Supramicron-sized particle clearance from alveoli: route and kinetics.
Langenback-EG; Bergofsky-EH; Halpern-JG; Foster-WM
J Appl Physiol 1990 Oct; 69(4):1302-1308
The clearance routes and kinetics of an inert insoluble carbonized polystyrene particle of supramicron size tagged with cobalt-57 (13981505) was examined in the adult unanesthetized sheep. The investigation was conducted to demonstrate, in a large animal comparable to a human, the kinetics of long term supramicron sized particle clearance from the alveoli, the routes of clearance followed by these particles exiting the alveoli, and some of the physiological characteristics of the later phase of alveoli clearance. The rate of particle clearance revealed a three exponential function, comprising a rapid initial phase in the first 44 hours of clearance for tracheobronchial deposition followed by a slower phase of mostly alveolar clearance in the next 30 days and a final phase of very slow relatively pure alveolar clearance. This supramicron sized particle cleared from alveoli predominantly via the mucociliary escalator of the tracheobronchial tree. Particle and macrophage recovery rates suggested a sequestered state for alveolar deposited particles which may partly account for their slow clearance rates. Macrophages engulfing these particles at low particle burdens traveled normally in only one direction, that is, from interstitium to alveolus and then to the mucociliary escalator.
NIOSH-Publication; NIOSH-Grant; Laboratory-animals; Respiratory-system-disorders; Particulates; Alveolar-cells; Lung-cells; Inhalation-studies; Airborne-particles
Medicine Suny at Stony Brook Hsc, T-17, Room 040 Stony Brook, N Y 11794
Journal of Applied Physiology
State University New York Stony Brook, Stony Brook, New York