Figure 3.

Alveolar development of adult mice exposed to air, hypoxia, or hyperoxia in the newborn period. (A–C) Representative photomicrographs of H&E–stained lung sections of 14-week-old mice exposed to air (A), hypoxia (B), or hyperoxia (C) in the newborn period (100×; calibration bars, 250 μm). Radial alveolar count, an index of alveolar number, was reduced in 14-week-old mice exposed to neonatal hypoxia or hyperoxia (D). The reduction in number of alveoli persisted from 2 to 14 weeks of age (F). Mean linear intercept, a measure of alveolar diameter, was increased in adult mice exposed to neonatal hypoxia or hyperoxia (E). The increase in the size of the alveoli persisted from 2 to 14 weeks of age (G) (n = 18 at each time point with 6 per group; means ± SE). *P < 0.05 versus corresponding air group.