Generation of free radicals from phagocytes induced by occupational minerals.
Vallyathan-V; Dalal-NS; Mega-JF; Shi-X
Toxicologist 1992 Feb; 12(1):291
This study was undertaken to determine and differentiate the potential of occupational dusts to stimulate the production of oxygen radicals by human polymorphonuclear leukocytes (PMN) and rat alveolar macrophages (AM) in vitro using electron spin resonance spectrometry (ESR) and spin trap technique. PMN and AM were exposed to amosite, chrysotile or crocidolite asbestos, to freshly fractured or aged silica, and to an inert dust barite in the presence of a lipid soluble spin trap alpha-phenyl-t-butyl nitrone (PBN). Free radicals generated during phagocytosis were trapped by the PBN forming a stable PBN adduct. Lipid extract of the reaction medium was subjected to ESR measurement to determine the relative intensities of radicals generated. Amosite and crocidolite asbestos generated greater concentrations of oxygen free radicals than silica and chrysotile asbestos. Catalase, but not superoxide dismutase, inhibited more than 70% of the generation of radicals. Desferoxamine inhibited the radical generation and 1,3-bis(2- chloroethyl-l-nitrosouria (carmustine), an inhibitor of glutathione reductase systems, enhanced radical production four-fold. These data indicate that in vitro exposure of phagocytes to particles will generate significant levels of oxygen radicals.
Occupational-exposure; Dust-exposure; Dust-inhalation; Dust-analysis; Blood-cells; In-vitro-studies; Silica-dusts; Mineral-dusts; Free-radicals; Oxidative-processes; Lung-cells; Free-radical-generation; Cytotoxic-effects
12172-73-5; 12001-29-5; 12001-28-4
The Toxicologist. Society of Toxicology 31st Annual Meeting, February 23-27,1992, Seattle, Washingtion