Nongenomic, inhibitory effect of corticosterone (Cort; 5 μM) on formoterol uptake by human bronchial smooth muscle cells. A, The rapid (15 min) inhibitory corticosteroid effect was not enhanced by prolonged corticosteroid pretreatment for 45 and 90 min (+pre45’ and +pre90’, respectively). B, Corticosterone effect in the presence of the transcription inhibitor actinomycin D (Act; 100 μM). C, Formoterol uptake in cells exposed to corticosterone for 15 min followed by corticosterone washout prior to transport measurements (post-Cort). Bars represent mean ± SD (n = 6 experiments).