Aalto M, Heppleston A G
Br J Exp Pathol. 1984 Feb;65(1):91-9.
Evidence on the mechanism by which inhaled mineral fibres lead to pulmonary fibrosis has not been forthcoming. As with silica, a biphasic cell culture system was required to distinguish phagocytosis from collagen formation. Synthesis of total protein and collagen by rat fibroblasts was estimated by incorporation of labelled proline after treatment with the medium from rat peritoneal macrophages that had been cultured in the presence of different types of mineral fibre. The influence of fibre length was also examined. All the main varieties of asbestos reacted with macrophages to produce or release a fibrogenic factor. However, chrysotile and the longer amosite fibres evoked the response only after prolonging the period of incubation with macrophages, presumably by permitting more complete phagocytosis of curled or longer fibres. Short amosite fibres proved to be more active than longer ones and under certain conditions were as potent as quartz. Fibrous glass also possessed stimulatory properties and again a sample having a short length gave a stronger response than a long one. Collagen formation by asbestos thus appears to be mediated by a macrophage factor, so operating in a manner similar to that previously demonstrated for quartz. The conventional view that short fibres are comparatively insignificant in asbestos fibrogenesis cannot, on the present evidence, be sustained. Furthermore, it should not be assumed than man-made mineral fibres of respirable diameter are innocuous or that short ones can be ignored.
关于吸入性矿物纤维导致肺纤维化的机制，目前尚无相关证据。与二氧化硅一样，需要一个双相细胞培养系统来区分吞噬作用和胶原蛋白形成。在用不同类型矿物纤维培养的大鼠腹腔巨噬细胞培养基处理大鼠成纤维细胞后，通过掺入标记的脯氨酸来估计总蛋白和胶原蛋白的合成。还研究了纤维长度的影响。所有主要种类的石棉都与巨噬细胞发生反应，产生或释放一种致纤维化因子。然而，温石棉和较长的铁石棉纤维只有在延长与巨噬细胞的孵育时间后才会引发反应，这可能是因为卷曲或较长的纤维更易被完全吞噬。短铁石棉纤维比长纤维更具活性，在某些条件下其效力与石英相当。玻璃纤维也具有刺激特性，同样，短纤维样品的反应比长纤维更强。因此，石棉诱导的胶原蛋白形成似乎是由巨噬细胞因子介导的，其作用方式与先前证明的石英类似。根据目前的证据，短纤维在石棉纤维形成过程中相对不重要这一传统观点无法成立。此外，不应假定可吸入直径的人造矿物纤维是无害的，也不应忽视短纤维。
