Figure 4.

Immunofluorescent analysis of alveolar type I and II cells in the lungs of intranasally ricin-exposed and antitoxin-treated mice 30 days following ricin intoxication. 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 immunohistological staining was conducted for (A,B) type I epithelial cells (T1α staining in red; DAPI in blue), (C,D) type II epithelial cells (pro-SPC staining in red; DAPI in blue). (A,C) Sham and (B,D) ricin + antitoxin-treated mice. Scale bar 50 µm, n = 3 per group. (E) Number of pro-SPC⁺ cells per field of view (n = 3 per group; 5–6 fields of view per mouse). Data are expressed as means ± SEM. *** p < 0.001.