Figure 3.

Collagen deposition in the lungs of surviving intranasally ricin-exposed and antitoxin-treated mice. Mice were intranasally intoxicated with 2LD₅₀ (7 µg/kg) ricin. Antitoxin was administered at 24 h PE. Sham group was administered PBS instead of either ricin or antitoxin. At 30 days PE, lungs were harvested, and histological staining was conducted. Masson’s Trichrome staining of lung sections in (A,B) sham and (C,D) ricin + antitoxin-treated mice. (A,C) Magnification ×2; (B,D) magnification ×10. Black arrows represent collagen accumulation and enlarged perivascular and peribronchial areas. (E) Percentage of fibrotic areas in lungs of individual mice. Scale bar 500 (A,C) and 100 (B,D) µm, n = 3 per group, 3 fields of view per mouse. Data are expressed as means ± SEM. * p < 0.05.