Retention and clearance of 0. 9-micron particles inhaled by hamsters during rest or exercise

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Applied Physiology (1985); (USA)

OSTI ID:5760704

Zeltner, T B; Sweeney, T D; Skornik, W A; Feldman, H A; Brain, J D ^[1]

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1. Harvard School of Public Health, Boston, MA (USA)

We assessed the retention and clearance of inhaled particles in six anatomic compartments of the respiratory tract. Hamsters were exposed for 45 min to 0.9-micron fluorescent latex particles either at rest (n = 9) or while running on a laddermill (n = 9). Oxygen consumption, which was used to estimate minute ventilation, was continuously monitored. Three animals from each group, rest and exercise, were killed at 10 min, 24 h, or 7 days after the exposure. Morphometric techniques were used to determine the number of particles retained in nose and oropharynx (NOSE), trachea and extrapulmonary airways, intrapulmonary conducting airways, respiratory bronchioles, alveolar ducts (AD), and alveoli (ALV). At 10 min, total particle retention increased linearly as a function of O{sub 2} consumption (slope = 1.4 +/- 0.3 x 10(6) particles.ml-1.g-1.h-1, P less than 0.015). Exercised hamsters retained 4.4 times more total particles in their NOSE than rested hamsters, but parenchymal retention (AD + ALV) was unaffected. After 7 days, 95% of the particles were cleared from the NOSE, 80% from the trachea and extrapulmonary airways, 44% from intrapulmonary conducting airways and respiratory bronchioles, and 16% from AD and ALV. There was evidence of particle redistribution from AD to ALV during the 1st day. We conclude that exercise enhances the deposition of 0.9-micron particles in the upper respiratory tract but not in the parenchyma. Subsequently, the deposited particles are cleared at varying rates depending on the lung compartment.

• OSTI ID: 5760704
• Journal Information: Journal of Applied Physiology (1985); (USA), Journal Name: Journal of Applied Physiology (1985); (USA) Vol. 70:3; ISSN 8750-7587; ISSN JAPHE
• 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.
AIR POLLUTION
ANIMALS
CLEARANCE
DISTRIBUTION
EXCRETION
HAMSTERS
LUNG CLEARANCE
MAMMALS
PARTICLE SIZE
PARTICLES
PARTICULATES
POLLUTION
RESPIRATION
RESPIRATORY SYSTEM
RETENTION
RODENTS
SENSITIVITY
SIZE
TISSUE DISTRIBUTION
VERTEBRATES