title: Role of transient receptor potential ankyrin 1 in gastric accommodation in conscious guinea pigs.
abstract: We report the establishment of a new model for measuring gastric tone and liquid meal-induced accommodation in conscious guinea pigs and the role played by transient receptor potential ankyrin 1 (TRPA1). An indwelling polyethylene bag was placed in proximal stomachs of 5-week-old male Hartley guinea pigs. Gastric tone was measured by distending the bag and recording changes in intrabag pressure at various volumes. Gastric accommodation was measured by administering liquid meals and recording intrabag pressure over time. N(ω)-nitro-L-arginine methyl ester hydrochloride (L-NAME) (a nitric-oxide synthase inhibitor), atropine sulfate (atropine) (a muscarinic receptor antagonist), allyl isothiocyanate (AITC) (a TRPA1 agonist), or theophylline-7-(N-4-isopropylphenyl) acetamide (HC-030031) (a selective TRPA1 antagonist) was administered 15 to 60 min before measurement. Gastric tone was increased by stepwise distension of the bag and was further significantly increased by L-NAME and significantly decreased by atropine. A liquid meal (15% w/v; 1.7 kcal) significantly decreased intrabag pressure 5 to 20 min after administration, indicating gastric accommodation; this was completely suppressed by L-NAME and further enhanced by atropine. AITC significantly increased gastric tone; this increase was decreased by HC-030031 and atropine. A combination of AITC and L-NAME significantly increased gastric tone compared with L-NAME alone. HC-030031 alone significantly decreased gastric tone. Liquid meal-induced gastric accommodation was significantly suppressed by pretreatment with AITC. We established a new model for measuring gastric tone and accommodation in conscious guinea pigs. TRPA1 activation suppresses gastric accommodation by increasing gastric tone through cholinergic neuronal pathways.
authors.affiliation: Division of Upper Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Koseki
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tomita
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Fukui
authors.forename: Jiro
authors.initials: J
authors.lastname: Watari
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hattori
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kase
authors.forename: Hiroto
authors.initials: H
authors.lastname: Miwa
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000502:physiology*; D059329:Cholinergic Neurons / Q000502:physiology; D005746:Gastric Emptying / Q000502:physiology; D005753:Gastric Mucosa / Q000378:metabolism; D006168:Guinea Pigs; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology; D009130:Muscle, Smooth / Q000166:cytology / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D013270:Stomach / Q000166:cytology / Q000502:physiology*; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
chemical_list: D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050051:Transient Receptor Potential Channels