Fig. 3.

Morphologic observation. (A) Representative gross findings. Mice were sacrificed at the indicated timepoints after irradiation, 4% buffered paraformaldehyde in phosphate-buffered saline (PBS) was instilled via the trachea, and the lungs were immersed in fixation solution for several days. Lungs were photographed after complete fixation. (B) Hematoxylin–eosin-stained lung sections from a minimum of three mice were examined at each timepoint. Representative images of the major findings are shown. The arrows indicate the injury area (magnification: ×12.5).