Pinkerton K E, Plopper C G, Mercer R R, Roggli V L, Patra A L, Brody A R, Crapo J D
Lab Invest. 1986 Dec;55(6):688-95.
The degree to which various anatomic components of the lung influence the distribution of inhaled particles is not entirely clear. Therefore, we have studied the role intrapulmonary airways play in the localization of respired asbestos fibers and have correlated local asbestos fiber burden with tissue injury in rats following exposure to aerosolized chrysotile asbestos for 7 hours per day, 5 days per week for 12 months. Tissues arising from anatomically distinct pathways of the tracheobronchial tree were isolated by using microdissection. Adjacent tissue blocks from regions immediately distal to the last dissected airway were prepared for light microscopic evaluation or digested in hypochlorite solution to determine alveolar septal tissue density and asbestos fiber concentration respectively. These studies demonstrated regional differences in asbestos fiber number, size, and mass which were inversely related to airway pathlength and to bifurcation number along each airway path. Fiber burden within each region was found to be proportional to the relative degree of tissue injury present. These findings suggest that differences in tissue injury from region to region in the lungs following exposure to asbestos are a result of regional differences in the deposition and retention of these substances in the lungs. These airway characteristics which influence fiber deposition may also play an important role in the deposition and subsequent lung injury caused by other particulates and environmental pollutants.
肺部的各种解剖结构对吸入颗粒分布的影响程度尚不完全清楚。因此，我们研究了肺内气道在呼吸性石棉纤维定位中的作用，并将局部石棉纤维负荷与大鼠在每周5天、每天7小时雾化温石棉暴露12个月后的组织损伤进行了关联。通过显微切割分离出气管支气管树不同解剖路径产生的组织。对紧邻最后切割气道远端区域的相邻组织块进行光镜评估，或分别在次氯酸盐溶液中消化以确定肺泡间隔组织密度和石棉纤维浓度。这些研究表明，石棉纤维数量、大小和质量存在区域差异，这些差异与气道路径长度以及每条气道路径上的分支数量呈负相关。发现每个区域内的纤维负荷与存在的组织损伤相对程度成正比。这些发现表明，接触石棉后肺部不同区域的组织损伤差异是这些物质在肺部沉积和滞留的区域差异所致。这些影响纤维沉积的气道特征也可能在其他颗粒和环境污染物引起的沉积及随后的肺损伤中起重要作用。
