The Cytotoxicity of Microglass Fibers on Alveolar Macrophages of Fischer 344 Rats Evaluated by Cell Magnetometry, Cytochemisry and Morphology

ABSTRACT

Objectives: The toxicity of microglass fibers (MG), one of the man-made mineral fibers, has not been sufficiently evaluated. The aim of the current study was to evaluate the cytotoxicity of MG in vitro. Methods: Alveolar macrophages were obtained from the bronchoalveolar lavage of male F344/N rats. The macrophages were exposed to MG at concentrations of 0, 40, 80, 160 and 320 μg/ml. The effects of MG on the macrophages were examined by cell magnetometry, LDH assay and morphological observation. Results: In the cell magnetometry experiment, a significant delay of relaxation (the reduction of remanent magnetic field strength) was observed in the cells treated with 160 and 320 μg/ml of MG in a dose-dependent manner. A significant increase in LDH release was also observed in the cells with 160 and 320 μg/ml in a dose-dependent manner. Changes in the cytoskeleton were observed after exposure to MG, by immunofluorescent microscopy using an α-tubulin antibody. Conclusions: The cytotoxicity of MG on alveolar macrophages was demonstrated with cell magnetometry. The mechanism of the toxic effects of MG was related to cytoskeleton damage.