Dose Response of Multiwalled Carbon Nanotube (MWCNT)-Induced Lung Tumors

Details

• Personal Author:
  Reynolds S
• Description:
  Mitsui-7 MWCNTs (MWCNTs) are strong lung tumor promoters in B6C3F1 mice. B6C3F1 mouse lung tumors have many molecular and morphological similarities to human pulmonary tumors. In previous work, we demonstrated that exposure to inhaled MWCNTs following exposure to a DNA damaging agent caused potent promotion of lung tumors. To investigate a possible threshold for MWCNT-induced carcinogenesis, we exposed B6C3F1 mice to a single dose of either methylcholanthrene (MC, 10 microg/g BW, i.p.) or vehicle (corn oil). One week after i.p. injections, mice were exposed by inhalation to MWCNTs (5 mg/ m3, 5 hours/day, 5 days/week) or filtered air (controls) for a total of 2, 5 or 10 days. At 17 months post-exposure, mice were euthanized and examined for lung tumor formation. Thirty-six percent of the filtered air controls, 33% of the MWCNT- exposed, and 47% of the MC-exposed, had a mean of 0.33, 0.33 and 0.4 tumors per mouse, respectively. By contrast, 94% of mice receiving MC followed by 10 days MWCNT had an average of 2.9 tumors per mouse while 81% of mice exposed to MWCNTs for 5 days had an average of 1.9 tumors per mouse, and 73% of mice exposed to MWCNTs for 2 days had an average of 1.2 tumors per mouse. Additionally, mice exposed to MWCNTs or MC followed by MWCNTs had larger tumor volumes than their corresponding control groups. Preliminary data indicate a dose response in the percent of animals with tumors as well as the number of tumors per animal following exposure to MC and MWCNTs. In this study, mouse MWCNT lung burden approximates feasible human occupational exposures. Therefore, the results of this ongoing study indicate that caution should be used to limit human exposures to MWCNTs. [Description provided by NIOSH]
• Subjects:
  Carcinogens Environmental Exposure Laboratories Lung Neoplasms Occupational Health Respiratory System Safety Toxicology
• Keywords:
  Carbon Nanotubes Carcinogenesis Dose Response Exposure Assessment Exposure Levels Laboratory Animals Laboratory Testing Lung Burden Lung Cells Methyl Compounds Multi-walled Carbon Nanotubes MWCNT Nanotechnology Nanotoxicology Pulmonary Effects Toxic Effects Tumors

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; OSHA Region 6 ; 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
• Volume:
  162
• Issue:
  1
• NIOSHTIC Number:
  nn:20051245
• Citation:
  Toxicologist 2018 Mar; 162(1):408
• CAS Registry Number:
  3-Methylcholanthrene (CAS RN 56-49-5) ; Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2018
• 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:b37d1282ddc1eb7e20706d984550b64285d83db3a0db2cfe90c58365256e743e1b2422577676bf3ace3c937cc3d22e9f545bdf0f5a04feea35562ba7684c95d3
• Download URL:
  https://stacks.cdc.gov/view/cdc/211311/cdc_211311_DS1.pdf
• File Type:
  [PDF - 832.33 KB ]