Shibata Kaori, Kudo Yuichiro, Tsunoda Masashi, Hosokawa Mayuko, Sakai Yasuhiro, Kotani Makoto, Aizawa Yoshiharu
Department of Preventive Medicine and Public Health, Kitasato University School of Medicine, Kanagawa, Japan.
Ind Health. 2007 Jun;45(3):426-36. doi: 10.2486/indhealth.45.426.
The toxic effects of man-made mineral fibers (MMMFs) have been evaluated by cell magnetometry using alveolar macrophages (AMs). Recently, on the other hand, the murine macrophage cell line, RAW 264.7, became available and has been used as an in vitro model of AMs. The objective of this study was to determine whether or not cell magnetometry using RAW 264.7 cells can be used to evaluate the toxic effects of MMMFs. RAW 264.7 cells were exposed to one of the MMMFs, potassium octatitanate (PT) or silicon carbide whisker (SiC) at 0, 20, 40 and 60 microg/ml, or chrysotile as a positive control at 0, 15, 20 and 25 microg/ml. The toxic effects of fibers were evaluated by cell magnetometry and LDH assay. For this comparison, AMs were also exposed to chrysotile fibers (CF). In the RAW 264.7 cells exposed to PT 20, 40, 60 or SiC 20, 40, 60, CF 15, 20 and 25 microg/ml, significant delayed relaxation were observed compared with the respective control. In the LDH assay, significant increases in LDH in the supernatant of the cells exposed to PT 20, 40, 60, SiC 20, 40, 60 and CF 15, 20, 25 microg/ml were observed. In AMs exposed to CF 20, 25 microg/ml significant delayed relaxation and significant increases in LDH compared with the control were observed. The levels of MMMFs that induced significant differences were similar for cell magnetometry and LDH. The levels of CF that induced significant differences in cell magnetometry and LDH were identical for RAW 264.7 cells and AMs. Our results suggest that cell magnetometry using RAW 264.7 cells is adequate to evaluate the cytotoxicity of exposure to MMMFs.
利用肺泡巨噬细胞（AMs）通过细胞磁测量法评估了人造矿物纤维（MMMFs）的毒性作用。另一方面，近年来，鼠巨噬细胞系RAW 264.7已可获取，并被用作AMs的体外模型。本研究的目的是确定使用RAW 264.7细胞的细胞磁测量法是否可用于评估MMMFs的毒性作用。将RAW 264.7细胞暴露于以下物质之一：八钛酸钾（PT）或碳化硅晶须（SiC），浓度分别为0、20、40和60微克/毫升，或以温石棉作为阳性对照，浓度分别为0、15、20和25微克/毫升。通过细胞磁测量法和乳酸脱氢酶（LDH）测定评估纤维的毒性作用。为进行此比较，也将AMs暴露于温石棉纤维（CF）。在暴露于20、40、60微克/毫升PT或20、40、60微克/毫升SiC、15、20和25微克/毫升CF的RAW 264.7细胞中，与各自的对照组相比，观察到显著的延迟弛豫。在LDH测定中，观察到暴露于20、40、60微克/毫升PT、20、40、60微克/毫升SiC和15、20、25微克/毫升CF的细胞上清液中LDH显著增加。在暴露于20、25微克/毫升CF的AMs中，与对照组相比，观察到显著的延迟弛豫和LDH显著增加。细胞磁测量法和LDH测定中诱导显著差异的MMMFs水平相似。RAW 264.7细胞和AMs中细胞磁测量法和LDH测定中诱导显著差异的CF水平相同。我们的结果表明，使用RAW 264.7细胞的细胞磁测量法足以评估暴露于MMMFs的细胞毒性。
