Bodyweight following lateral hypothalamic lesions: set point upset by glucose infusions

Rats which had recovered to Stage 3 or 4 following lateral hypothalamic lesions maintained their bodyweight at a chronically lowered level when eating dry food. Continuous, long term intravenous and intragastric water infusions increased food intake and promoted a slow weight gain. Infusions of a similar volume of 30% glucose led to a small reduction in food intake and a rapid weight gain. Four rats doubled their weight during infusion; when the infusions were stopped all lost weight back to their starting level. These results are discussed in terms of the problems they present for lowered set point interpretations in such animals.