Wylie A G, Skinner H C, Marsh J, Snyder H, Garzione C, Hodkinson D, Winters R, Mossman B T
Department of Geology, University of Maryland, College Park, Maryland 20742, USA.
Toxicol Appl Pharmacol. 1997 Nov;147(1):143-50. doi: 10.1006/taap.1997.8276.
Inhalation of asbestos fibers causes cell damage and increases in cell proliferation in various cell types of the lung and pleura in vivo. By using a colony-forming efficiency (CFE) assay, the cytotoxicity and proliferative potential of three mineral samples containing various proportions of fibrous talc were compared to NIEHS samples of crocidolite and chrysotile asbestos in cell types giving rise to tracheobronchial carcinomas, i.e., hamster tracheal epithelial (HTE) cells, and mesotheliomas, i.e., rat pleural mesothelial (RPM) cells. Characterization of mineralogical composition, surface area, and size distributions as well as proportions of fibers in all mineral samples allowed examination of data by various dose parameters including equal weight concentrations, numbers of fibers >5 micron in length, and equivalent surface areas. Exposure to samples of asbestos caused increased numbers of colonies of HTE cells, an indication of proliferative potential, but fibrous talc did not. RPMs did not exhibit increased CFE in response to either asbestos or talc samples. Decreased numbers of colonies, an indication of cytotoxicity, were observed in both cell types and were more striking at lower weight concentrations of asbestos in comparison to talc samples. However, all samples of fibrous minerals produced comparable dose-response effects when dose was measured as numbers of fibers greater than 5 micron or surface area. The unique proliferative response of HTE cells to asbestos could not be explained by differences in fiber dimensions or surface areas, indicating an important role of mineralogical composition rather than size of fibers.
吸入石棉纤维会导致体内肺和胸膜的各种细胞类型出现细胞损伤并增加细胞增殖。通过使用集落形成效率（CFE）测定法，将三种含有不同比例纤维状滑石的矿物样品与来自国家环境卫生科学研究所（NIEHS）的青石棉和温石棉样品，在引发气管支气管癌的细胞类型即仓鼠气管上皮（HTE）细胞，以及间皮瘤即大鼠胸膜间皮（RPM）细胞中，比较其细胞毒性和增殖潜力。对所有矿物样品的矿物成分、表面积、尺寸分布以及纤维比例进行表征，从而能够通过各种剂量参数来检查数据，这些参数包括等重浓度、长度大于5微米的纤维数量以及等效表面积。暴露于石棉样品会导致HTE细胞集落数量增加，这表明其具有增殖潜力，但纤维状滑石则不会。RPM细胞对石棉或滑石样品均未表现出CFE增加。在两种细胞类型中均观察到集落数量减少，这表明存在细胞毒性，并且与滑石样品相比，在较低重量浓度的石棉中更为明显。然而，当以长度大于5微米的纤维数量或表面积来衡量剂量时，所有纤维状矿物样品产生的剂量反应效应相当。HTE细胞对石棉的独特增殖反应无法通过纤维尺寸或表面积的差异来解释，这表明矿物成分而非纤维大小起着重要作用。
