Radiation enhances silica translocation to the pulmonary interstitium and increases fibrosis in mice

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Environmental Health Perspectives; (United States)

DOI:https://doi.org/10.1289/ehp.9297233· OSTI ID:6790241

Adamson, I Y.R. ^[1]

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1. Univ. of Manitoba, Winnipeg (Canada)

The effects of whole body irradiation (WBR) on particle clearance and the development of pulmonary fibrosis have been investigated. Using carbon, clearance is accomplished by polymorphonuclear leukocytes (PMN) and alveolar macrophages (AM), and only a few particles reach the interstitum. However, in preirradiated mice, the usual eflux of inflammatory cells is much delayed so that more free carbon remains in the alveoli, and by 1 week, many particles cross the epithelium to be phagocytized by interstitial macrophages. Carbon is found in the peribronchiolar interstitium 6 months later with no evidence of fibrosis. In the present study, mice received 1 mg silica intratracheally 2 days after 6.5 Gy WBR when the white blood cell count was low. A much-reduced Am and PMN response was found in the following 2 weeks compared to the reaction to silica alone, and many silica particles reached interstitial macrophages. In this case, macrophage activation by silica was associated with fibroblast proliferation, and by 16 weeks, much more pulmonary fibrosis was produced than after silica or irradiation only. This was measured biochemically and correlated with a large increase in retained silica in the irradiation-silica group. The results indicate that radiation inhibits the inflammatory response to particle instillation, resulting in greater translocation of free particles to the pulmonary interstitium. In the case of silica, the greater, prolonged interaction with interstitial macrophages leads to a much exaggerated fibrotic reaction. 17 refs., 11 figs.

• OSTI ID: 6790241
• Journal Information: Environmental Health Perspectives; (United States), Journal Name: Environmental Health Perspectives; (United States) Vol. 97; ISSN EVHPAZ; ISSN 0091-6765
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550300 -- Cytology
550500 -- Metabolism
560150* -- Radiation Effects on Animals
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARBON
CHALCOGENIDES
CLEARANCE
CONNECTIVE TISSUE CELLS
ELEMENTS
EXCRETION
EXTERNAL IRRADIATION
FIBROSIS
IRRADIATION
LEUKOCYTES
LUNG CLEARANCE
LUNGS
MACROPHAGES
MAMMALS
MATERIALS
METABOLIC ACTIVATION
MICE
MINERALS
NONMETALS
ORGANS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PHAGOCYTES
RADIATION EFFECTS
RADIOSENSITIVITY
RESPIRATORY SYSTEM
RODENTS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SOMATIC CELLS
TRANSLOCATION
VERTEBRATES
WHOLE-BODY IRRADIATION