Cold-induced free fatty acid mobilization is impaired in rats with lesions in the preoptic area.

The increase in plasma free fatty acids (FFA) induced by cold (2 h at 5 degrees C) in rats with bilateral electrolytic lesions in the preoptic area was reduced to 30% compared to sham-operated controls. Blood glucose of lesioned rats increased 35% over initial levels and remained elevated, whereas in controls it returned to initial levels after 2 h. Rectal temperature decreased 3 degrees C in lesioned rats but not in controls. These data demonstrate the participation of the preoptic area in cold-induced FFA mobilization and provide evidence for the role of this area in the integration of thermal inputs with energy-linked metabolic processes.