【摘要】 作者采用气管内非暴露式染尘,给大鼠一次性注入新康短纤维温石棉粉尘混悬液1ml(含石棉25mg),对照组注入等量生理盐水,光镜及电镜下观察其细支气管肺泡炎的病理改变。结果显示:染尘后3天,实验组大鼠肺内细支气管肺泡炎最显著,同时伴有气腔上皮和基底膜的损伤;7天后,炎性渗出物开始为巨噬细胞肉芽肿所代替;14～45天后,逐渐出现附壁型或腔内型纤维化。由此表明:国产新康短纤维温石棉具有肯定的致肺泡炎和致纤维化作用。更多还原

【Abstract】 Eighty-four rats were exposed intra-tracheally to 25 mg of locally producedXinkang short-fiber chrysotile asbestos (98%of the fibers are less than 5 μm in length).In 1 to 3 d after instillation, the patho-logical changes in rat lungs demonstratedthat the affection was mainly acute bron-chio-alveolitis characterized by acute in-flammatory exudation and injuries of thesmall airways and alveolar structural units.The four main manifestations of alveolitisinduced by the chrysotile asbestos were ofthe neutrophillic, serous, alveolar macro-phages and granulomatous varieties. Threetypes of pulmonary fibrosis developed grad-ually from 7 to 90 d following the exposureto the asbestos, i. e. the intraluminal,murally incorporated, and interstitial fibro-sis. Findings showed the complete processfrom the acute inflammatory exudation andthe damage to lung tissue,with the follow-ing repair and proliferation of injuriedlung tissue and organization of exudate,tothe final fibrosis and destruction of the lung.The results suggested that the persistentand irreversible damage to the epithelialcells of respiratory bronchioles and pneu-mocytes, and denudation and destruction ofthe basement membrane played an impor-tant role in the development of pulmonaryfibrosis by forming a channel for the inflam-matory exudates and fibroblasts migratinginto the bronchioalveolar spaces. Therefore,the experimental results have proved thatXinkang chrysotile asbestos fibers less than5 μm in length certainly have a fibrogeniceffect.更多还原