A peptide hormone; levels are decreased in rat plasma in response to fasting and in rat fundus and intestine following treadmill exercise training; inhibits release of insulin, somatostatin, and pancreatic polypeptide and stimulates glucagon release from mouse and rat pancreatic islets in vitro in a concentration-dependent manner; reduces food intake without affecting growth hormone or corticosterone release in mice (320 μg/kg); inhibits water intake and dehydration-induced vasopressin secretion in response to a hypovolemic challenge in rats,