A COMPARISON OF THE EFFECTS OF FOOD-DEPRIVATION AND 2,5-ANHYDRO-D-MANNITOL ON METABOLISM AND INGESTION

Using respiratory quotient as an index of metabolic state, we compared the effects of administration of the fructose analogue 2,5-anhydro-D- mannitol (2,5-AM) at a dose of 300 mg/kg with the effect-of 10 h of fo od deprivation. We measured behavioral and physiological responses of the animals receiving the two treatments, including food intake, energ y expenditure, rates of carbohydrate and fatty acid utilization, and p lasma levels of glucose, insulin, corticosterone, epinephrine, and nor epinephrine. A vehicle-treated control group was also included. Fastin g produced a greater food intake than 2,5-AM administration. Although plasma glucose, insulin, and norepinephrine levels were similar betwee n the two treatments, plasma corticosterone and epinephrine levels wer e significantly elevated in animals receiving 2,5-AM. We conclude that although 2,5-AM can produce a metabolic state similar to fasting, as measured by an index of whole body metabolic state (respiratory quotie nt), there remain factors that influence food intake that are not simi lar in the two conditions.