title: Beraprost, a stable analog of prostacyclin, enhances cough reflex sensitivity to capsaicin in bronchitic patients.
abstract: OBJECTIVE
  Inflammatory mediators are involved in the pathophysiology of neutrophilic bronchial disorders presenting with chronic productive cough. Accumulating evidence indicates that prostanoids are key elements in the pathophysiology of these disorders. However, little is known about the role of prostacyclin in neutrophilic bronchial inflammation.
  
  
  METHODS
  The effect of beraprost, a chemically and biologically stable analog of prostacyclin, on cough response to inhaled capsaicin was examined in 14 patients with chronic bronchitis, a neutrophilic bronchial disorder, in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of the airway cough reflex sensitivity.
  
  
  RESULTS
  After a 2-week treatment with beraprost (80 μg twice a day orally), the cough threshold was significantly (P < .05) decreased as compared with placebo [12.2 (geometric standard error of the mean [GSEM] 1.5) μM vs. 24.4 (GSEM 1.3)].
  
  
  CONCLUSIONS
  These findings indicate that prostacyclin is involved in the pathophysiology of cough reflex sensitivity in patients with chronic bronchitis, a frequently encountered neutrophilic bronchial disorder presenting with chronic productive cough.
authors.affiliation: 1Respiratory Medicine, Toyama City Hospital , Toyama , Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Ishiura
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujimura
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Shiba
authors.forename: Hideko
authors.initials: H
authors.lastname: Ikeda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ohkura
authors.forename: Johsuke
authors.initials: J
authors.lastname: Hara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kasahara
mesh_terms: D000280:Administration, Inhalation; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D001985:Bronchial Provocation Tests; D029481:Bronchitis, Chronic / Q000503:physiopathology*; D002211:Capsaicin / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D003371:Cough / Q000503:physiopathology*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D014797:Vital Capacity / Q000187:drug effects / Q000502:physiology
chemical_list: C048081:beraprost; D011464:Epoprostenol; D002211:Capsaicin
keywords: airway cough sensitivity; capsaicin; chronic bronchitis; chronic productive cough; prostacyclin