EFFECTS OF DIETARY-FAT ON FOOD-INTAKE AND BRAIN UPTAKE AND OXIDATION OF FATTY-ACIDS

The present study was designed to investigate (a) whether dietary fat manipulation, quantitatively and/or qualitatively, may influence the t ransport of fatty acids into the brain and oxidation of fatty acids in the hypothalamus; and (b) if an inhibitor of fatty acid oxidation cha nged food intake on these diets. Rats were fed for 4 wk 5% or 34% corn oil or tallow diets that were isocaloric and isonitrogenous. It was f ound that rats fed corn oil diets had significantly higher brain uptak e index of palmitate than did rats fed tallow diets. In a second exper iment, rats were fed either 30% corn oil or tallow diets and injected with either saline or mercaptoacetate (MA). Both saturated fat diets a nd mercaptoacetate injection reduced lateral hypothalamic, but not ven tromedial hypothalamic fatty acid oxidation. Mercaptoacetate increased food intake only in the corn oil fed rats. It is proposed that these uptake and metabolic changes contribute to alterations in either energ y expenditure or feeding behavior.