tailieunhanh - Báo cáo khoa học: "A Reactive oxygen species: toxic molecules or spark of life"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: A Reactive oxygen species: toxic molecules or spark of life? | Available online http content 10 1 208 Review Reactive oxygen species toxic molecules or spark of life Sheldon Magder McGill University Health Centre Royal Victoria Hospital Division of Critical Care Pine Av W Montreal Quebec Canada H3A 1A1 Corresponding author S Magder Published 3 February 2006 Critical Care 2006 10 208 doi cc3992 This article is online at http content 10 1 208 2006 BioMed Central Ltd Abstract Increases in reactive oxygen species ROS and tissue evidence of oxidative injury are common in patients with inflammatory processes or tissue injury. This has led to many clinical attempts to scavenge ROS and reduce oxidative injury. However we live in an oxygen rich environment and ROS and their chemical reactions are part of the basic chemical processes of normal metabolism. Accordingly organisms have evolved sophisticated mechanisms to control these reactive molecules. Recently it has become increasingly evident that ROS also play a role in the regulation of many intracellular signaling pathways that are important for normal cell growth and inflammatory responses that are essential for host defense. Thus simply trying to scavenge ROS is likely not possible and potentially harmful. The normal level of ROS will also likely vary in different tissues and even in different parts of cells. In this paper the terminology and basic chemistry of reactive species are reviewed. Examples and mechanisms of tissue injury by ROS as well as their positive role as signaling molecules are discussed. Hopefully a better understanding of the nature of ROS will lead to better planned therapeutic attempts to manipulate the concentrations of these important molecules. We need to regulate ROS not eradicate them. Introduction Production of reactive oxygen species ROS and oxidative stress are associated with tissue injury and many pathological processes including septic shock 1 2 . This has prompted clinical attempts to .