title: Comparing the role of silica particle size with mineral fiber geometry in the release of superoxide from rat alveolar macrophages.
abstract: Particulate air pollutants and mineral fibers activate inflammatory cells to release oxidants, which contribute to inflammation and injury in the lower respiratory tract. Our aim was to compare the role of silica particle size with mineral fiber length and width in the ability to induce superoxide release from rat alveolar macrophages. We estimated the ability of four types of silica particle samples, with different mode diameter, and three types of mineral fiber samples, with different geometric mean lengths and widths, to induce lucigenin-dependent chemiluminescence (CL) from the cells per number of dust particles (i.e., silica particles and mineral fibers). A close positive correlation was observed between dust size and the ability to induce CL in silica as well as mineral fiber samples. Moreover, the ability of silica samples to induce CL was weaker than that of long mineral fiber sample. This ability increased at a larger rate in small silica particle and thin mineral fiber samples than in large silica particle and thick mineral fiber samples at the initial stage of administration. These results suggest that the kinetics of the induction superoxide release from macrophages is similar between silica particles and mineral fibers; moreover, this depends on silica particle size and mineral fiber geometry. Finally, large silica particles were more active than small ones.
authors: Department of Environmental Health, Osaka Prefectural Institute of Public Health.
authors: Masayuki
authors: M
authors: Ohyama
authors: Hideki
authors: H
authors: Tachi
authors: Chika
authors: C
authors: Minejima
authors: Takayuki
authors: T
authors: Kameda
mesh_terms: D000166:Acridines; D000818:Animals; D002478:Cells, Cultured; D049449:Luminescence; D016676:Macrophages, Alveolar / Q000378:metabolism*; D008297:Male; D019016:Mineral Fibers / Q000633:toxicity*; D016877:Oxidants / Q000633:toxicity*; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D011916:Rats, Inbred F344; D012822:Silicon Dioxide / Q000633:toxicity*; D013481:Superoxides / Q000378:metabolism*
chemical_list: D000166:Acridines; D019016:Mineral Fibers; D016877:Oxidants; D052638:Particulate Matter; D013481:Superoxides; C033472:10,10'-dimethyl-9,9'-biacridinium; D012822:Silicon Dioxide