Corticotropin releasing hormone produces profound anorexigenic effects in the rhesus monkey

The behavioral consequences of the central administration of corticotropin releasing hormone (CRH) in rhesus monkeys was determined using food-maintained behavior. Acute doses of CRH (0.003 ng/kg-10 micrograms/kg, i.c.v.), decreased responding for food in a dose- and time-related manner. With intermediate doses, responding occurred at a high rate until food was delivered, and then abruptly ceased for several minutes. Previous studies have attributed similar effects to the noxious properties of certain drugs. Acute doses had no effect on home cage food consumption, body weight, or responding for food on subsequent days. When CRH was given repeatedly for several days, its behavioral suppressant effects increased. Home cage food intake, body weight, and subsequent responding for food decreased for up to 6 weeks before returning to normal. These results suggest that sustained elevations in central levels of CRH can result in a sensitization to its anorexigenic effects, an effect that has not been reported in other species. Because hyperaroused clinical states such as depression and anorexia nervosa are characterized biochemically by hypercortisolism and elevated CRH in CSF, these anorexigenic effects may corroborate a potential role for CRH in affective disorders.