title: Endothelin-1 in exhaled breath condensate of allergic asthma patients with exercise-induced bronchoconstriction.
abstract: BACKGROUND
  Exercise-induced bronchoconstriction (EIB) is a highly prevalent condition, whose pathophysiology is not well understood. Endothelins are proinflammatory, profibrotic, broncho- and vasoconstrictive peptides which play an important role in the development of airway inflammation and remodeling in asthma. The aim of the study was to evaluate the changes in endothelin-1 levels in exhaled breath condensate following intensive exercise in asthmatic patients.
  
  
  METHODS
  The study was conducted in a group of 19 asthmatic patients (11 with EIB, 8 without EIB) and 7 healthy volunteers. Changes induced by intensive exercise in the concentrations of endothelin-1 (ET-1) in exhaled breath condensate (EBC) during 24 hours after an exercise challenge test were determined. Moreover, the possible correlations of these measurements with the results of other tests commonly associated with asthma and with the changes of airway inflammation after exercise were observed.
  
  
  RESULTS
  In asthmatic patients with EIB a statistically significant increase in the concentration of ET-1 in EBC collected between 10 minutes and 6 hours after an exercise test was observed. The concentration of ET-1 had returned to its initial level 24 hours after exercise. No effects of the exercise test on changes in the concentrations of ET-1 in EBC in either asthmatic patients without EIB or healthy volunteers were observed. A statistically significant correlation between the maximum increase in ET-1 concentrations in EBC after exercise and either baseline FENO and the increase in FENO or BHR to histamine 24 hours after exercise in the groups of asthmatics with EIB was revealed.
  
  
  CONCLUSIONS
  The release of ET-1 from bronchial epithelium through the influence of many inflammatory cells essential in asthma and interactions with other cytokines, may play an important role in increase of airway inflammation which was observed after postexercise bronchoconstriction in asthmatic patients.
authors.affiliation: Department of Allergology and Internal Medicine, Medical University of Bialystok, Poland. z.zietkowski@wp.pl
authors.forename: Ziemowit
authors.initials: Z
authors.lastname: Zietkowski
authors.forename: Roman
authors.initials: R
authors.lastname: Skiepko
authors.forename: Maria M
authors.initials: MM
authors.lastname: Tomasiak
authors.forename: Anna
authors.initials: A
authors.lastname: Bodzenta-Lukaszyk
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001250:Asthma, Exercise-Induced / Q000276:immunology / Q000503:physiopathology*; D001944:Breath Tests / Q000379:methods; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000276:immunology; D016022:Case-Control Studies; D018450:Disease Progression; D019332:Endothelin-1 / Q000032:analysis*; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000032:analysis; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D013147:Spirometry
chemical_list: D019332:Endothelin-1; D018836:Inflammation Mediators; D009569:Nitric Oxide