Chapter 14 Free radicals in cell biology

摘要: Summary Free radicals are reactive chemical species that differ from other compounds in they have unpaired electrons their outer orbitals. They capable of damaging cellular components, and accumulating evidence suggests may contribute to various disease entities. Biologic systems exposed free been formed endogenously or result external influences, such as ionizing radiation. Oxygen continuously being produced intracellularly by oxidation-reduction reactions. The sequential univalent reduction molecular oxygen initially forms the superoxide anion radical, which turn is converted, presence transition metal ions, into highly hydroxyl radical. All aerobic organisms possess elaborate antioxidant prevent radical-mediated injury. These include vitamin E enzymes dismutase glutathione peroxidase. Tissue damage occur when these host defense mechanisms abnormally deficient there excess radical production. last two decades witnessed an increasing body knowledge implicating processes a wide spectrum different types human disease. Even this not totally responsible for particular entity, often appear play part process. Confirmation involvement clinical relevance. Clinically applicable techniques currently developed remove sites where injurious and, situations chemotherapy, drugs produce available destroy harmful cells.