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Characterization of the early pulmonary inflammatory response associated with PTFE fume exposureHeating of polytetrafluoroethylene (PTFE) has been described to release fumes containing ultrafine particles (approximately 18 nm diam). These fumes can be highly toxic in the respiratory tract inducing extensive pulmonary edema with hemorrhagic inflammation. Fischer-344 rats were exposed to PTFE fumes generated by temperatures ranging from 450 to 460 degrees C for 15 min at an exposure concentration of 5 x 10(5) particles/cm3, equivalent to approximately 50 micrograms/m3. Responses were examined 4 hr post-treatment when these rats demonstrated 60-85% neutrophils (PMNs) in their lung lavage. Increases in abundance for messages encoding the antioxidants manganese superoxide dismutase and metallothionein (MT) increased 15- and 40-fold, respectively. For messages encoding the pro- and anti-inflammatory cytokines: inducible nitric oxide synthase, interleukin 1 alpha, 1 beta, and 6 (IL-1 alpha, IL-1 beta, and IL-6), macrophage inflammatory protein-2, and tumor necrosis factor-alpha (TNF alpha) increases of 5-, 5-, 10-, 40-, 40-, and 15-fold were present. Vascular endothelial growth factor, which may play a role in the integrity of the endothelial barrier, was decreased to 20% of controls. In situ sections were hybridized with 33P cRNA probes encoding IL-6, MT, surfactant protein C, and TNF alpha. Increased mRNA abundance for MT and IL-6 was expressed around all airways and interstitial regions with MT and IL-6 demonstrating similar spatial distribution. Large numbers of activated PMNs expressed IL-6, MT, and TNF alpha. Additionally, pulmonary macrophages and epithelial cells were actively involved. These observations support the notion that PTFE fumes containing ultrafine particles initiate a severe inflammatory response at low inhaled particle mass concentrations, which is suggestive of an oxidative injury. Furthermore, PMNs may actively regulate the inflammatory process through cytokine and antioxidant expression.
Document ID
20040173156
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Johnston, C. J. (University of Rochester New York 14642, United States)
Finkelstein, J. N.
Gelein, R.
Baggs, R.
Oberdorster, G.
Clarkson, T. W.
Date Acquired
August 22, 2013
Publication Date
September 1, 1996
Publication Information
Publication: Toxicology and applied pharmacology
Volume: 140
Issue: 1
ISSN: 0041-008X
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: ES01247
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Environmental Health