Pituitary adenylate cyclase activating polypeptide and vasoactive intestinal peptide inhibit feeding in the chick brain by different mechanisms

• Published in: Neuroscience letters 2003-09, Vol.348 (1), p.25-28
• Main Authors: Tachibana, Tetsuya, Tomonaga, Shozo, Oikawa, Daichi, Saito, Shin, Takagi, Tomo, Saito, Ei-Suke, Boswell, Tim, Furuse, Mitsuhiro
• Format: Article
• Language: English
• Subjects: Animals; Animals, Newborn; Behavior, Animal; Biological and medical sciences; Brain - drug effects; Brain - physiology; Brain Chemistry; Chick; Chickens; Dose-Response Relationship, Drug; Drug Combinations; Eating - drug effects; Feeding; Feeding Behavior - drug effects; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Gastrointestinal Agents - pharmacology; Humans; Immune Sera - pharmacology; Injections, Intraventricular - methods; Intracerebroventricular injection; Male; Neuropeptides - pharmacology; Peptide Fragments - pharmacology; Pituitary adenylate cyclase 1 receptor; Pituitary Adenylate Cyclase-Activating Polypeptide; Time Factors; Vasoactive intestinal peptide; Vasoactive Intestinal Peptide - immunology; Vasoactive Intestinal Peptide - pharmacology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; VPAC receptor
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(03)00646-3

Intracerebroventricular (ICV) injections of pituitary adenylate cyclase-activating polypeptide-38 (PACAP) and vasoactive intestinal peptide (VIP) inhibit feeding in chicks. However, the precise anorexigenic mechanisms have not been investigated, since both peptides activate the VPAC receptor in mammals. We investigated which receptor mediates the anorexigenic effects of these peptides in chicks. ICV co-injection of PACAP (6–38), a PAC1 receptor antagonist, attenuated the anorexigenic effect of PACAP but not VIP. On the other hand, ICV co-injection of [ d-p-Cl-Phe6, Leu17]-VIP, a VPAC receptor antagonist, did not affect the effects of both peptides. Although these results imply that the effect of VIP was not specific, a subsequent experiment demonstrated that ICV injection of anti-chicken VIP antiserum stimulated feeding and suggested that endogenous VIP inhibits feeding in the chick brain. Collectively, the data suggest that the anorexigenic mechanism of PACAP is different from that of VIP and that an undiscovered VIP receptor may be present in the chicken brain.