Reactive Oxygen Intermediates as Signaling Molecules Regulating Leukocyte Activation

摘要: The purpose of the inflammatory process is to combat infection by pathogenic microorganisms. primary effectors this response are leukocytes including neutrophils, monocytes, and macrophages. Of necessity, these cells have evolved many properties that facilitate their effective function in inflammation ability move site (Chemotaxis) ingest kill pathogens release toxic products proteolytic enzymes, reactive oxygen intermediates (ROI), cationic proteins. Leukocytes also respond signals released an milieu such as bacterial (formyl peptides lipopolysaccharide), components complement clotting cascades, soluble factors cytokines other cells. processes whereby activate leukocyte effector functions (Chemotaxis, enzyme secretion, oxidative burst) involve complex interconnected transmembrane signaling pathways. Many pathways been elucidated molecular characterization membrane receptors, GTP-binding proteins, phospholipases, protein kinases, phosphatases (reviewed Refs. 1 2). Recent studies provided evidence free radicals intermediates, traditionally viewed potent microbicidal agents,3 may regulation Reactive fulfill important prerequisites for intracellular messenger molecules: they small, diffusible, ubiquitous molecules can be synthesized well destroyed rapidly Ref. 4). However, because toxicity, there might only a narrow concentration range which exclusively second messengers.