Donaldson K, Beswick P H, Gilmour P S
Department of Biological Sciences, Napier University, Edinburgh, Scotland, UK.
Toxicol Lett. 1996 Nov;88(1-3):293-8. doi: 10.1016/0378-4274(96)03752-6.
Using a sensitive phi X174 RF plasmid DNA assay, free radical activity was detected at the surface of normal and ultrafine titanium dioxide (TiO2), environmental particles (PM-10), asbestos and a range of man-made fibres. There were differences in the amount of free radical activity that was detected, with ultrafine TiO2 being much more active than normal-sized TiO2; PM-10 also had substantial free radical activity. Amphibole asbestos samples were highly active, whilst man-made fibres were much less active than asbestos. For all of the particles, the DNA damage could be ameliorated by mannitol, showing that hydroxyl radicals were involved. The ability of particles to generate free radicals at or near their surface, and thereby impose oxidant stress in key target cells, could be central to determining their pathogenicity.
使用灵敏的φX174 RF质粒DNA检测方法，在正常二氧化钛和超细二氧化钛（TiO₂）、环境颗粒物（PM - 10）、石棉以及一系列人造纤维的表面检测到了自由基活性。所检测到的自由基活性量存在差异，超细TiO₂比普通尺寸的TiO₂活性高得多；PM - 10也具有大量的自由基活性。闪石石棉样本活性很高，而人造纤维的活性比石棉低得多。对于所有颗粒，甘露醇可减轻DNA损伤，表明其中涉及羟基自由基。颗粒在其表面或表面附近产生自由基并由此在关键靶细胞中施加氧化应激的能力，可能是决定其致病性的关键因素。
