Change in forced expiratory volume per second (FEV₁) following inhalation of saline (a), 75 μg (b), 150 μg (c), or 300 μg DPM (d). Data in (a)–(d) are shown as mean SEM. (e) is an overlay of the curves from (a)–(d) for comparison of means. In (a)–(d), *significant decrease in FEV₁ from baseline (BL) by 1-way repeated measures ANOVA; ^†significant difference from 24 h by 1-way repeated measures ANOVA. In (e), *significant difference between the doses by repeated measures ANOVA.