Central administration of vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide differentially regulates energy metabolism in chicks.
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are the members of the glucagon superfamily and bind to common receptors while PACAP also acts via the PACAP-specific receptor, PAC1. The aim of the present study was to investigate whether intracerebroventricular (i.c.v.) injection of VIP and PACAP acts in a similar or different manner to affect body temperature and energy expenditure in the domestic chick. I.c.v. injection of VIP did not significantly affect rectal temperature, but decreased energy expenditure. On the other hand, i.c.v. injection of PACAP significantly increased both body temperature and energy expenditure. These specific actions of PACAP could be explained by an interaction with the PAC1 receptor, since they were partly, but not entirely, attenuated by PACAP (6-38), a PAC1 receptor antagonist. In addition, it was observed that central administration of both VIP and PACAP induced a reduction in respiratory quotient and increased plasma non-esterified fatty acid concentrations. This suggests that both peptides act centrally to regulate a catabolic response. In summary, brain VIP and PACAP both appear to exert generally catabolic effects on energy metabolism in the chick, but their influence on body temperature and glucose metabolism differs and their central effects do not appear to be mediated by the same receptors.
Tachibana
Tetsuya
T
Laboratory of Advanced Animal and Marine Bioresources, Division of Animal and Marine Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan. tetsu@agr.ehime-u.ac.jp
Oikawa
Daichi
D
Adachi
Nami
N
Boswell
Tim
T
Furuse
Mitsuhiro
M
D000818:Animals; D001786:Blood Glucose; D001831:Body Temperature / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D002645:Chickens / Q000502:physiology*; D004734:Energy Metabolism / Q000187:drug effects*; D005227:Fatty Acids / Q000097:blood; D006979:Hyperthermia, Induced; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000008:administration & dosage* / Q000494:pharmacology*; D051381:Rats; D014280:Triglycerides / Q000097:blood; D014660:Vasoactive Intestinal Peptide / Q000008:administration & dosage* / Q000494:pharmacology*
D001786:Blood Glucose; D005227:Fatty Acids; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D014280:Triglycerides; D002245:Carbon Dioxide; D014660:Vasoactive Intestinal Peptide