Production of oxygen radicals by the reduction of oxygen arising from the surface activity of mineral fibres.

摘要: According to certain hypotheses, the production of oxygen radicals within biological medium (the phenomenon oxidative stress) may play an important role in fibrosis and steps carcinogenesis. The mineral fibres various materials are capable participating this phenomenon, owing reducing nature their surface activity, so that OH. can be produced from 3 steps. activity inorganic which insoluble or only very slightly soluble is due presence electron donor active sites, generally linked Fe2+ ions found neighbourhood surface. In systems, these sites emerge on as a result partial dissolution particle, action agent, deposition surfaces cation exchange. We have explored properties number fibres, aqueous buffer medium, by paramagnetic resonance (EPR) measurement adduct with radical-trapping agent 5,5'-dimethyl-l-pyrrolidine-N-oxide (DMPO), initially formed (OH. R.). highly effective producing dissolved (Canadian chrysotile, nemalite, freshly ground amphiboles) while others little effect. markedly increased prior treatment ferrous salt (as case erionite) addition glutathione reaction UICC crocidolite). It suggested carcinogenic at pulmonary level properties. These either present time inhalation acquired medium. This hypothesis not conflict observation dimensional characteristics mesothelioma.