Assessment of AHR to Mch
AHR was assessed using a whole-body plethysmography system (Enterprise
EMKA Technologies, Paris, France), as described
elsewhere[19]. Unrestrained,
spontaneously breathing mice were placed into chambers. The
enhanced pause
(Penh), a function of the maximal
expiratory and inspiratory box pressure signals and the timing of
expiration that is closely related to pulmonary resistance, was
calculated. Mice were exposed for 2 min to nebulized PBS, then to
increasing concentrations (3.125, 6.25, 12.5, 25, and 50 mg/mL) of
nebulized Mch in PBS. After each nebulization, 3 min recordings were
taken. Penh measurements were averaged for each Mch concentration.