Oxygen toxicity

[TF8: 182]

Effects of O2 toxicity

• Retrolental fibroplasia
• Bronchopulmonary dysplasia in neonates
• Loss of hypoxic drive in COPD
• Traheobronchial irritation
• Thickening of alveolar-capillary membrane with proliferation of type I pneumocytes

Mechanism

Ferrous iron loses electron
--> Production of superoxide anion
--> Interaction with hydrogen peroxide
--> production of free radicals (hydroxyl free radicals or O2-)

Defense

• Superoxide dismutase (SOD) for superoxide anions
• Catalase (CAT) for H2O2