Tohoku J. Exp. Med., 1999, 189 (4)

In Vitro Toxicity of Gallium Arsenide in Alveolar Macrophages Evaluated by Magnetometry, Cytochemistry and Morphology

MITSUSHI OKADA, HITOMI KARUBE, MASATO NIITSUYA, YOSHIHARU AIZAWA, ISAO OKAYASU1 and MAKOTO KOTANI2

Department of Preventive Medicine and Public Health, 1Department of Pathology, School of Medicine, Kitasato University, Sagamihara 228-8555, and 2Department of Electronics, School of Technology, Tokyo Denki University, Tokyo 101-0054<

  • Gallium arsenide (GaAs), a chemical compound of gallium and arsenic, causes various toxic effects including pulmonary diseases in animals. Since the toxicity is not completely investigated, GaAs has been used in workplaces as the material of various semiconductor products. The present study was conducted to clarify the toxicity of GaAs particles in the alveolar macrophages of hamsters using magnetometry, enzyme release assays and morphological examinations. Alveolar macrophages obtained from hamsters by tracheobronchial lavage and adhered to the disks in the bottom of wells were exposed to ferrosoferric oxide and GaAs particles. Ferrosoferric oxide particles were magnetized externally and the remanent magnetic field was measured. Relaxation, a fast decline of the remanent magnetic fields radiated from the alveolar macrophages, was delayed and decay constants were decreased dose-dependently due to exposure to GaAs. Because the relaxation is thought to be associated with cytoskeleton, the exposure of GaAs may have impaired the motor function of them. Enzyme release assay and morphological findings indicated the damage to the macrophages. Thus the cytotoxicity causes cytostructural changes and cell death. According to DNA electrophoresis and the TUNEL method, necrotic changes occur more frequently than apoptotic changes.
    Key words--- magnetometry; toxicity; alveolar macrophages; gallium arsenide
    © 1999 Tohoku University Medical Press

    Tohoku J. Exp. Med., 1999, 189, 267-281
    Address for reprints: Mitsushi Okada, Department of Preventive Medicine and Public Health, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara 228-8555, Japan.
    e-mail: okap@med.kitasato-u.ac.jp

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