Modifications of Silica-Induced Pulmonary Toxicity by Diet-Induced Obesity

Details

• Personal Author:
  Chen T ; Frye BL ; Joseph P ; Kashon M ; McKinney W ; Orandle M ; Sager TM ; Umbright CM
• Description:
  From an occupational standpoint, exposure to silica can have devastating consequences. An estimated 2.3 million workers in the US are exposed to dust containing crystalline silica, annually. In addition, of the 140 million people over the age of 20 employed in the US, 30% are obese. If and how diet-induced obesity modifies silica-induced pulmonary toxicity is unknown. Therefore, the objective of this study was to determine the effect of diet-induced obesity, if any, on silica-induced pulmonary toxicity. Rats (Fischer 344, male) were fed either a regular-fat diet (RFD; 18% kcal as fat) or a high-fat diet (HFD; 60% kcal as fat) and exposed by whole-body inhalation to either air or crystalline silica (15 mg/m3, 6 hours/day, 5 days). At designated post-exposure time intervals (1, 3, 6, and 9 months), pulmonary toxicity was determined. Toxicity parameters including lactate dehydrogenase (LDH) activity, oxidant production, cell counts (including infiltrating neutrophils and alveolar macrophages), inflammatory cytokine levels (IL-1beta, IL-10, TNF-alpha, MCP-1, and MIP-2), and lung histopathology were assessed. Body weights and serum triglyceride levels, indicators of diet-induced obesity, in the HFD rats were higher compared to those in RFD rats. The results showed that silica particles were seen in lung sections from the exposed animals. Silica inhalation resulted in pulmonary toxicity, which progressed across all post-exposure time points, as evidenced by enhanced neutrophil infiltration, increased LDH levels, enhanced oxidant production, and increased inflammatory cytokine levels. The incidence and severity of silica-induced lung pathology was similar between the two diet groups up to 6 months post-exposure. However, by 9 months post-exposure, silica-induced pathology tended to be slightly more severe in animals fed a RFD compared to those fed a HFD. In summary, our results indicated that certain pulmonary toxicity parameters induced by silica inhalation were modified by diet-induced obesity in rats. [Description provided by NIOSH]
• Subjects:
  Animals Blood Body Weight Diet Dust Environmental Exposure Enzymes Esters Immune System Laboratories Lung Lung Diseases Macrophages Occupational Health Respiratory System Respiratory Tract Diseases Safety Silicon Dioxide Toxicology

  More +
• Keywords:
  Alveolar Cells Body Weight Caloric Intake Crystalline Silica Cytokines Dietary Effects Dust Inhalation Enzyme Activity Exposure Assessment Exposure Levels Fats Fatty Acid Esters Fatty Acids Glycerides Histopathology Immune Reaction Laboratory Animals Laboratory Testing Lung Cells Lung Tissue Neutrophils Obesity Oxidative Enzymes Pulmonary Effects Pulmonary System Disorders Serum Cholesterol Silica Silica Dusts Toxic Effects

  More +
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Florida ; OSHA Region 3 ; OSHA Region 4 ; OSHA Region 6 ; Pennsylvania ; Texas ; 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:
  44
• Volume:
  162
• Issue:
  1
• NIOSHTIC Number:
  nn:20051139
• Citation:
  Toxicologist 2018 Mar; 162(1):44
• CAS Registry Number:
  Lactic acid (CAS RN 50-21-5) ; Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  2018
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 57th Annual Meeting and ToxExpo, March 11-15, 2018, San Antonio, Texas
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5fe1fc23388c595ffbb9fa93d310148968c38cf17151e0e7ac366b08f7d0e8554053d22af6f5d85a816715715f54a5dfae11ff23c98ce1c16ee1f8e140d5457c
• Download URL:
  https://stacks.cdc.gov/view/cdc/211247/cdc_211247_DS1.pdf
• File Type:
  [PDF - 832.68 KB ]