Finepointe resistance and compliance

The airway hyper‐responsiveness 24 hrs after the last provocation of OVA was measured using the FinePointe Resistance and Compliance (Buxco, Wilmington, NC, USA) as lung resistance (RL). The concentrations of methacholine for provocation were 6.25, 12.5 and 25 mg/ml, respectively. The percentage of RL value and basal RL value were used to reflect the airway responsiveness after the provocation of methacholine.

Twenty-four hours after the last HDM instillation, airway hyperreactivity (AHR) was measured using a Buxco small ventilator (Buxco^® FinePointe Resistance and Compliance, Winchester, UK). Mice were anaesthetized with pentobarbital sodium (50 mg/kg; Sigma-Aldrich), and a tracheostomy was performed to insert a 20-gauge needle. Mice were kept under ventilation at 160 breaths/minute with a tidal volume of 0.25 mL. Mice were acclimatized to the ventilator before measuring the baseline. Lung resistance (R_L) and dynamic compliance (C_dyn) were measured using a dose-response curve for methacholine by administering increasing doses of nebulized methacholine (0 – 50 mg/mL; Sigma-Aldrich).