Figure 4.

Inhibition of α₁AR abrogates EPI-induced pMLC in HASM following β₂AR desensitization. Representative immunoblot of HASM pretreated with DM (1 µM, 10 min pretreatment) before EPI (10 µM, 10 min) stimulation. Band densities measured by fold change pMLC relative fluorescence units normalized to total MLC relative to Alb-PT control (values are means ± SE, n = 5–13 experiments from 5 unique cell lines) (*P ≤ 0.05). β₂AR, β₂-adrenergic receptor; CCh, carbachol; EPI, epinephrine; HASM, human airway smooth muscle; pMLC, myosin light chain phosphorylation.