Decrease of Metabolic Rate by Preoptic Lesions as Cause of Hypothermia in Cats

摘要

The persistence of hypothermia in eight cats with lesions in the medial preoptic region of the forebrain was due in large part to their lower oxygen consumption per unit body weight after operation. Vasodilation inappropriate to the low body temperature occurred sometimes, as did vasoconstriction inappropriate to the rare high body temperature. Usually the cats were appropriately vasoconstricted. There was no decrease of the oxygen consumption per kilogram by five unoperated cats fasted until they lost 16.3% (mean) of their body weight. (The operated cats ahd lost 14.1% of their body weight). The lower metabolic rate of the lesioned cats, therefore, did not result from weight loss or reduced food intake, but from loss of preoptic tissue which normally, when its temperature falls, stimulates metabolism. (Author)