than in the control mice, and there wa s no difference in carbohydrate oxidation. Serum concentrations of noradren alin and adrenalin in the CLA administered mice were significantly higher t han in the control mice. These results suggested that CLA enhanced sympathe tic nervous activity and energy metabolism.