Journal of Applied Physiology, Vol 53, Issue 6 1423-1428, Copyright © 1982 by American Physiological Society
Deposition and clearance of inhaled aerosol in the respiratory tract of chickens
G. A. Mensah and J. D. Brain
Sixteen unanesthetized adult White Leghorn chickens (Gallus domesticus)
were exposed to an aerosol of 99mTc-labeled submicrometric particles and
killed 0, 1, 12, or 36 h later. The amount and distribution of radioactive
particles retained in the lungs and skeletal system were measured to
describe regional deposition and clearance. Particles were present in the
lungs, air sacs, and skeletal system immediately after exposure. Reduction
in activity with time suggested clearance of aerosol from the lungs and
pneumatized bones. Aerosol particles were not distributed uniformly within
the lungs; there was greater retention in the caudal regions. No
dorsoventral gradients were observed. Of the initial lung deposition, 54
+/- 13.9% (SD) remained 1 h postexposure and 35.6 +/- 20.9% remained 36 h
later. These data suggest an early fast phase of lung clearance followed by
a slower phase. Detailed morphological studies are needed to understand the
underlying clearance mechanisms and the bases for the differences in
regional deposition.
