Silica-induced pulmonary inflammation and fibrosis in mice is altered by acute exposure to nitrogen dioxide

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of Toxicology and Environmental Health; (United States)

DOI:https://doi.org/10.1080/15287399209531681· OSTI ID:6943935

Vetrano, K M; Morris, J B; Hubbard, A K ^[1]

---

1. Univ. of Connecticut, Storrs (United States)

The biologic impact of consecutive exposures to two environmental pollutants was examined in mice exposed to silica crystals (SI) by intratracheal (IT) injection followed by an inhalation exposure to nitrogen dioxide (NO2). C57Bl/6 mice received an IT injection of 2 mg SI or sterile saline (SAL) followed by a 2-h inhalation exposure to NO2 at 20 ppm either within 2 h of or 24 h after SI instillation. During acute inflammation (d 3 postsilica), mice exposed to NO2 at either time showed a dramatic and significant reduction in the number of lavaged alveolar neutrophils (PMN) when compared to silica/air-exposed mice. Animals exposed to NO[sub 2] 24 h after silica also evidenced significant decreases in levels of lavage albumin and lactate dehydrogenase (LDH) 3 d after silica, as well as significant decreases in hydroxyproline content of the lung 30 and 60 d postsilica injection when compared to silica/air-exposed animals. NO[sub 2] administration 24 h after silica appeared to shift the appearance of PMN in the lung from d 3 to d 14, but did not otherwise alter chronic cellular inflammation. These data suggest that the marked neutrophil response and collagen deposition induced by SI can be modulated by NO[sub 2] exposure and that the time of oxidant gas exposure after silica administration is critical to this modulation.

• OSTI ID: 6943935
• Journal Information: Journal of Toxicology and Environmental Health; (United States), Journal Name: Journal of Toxicology and Environmental Health; (United States) Vol. 37:3; ISSN 0098-4108; ISSN JTEHD6
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACUTE EXPOSURE
AIR POLLUTION
AMINES
AMINO ACIDS
ANIMALS
AZOLES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARBOXYLIC ACIDS
CHALCOGENIDES
CHRONIC EXPOSURE
COLLAGEN
CRYSTALS
DEPOSITION
DISEASES
ENZYMES
FIBROSIS
HEMIACETAL DEHYDROGENASES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
HYDROXYPROLINE
INFLAMMATION
INHALATION
INTAKE
LACTATE DEHYDROGENASE
LAVAGE
LEUKOCYTES
LUNGS
MAMMALS
MATERIALS
MICE
NEUTROPHILS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDES
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PNEUMONIA
PNEUMONITIS
POLLUTANTS
POLLUTION
PROTEINS
PYRROLES
PYRROLIDINES
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RODENTS
SCLEROPROTEINS
SILICATES
SILICON COMPOUNDS
SYMPTOMS
VERTEBRATES