title: Comparison of metabolites in exhaled breath and bronchoalveolar lavage fluid samples in a mouse model of asthma.
abstract: BACKGROUND
  A multi-capillary column ion mobility spectrometer (MCC/IMS) was developed to provide a method for the noninvasive diagnosis of lung diseases. The possibility of measuring the exhaled breath of mice was evaluated previously. The aim of the present study was to reveal whether mice affected by airway inflammation can be identified via MCC/IMS.
  
  
  METHODS
  Ten mice were sensitized and challenged with ovalbumin to induce allergic airway inflammation. The breath and volatile compounds of bronchoalveolar lavage fluid (BALF) were measured by MCC/IMS. Furthermore, histamine, nitric oxide, and arachidonic acid were determined as inflammatory markers in vitro.
  
  
  RESULTS
  Six volatile molecules were found in the BALF headspace at a significantly higher concentration in mice with airway inflammation compared with healthy animals. The concentration of substances correlated with the numbers of infiltrating eosinophilic granulocytes. However, substances showing a significantly different concentration in the BALF headspace were not found to be different in exhaled breath. Histamine and nitric oxide were identified by MCC/IMS in vitro but not in the BALF headspace or exhaled breath.
  
  
  CONCLUSIONS
  Airway inflammation in mice is detectable by the analysis of the BALF headspace via MCC/IMS. Molecules detected in the BALF headspace of asthmatic mice at a higher concentration than in healthy animals may originate from oxidative stress induced by airway inflammation. As already described for humans, we found no correlation between the biomarker concentration in the BALF and the breath of mice. We suggest using the model described here to gain deeper insights into this discrepancy.
authors.affiliation: Department of Experimental Pneumology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Neuhaus
authors.forename: Luzia
authors.initials: L
authors.lastname: Seifert
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Vautz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Nolte
authors.forename: Albrecht
authors.initials: A
authors.lastname: Bufe
authors.forename: Marcus
authors.initials: M
authors.lastname: Peters
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000737:chemistry; D001249:Asthma / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D004195:Disease Models, Animal; D045853:Exhalation / Q000502:physiology*; D005260:Female; D006098:Granulocytes / Q000378:metabolism; D006632:Histamine / Q000737:chemistry; D007249:Inflammation / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D016718:Arachidonic Acid; D009569:Nitric Oxide; D006632:Histamine