title: Airway reactivity measured by barometric whole-body plethysmography in healthy cats.
abstract: OBJECTIVE
  To assess the validity of barometric whole-body plethysmography (BWBP) as a means of monitoring airway responses to induced bronchoconstriction in healthy cats.
  
  
  METHODS
  8 healthy cats without history of bronchopulmonary disease or exposure to indoor tobacco smoke.
  
  
  METHODS
  Cats were placed into a barometric plethysmograph with an internal volume of 38 L, and air flow was recorded at baseline and after carbachol (concentrations 0.005, 0.01, 0.02, 0.05, 0.1, and 0.2%) was introduced into the chamber. A dose-response curve was generated for several flow-derived measurements, and airway reactivity was determined by interpolation of the dose-response curve for enhanced pause.
  
  
  RESULTS
  Peak inspiratory and expiratory flows increased significantly, but respiratory rate, inspiratory and expiratory times, relaxation time, and tidal volume did not differ significantly from baseline values. Flow-derived measurements (pause, enhanced pause, and end-expiratory pause) increased significantly at carbachol concentrations > 0.02%. Baseline measurements did not correlate with indices of airway reactivity.
  
  
  CONCLUSIONS
  Airway reactivity can be measured by use of BWBP, which is noninvasive. Airway reactivity was highly variable among cats and was not a function of baseline airway caliber, suggesting that other intrinsic mechanisms may be important.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Hoffman
authors.forename: N
authors.initials: N
authors.lastname: Dhupa
authors.forename: L
authors.initials: L
authors.lastname: Cimetti
mesh_terms: D000818:Animals; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000187:drug effects; D002217:Carbachol; D002415:Cats / Q000502:physiology*; D018679:Cholinergic Agonists; D010993:Plethysmography, Whole Body / Q000662:veterinary*
chemical_list: D018679:Cholinergic Agonists; D002217:Carbachol