title: Urocortin 2 blocks the suppression of gastric antral contractions induced by lipopolysaccharide in freely moving conscious rats.
abstract: Lipopolysaccharide (LPS) inhibits gastric antral contractions in conscious rats. Since LPS regulates corticotropin-releasing factor type 2 receptor (CRF2) expression in the rat stomach, and activation of peripheral CRF2 alters gastric motility, we tried to determine the role of peripheral CRF2 in the LPS-induced suppression of gastric antral contractions. Intraluminal gastric pressure waves were measured in freely moving conscious non-fasted rats using the perfused manometric method. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1h before and after intraperitoneal injection of drugs. LPS (0.2 mg/kg) significantly decreased MI. Indomethacin (10 mg/kg) itself did not alter MI but blocked this inhibitory action by LPS. Astressin 2-B (200 μg/kg), a selective CRF2 antagonist, modified neither the basal MI nor the action by LPS. Meanwhile, urocortin 2 (30 μg/kg), a selective CRF2 agonist, reversed the suppression by LPS without affecting the basal MI. This action by urocortin 2 was blocked by pretreatment with astressin 2-B. In conclusion, LPS inhibited gastric antral contractions possibly through a prostaglandin-dependent pathway. Peripheral CRF2 stimulation reversed this response by LPS.
authors.affiliation: Department of Regional Medicine and Education, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa 078-8510, Japan. Electronic address: tnozu@sea.plala.or.jp.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nozu
authors.affiliation: Research Center for Brain Function and Medical Engineering, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa 078-8510, Japan. Electronic address: kusaki@tasahikawa-med.ac.jp.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takakusaki
authors.affiliation: Department of General Medicine, Asahikawa Medical University, Midorigaoka Higashi 2-1-1-1, Asahikawa 078-8510, Japan. Electronic address: okumurat@asahikawa-med.ac.jp.
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Okumura
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003243:Consciousness / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D011706:Pyloric Antrum / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013329:Structure-Activity Relationship; D054832:Urocortins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D008070:Lipopolysaccharides; D054832:Urocortins
keywords: CRF receptor; Gastric contractions; IL-1; Lipopolysaccharide; Peripheral; Urocortin 2