Figure 2. Airway responsiveness to methacholine by forced oscillation technique. Airway responsiveness was expressed in terms of respiratory systemic Rrs. Baseline Rrs value was assessed after 3 minutes of nebulized PBS. Rrs was measured in response to increasing challenges of methacholine dose (6.25 mg/mL, 12.5 mg/mL, 25 mg/mL, and 50 mg/mL) in control, O+L, O+L+C, O+L+D, and O+L+D+C group. Rrs was increased after OVA+LPS challenge. Rrs of combination of CAM+DXM group was significantly changed compared to the CAM or DXM group especially at 50 mg/mL of methacholine challenge. O+L vs. all (^*p<0.05, ^**p<0.01, ^***p<0.001), O+L+C vs. O+L+D+C (^†p<0.05), O+L+D vs. O+L+D+C (^‡‡p<0.01). Rrs: resistance; PBS: phosphate buffered saline; O: ovalbumin; L: lipopolysaccharide; C: clarithromycin; D: dexamethasone.