The presence of caveolae and caveolin-1 in ASMCs. (A) Normal caveolae structures were observed in the control group by scanning electron microscope (×7000). All the scale bars are 2 μm. However, there were fewer caveolae structures observed in the asthma group compared with control group. The locations of caveolae were indicated with arrows. (B) Western blot was used for analysis of caveolin-1 in separate group. GAPDH served as a loading control. The expression of caveolin-1 protein was significantly decreased in the asthma group. Data are expressed as mean ± SD for each group. (*P < 0.05 versus control).