Free Radical Pathophysiology

ALVAREZ, SILVIA; EVELSON, PABLO; BOVERIS, ALBERTO

Research Signpost

Lugar: Kerala, India; Año: 2008 p. 450

978-81-7895-311-3

Free radicals are defined as any chemical species capable of independent existence, which contains at least one unpaired electron. Molecular divalent oxygen itself is by definition a free radical. The term reactive oxygen species (ROS) and reactive nitrogen species (RNS) are freely used in the literature. They refer to free radicals such as superoxide anion (O2•-), hydroxyl radical (HO•) and nitric oxide (NO), and even to the non-radicals such as hydrogen peroxide (H2O2) and peroxynitrite (ONOO-). It has been shown that ROS and RNS are involved in a variety of physiological and pathological processes such as mutation, carcinogenesis, aging, atherosclerosis, inflammation, ischemia-reperfusion, and neurodegenerative diseases. Moreover, the importance of mitochondrial metabolism of these species in pathophysiological events, has been addressed. We believe that the readers of this book will find the real frontline areas of free radical research in pathophysiology. There is a bright future for investigations in this area, and we hope that this book will be helpful to every person interested in free radicals. This book has 24 chapters that are divided into 5 major sections that lead from basic concepts in free radical biology to clinically applied investigations. The book begins with an updated overview of basic principles on oxidative and nitrosative stress (Section 1). It takes us through the concept of oxidative stress and lipid peroxidation, 3-nitrotyrosine and nitrated lipids as markers of nitrosative stress, the effect of ferritin on ascorbyl radical content, and ends with the description of the antioxidant network and the relevance of flavanols and procyanidins for disease. Section 2 addresses the importance of mitochondria in pathophysiology. It is reviewed not only the role of mitochondria in cell death and the importance of the uncoupling proteins, but the nitric oxide metabolism and mitochondrial nitric oxide synthase from heart, as well. This section ends reviewing the relationship between mitochondrial oxidative stress and the permeability transition. The role of free radicals in inflammatory conditions is described in section 3. By starting with the discussion of the oxygen/nitric oxide metabolism in sepsis and the oxidative stress generated by the exposition to particulate matter, it ends with actualizations on the role of iron and the therapeutic role of melatonin in inflammation and sepsis. Section 4 focuses on the involvement of free radicals in neurodegeneration. The topics discussed includes: the importance of nitric oxide metabolism in neurodegenerative pathways, mitochondrial function in neuronal aging and plasticity, and the role of vitagenes in the cellular stress tolerance during aging and neurodegeneration. The last, but not least section (section 5) returns to the concept of oxidative stress and is discussed within the scope of different pathologies and related processes. This section begins with pathologies as alcoholic fatty liver disease associated with obesity and age related macular degeneration and glaucoma. It ends with the role and importance of oxygen free radicals in liver preconditioning, myocardial ischemia-reperfusion and in an experimental model of choline deficiency.