Figure 6. Airway smooth muscle cells in α₉smKO lung slices have increased calcium wave and MLC phosphorylation in response to methacholine.

(A) Representative calcium oscillations induced by 10 μM methacholine in lung slices from WT control and α₉smKO mice. Final fluorescence values are expressed as ratios (F/F₀), normalized to the fluorescence immediately prior to the addition of an agonist (F₀). (B) Effects of the SSAT stabilizer BE3-3-3 (50 μM) or exogenous spermine (100 μM) on calcium oscillations induced by 10 μM methacholine in lung slices from control or α₉smKO mice. Data (mean ± SEM) represent 3 independent experiments with similar results. *P < 0.05; **P < 0.01. (C) Western blot of total MLC or phosphorylated MLC (MLCp) in lysates enriched for airway smooth muscle dissected from control and α₉smKO tracheas treated with or without methacholine (10 μM) in vitro. Sp, spermine.