Role of polymorphonuclear leukocytes in silica-induced pulmonary fibrosis

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · Am. J. Pathol.; (United States)

OSTI ID:6134072

Adamson, I Y; Bowden, D H

Silicosis is usually attributed to fibroblast stimulation by secretion of damaged alveolar macrophages (AMs), but the role of polymorphonuclear leukocytes (PMNs) and of continuing cell injury in the pathogenesis has not been fully studied. Mice given intratracheal injections of 2 mg of silica received 3H-thymidine 1 hour before death at intervals to 20 weeks. Cellular populations and lysosomal content of lavage fluids were correlated with morphology, DNA synthesis, and collagen content of the lung. The initial response involved rapid PMN and AM recruitment to the alveoli. Some free particles crossed Type 1 epithelial cells, and silica was found in interstitial macrophages. Focal Type 1 cell damage was rapidly repaired by Type 2 cell proliferation. Although PMN numbers dropped after a few days, they never reached control levels and rose again after 8 weeks; the number of AMs fell to control values from 2 to 8 weeks, then increased again. Glucosaminidase and glucuronidase levels in the lavage fluid were much higher than control levels throughout the study. Increased DNA synthesis by interstitial cells occurred from 2 days to 20 weeks; increased collagen synthesis was found from 4 weeks onward. The continuing inflammatory response of the lung to silica suggests may contribute to fibroblastic stimulation.

• Research Organization: Univ. of Manitoba, Winnipeg
• OSTI ID: 6134072
• Journal Information: Am. J. Pathol.; (United States), Journal Name: Am. J. Pathol.; (United States) Vol. 117:1; ISSN AJPAA
• Country of Publication: United States
• Language: English

Related Subjects

550901 -- Pathology-- Tracer Techniques
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CELL PROLIFERATION
CHALCOGENIDES
CONNECTIVE TISSUE CELLS
DISEASES
DNA
FIBROSIS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUKOCYTES
LUNGS
MACROPHAGES
MAMMALS
MATERIALS
MICE
MINERALS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PATHOGENESIS
PATHOLOGICAL CHANGES
PHAGOCYTES
PYRIMIDINES
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RIBOSIDES
RODENTS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SOMATIC CELLS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES