Cytokinetic and morphological changes in the lungs and lung-associated lymph nodes of rats after inhalation of fly ash
Fischer-344 rats (male and female) were exposed to 36 mg/mT of fluidized bed coal combustion fly ash or sham-exposed for 7 hr/day, 5 days/week for 4 weeks, and sacrificed after 2 or 4 weeks of exposure and at 2, 22, and 42 weeks after the end of exposure. Animals were injected with tritiated thymidine 2 hr before sacrifice and autoradiographs prepared from 1- m sections of lung and lymph node tissue embedded in glycol methacrylate plastic. Differences in labeling indices of pulmonary epithelial cells, alveolar macrophages, airway epithelial cells, and cells of the lung-associated lymph nodes between the exposed and control animals were maximal after 2 and 4 weeks of exposure. Labeling indices for lung epithelial cells were about the same in control and exposed animals at 2, 22, and 42 weeks after the end of exposure. However, these values were elevated relative to earlier control levels. In contrast, morphological changes in the fly ash-exposed animals were most prominent after the end of the exposure. These changes included thickening of the alveolar walls, clusters of particle-filled macrophages in the alveolar region, and perivascular inflammation. Additionally, there were small granulomas in the alveolar region at 42 weeks after the end of exposure. Granulomas were also formed in the lung-associated lymph nodes and bronchus-associated lymphoid tissue. The authors conclude that the inhalation of fly ash alone had little detrimental effect upon the rat lung. However, the increases in proliferation indicate the potential for fly ash combined with a carcinogen to enhance the carcinogen's effect. 50 references, 10 figures.
- Research Organization:
- Inhalation Toxicology Research Institute, Albuquerque, NM
- DOE Contract Number:
- AC04-76EV01013
- OSTI ID:
- 6289822
- Journal Information:
- Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 35; ISSN ENVRA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROSOL WASTES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
ASHES
AUTORADIOGRAPHY
AZINES
BODY
CARCINOGENS
CONNECTIVE TISSUE CELLS
DATA
DISEASES
EPITHELIUM
EXPERIMENTAL DATA
FLY ASH
GRANULOMAS
HETEROCYCLIC COMPOUNDS
INFORMATION
INHALATION
INTAKE
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LUNGS
LYMPH NODES
LYMPHATIC SYSTEM
MACROPHAGES
MAMMALS
MORPHOLOGICAL CHANGES
NEOPLASMS
NUCLEOSIDES
NUCLEOTIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHAGOCYTES
PYRIMIDINES
RATS
RESIDUES
RESPIRATORY SYSTEM
RIBOSIDES
RODENTS
SOMATIC CELLS
SYNERGISM
THYMIDINE
TISSUES
TOXICITY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
WASTES