Figure 3.

Effects of phosphate-buffered saline (PBS) and ovalbumin (OVA) 3 hours after challenge on Day 21in the lungs of Plg^+/+ and Plg^−/− mice. Representative photomicrographs of hematoxylin-and-eosin–stained lung sections are shown; n = 3–9 mice/group. PBS treatment had no effect on the lungs of either Plg^+/+ (A) or Plg^−/− (C) mice. However, OVA induced peribronchial and perivascular leukocytosis in Plg^+/+ mice (B), but not in Plg^−/− (D) mice. Original magnifications for A–D are ×100. Higher magnification (×400) insets in B and D highlight the differences in leukocytosis in the peribronchial areas between the genotypes and the eosinophilic nature of the infiltrate in OVA-treated Plg^+/+ mice. Bars = 137 μm.