Sjöstrand M, Rylander R, Bergström R
Department of Environmental Hygiene, University of Gothenburg, Sweden.
Toxicology. 1989 Jul 3;57(1):1-14. doi: 10.1016/0300-483x(89)90030-9.
To study the long-term effect of inhaled asbestos, guinea-pigs were exposed to airborne amosite at a concentration of 49 mg/m3, 2 h/day for 3 or 6 weeks and examined up to 2 years after exposure. Macrophages in lung lavage fluid (LLF) were increased at 16, 24 and 93 weeks and lymphocytes at 24 weeks. Examination of lung wall cells (LWC) 2 years after exposure compared to cells obtained by LLF showed higher proportions of LWC lymphocytes and neutrophils. Percoll gradient centrifugation of these cells showed a higher proportion of high density macrophages in LLF from the amosite-exposed animal and an increased number of low density lymphocytes in the LW. Cathepsin D was increased in LLF at 8 and 24 weeks and in alveolar macrophages 24 weeks and 2 years after exposure. Fibroblast cultures exposed to LLF did not show any statistical significant changes in their collagen synthesis. Histology 93 weeks after exposure showed macrophage and mediastinal lymph node accumulation of asbestos, as well as collagen in alveolar walls. Granulomas were found in the vicinity of blood vessels and in connection with the bronchioles. The data suggest that amosite at low doses ultimately causes fibrosis with a reaction pattern different from that seen in silicosis. The inflammation and fibrosis seems to develop only within the interstitium.
为研究吸入石棉的长期影响，将豚鼠暴露于浓度为49毫克/立方米的空气中铁石棉中，每天2小时，持续3或6周，并在暴露后长达2年进行检查。肺灌洗液（LLF）中的巨噬细胞在16周、24周和93周时增加，淋巴细胞在24周时增加。与通过LLF获得的细胞相比，暴露2年后对肺壁细胞（LWC）的检查显示LWC淋巴细胞和中性粒细胞的比例更高。对这些细胞进行Percoll梯度离心显示，来自暴露于铁石棉的动物的LLF中高密度巨噬细胞的比例更高，LW中低密度淋巴细胞的数量增加。组织蛋白酶D在暴露后8周和24周时在LLF中增加，在暴露后24周和2年时在肺泡巨噬细胞中增加。暴露于LLF的成纤维细胞培养物在其胶原蛋白合成方面未显示任何统计学上的显著变化。暴露93周后的组织学检查显示石棉在巨噬细胞和纵隔淋巴结中积聚，以及肺泡壁中有胶原蛋白。在血管附近和与细支气管相关处发现肉芽肿。数据表明，低剂量的铁石棉最终会导致纤维化，其反应模式不同于矽肺。炎症和纤维化似乎仅在间质内发展。
