Toxicological Sciences 53, 430-437 (2000)
Copyright © 2000 by the Society of Toxicology
The Effect of Heterogeneity of Lung Structure on Particle Deposition in the Rat Lung
* Institute of Physics and Biophysics, University of Salzburg, Hellbrunner Str. 34, A-5020, Salzburg, Austria;
Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709; and
Department of Neuroscience, New York State Psychiatric Institute, West New York, New York 10032
Differences in particle deposition patterns between human and rat lungs may be attributed primarily to their differences in breathing patterns and airway morphology. Heterogeneity of lung structure is expected to impact acinar particle deposition in the rat. Two different morphometric models of the rat lung were used to compute particle deposition in the acinar airways: the multiple-path lung (MPL) model (Anjilvel and Asgharian, 1995, Fundam. Appl. Toxicol. 28, 41–50) with a fixed airway geometry, and the stochastic lung (SL) model (Koblinger and Hofmann, 1988, Anat. Rec. 221, 533–539) with a randomly selected branching structure. In the MPL model, identical acini with a symmetric subtree (Yeh et al., 1979, Anat. Rec. 195, 483–492) were attached to each terminal bronchiole, while the respiratory airways in the SL model are represented by an asymmetric stochastic subtree derived from morphometric data on the Sprague-Dawley rat (Koblinger et al., 1995, J. Aerosol. Med. 8, 7–19). In addition to the original MPL and SL models, a hybrid lung model was also used, based on the MPL bronchial tree and the SL acinar structure. Total and regional deposition was calculated for a wide range of particle sizes under quiet and heavy breathing conditions. While mean total bronchial and acinar deposition fractions were similar for the three models, the SL and hybrid models predicted a substantial variation in particle deposition among different acini. The variances of acinar deposition in the MPL model were consistently much smaller than those for the SL and the hybrid lung model. The similarity of acinar deposition variations in the two latter models and their independence on the breathing pattern suggests that the heterogeneity of the acinar airway structure is primarily responsible for the heterogeneity of acinar particle deposition.
Key Words: inhalation; particle deposition; rat; lung morphology; mathematical modeling.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P. Ewing, B. Blomgren, A. Ryrfeldt, and P. Gerde Increasing Exposure Levels Cause an Abrupt Change in the Absorption and Metabolism of Acutely Inhaled Benzo(a)pyrene in the Isolated, Ventilated, and Perfused Lung of the Rat Toxicol. Sci., June 1, 2006; 91(2): 332 - 340. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. M. Wang and S. S. Kraman Fractal branching pattern of the monopodial canine airway J Appl Physiol, June 1, 2004; 96(6): 2194 - 2199. [Abstract] [Full Text] [PDF]
|
|