Kucukcelebi A, Mohamed F, Barnhart M I
Scan Electron Microsc. 1983(Pt 4):1835-50.
The structural physiology of airways from 80 guinea pigs was examined for changes induced by diesel exhaust (DE) exposure. Acute, subacute and chronic studies contrasted inhalation effects of 250, 750, 1500 and 6000 micrograms DE/m3 with "clean air" breathing of age-matched controls. Nonciliated epithelial (Clara) cells, epithelial type 2 cells and alveolar macrophages were increased in a DE dose dependent fashion. Also, eosinophils, were recruited. Epithelial type 1 cells of the distal airways internalized DEP. The relative dustiness (particulate density) of airways was assessed from coded specimens. Some 86% of DE exposed animals were correctly identified. Scanning Electron Microscopy (SEM) resolved surface located DE particulates (DEP). Single particles, loose clusters, low density agglomerates occurred. While SEM visual clues are insufficient for absolute identification of DE particles, there was supporting evidence from transmission electron microscopy (TEM) and from SEM studies comparing vascular with intratracheally fixed specimens. Presumptive DEP were notable on bifurcation bridges in respiratory bronchioles and alveolar ducts while alveolar outpockets had heavy dust burdens. Clumps of macrophages in such alveoli almost occluded the airspace. We conclude that normal guinea pigs appear to adapt to a chronic DE stress environment. But, the ultrastructural basis (cellular protrusions, DEP agglomerates and secretional debris) exists in peripheral airways for airflow instability and increased airflow resistance.
研究了80只豚鼠气道的结构生理学，以检测柴油废气（DE）暴露所引起的变化。急性、亚急性和慢性研究对比了250、750、1500和6000微克DE/m³的吸入效应与年龄匹配的对照组呼吸“清洁空气”的情况。非纤毛上皮（克拉拉）细胞、2型上皮细胞和肺泡巨噬细胞呈DE剂量依赖性增加。此外，嗜酸性粒细胞也被募集。远端气道的1型上皮细胞内化了可吸入颗粒物（DEP）。从编码标本评估气道的相对含尘量（颗粒密度）。约86%暴露于DE的动物被正确识别。扫描电子显微镜（SEM）分辨出位于表面的DE颗粒（DEP）。出现了单个颗粒、松散团簇、低密度聚集体。虽然SEM的视觉线索不足以绝对识别DE颗粒，但来自透射电子显微镜（TEM）以及比较血管与气管内固定标本的SEM研究提供了支持证据。在呼吸性细支气管和肺泡管的分叉桥上，推定的DEP很明显，而肺泡小凹有大量的灰尘负荷。此类肺泡中的巨噬细胞团几乎阻塞了气腔。我们得出结论，正常豚鼠似乎能适应慢性DE应激环境。但是，在外周气道中存在超微结构基础（细胞突起、DEP聚集体和分泌性碎片），可导致气流不稳定和气流阻力增加。
