Acute respiratory bronchiolitis: an ultrastructural and autoradiographic study of epithelial cell injury and renewal in Rhesus monkeys exposed to ozone

Journal Article · Sat Mar 01 04:00:00 EST 1980 · Am. J. Pathol.; (United States)

OSTI ID:5993615

Castleman, W L; Dungworth, D L; Schwartz, L W; Tyler, W S

The pathogenesis of acute respiratory bronchiolitis was examined in Rhesus monkeys exposed to 0.8 ppM ozone for 4 to 50 hours. Epithelial injury and renewal were qualitatively and quantitatively characterized by correlated techniques of scanning and transmission electron microscopy as well as by light-microscopic autoradiography following labeling with tritiated thymidine. Extensive degeneration and necrosis of Type 1 epithelial cells occurred on the respiratory bronchiolar wall during the initial 4 to 12 hours of exposure. Increased numbers of labeled epithelial cells were present in this region after 18 hours of exposure, and the highest labeling index (18%) was measured after 50 hours of exposure. Most (67 to 80%) of the labeled cells and all the mitotic epithelial cells (22) observed ultrastructurally were cuboidal bronchiolar epithelial cells. Of the labeled epithelial cells, 20 to 33% were Type 2 epithelial cells. After 50 hours of exposure the respiratory bronchiolar epithelium was hyperplastic. The predominant inflammatory cell in respiratory bronchiolar exudate was the alveolar macrophage. Monkeys that were exposed for 50 hours and allowed to recover in unozonized air for 7 days had incomplete resolution of respiratory bronchiolar epithelial hyperplasia. The results indicate that Type 1 epithelial cells lining respiratory bronchioles are the cell types most sensitive to injury and that both cuboidal bronchiolar epithelial cells and Type 2 epithelial cells function as stem cells in epithelial renewal.

• OSTI ID: 5993615
• Journal Information: Am. J. Pathol.; (United States), Journal Name: Am. J. Pathol.; (United States) Vol. 98:3; ISSN AJPAA
• Country of Publication: United States
• Language: English

Related Subjects

551001 -- Physiological Systems-- 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
ANIMAL TISSUES
ANIMALS
AUTORADIOGRAPHY
AZINES
BIOLOGICAL EFFECTS
BODY
BRONCHI
BRONCHITIS
CONNECTIVE TISSUE CELLS
DISEASES
ELECTRON MICROSCOPY
EPITHELIUM
HETEROCYCLIC COMPOUNDS
LABELLED COMPOUNDS
MACROPHAGES
MAMMALS
MICROSCOPY
MONKEYS
MORPHOLOGICAL CHANGES
NECROSIS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OZONE
PATHOGENESIS
PATHOLOGICAL CHANGES
PHAGOCYTES
PRIMATES
PYRIMIDINES
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RIBOSIDES
SCANNING ELECTRON MICROSCOPY
SOMATIC CELLS
THYMIDINE
TISSUES
TRANSMISSION ELECTRON MICROSCOPY
TRITIUM COMPOUNDS
ULTRASTRUCTURAL CHANGES
VERTEBRATES