CORTICOTROPIN-RELEASING HORMONE DECREASES FEEDING, OXYGEN-CONSUMPTIONAND ACTIVITY OF GENETICALLY-OBESE (OB OB) AND LEAN MICE/

Acute effects of intracerebroventricularly administered corticotropin- releasing hormone (CRH) on deprivation-induced food intake, whole-body oxygen consumption, brown adipose tissue metabolism, and several loco motive behaviors were examined in 6- to 7-wk-old female genetically ob ese (ob/ob) and lean mice. Corticotropin-releasing hormone depressed f ood intake in a dose-dependent manner, with a tendency for greater sup pression of intake in intact ob/ob mice than in lean mice. Adrenalecto my abolished this tendency for CRH to be more potent in ob/ob mice tha n in lean mice. Corticotropin-releasing hormone also lowered the oxyge n consumption of ob/ob and lean mice, without affecting brown adipose tissue metabolism as assessed by measurement of GDP binding to brown a dipose tissue mitochondria. Grooming activity was lowered in CRH-injec ted mice. The CRH-induced lowering of oxygen consumption and grooming activity in mice contrasts with CRH-induced elevations of oxygen consu mption and grooming in rats, suggesting species-specific responses to this peptide. Because effects of CRH were similar in adrenalectomized ob/ob and lean mice, it is unlikely that obesity-producing abnormaliti es in ob/ob mice are related to abnormal CRH action mechanisms. Howeve r, potential abnormalities in CRH synthesis and/or release cannot be e xcluded.