Suppression in Lung Defense Responses After Bacterial Infection in Rats Pretreated with Different Welding Fumes

Details

• Personal Author:
  Antonini JM ; Bebout AR ; Millecchia L ; Roberts, Jennifer R. ; Taylor MD
• Description:
  Epidemiology suggests that inhalation of welding fumes increases the susceptibility to lung infection. The effects of chemically distinct welding fumes on lung defense responses after bacterial infection were compared. Fume was collected during gas metal arc (GMA) or flux-covered manual metal arc (MMA) welding using two consumable electrodes: stainless steel (SS) or mild steel (MS). The fumes were separated into water-soluble and -insoluble fractions. The GMA-SS and GMA-MS fumes were found to be relatively insoluble, whereas the MMA-SS was highly water soluble, with the soluble fraction comprised of 87% Cr and 11% Mn. On day 0, male Sprague-Dawley rats were intratracheally instilled with saline (vehicle control) or the different welding fumes (0.1 or 2 mg/rat). At day 3, the rats were intratracheally inoculated with 5 x 10(3) Listeria monocytogenes. On days 6, 8, and 10, left lungs were removed, homogenized, cultured overnight, and colony-forming units were counted to assess pulmonary bacterial clearance. Bronchoalveolar lavage (BAL) was performed on right lungs to recover phagocytes and BAL fluid to measure the production of nitric oxide (NO) and immunomodulatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-2, IL-6, and IL-10. In contrast to the GMA-SS, GMA-MS, and saline groups, pretreatment with the highly water soluble MMA-SS fume caused significant body weight loss, extensive lung damage, and a dramatic reduction in pulmonary clearance of L. monocytogenes after infection. NO concentrations in BAL fluid and lung immunostaining of inducible NO synthase were dramatically increased in rats pretreated with MMA-SS before and after infection. MMA-SS treatment caused a significant decrease in IL-2 and significant increases in TNF-alpha, IL-6, and IL-10 after infection. In conclusion, pretreatment with MMA-SS increased production of NO and proinflammatory cytokines (TNF-alpha and IL-6) after infection, which are likely responsible for the elevation in lung inflammation and injury. In addition, MMA-SS treatment reduced IL-2 (involved in T cell proliferation) and enhanced IL-10 (involved in inhibiting macrophage function) after bacterial infection, which might result in a possible suppression in immune response and an increase in susceptibility to infection. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Animals Bacterial Infections Epidemiology Laboratories Lung Lung Diseases Microbiology Nitric Oxide Occupational Health Respiratory System Respiratory Tract Diseases Safety Welding

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• Keywords:
  Animal-studies Author Keywords: Welding Fume Bacteria Bacterial-disease Bacterial-infections Bacterial Clearance Cytokines Fumes Laboratory-animals Listeria Monocytogenes Lung-disorders Lung-irritants Macrophage Microorganisms Nitric Oxide Pulmonary-system-disorders Respiratory-system-disorders Welders-lung

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• ISSN:
  0041-008X
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  206-218
• Volume:
  200
• Issue:
  3
• NIOSHTIC Number:
  nn:20025833
• Citation:
  Toxicol Appl Pharmacol 2004 Nov; 200(3):206-218
• Contact Point Address:
  Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
• Email:
  jga6@cdc.gov
• CAS Registry Number:
  Nitric oxide (CAS RN 10102-43-9)
• Federal Fiscal Year:
  2005
• NORA Priority Area:
  Work Environment and Workforce: Mixed Exposures
• Peer Reviewed:
  True
• Source Full Name:
  Toxicology and Applied Pharmacology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a8fd3c96d4b9f6a247372669d7849e6f1093c6d2ceafac448ca06d426fb7549a50592760a319fd842f7b67893e24bc802df85b481ba9a56de4f508d5ed5fd009
• Download URL:
  https://stacks.cdc.gov/view/cdc/197045/cdc_197045_DS1.pdf
• File Type:
  [PDF - 960.48 KB ]