title: Characterization of the motor inhibitory role of colonic mucosa under chemical stimulation in mice.
abstract: The main roles of the colonic mucosa are the absorption of water and electrolytes and the barrier function that preserves the integrity of the colonic wall. The mediators and mechanisms to accomplish these functions are under continuous investigation, but little attention has been paid to a possible control of colonic motility by the mucosa that would fine tune the relationship between absorption and motility. The purpose of this study was to establish the role of the mucosa in the control of induced colonic contractility. Young ICR-CD1 mice (3-5 mo old) were studied. Isometric tension transducers were used to record contractility in full-thickness (FT) and mucosa-free (MF) strips from proximal colon. Proximal FT strips showed lower KCl- and bethanechol-induced responses than MF strips. The difference was not due to mechanical artefacts since the contractile response of FT strips to electrical field stimulation was around 50% lower than in MF. The inhibitory effects of the mucosa on FT strips were mimicked by immersion of separate strips of mucosa in the organ bath but not by addition of mucosal extract, suggesting gaseous molecules as mediators of this effect. Incubation of MF strips with synthase inhibitors of nitric oxide, carbon monoxide, and hydrogen sulfide abolished the inhibition caused by addition of the mucosal strip, indicating that mucosal gasotransmitters are the mediators of these effects. This suggests that the control of colonic motility exerted by the mucosa could fine tune the balance between transit and absorption.
authors: Faculty of Nursing and Occupational Therapy, Department of Physiology, University of Extremadura, Caceres, Spain.
authors: Francisco E
authors: FE
authors: Martín-Cano
authors: Pedro J
authors: PJ
authors: Camello
authors: María J
authors: MJ
authors: Pozo
mesh_terms: D000818:Animals; D018723:Bethanechol / Q000494:pharmacology; D002248:Carbon Monoxide / Q000378:metabolism; D003106:Colon / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D064426:Gasotransmitters / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006862:Hydrogen Sulfide / Q000378:metabolism; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009119:Muscle Contraction / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011312:Pressure; D013268:Stimulation, Chemical; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D064426:Gasotransmitters; D018723:Bethanechol; D009569:Nitric Oxide; D011189:Potassium Chloride; D002248:Carbon Monoxide; D019001:Nitric Oxide Synthase; D006862:Hydrogen Sulfide
keywords: bethanechol; carbon monoxide; colon; gasotransmitters; hydrogen sulfide; nitric oxide