Fig. 1.

Airway mast cell detection. Lung sections were stained with toluidine blue (1%) or immunostained with an anti-mMCP-1 Ab to detect mast cells. No toluidine blue-positive mast cells were detected in non-OVA-challenged BALB/c mice (a), whereas several toluidine blue-positive mast cells (arrows) were detected in the airway epithelium in BALB/c mice chronically challenged with OVA for 3 months (b). Similarly, no mMCP-1-positive mast cells were detected in non-OVA-challenged BALB/c mice (c), whereas several mMCP-1-positive mast cells were detected in the airway epithelium in BALB/c mice chronically challenged with OVA for 3 months (d)