EFFECTS OF CORTICOTROPIN-RELEASING FACTOR ON FEEDING AND PANCREATIC-POLYPEPTIDE RESPONSE IN THE DOG

We have previously reported that corticotropin-releasing factor (CRF) is a potent stimulator of adrenocorticotropic hormone and cortisol sec retion in the dog. Therefore, in the present study, we investigated th e extrahypophysiotropic actions of CRF in this species. When CRF was i njected into the third cerebral ventricle, it failed to inhibit food i ntake significantly at doses of 1.19, 3.57 and 11.9 nmol. This is in s harp contrast with the results in rodents. At the 3.57 and 11.9 nmol d oses, CRF markedly stimulated the secretion of pancreatic polypeptide (PP), a hormone under vagal control, and at the highest dose CRF incre ased plasma glucose levels. These results suggest species differences in the feeding response to CRF and activation of the parasympathetic n ervous system in the dog.