FIGURE 1.

Halogen (Cl₂ and Br₂)-induced acute lung and systemic injury A: schema showing interaction of halogens with various components of the epithelial lining fluid and lung epithelial cells. At higher concentrations (>50 ppm), inhaled halogens reach the distal lung regions (from Ref. 48, with permission from the publisher). ASC, ascorbate; GSH, reduced glutathione. B: extensive denudation of airway epithelium in a rat exposed to Cl₂ (400 ppm for 30 min) and returned to room air for 24 h. Lung sections were stained with hematoxylin-eosin. C: lungs of a mouse exposed to Cl₂ (600 ppm and 45 min) and returned to room air for 24 h. There was significant hemorrhage and alveolar spaces were filled with protein-rich edema. D: Cl₂ decreases endothelial nitric oxide synthase (eNOS) protein expression. I and II: representative immunofluorescence images for eNOS staining from aorta collected 24 h after exposure to air (I) or Cl₂ (400 ppm, 30 min) (II). Red: eNOS; blue: Hoechst staining for nuclei (modified from Ref. 46, with permission from the publisher). E: bromine (Br₂) inhalation causes disruption of the cardiac cytoskeleton and loss of the normal highly organized linear mitochondrial sarcomere integrity. Representative transmission electron microscopy (×3,200) images demonstrating a normal control heart (top left). The remaining 3 images demonstrate myofibrillar loss, contraction band necrosis (red arrow), loss of I bands, and disruption of z-disks (yellow arrowheads) in the left ventricle 3 h after Br₂ exposure in addition to mitochondrial swelling (yellow arrows) and cristae lysis (red asterisk) [nucleus (N)] (modified from Ref. 54, with permission from the publisher). F: pregnant [embryonic day 14.5 (E14.5)] mice were exposed to air or 600 ppm Br₂ for 30 min, returned to room. Representative hematoxylin-eosin-stained placenta sections at E18.5 with the junctional zone demarcated with yellow highlighting (left) as well as periodic acid-Schiff staining (right) of Br₂-exposed pregnant mice revealed a reduced junctional zone (black bars) at E18.5 (modified from Ref. 55, with permission from the publisher). M, male; F, female; A, air; B, bromide. G: pregnant mice were exposed to air or Br₂ (400 or 600 ppm for 30 min) at E14.5 and were returned to room air. Fetuses were delivered by C-section on E18.5. Notice marked fetal growth restriction that was dependent on Br₂ concentration (modified from Ref. 55).