Phagocyte-derived Free Radicals

As a consequence of the inhalation of mineral dusts, infiltration into the lung of inflammatory phagocytic cells, namely PMN and macrophages, occurs (Rola-Pleszczynski et al., 1984). Analysis of the cell populations of the rat pleural cavities after injection with asbestos and silica dust also showed both degranulation and reduction of the mast cell population (Edwards etal., 1984), and it is of interest to note that histamine augments the particle-stimulated generation of macrophage superoxide production (Diaz et al., 1979). 

Phagocyte-derived ROMs have been implicated in the pathogenesis of a number of pulmonary diseases, including emphysema, acute respiratory distress syndrome, and various environmental diseases such as asbestos-related fibrosis and cancer (Mossman and Marsh, 1985). The relatively high oxygen tension in pulmonary tissue renders the lung prone to oxidative stress (Edwards and Lloyd, 1988). 

Likewise, the related zeolite mineral clinoptolite is an active stimulant of macrophage chemiluminescence (Velichkovsky et al., 1983). Evidence of the genotoxic and clastogenic activity of erionite to cultured cells has also been presented (Poole et al., 1983 Kelsey et al., 1986). 

Mesotheliomas are the characteristic asbestos-related tumours of the pleura. Exposure of explants of human pleura to crocidolite blue asbestos in culture produces a 

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Witko-Sarsat, V., Nguyen Anh Thu, Knight, J., and Descamps-Latscha, B. (1992). Pholasin a new chemiluminescent probe for the detection of chloramines derived from human phagocytes. Free Radic. Biol. Med. 13 83-88. 

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