Effects of Depleted Uranium On Survival, Growth, and Metamorphosis in the African Clawed Frog (Xenopus laevis)
Coastal Sciences, Gulf Coast Research Laboratory
Embryos (stage 8-47, Nieuwkoop and Faber) of the African clawed frog (Xenopus laevis) were subjected to water-borne depleted uranium (DU) concentrations that ranged from 4.8 to 77,7 mg/L using an acute 96-h frog embryo teratogenesis assay-Xenopus (FETAX). In a chronic 64-d assay, X. laevis (from embryo through metamorphosis; stages 8-66) were subjected to concentrations of DU that ranged from 6.2 to 54.3 mg/L. Our results indicate DU is a non teratogenic metal. No effects on mortality, malformations, or growth were observed in the 96-h FEIAX with concentrations of DU that ranged from 4.8 to 77.7 mg/L. From stage 8 to stage 47, X. laevis tadpoles do not actively feed and the gills are not well developed. Thus, uptake of DU was reduced despite exposure to elevated concentrations. The 64-d assay resulted in no concentration response for either mortality or malformations; however, a delay in metamorphosis was observed in tadpoles subjected to elevated DU concentrations (from 13.1 to 54.3 mg/L) compared to tadpoles in both the well-water control and reference. The delay in metamorphosis was likely due to increasing body burden of DU that ranged from 0.98 to 2.82 mg/kg.
Journal of Toxicology and Environmental Health-Part A-Current Issues
Mitchell, S. E.,
Caldwell, C. A.,
Gould, W. R.,
(2005). Effects of Depleted Uranium On Survival, Growth, and Metamorphosis in the African Clawed Frog (Xenopus laevis). Journal of Toxicology and Environmental Health-Part A-Current Issues, 68(11-12), 951-965.
Available at: http://aquila.usm.edu/fac_pubs/2738