Oxidative Stress in Silicosis: Evidence for the Enhanced Clearance of Free Radicals from Whole Lungs

Details

• Personal Author:
  Chzhan M ; Kuppusamy P ; Leonard, Stephanie ; Pack D ; Sanders SP ; Vallyathan V ; Zweir JL
• Description:
  We hypothesized that reactive oxygen species (ROS) may be involved in the pathogenesis of silicosis. To investigate ROS' dependent pathophysiological processes during silicosis we studied the kinetic clearance of instilled stable nitroxide radicals (TEMPO). Antioxidant enzymes' superoxide dismutase (SOD) and glutathione peroxidase (GPx), and lipid peroxidation were also studied in whole lungs of rats exposed to crystalline silica (quartz) and sham exposed controls. Low frequency L-band electron spin resonance spectroscopy was used to measure the clearance of TEMPO in whole-rat lungs directly. The clearance of TEMPO followed first order kinetics showing significant differences in the rate for clearance between the diseased and sham exposed control lungs. Comparison of TEMPO clearance rates in the sham exposed controls and silicotic rats showed an oxidative stress in the rats exposed to quartz. Studies on the antioxidant enzymes SOD and GPx in the lungs of silicotic and sham exposed animals supported the oxidative stress and accelerated clearance of TEMPO by up regulated levels of enzymes in quartz exposed animals. Increased lipid peroxidation potential in the silicotics also supported a role for enhanced generation of ROS in the pathogenesis of silica-induced lung injury. These in vivo experiments directly demonstrate, for the first time, that silicotic lungs are in a state of oxidative stress and that increased generation of ROS is associated with enhanced levels of oxidative enzymes and lipid peroxidation. This technique offers great promise for the elucidation of ROS induced lung injury and development of therapeutic strategies for the prevention of damage. [Description provided by NIOSH]
• Subjects:
  Free Radicals Lung Lung Diseases Occupational Health Respiratory System Respiratory Tract Diseases Safety Silicosis
• Keywords:
  Antioxidant Enzymes Author Keywords: Oxidative Stress Free Radicals Lipid Peroxidation Lung Disease Lung Disorders Lung Fibrosis Oxidative Stress Reactive Oxygen Species Respiratory Diseases Respiratory System Disorders ROS

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• ISSN:
  0300-8177
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  125-132
• Volume:
  168
• Issue:
  1
• NIOSHTIC Number:
  nn:20052393
• Citation:
  Mol Cell Biochem 1997 Mar; 168(1-2):125-132
• Contact Point Address:
  V Vallyathan, National Institute for Occupational Safety and Health, Pathology Section, 1095 Willowdale Rd., Morgantown, WV 26505
• Federal Fiscal Year:
  1997
• Peer Reviewed:
  True
• Source Full Name:
  Molecular and Cellular Biochemistry
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:92c9a5a09ff0bb9c4f76b03e05af0b4f6abc9e9fb71847cfd53910770591d0ecb27229e1df0d0ce5acf2917536ffc013468f7e45187e3850de7f63fab41e9ef0
• Download URL:
  https://stacks.cdc.gov/view/cdc/211924/cdc_211924_DS1.pdf
• File Type:
  [PDF - 299.30 KB ]