Figure 5.

TUNEL assay of GGT^enu1 and wild-type (WT) Lungs. Lung sections from GGT^enu1 (A) and wild-type (B) mice were assayed for DNA fragmentation after exposure to hyperoxia for 96 hours as described in Materials and Methods, and TUNEL positive cells/500 nuclei were quantified (C). Exposure to hyperoxia (H) increased the number of TUNEL positive cells in the lungs of GGT^enu1 and wild-type mice. The number increased by 30-fold over the normoxia (N) baseline for GGT^enu1 mouse lung and this was almost threefold higher than that observed in the hyperoxia-exposed wild-type mouse lung. TUNEL-positive cells/500 nuclei increased almost tenfold in the wild-type mouse lung in hyperoxia compared with normoxia (WT-N). *P < 0.05.