title: Cough threshold and reactivity to mechanical stimulation of the trachea in the rabbit preliminary observations.
abstract: OBJECTIVE
  The aim of the study was to characterise mechanically induced cough threshold and reactivity by exposing the trachea to stimuli of variable duration in rabbit.
  
  
  BACKGROUND
  Long lasting mechanical stimulation is widely used in experimental protocols studying cough reflex. The cough threshold and reactivity to chemical agents is known to change due to e.g. airway inflammation but similar evidence for mechanical stimulation has not been reported.
  
  
  METHODS
  The tracheal provocation was realized in two anesthetized tracheotomized rabbits with a rotating probe actuated by a small electrical motor with mechanical stimulus times (ST) lasting 50, 150, 300 and 600 ms. Cough reflex was evaluated from tidal volume and airflow signals.
  
  
  RESULTS
  The incidence of cough reflex (single or multiple) increased from 8% (ST 50 ms) to 84% (ST 600 ms). With the lengthening of stimulus, the rate of multiple responses increases.
  
  
  CONCLUSIONS
  The technique developed here may prove useful to standardize the protocols of mechanical cough in the experimental animal using an approach similar to chemical tussigenic agents. The cough threshold could be defined as minimal ST (STmin) capable to elicit 1 cough and cough reactivity obtained by interpolation as ST that provokes 50 % of cough responses (STso) (Tab. 1, Fig. 3, Ref. 27).
authors: EA 3450, Laboratoire de Physiologie Faculté de Médecine, Université Henri Poincaré, Vandoeuvre les Nancy, France.
authors: S
authors: S
authors: Varechova
authors: B
authors: B
authors: Demoulin
authors: M
authors: M
authors: Poussel
authors: B
authors: B
authors: Chenuel
authors: F
authors: F
authors: Marchal
mesh_terms: D000818:Animals; D003371:Cough / Q000503:physiopathology*; D010812:Physical Stimulation; D011817:Rabbits; D012018:Reflex; D012684:Sensory Thresholds; D014132:Trachea / Q000503:physiopathology*