Figure 1

BrdU does not affect the intensity of acute airway epithelial damage, recovery, or inflammation after a single exposure to NA. Mice were intraperitoneally injected with NA or corn oil vehicle (day 0) and then intraperitoneally injected with BrdU or 0.3% carboxymethycellulose on days 1, 2, and 3. Animals were killed on days 1, 2, 3, 4, and 11. On days 1, 2, and 3 the mice were killed before the BrdU injection. (A) Hematoxylin-eosin stained (upper panels) and anti-CC10 immunostained (lower panels) lung tissue of mice on day 1 after exposure to NA or control vehicle. The lungs of the mice exposed to NA contain many distal airway epithelial cells (Clara cells) that are vacuolated, swollen, and have exfoliated into the airway lumen. (B-D) Time course of epithelial cell damage and airway inflammation after a single exposure to NA. Open circles: mice injected with NA alone. Closed circles: mice injected with both NA and BrdU. BrdU had not affected the degree of NA-induced epithelial cell damage, recovery (B and C), or airway inflammation (D) at any of the time points evaluated. Data are expressed as the means ± SEM. N = 4-5 at each time point for each group of mice. BM: basement membrane. No histological changes were observed in the lungs of mice injected with BrdU alone (photographs not shown).