INFLUENCE OF FATTY-ACID OXIDATION IN LATERAL HYPOTHALAMUS ON FOOD-INTAKE AND BODY-COMPOSITION

This study tested the concept that the level of fatty acid oxidation in the ventrolateral hypothalamus (VLH) reflects peripheral energy stores and elicits compensatory responses to changes in energy balance status. Fatty acid oxidation rates in the VLH were chronically altered over a 14-day period by infusing into the VLH either 0.1 mM 4-pentenoic acid (4-PA; 5 ng/h) or 1.0 mM L-carnitine (L-Carn; 98 ng/h). Fatty acid oxidation rates in the VLH were altered to a similar extent as by overfeeding (reduced 37% by 4-PA) and dietary restriction (increased 28% by L-Carn). Diffusion of infusates was limited, since there were normal rates of fatty acid oxidation in the ventromedial hypothalamus and cortex. There were no significant effects of altering fatty acid oxidation in the VLH on food intake, body weight, body composition, or serum levels of glucose, insulin, and free fatty acids. The results of this experiment indicate that the level of fatty acid oxidation in the VLH is unlikely to independently elicit changes in food intake or peripheral metabolism.