Tohoku J. Exp. Med., 1998, 186 (2)

Magnetometric Evaluation for the Effect of Chrysotile on Alveolar Macrophages

TOHRU KEIRA, MITSUSHI OKADA, HIROSHI KATAGIRI,1 YOSHIHARU AIZAWA, ISAO OKAYASU2 and MAKOTO KOTANI3

Department of Preventive Medicine and Public Health, Kitasato University School of Medicine, 1Department of Public Health, Kitasato University School of Allied Health Sciences, 2Department of Pathology, Kitasato University School of Medicine, Sagamihara 228-8555, and 3Department of Electronics, Faculty of Engineering, Tokyo Denki University, Tokyo 101-0054

  • Alveolar macrophages are thought to play an important role in fibrogenesis due to asbestos exposure. In this experiment, we evaluated the effect mainly by unique magnetometry and also by conventional methods such as lactate dehydrogenase (LDH) activity measurement and morphological observations. Alveolar macrophages obtained from Syrian golden hamsters by bronchoalveolar lavages were exposed 18 hours in vitro to Fe3O4 as an indicator for magnetometry and chrysotile for experiments. A rapid decrease of the remanent magnetic field, so called "relaxation", was observed after the cessation of an external magnetic field in macrophages phagocytizing Fe3O4 alone, while relaxation was delayed in those concurrently exposed to chrysotile. Since relaxation is thought due to the cytoskeleton-driven random rotation of phagosomes containing iron oxide particles, chrysotile is considered to interfere with the cytoskeletal function of macrophages. Release of LDH from chrysotile-exposed macrophages into the medium was recognized, but it was not significantly higher than the controls. Apoptosis was negligible in macrophages exposed to chrysotile by the DNA ladder detection, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling method and morphological observations. Electron microscopical examinations revealed early necrotic changes in macrophages exposed to chrysotile. These findings indicate that cell magnetometry detects impaired cytoskeletal function due to in vitro exposure to chrysotile.
    Key words--- magnetometry; chrysotile; alveolar macrophage; cytoskeleton; apoptosis
    © 1998 Tohoku University Medical Press

    Tohoku J. Exp. Med., 1998, 186, 87-98
    Address for reprints: Tohru Keira, Depertment of Preventive Medicine and Public Health, Kitasato University School, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
    e-mail: aizawa@kitasato-u.ac.jp

    Back to CONTENTS.