title: Rikkunshito induces gastric relaxation via the β-adrenergic pathway in Suncus murinus.
abstract: BACKGROUND
  Rikkunshito (RKT) is a gastroprotective herbal medicine. In this study, we investigated the role of RKT in the relaxation of the gastric body (fundus and corpus) and antrum.
  
  
  METHODS
  We used Suncus murinus, a unique small model animal with similar gastrointestinal motility to humans and dogs. RKT was added at 0.1, 1.0, and 5.0 mg/mL to induce relaxation in vitro; the outcome measure was the intensity of relaxation. The number of spontaneous antral contractions in the absence or the presence of RKT was also counted.
  
  
  RESULTS
  Rikkunshito induced the relaxation of the gastric body and antrum and decreased the number of spontaneous antral contractions in a dose-dependent manner. The responses to RKT (1.0 mg/mL) were not affected by pretreatment with atropine, N-nitro-l-arginine methyl ester, ritanserin, or ondansetron. On the other hand, timolol almost completely reversed the relaxation induced by RKT (1.0 mg/mL) on the gastric body and antrum and the occurrence of the spontaneous antral contractions. Both butoxamine, a β(2) -adrenoreceptor antagonist, and L 748337, a β(3) -adrenoreceptor antagonist, but not CGP 20712, a β(1) -adrenoreceptor antagonist, significantly reversed the RKT-induced (1.0 mg/mL) gastric relaxation.
  
  
  CONCLUSIONS
  These results indicate that RKT stimulates and modulates gastric relaxation through β(2) - and β(3) -adrenergic, but not β(1) -adrenergic, pathways in S. murinus.
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mondal
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takehara
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Aizawa
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, Sakado-shi, Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Fujitsuka
authors.affiliation: Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hattori
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Sakata
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists / Q000494:pharmacology; D058672:Adrenergic beta-2 Receptor Antagonists / Q000494:pharmacology; D058673:Adrenergic beta-3 Receptor Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000627:Aminophenols / Q000494:pharmacology; D000818:Animals; D002078:Butoxamine / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005748:Gastric Fundus / Q000187:drug effects*; D005769:Gastrointestinal Motility / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011706:Pyloric Antrum / Q000187:drug effects*; D018342:Receptors, Adrenergic, beta-1 / Q000187:drug effects; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects; D022702:Receptors, Adrenergic, beta-3 / Q000187:drug effects; D012788:Shrews; D013270:Stomach / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D013999:Timolol / Q000494:pharmacology
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D058672:Adrenergic beta-2 Receptor Antagonists; D058673:Adrenergic beta-3 Receptor Antagonists; D000319:Adrenergic beta-Antagonists; D000627:Aminophenols; D004365:Drugs, Chinese Herbal; D007093:Imidazoles; C120576:L 748,337; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D022702:Receptors, Adrenergic, beta-3; D013449:Sulfonamides; C084136:liu-jun-zi-tang; D002078:Butoxamine; D013999:Timolol; C049763:CGP 20712A
keywords: Rikkunshito; adrenergic receptor; gastric relaxation