A comparison of cell-counting methods in rodent pulmonary inhalation toxicity studies

Details

• Personal Author:
  Antonini JM ; Erdely A ; Hulderman T ; Meighan TG ; Young S ; Zeidler-Erdely PC
• Description:
  Pulmonary toxicity studies use bronchoalveolar lavage (BAL) to assess lung responses to particulates. The BAL cellular fraction BAL is counted, using an automated (i.e., Coulter Counter or flow cytometer) or manual (i.e., hemocytometer) method, to determine inflammatory cell influx. The goal is to compare different, commonly used, counting methods to determine which is optimal for examining cell influxes after particle inhalation. Inhalation exposures consisted of carbon nanotubes (CNT) at 5 and 0.5 mg/m3 x 5h/d x 19d in mice and mild and stainless steel welding fume (WF) at 30 mg/m3 x 3h/d x 4d in rats. High dose CNT inhalation resulted in marked lung cytotoxicity (3.5-fold increase in BAL fluid lactate dehydrogenase [LDH]) 1d post-inhalation. BAL cell counts by the automated counter (Coulter Counter) indicated a 3.2-fold increase in cellular influx. Conversely, the hemocytometer method showed a slight decrease in total cells (0.84) compared to sham, which agreed with flow cytometry results (0.81 decrease). Similar changes were observed 28 and 84d post at time points associated with significant increased LDH levels (2.5 and 2.0-fold, respectively). At the lower CNT dose, LDH increased minimally (1.4 fold) and the three methods generally agreed at 0.93, 1.20, and 1.00 versus sham for flow cytometry, automated counter, and hemocytometer, respectively. Similarly, a highly cytotoxic (>5-fold increase in LDH) stainless steel WF exposure produced fold changes over sham for the automated (4.0) and manual (1.2) methods at 1d post that were also seen at 7d. By 28d, however, when cytotoxicity was near baseline (1.4 fold change), the two methods gave similar results, with fold changes of 1.6 and 1.8 for the automated and manual methods, respectively. After exposure to non-cytotoxic mild steel WF, there was agreement between the automated counter and manual methods with a fold change of 1.1 over sham for both. The results suggest a threshold of cytotoxicity magnitude may be important in determining whether an automated or manual method of cell counting is best suited for BAL studies. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Blood Cells, Cultured Cytotoxins Environmental Monitoring Immune System Laboratories Lung Occupational Health Particulate Matter Respiratory System Safety Toxicology

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• Keywords:
  Alveolar-cells Analytical-instruments Analytical-methods Blood-cells Carbon-compounds Cell-cultures Cellular-reactions Cytotoxicity Dose-response Equipment-reliability Exposure-assessment Exposure-levels Fumes Immune-reaction Inhalation-studies Laboratory-animals Laboratory-techniques Laboratory-testing Lung-cells Nanotechnology Particle-counters Performance-capability Stainless-steel

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; OSHA Region 3 ; OSHA Region 9 ; 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:
  35
• Volume:
  144
• Issue:
  1
• NIOSHTIC Number:
  nn:20045882
• Citation:
  Toxicologist 2015 Mar; 144(1):35
• CAS Registry Number:
  Carbon (CAS RN 7440-44-0) ; Stainless Steel (CAS RN 12597-68-1)
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Construction
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 54th Annual Meeting and ToxExpo, March 22-26, 2015, San Diego, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:769109e280c234ba15c30743744edd9e0bc64b234f4164b263ef82502ab7b1fa8c1b6f4c9301cee89f3c7c8ec4f7e6deea6c641170d86e5cab016fe794c3c10a
• Download URL:
  https://stacks.cdc.gov/view/cdc/201131/cdc_201131_DS1.pdf
• File Type:
  [PDF - 227.67 KB ]