We determined airway mucosal blood flow (Qaw) and FEV (1) before and after inhaled albuterol in 19 glucocorticosteroid (GS)-naive patients with mild intermittent asthma, and assessed the effects of a 2-wk course of fluticasone propionate (FP; 440 microg daily) on these parameters. Twelve healthy nonsmokers served as controls. Baseline Qaw was 55.5 +/- 0.7 microl/min/ml (mean +/- SE) in the asthmatic subjects and 44.2 +/- 0.7 microl/min/ml in the controls; the respective FEV(1) values were 2.8 +/- 0.2 L and 3.4 +/- 0.2 L (p < 0.01 for both parameters). Albuterol increased Qaw by 27 +/- 3% in the control subjects (p < 0.01) but had no effect on Qaw in the asthmatic subjects; it increased FEV (1) by 7 +/- 1% and 6 +/- 1% in the two groups, respectively. Qaw decreased to 49.2 +/- 0.8 microl/min/ml (p < 0.05 versus baseline), and the Qaw responsiveness to albuterol was restored ( +21 +/- 2%; p < 0.05) in the asthmatic subjects after FP. Eleven asthmatic subjects stopped using FP at this time; 2 wk later, their Qaw returned to baseline (55.2 +/- 0.9 microl/min/ml) and they lost the Qaw responsiveness to albuterol. Mean ( +/- SE) FEV(1) and FEV(1) responsiveness to albuterol were not affected by FP. The GS-sensitive increase in Qaw and its hyporesponsiveness to albuterol in asthmatic subjects may be consequences of airway inflammation.