Involvement of CRF on the anorexic effect of GLP-1 in layer chicks.
Glucagon-like peptide-1 (GLP-1) is recognized as an anorexic peptide in the brain of chicks. However, the mechanism underlying the inhibition of feeding has not been well studied. It is reported that GLP-1 activates neurons containing corticotrophin-releasing factor (CRF) in the brain of mammals. Since CRF is also an anorexic peptide, it is possible that the anorexic effect of GLP-1 is mediated by CRF in chicks. The present study was carried out to test this. First, we determined plasma corticosterone (CORT) concentrations after intracerebroventricular (ICV) injection of GLP-1 and found that this treatment increased CORT release in layer chicks. The CORT-releasing effect was partly attenuated by co-injection of astressin, a CRF receptor antagonist, demonstrating that GLP-1 stimulated CORT secretion by activation of CRF neurons. CRF neurons also appear to be involved in mediating the inhibition of food intake by GLP-1 because this effect was also partly attenuated by astressin. Furthermore, we demonstrated that the anorexic effect of GLP-1 was weaker in broiler than layer chicks. The present results suggest that the anorexic effect of GLP-1 might be mediated by CRF neurons in the chick brain and that the sensitivity of the inhibitory response to GLP-1 differs between chick strains.
Tachibana
Tetsuya
T
Department of Animal Science, Division of Animal and Marine Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan. tetsu@brs.kyushu-u.ac.jp
Sato
Momoka
M
Oikawa
Daichi
D
Furuse
Mitsuhiro
M
D000818:Animals; D000831:Animals, Newborn; D000855:Anorexia / Q000097:blood / Q000209:etiology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002645:Chickens; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000502:physiology*; D004435:Eating; D005247:Feeding Behavior / Q000502:physiology; D052216:Glucagon-Like Peptide 1 / Q000008:administration & dosage / Q000502:physiology*; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology; D013045:Species Specificity
D018696:Neuroprotective Agents; D010446:Peptide Fragments; D052216:Glucagon-Like Peptide 1; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone