Effect of enzyme-induced pulmonary emphysema in Syrian hamsters on the deposition and long-term retention of inhaled particles
Experimental emphysema was induced in Syrian hamsters by: (a) intratracheal instillation of elastase; or (b) inhalation of paparin aerosols. After 3 wk, treated and control groups were simultaneously exposed to an aerosol of relatively insoluble /sup 137/Cs-labeled, heat-treated aluminosilicate particles with an aerodynamic diameter of 1.4 or 1.6 ..mu..m. The lung deposition of particles measured 3 hr after inhalation exposure was significantly lower in hamsters exposed to elastase or papain. The mean whole-body retention data for each group were fitted with three-component exponential equations. The first component, which represented early clearance and constituted 78% to 83% of the initial body burden in all groups, occurred rapidly with a half-time of 0.6 to 0.8 days, and probably represented particles deposited in the nasopharynx and ciliated airways. The second component represented an intermediate clearance phase and was much faster in animals with emphysema than in controls. The enzyme treatments resulted in a prolonged half-time in the long-term clearance component. The effect of both enzyme treatments on the retention of particles was similar although the patterns of emphysema produced differed. Elastase instilled intratracheally caused diffuse destruction and enlargement of alveoli with a loss of pulmonary elastic recoil. Papain aerosols caused focal destruction and enlargement of alveoli around terminal bronchioles with no loss of elastic recoil. A common feature was an increased number of alveolar macrophages, which may account for the increased, early clearance of particles. The prolonged retention of a small fraction of particles may be due to focal accumulations of particle-laden macrophages which were prominent in distal alveoli of the papain-exposed hamsters and, to a lesser degree, in the elastase-treated hamsters.
- Research Organization:
- Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM
- OSTI ID:
- 5590021
- Journal Information:
- Arch. Environ. Health; (United States), Vol. 34:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
EMPHYSEMA
LUNG CLEARANCE
AEROSOLS
AIR POLLUTION
ALUMINIUM SILICATES
BIOLOGICAL HALF-LIFE
CESIUM 137
ENZYMES
HAMSTERS
INHALATION
LUNGS
MACROPHAGES
PARTICLE SIZE
PARTICLES
PATHOLOGICAL CHANGES
ALKALI METAL ISOTOPES
ALUMINIUM COMPOUNDS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CESIUM ISOTOPES
CLEARANCE
COLLOIDS
CONNECTIVE TISSUE CELLS
DISEASES
DISPERSIONS
EXCRETION
INTAKE
ISOTOPES
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANS
OXYGEN COMPOUNDS
PHAGOCYTES
POLLUTION
RADIOISOTOPES
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RODENTS
SILICATES
SILICON COMPOUNDS
SIZE
SOLS
SOMATIC CELLS
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)
551001 - Physiological Systems- Tracer Techniques
550901 - Pathology- Tracer Techniques