Effects of agouti-related protein, orexin and melanin-concentrating hormone on oxygen consumption in mice.
Neuropeptides in the hypothalamus play a pivotal role in the regulation of energy balance. Agouti-related protein (AGRP), orexin and melanin-concentrating hormone (MCH) have been identified in the hypothalamus as orexigenic peptides. This study was undertaken to investigate the effects of AGRP, orexin and MCH on oxygen consumption. Oxygen consumption was determined by an O2/CO2 metabolism measuring system at 22 degrees C. Mice were kept unrestrained in the chamber without food or water during the light cycle, and the oxygen consumption was measured for 2 h after intra-cerebroventricular (ICV) administration. ICV administered AGRP (1 nmol/mouse) significantly decreased oxygen consumption compared to ACSF-treated controls. Orexin (1 nmol/mouse) significantly increased oxygen consumption, while MCH (1 nmol/mouse) had no significant effect compared to ACSF-treated controls. These results suggest that AGRP, orexin and MCH might have different effects on energy expenditure, thereby regulating appetite and body weight.
Asakawa
Akihiro
A
Division of Diabetes, Digestive and kidney Diseases, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
Inui
Akio
A
Goto
Kyoko
K
Yuzuriha
Hideki
H
Takimoto
Yoshiyuki
Y
Inui
Toshio
T
Katsuura
Goro
G
Fujino
Masayuki A
MA
Meguid
Michael M
MM
Kasuga
Masato
M
D054369:Agouti-Related Protein; D000818:Animals; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D007028:Hypothalamic Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D007031:Hypothalamus / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008543:Melanins / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D000068797:Orexins; D010101:Oxygen Consumption / Q000187:drug effects*; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology; D010907:Pituitary Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D011506:Proteins / Q000008:administration & dosage / Q000494:pharmacology*
D054369:Agouti-Related Protein; C515199:Agrp protein, mouse; D002352:Carrier Proteins; D007028:Hypothalamic Hormones; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008543:Melanins; D009479:Neuropeptides; D000068797:Orexins; D010455:Peptides; D010907:Pituitary Hormones; D011506:Proteins; C019463:melanin-concentrating hormone