title: Endogenous orexin-A in the brain mediates 2-deoxy-D-glucose-induced stimulation of gastric motility in freely moving conscious rats.
abstract: BACKGROUND
  Increasing evidence has indicated that brain orexin plays a vital role in the regulation of gastrointestinal (GI) physiology such as gastric acid secretion and GI motility. The aim of this study was to elucidate the effects and mechanisms of orexin on gastric motility in non-fasted rats.
  
  
  METHODS
  In this study, we recorded intraluminal gastric pressure waves in freely moving conscious rats with a manometric catheter located in the antrum. We assessed the area under the manometric trace as the motor index (MI), and compared its values for 1 h before and after drug administration.
  
  
  RESULTS
  Intracisternal (ic) injection of orexin-A (10 μg) significantly increased the MI, but intraperitoneal (ip) injection did not have any effect. Pretreatment of ip injection of atropine significantly blocked the orexin-A-induced stimulation of gastric motility. Intravenous injection of 2-deoxy-D-glucose (2-DG, 200 mg/kg), a central vagal stimulant, significantly increased the MI. The ic injection of SB-334687 (40 μg), a selective orexin-A antagonist, did not modify the basal MI, but this antagonist significantly suppressed the stimulant action of 2-DG.
  
  
  CONCLUSIONS
  These results suggest that endogenous orexin-A in the brain is involved in the vagal-dependent stimulation of gastric contractions.
authors.affiliation: Department of Regional Medicine and Education, Asahikawa Medical University, 2-1-1-1 Midorigaoka Higashi, Asahikawa 078-8510, Japan. tnozu@sea.plala.or.jp
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nozu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tuchiya
authors.forename: Shima
authors.initials: S
authors.lastname: Kumei
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takakusaki
authors.forename: Koji
authors.initials: K
authors.lastname: Ataka
authors.forename: Mineko
authors.initials: M
authors.lastname: Fujimiya
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Okumura
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000187:drug effects*; D003243:Consciousness; D003847:Deoxyglucose / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects* / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology* / Q000502:physiology; D008297:Male; D008365:Manometry; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology; D018377:Neurotransmitter Agents / Q000494:pharmacology* / Q000502:physiology; D000068797:Orexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000187:drug effects / Q000502:physiology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D000068797:Orexins; D001285:Atropine; D003847:Deoxyglucose