Anjilvel S, Asgharian B
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Fundam Appl Toxicol. 1995 Nov;28(1):41-50. doi: 10.1006/faat.1995.1144.
A multiple-path model of particle deposition in the entire rat lower respiratory tract was developed. Deposition in every branch of an asymmetric lung model was calculated using published analytic formulas for efficiencies of deposition by sedimentation, diffusion, and impaction. The conducting airway tree of the model included the entire set of airway measurements for the Long-Evans rat collected by Raabe et al. (1976). A model acinus defined by Yeh et al. (1979) was attached to each terminal bronchiole. Deposition was calculated for each acinus. Substantial variations in acinar deposition were predicted. These depended on inhaled particle size and tidal volume. The standard deviation in acinar dose was on the order of 0.2 times the average dose. Dose to some pulmonary acini was nearly twice the average acinar dose, suggesting that the geometry of the conducting airway tree of the rat lung may cause a fraction of pulmonary sites to sustain damage from inhaled particles at levels of exposure which cause no effect in the majority of the lung. The results represent a first step toward a complete model of inhaled particle deposition which assesses the effect of heterogeneity of lung structure on deposition at the level of individual airways.
建立了大鼠整个下呼吸道颗粒沉积的多路径模型。使用已发表的关于沉降、扩散和撞击沉积效率的解析公式，计算了非对称肺模型各分支中的沉积情况。该模型的传导气道树包括Raabe等人（1976年）收集的Long-Evans大鼠的整套气道测量数据。Yeh等人（1979年）定义的模型腺泡附着于每个终末细支气管。计算每个腺泡的沉积情况。预测腺泡沉积存在显著差异。这些差异取决于吸入颗粒大小和潮气量。腺泡剂量的标准差约为平均剂量的0.2倍。一些肺腺泡的剂量几乎是平均腺泡剂量的两倍，这表明大鼠肺传导气道树的几何结构可能导致一部分肺部区域在吸入颗粒暴露水平下受到损伤，而在大多数肺部区域该暴露水平并无影响。这些结果代表了迈向完整吸入颗粒沉积模型的第一步，该模型可评估肺结构异质性对单个气道水平沉积的影响。
