Hofmann W, Asgharian B, Bergmann R, Anjilvel S, Miller F J
Institute of Physics and Biophysics, University of Salzburg, Austria.
Toxicol Sci. 2000 Feb;53(2):430-7. doi: 10.1093/toxsci/53.2.430.
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.
人类和大鼠肺部颗粒沉积模式的差异可能主要归因于它们呼吸模式和气道形态的差异。预计肺部结构的异质性会影响大鼠腺泡内的颗粒沉积。使用两种不同的大鼠肺部形态计量模型来计算腺泡气道中的颗粒沉积：具有固定气道几何形状的多路径肺（MPL）模型（Anjilvel和Asgharian，1995年，《基础与应用毒理学》28卷，41 - 50页），以及具有随机选择分支结构的随机肺（SL）模型（Koblinger和Hofmann，1988年，《解剖学记录》221卷，533 - 539页）。在MPL模型中，具有对称子树的相同腺泡（Yeh等人，1979年，《解剖学记录》195卷，483 - 492页）连接到每个终末细支气管，而SL模型中的呼吸气道由源自Sprague - Dawley大鼠形态计量数据的不对称随机子树表示（Koblinger等人，1995年，《气溶胶医学杂志》8卷，7 - 19页）。除了原始的MPL和SL模型外，还使用了一种混合肺模型，该模型基于MPL支气管树和SL腺泡结构。在安静和深呼吸条件下，针对广泛的颗粒尺寸计算了总沉积和区域沉积。虽然三种模型的平均总支气管和腺泡沉积分数相似，但SL模型和混合模型预测不同腺泡之间的颗粒沉积存在显著差异。MPL模型中腺泡沉积的方差始终远小于SL模型和混合肺模型。后两种模型中腺泡沉积变化的相似性及其对呼吸模式的独立性表明，腺泡气道结构的异质性是腺泡颗粒沉积异质性的主要原因。
