Toxicological effects of inhaled multi-walled carbon nanotubes on reactivity of isolated rat trachea

Details

• Personal Author:
  Chen BT ; Cumpston A ; Fedan, Jeffery S. ; McKinney W ; Russ KA
• Description:
  Occupational exposure to multi-walled carbon nanotubes (MWCNT) can occur in many different settings such as research and product development, manufacturing, and waste disposal. Current studies of their health effects demonstrate that some MWCNT cause pulmonary inflammation and fibrosis, mesothelioma, and elicit changes in the cardiovascular and central nervous systems in animal models. However, whether changes in airways occur as a result of MWCNT inhalation has not been explored. To investigate the toxicological effects of inhaled MWCNT, rats were exposed to 1 or 5 mg/m3 inhaled MWCNT (MWNT-7 provided by Mitsui & Co.) for 6 hours. Characterization of the MWCNT showed the expected crystalline structure, 20-50 walls, and little trace metal contamination. The MWCNT had a mass median aerodynamic diameter of 1.5 microm and a geometric standard deviation of 1.67. Tracheas from MWCNT and air-exposed animals were isolated from euthanized animals for in vitro examination using isolated, perfused trachea preparations at 18 hours and 7 days post-exposure. After exposure to 5 mg/m3 MWCNT, no statistically significant changes in reactivity to intraluminally or extraluminally-applied methacholine (MCh) were observed at either 18 hours or 7 days post-exposure. However, after exposure to 1 mg/m3 MWCNT for 6 hours, there was a significant increase in reactivity to intraluminal MCh as indicated by a decrease in the EC50 value in comparison to the air-breathing control animals. By day 7 post-exposure, the changes in reactivity to MCh had resolved. The increase in reactivity to intraluminally-applied but not extraluminally-applied MCh in the 1 mg/m3 MWCNT-exposed animals indicates that the epithelial cells lining the trachea are affected by inhaled MWCNT, which could alter their regulatory effect on airway reactivity. [Description provided by NIOSH]
• Subjects:
  Esters Immune System Laboratories Lung Metals Methacholine Compounds Occupational Health Particulate Matter Respiratory System Safety Toxicology

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• Keywords:
  Airway Obstruction Airway Resistance Carbon Nanotubes Cellular Reactions Cholinergic Receptors Crystal Structure Exposure Assessment Immune Reaction Immune System Inhalation In Vitro Study Laboratory Animals Laboratory Testing Lung Clearance Methacholines Multi-walled Carbon Nanotubes MWCNT Nanotechnology Nanotoxicology Nanotubes Particle Diameter Particle Size Pulmonary Effects Pulmonary System Throat Trace Metals

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• ISSN:
  1096-6080
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; New Mexico ; OSHA Region 3 ; OSHA Region 6 ; Virginia ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  156
• Issue:
  1
• NIOSHTIC Number:
  nn:20049486
• Citation:
  Toxicologist 2017 Mar; 156(1):445
• CAS Registry Number:
  Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Oil and Gas Extraction ; Manufacturing
• Performing Organization:
  University of New Mexico Health Sciences Center, Albuquerque, New Mexico
• Peer Reviewed:
  False
• Start Date:
  20150930
• Source Full Name:
  The Toxicologist. Society of Toxicology 56th Annual Meeting and ToxExpo, March 12-16, 2017, Baltimore, Maryland
• End Date:
  20190929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:57758f71feb58e51e8e0635561e2103248459c8d70cc1ef3be9c5da7e772097d7d27c6fad0b3f61f5e02b4e269a0b932240fcc0ec550e2eb9d126ec5d0ea2345
• Download URL:
  https://stacks.cdc.gov/view/cdc/203927/cdc_203927_DS1.pdf
• File Type:
  [PDF - 949.78 KB ]