7. The role of taurine in acute lung injury, oxidative stress and apoptosis by endoxin and cigarette smoke

In comparison to other vital organs such as the liver, kidney and brain, the lung is at a greater risk of developing oxidative stress and oxidative injury as a result of its continuous exposure to higher oxygen tensions, to other sources of oxidative stress in the form of environmental pollutants, irritants and free radical-generating carcinogens, and of having a large epithelial surface area [Crapo 2003; Kinnula et al., 2003]. Fortunately, the lung lining fluids, airways, alveolar septa and extracellular spaces are equipped with antioxidant defenses represented by antioxidant enzymes, high levels of glutathione, and hydrogen peroxide-consuming enzymes [Crapo, 2003]. Under conditions of high oxidative stress these antioxidant defenses may work in unison and their physiological levels may, in some instances, become genetically upregulated in intracellular and extracellular spaces to protect the lung against inflammatory reactions by reducing the influx of inflammatory