Reactive Oxygen Species in Normal Physiology, Cell Injury and Phagocytosis

Abstract

This presentation will examine major processes by which biological systems cope with reactive oxygen species (ROS). Peroxidation of membrane lipids will be considered as one example of the destructive processes that occur when ROS are not controlled by the protection systems that detoxify reactive species. In contrast, enzymatic peroxidation of arachidonic acid initiates the biosynthesis of chemotactic leukotrienes. Phagocytic cell formation of ROS by the “oxidative burst” will be examined because of its important role in the defense against invading organisms. The focus will be on the processes that stringently control activation of the NADPH oxidase of phagocytic cells.