title: Molecular cloning of motilin and mechanism of motilin-induced gastrointestinal motility in Japanese quail.
abstract: Motilin, a peptide hormone produced in the upper intestinal mucosa, plays an important role in the regulation of gastrointestinal (GI) motility. In the present study, we first determined the cDNA and amino acid sequences of motilin in the Japanese quail and studied the distribution of motilin-producing cells in the gastrointestinal tract. We also examined the motilin-induced contractile properties of quail GI tracts using an in vitro organ bath, and then elucidated the mechanisms of motilin-induced contraction in the proventriculus and duodenum of the quail. Mature quail motilin was composed of 22 amino acid residues, which showed high homology with chicken (95.4%), human (72.7%), and dog (72.7%) motilin. Immunohistochemical analysis showed that motilin-immunopositive cells were present in the mucosal layer of the duodenum (23.4±4.6cells/mm(2)), jejunum (15.2±0.8cells/mm(2)), and ileum (2.5±0.7cells/mm(2)), but were not observed in the crop, proventriculus, and colon. In the organ bath study, chicken motilin induced dose-dependent contraction in the proventriculus and small intestine. On the other hand, chicken ghrelin had no effect on contraction in the GI tract. Motilin-induced contraction in the duodenum was not inhibited by atropine, hexamethonium, ritanserin, ondansetron, or tetrodotoxin. However, motilin-induced contractions in the proventriculus were significantly inhibited by atropine and tetrodotoxin. These results suggest that motilin is the major stimulant of GI contraction in quail, as it is in mammals and the site of action of motilin is different between small intestine and proventriculus.
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Auvijit Saha
authors.initials: AS
authors.lastname: Apu
authors.affiliation: Area of Life-NanoBio, Division of Strategy Research, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Anupom
authors.initials: A
authors.lastname: Mondal
authors.affiliation: Comparative Animal Pharmacology Department of Veterinary Science, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
authors.forename: Takio
authors.initials: T
authors.lastname: Kitazawa
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Takemi
authors.affiliation: Area of Life-NanoBio, Division of Strategy Research, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Area of Regulatory Biology, Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. Electronic address: isakata@mail.saitama-u.ac.jp.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakata
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D003370:Coturnix / Q000235:genetics* / Q000502:physiology; D004386:Duodenum / Q000187:drug effects / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000235:genetics* / Q000502:physiology; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000378:metabolism; D054439:Ghrelin / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D009037:Motilin / Q000235:genetics* / Q000494:pharmacology / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects / Q000235:genetics; D011531:Proventriculus / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D017385:Sequence Homology
chemical_list: D054439:Ghrelin; D009037:Motilin
keywords: Gastrointestinal motility; Ghrelin; Japanese quail; Motilin