Orexin reverses cholecystokinin-induced reduction in feeding.
OBJECTIVE
This study was designed to investigate the effect of orexin on anorexia induced by cholecystokinin (CCK),a peripheral satiety signal.


METHODS
We administered orexin A (0.01-1 nmol/mouse) and CCK-8 (3 nmol/mouse) to mice. Food intake was measured at different time-points: 20 min, 1, 2 and 4 h post-intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) administrations.


RESULTS
Intracerebroventricular-administered orexin significantly increased food intake in a dose-dependent manner. The inhibitory effect of i.p.-administered CCK-8 on food intake was significantly negated by the simultaneous i.c.v. injection of orexin in a dose-dependent manner.


CONCLUSIONS
Orexin reversed the CCK-induced loss of appetite. Our results indicate that orexin might be a promising target for pharmacological intervention in the treatment of anorexia and cachexia induced by various diseases.
Asakawa
A
A
Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Inui
A
A
Inui
T
T
Katsuura
G
G
Fujino
M A
MA
Kasuga
M
M
D000704:Analysis of Variance; D000818:Animals; D000855:Anorexia / Q000139:chemically induced*; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D002766:Cholecystokinin / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D000068797:Orexins; D015431:Weight Loss
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D002766:Cholecystokinin