Different genotoxic profiles between depleted and enriched uranium

Uranium is an alpha-particle-emitting heavy metal Its genotoxicity results from both its chemical and its radiological properties that vary with its isotopic composition (12% enriched Uranium in U-235 (EU) has a specific activity 20 times higher than 0 3% depleted uranium in U-235 (DU)) The influence of the isotopic composition of uranium on its genotoxic profile (clastogenic/aneugenic) has never been described The present study evaluated genotoxic profile Of Uranium with the cytokinesis-block micronuclues centromere assay C3H10T1/2 mouse embryo fibroblasts were contaminated with either DU or EU at different concentrations (5 mu M. 50 mu M and 500 mu M) Cells received low (loses ranging from 0.3 mu Gy to 760 5 mu Gy The frequency of binucleated cells with one micronucleus increased with increasing concentrations of both DU and EU in the same way EU induced more centromere-negative micronuclei and nucleoplasmic bridges than DU A correlation between these two clastogenic markers and ionizing radiation doses was observed Finally, this study showed that the genotoxic profile of uranium depends on its isotopic composition DU and EU are low and high clastogens, respectively However, DU aneugenic effects remain high Thus, there is a need to study the potential role of aneugenic effects of DU in carcinogenic risk assessment linked to uranium internal exposure (C) 2009 Elsevier Ireland Ltd All rights reserved