Figure 3.
Formoterol upregulates the expression of M3R in a dose-dependent manner. (A) Protein extracts were obtained from airway smooth muscle cells treated with increasing concentrations of formoterol for 24 h and the expression of M3R was analyzed by western blot analysis. (B) Protein expression of M3R was determined by densitometry and was normalized to the β-actin control. The data are expressed as the mean ± standard deviation from three independent experiments (*P<0.05, compared with the control). M3R, muscarinic M3 receptor; Con, control.