Figure 1
From: Bcl-2 Family Gene Expression during Severe Hyperoxia Induced Lung Injury
Hyperoxia induces DNA fragmentation. Adult mice were exposed to room air (A, D) or hyperoxia for 48 (B, E) or 84 (C, F) hours. Sections of lung were stained for the presence of free 3′-hydroxyl ends on DNA using terminal transferase and digoxigenin-conjugated nucleotides, visualized as a dark brown stain (A to C). Filled arrow, TUNEL positive cell; filled arrowhead, TUNEL positive debris; open arrow, TUNEL negative cell. Sections were counterstained with methyl green. Bar in A = 40 μm. Ultrastructural analysis by electron microscopy revealed intact chromatin at all times studied, with cell debris (open arrowhead) observed by 84 hours of hyperoxia. D to F, Magnification, ×2000.
