Smooth muscle thickening and lung fibrosis is strongest in the mice treated with all three allergens.

<p>Smooth muscle increase was detected by α-smooth muscle actin staining (SMA) (A). Sirius red staining was used to detect sub epithelial collagen deposition (B). Shown are representative sections of 8–12 mice/group. Scale bar = 100 µm. Smooth muscle area (C) and smooth muscle thickness (D) were assessed by automated analysis of α-smooth muscle actin stained lungs. Fibrosis was quantified by ELISA measurement of collagen I (E) and collagen III (F) in lung homogenates. Results represent mean ± SEM from 8–14 mice/group. *<i>P</i><0.05; **<i>P</i><0.01; ***<i>P</i><0.001 in comparison to the PBS control mice and ^§<i>P</i><0.05in comparison to the triple allergen combination (TAC) group.