title: Effect of a chloride channel activator, lubiprostone, on colonic sensory and motor functions in healthy subjects.
abstract: Lubiprostone, a bicyclic fatty acid chloride channel activator, is efficacious in treatment of chronic constipation and constipation-predominant irritable bowel syndrome. The study aim was to compare effects of lubiprostone and placebo on colonic sensory and motor functions in humans. In double-blind, randomized fashion, 60 healthy adults received three oral doses of placebo or 24 microg lubiprostone per day in a parallel-group, placebo-controlled trial. A barostat-manometry tube was placed in the left colon by flexible sigmoidoscopy and fluoroscopy. We measured treatment effects on colonic sensation and motility with validated methods, with the following end points: colonic compliance, fasting and postprandial tone and motility indexes, pain thresholds, and sensory ratings to distensions. Among participants receiving lubiprostone or placebo, 26 of 30 and 28 of 30, respectively, completed the study. There were no overall effects of lubiprostone on compliance, fasting tone, motility indexes, or sensation. However, there was a treatment-by-sex interaction effect for compliance (P = 0.02), with lubiprostone inducing decreased fasting compliance in women (P = 0.06) and an overall decreased colonic tone contraction after a standard meal relative to fasting tone (P = 0.014), with greater effect in women (P < 0.01). Numerical differences of first sensation and pain thresholds (P = 0.11 in women) in the two groups were not significant. We concluded that oral lubiprostone 24 microg does not increase colonic motor function. The findings of decreased colonic compliance and decreased postprandial colonic tone in women suggest that motor effects are unlikely to cause accelerated colonic transit with lubiprostone, although they may facilitate laxation. Effects of lubiprostone on sensitivity deserve further study.
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER) Group, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Seth
authors.initials: S
authors.lastname: Sweetser
authors.forename: Irene A
authors.initials: IA
authors.lastname: Busciglio
authors.forename: Michael
authors.initials: M
authors.lastname: Camilleri
authors.forename: Adil E
authors.initials: AE
authors.lastname: Bharucha
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Szarka
authors.forename: Athanasios
authors.initials: A
authors.lastname: Papathanasopoulos
authors.forename: Duane D
authors.initials: DD
authors.lastname: Burton
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Eckert
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000527:Alprostadil / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D065101:Chloride Channel Agonists; D003106:Colon / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D003187:Compliance; D004311:Double-Blind Method; D005215:Fasting; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D000068238:Lubiprostone; D008297:Male; D017288:Pain Threshold / Q000187:drug effects; D019518:Postprandial Period; D011312:Pressure; D012677:Sensation / Q000187:drug effects*; D012737:Sex Factors
chemical_list: D065101:Chloride Channel Agonists; D005765:Gastrointestinal Agents; D000068238:Lubiprostone; D000527:Alprostadil