Amphetamine anorexia and hypothalamic catecholamines in genetically obese mice (obob).

Genetically obese mice (obob) and their lean littermates were acclimated to a restricted food-access schedule of six hours and then treated with various doses of amphetamine (0, 3, 5 or 10 mg/kg). Saline-treated obob mice maintained on this schedule retained the primary characteristics of obob mice fed ad lib, i.e., hyperphagia, hyperglycemia, elevated hypothalamic norepinephrine (NE) levels. Both lean and obese mice treated with amphetamine showed a dose-dependent decrease in food intake and hypothalamic NE levels. In obob mice amphetamine treatment reduced food intake and hypothalamic NE levels to values which were not significantly different from those of similarly treated lean mice. When the drug dose was administered on a body weight basis, however, brain amphetamine levels were twice as high in obob as in lean mice. When the amphetamine dose was adjusted to produce approximately equivalent brain levels of amphetamine in obob and lean mice, the obob mice ate significantly more than lean mice. The results indicate that amphetamine is an effective anorectic agent capable of reducing food intake, body weight, and hypothalamic NE levels in obob mice.