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Particle Toxicology - Chapter 6

Có ba loại ôxy phản ứng (ROS): chứa oxy gốc tự do, phản ứng anion có chứa các nguyên tử oxy, hay phân tử có chứa các nguyên tử oxy có thể sản xuất các gốc tự do hoặc hóa học kích hoạt chúng. Ví dụ như các gốc tự do hydroxyl (% OH), superoxide triệt ð, OK 2 Þ, và hydrogen peroxide (H2O2). Tương tự như ROS, loài nitơ phản ứng (RNS) có thể được nitơ có chứa các gốc tự do, phản ứng anion có chứa các nguyên tử nitơ, hay phân tử có chứa các nguyên tử nitơ có thể sản xuất các. | 6 Particles and Cellular Oxidative and Nitrosative Stress Dale W. Porter Stephen S. Leonard and Vincent Castranova Health Effects Laboratory Division National Institute for Occupational Safety and Health CONTENTS 6.1 Introduction.120 6.2 Sources of Cellular ROS.120 6.2.1 Mitochondria.120 6.2.2 NADPH Oxidase.120 6.3 Non-Cellular Particle-Mediated ROS Generation.120 6.3.1 Silica.120 6.3.2 Coal Dust.122 6.3.3 Asbestos.122 6.3.4 Other Particles.123 6.4 Particle-Mediated Cellular ROS Generation.124 6.4.1 Silica.124 6.4.2 Coal Dust.125 6.4.3 Asbestos.125 6.4.4 Other Particles .126 6.5 Cellular RNS Generation.127 6.6 Particle-Mediated Cellular RNS Generation.127 6.6.1 Silica.127 6.6.2 Coal Dust.128 6.6.3 Asbestos.128 6.6.4 Other Particles .128 6.7 Particle-Induced Activation of Nuclear Factor-kB.128 6.7.1 ROS and RNS Regulation of Nuclear Factor-kB.128 6.7.2 Particle-Induced Activation of NF-kB.129 6.7.3 Particle-Induced Activation of AP-1 .129 6.8 Particle-Induced Apoptosis .130 6.9 Antioxidant Defenses and Particulate Exposure.131 6.9.1 Antioxidant Defenses.131 6.9.2 Particulate Exposure Induces Antioxidant Defenses.131 6.10 Summary.132 References.132 119 2007 by Taylor Francis Group LLC 120 Particle Toxicology 6.1 INTRODUCTION There are three types of reactive oxygen species ROS oxygen-containing free radicals reactive anions containing oxygen atoms or molecules containing oxygen atoms that can either produce free radicals or are chemically activated by them. Examples are hydroxyl radical OH superoxide radical OK and hydrogen peroxide H2O2 . Similar to ROS reactive nitrogen species RNS can be nitrogen-containing free radicals reactive anions containing nitrogen atoms or molecules containing nitrogen atoms that can either produce free radicals or are chemically activated by them. Examples of RNS include nitric oxide NO and peroxynitrite ONOOK . Under normal conditions an equilibrium exists between ROS and RNS generation and antioxidant defenses. This equilibrium can be