Selective exposure and analysis of the sheep tracheal lobe as a model for toxicological studies of respirable particles
A conscious sheep model, recently developed to study sequentially the bronchoalveolar milieu, was further refined to use in the rapid in vivo assessment of the biological effects of respirable particles. In this model, the anatomically isolated tracheal lobe was selectively exposed to either 100 ml phosphate buffered saline (PBS) (control group of 12 sheep), 100 mg of 0.1-..mu..m latex beads in 100 ml PBS (latex group of 12 sheep), or 100 mg of UICC Canadian chrysotile fibers in 100 ml PBS (asbestos group of 12 sheep). Bronchoalveolar lavages (BAL) of the tracheal lobe were obtained prior to exposure and at Days 1, 8, 15, 21, 29, 45, and 60 after exposure. Whole-lung detailed pulmonary function tests (PFT) were performed at the same times and the histopathology of the lobe was examined in six sheep in each group at Days 29 and 60. In the latex group, there was no significant change in PFT, the BAL analyses documented early transient increase in cellularity (macrophages and neutrophils at Day 1) and only macrophages after; lung histology documented an early macrophagic alveolitis which decreased to less than 10% of the initial inflammatory reaction at Day 60, without other distortion of the lung and airway architecture. In the asbestos sheep, the only change in whole-lung PFT was a 10-torr fall in arterial O/sub 2/ pressure. BAL analyses documented persistent increases in macrophages, neutrophils, and lactate dehydrogenase as well as increasing ..gamma..-globulins. Lung histology revealed a macrophagic and neutrophilic peribronchiolar alveolitis, early fibrosis, and severe distortion of the small airways, lesions comparable to those of early asbestosis in sheep or humans.
- Research Organization:
- Universite de Sherbrooke, Quebec
- OSTI ID:
- 5775069
- Journal Information:
- Environ. Res.; (United States), Vol. 36:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ASBESTOS
TOXICITY
LATEX
PARTICULATES
TRACHEA
PATHOLOGICAL CHANGES
DYNAMIC FUNCTION STUDIES
ENZYME ACTIVITY
EXPERIMENTAL DATA
LAVAGE
MACROPHAGES
NEUTROPHILS
OXIDOREDUCTASES
SHEEP
ANIMAL CELLS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CONNECTIVE TISSUE CELLS
DATA
DOMESTIC ANIMALS
ELASTOMERS
ENZYMES
INFORMATION
LEUKOCYTES
MAMMALS
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PARTICLES
PHAGOCYTES
POLYMERS
RESPIRATORY SYSTEM
RUBBERS
RUMINANTS
SOMATIC CELLS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)