Supercoiled plasmid DNA as a model target for assessing the generation of free radicals at the surface of fibres.
The ability of respirable amosite and crocidolite asbestos, refractory ceramic fibres (RCFs) and man made vitreous fibres (MMVFs) to cause free radical injury to plasmid, phiX174 RFI DNA was assessed. The amosite and crocidolite asbestos caused substantial damage to the DNA and, in the main, the free radicals responsible for the asbestos-mediated DNA damage were hydroxyl radicals as determined by inhibition with mannitol. Asbestos fibre-mediated damage to the DNA was completely ameliorated by the chelation of fibre-associated iron by pre-treatment of fibres with desferrioxamine-B, confirming the importance of iron in the production of free radicals. MMVFs and RCFs produced modest free radical damage to the DNA, which was prevented by mannitol but not by iron chelation.
Donaldson
K
K
Department of Biological Sciences Napier University, Edinburgh, UK.
Gilmour
P S
PS
Beswick
P H
PH
D017639:Asbestos, Amosite / Q000633:toxicity; D010584:Bacteriophage phi X 174 / Q000235:genetics; D002516:Ceramics / Q000633:toxicity; D004249:DNA Damage; D004278:DNA, Superhelical / Q000187:drug effects*; D005609:Free Radicals / Q000633:toxicity; D017665:Hydroxyl Radical / Q000633:toxicity; D007502:Iron Chelating Agents / Q000494:pharmacology; D019016:Mineral Fibers / Q000633:toxicity*; D008954:Models, Biological; D010957:Plasmids / Q000187:drug effects*
D004278:DNA, Superhelical; D005609:Free Radicals; D007502:Iron Chelating Agents; D019016:Mineral Fibers; D017639:Asbestos, Amosite; D017665:Hydroxyl Radical