Dual Roles of Oxidative Stress in the Lungs

摘要: The redox state of the cell plays an important part in processes such as tumor progression, aging, atherosclerosis, chronic inflammatory processes, lung injuries and neurodegenerative diseases. Increased levels intracellular reactive oxygen species (ROS) above normal basal are defined cellular oxidative stress. ROS include superoxide anions (O 2 ), hydroxyl radicals hydrogen peroxide (H O which can be further changed into highly via iron-catalyzed Fenton reactions under pathological conditions. •− also rapidly react with nitric oxide (NO) to generate a stable free radical, peroxynitrite (OONO), is strong cytotoxic oxidant. Typically, stress generated by increased production and/ or damage antioxidant defense system during (Sies, 1997; Hoidal, 2001; Sen Packer, 1996). Oxidative introduced exogenous sources air pollutants cigarette smoke. Since lungs contain largest surface area epithelial endothelial cells any organ, they at high risk for injury from inhalation concentrations ROS. Reactive oxidants associated pathogenesis pulmonary diseases affect various functions, proliferation apoptosis. While it desirable prevent death tissue induced asthma acute respiratory distress syndrome, opposite sought cancer. Oxidants have been shown exert growth control on airway modulating upstream factor receptor function (Ravid et al., 2002 2004; Goldkorn 2005; Khan 2006). Conversely, H -mediated modulates ceramide induce apoptosis epithelium (Goldkorn 1991, 2003; Chan Goldkorn, 2000; Ding, Barak 2001, 1994, Lavrentiadou Ravid Castillo 2007; Honn, 1995). Additionally, depletion glutathione (GSH) results accumulation,