Airway Resistance Measurement in Mice

This was performed as previously described [43 (link)]. Briefly, mice were: anesthetized with pentobarbital and xylazine, provided a tracheostomy through which a cannula was secured, ventilated mechanically with the flexiVent system (SCIREQ, Montreal, Canada) and paralyzed with pancuronium (Sigma, St. Louis, MO). After 2 minutes of default ventilation, 2 total lung capacity maneuvers were delivered for airway recruitment and before every exposure to aerosol. PBS was nebulized (Aeroneb Lab Nebulizer (Aerogen, Galway, Ireland)), followed by measurement of airway resistance through a series of 4 Snap-Shot perturbations, using the single compartment model of airway mechanics. A series of increasingly concentrated methacholine solutions were then administered by nebulization; airway resistance was measured 10 times after each methacholine dose and the highest value, with a coefficient of determination of at least 0.9, was used for analysis.