Fig. 2.

Effects of administration of β-AR ligands on the peak airway responsiveness to cholinergic stimulation. Peak R_aw was determined for each mouse by examining the individual methacholine dose-response curves and choosing the highest R_aw value produced by any of the methacholine doses (most often the next to last dose, 408 μg·kg^-1·min^-1). Shown are the mean peak R_aw ± SEM after treatments with the β-AR agonist salbutamol (A), after acute treatments (B), and after chronic treatment with β-blockers (C), in comparison with nontreated asthmatic mice (NTX; black bars, n = 7-25) and control mice (Ctrl; white bars, n = 6-21). Values are mean ± SEM for the peak R_aw to methacholine of n = 8-19 mice. Note the change in the scale of the y axis for B. ^*, P < 0.05 compared to NTX; #, P < 0.05 compared to Ctrl (ANOVA).