title: The interaction between bronchoconstriction and cough in asthma.
abstract: Variable airflow obstruction is a pathophysiological hallmark of asthma; however, the interactions between acute bronchoconstriction and the cough reflex are poorly understood. We performed a randomised, single-blind, placebo-controlled, crossover study to investigate the interaction between bronchoconstriction and cough in asthma. Capsaicin was administered to evoke coughs and methacholine to induce bronchoconstriction. We demonstrated that acute bronchoconstriction increased capsaicin-evoked coughs, which improved as airway calibre spontaneously resolved. However, capsaicin-evoked coughing had no impact on methacholine-induced bronchoconstriction. This study provides evidence that bronchoconstriction increases the activation of capsaicin-responsive airway nerves, but the precise mechanisms and mediators involved require further evaluation.
  
  
  
  ISRCTN14900082.
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.|University Hospital of South Manchester, Manchester, UK.
authors.forename: Imran
authors.initials: I
authors.lastname: Satia
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: Huda
authors.initials: H
authors.lastname: Badri
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.|Central Manchester NHS Foundation Trust, Manchester, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Woodhead
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.|Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Paul M
authors.initials: PM
authors.lastname: O'Byrne
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Fowler
authors.affiliation: Division of Infection, Immunity and Respiratory Medicine, University of Manchester and Manchester Academic Health Science Centre, Manchester, UK.|University Hospital of South Manchester, Manchester, UK.
authors.forename: Jaclyn A
authors.identifier: 0000-0001-8837-4928
authors.initials: JA
authors.lastname: Smith
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D016084:Bronchoconstriction / Q000502:physiology*; D002211:Capsaicin; D003371:Cough / Q000503:physiopathology*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D016037:Single-Blind Method; D055815:Young Adult
chemical_list: D016210:Methacholine Chloride; D002211:Capsaicin
keywords: Asthma; Asthma Mechanisms; Cough/Mechanisms/Pharmacology