House Dust Mite and Cat Dander Extract Induce Asthma-Like Histopathology with an Increase of Mucosal Mast Cells in a Guinea Pig Model

Figure 6

Repetitive allergen exposure induces a marked accumulation of mast cells in guinea pig airways and parenchyma as detected with immunohistochemical staining against tryptase and chymase. Micrographs of immunohistochemical staining of tryptase (a, b, e, f, i, and j) and chymase (c, d, g, h, k, and l) in airways and parenchyma, 8 weeks after challenge. PBS-treated animals (a–d); HDM (e–h); CDE (i–l). Quantification of tryptase-positive MCs in bronchi (m) and alveolar parenchyma (n) and chymase-positive MCs in bronchi (o) and alveolar parenchyma (p) expressed as MC per mm². Three airways and five fields of view of parenchyma (20x magnification) were quantified per animal. Data are of -5 animals per group. , , and . Scale bar: 50 μm. High magnification micrographs (60x) are shown as inserts in (a, c, e, g, i, and k). HDM: house dust mite extract; CDE: cat dander extract.