Figure 1

Apoptosis of alveolar epithelial cells. TUNEL assays were performed on the rat lung. Nuclei were stained yellow in apoptotic lung cells. The numbers of these cells were significantly increased in groups B, C, D, and E compared with those in group A. The lowest number of apoptotic cells was in group D. The percentage of TUNEL-positive cells was calculated by the ratio of TUNEL-positive cells to the total cell number in 10 fields at 400× magnification from each section. Scale bars = 100 μm. *P < 0.01 compared with the other four groups.