Free radical effects on lung metabolism.

Exposure to hyperoxia or a number of different environmental toxins can result in free radical-mediated lung injury. Specific toxins and their activated breakdown products can produce free radicals and markedly change normal lung metabolism by reacting with cell membranes, intracellular proteins, and nucleic acids. Endogenous production of free radicals by polymorphonuclear leukocytes sequestered in the lung can also lead to lung damage. Numerous intracellular and extracellular free radical defenses are present in human lung to detoxify these oxygen species as they are being formed. Lung injury will begin to occur if free radical production overcomes lung antioxidant defenses.