Mitchell Sarah E, Caldwell Colleen A, Gonzales Gil, Gould William R, Arimoto Richard
University of Southern Mississippi, Gulf Coast Research Laboratory, Ocean Springs, Mississippi, USA.
J Toxicol Environ Health A. 2005;68(11-12):951-65. doi: 10.1080/15287390590912595.
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 FETAX 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.
使用急性96小时青蛙胚胎致畸试验 - 非洲爪蟾（FETAX），将非洲爪蟾（爪蟾）处于8 - 47期（Nieuwkoop和Faber分期）的胚胎暴露于浓度范围为4.8至77.7毫克/升的水中贫铀（DU）环境中。在一项为期64天的慢性试验中，将爪蟾（从胚胎到变态发育；8 - 66期）暴露于浓度范围为6.2至54.3毫克/升的DU环境中。我们的结果表明，DU是一种无致畸性的金属。在96小时的FETAX试验中，当DU浓度范围为4.8至77.7毫克/升时，未观察到对死亡率、畸形或生长的影响。从8期到47期，爪蟾蝌蚪不主动进食且鳃发育不完善。因此，尽管暴露于高浓度环境中，DU的摄入量仍有所减少。64天的试验在死亡率或畸形方面均未产生浓度响应；然而，与井水对照和参考组中的蝌蚪相比，暴露于高DU浓度（13.1至54.3毫克/升）的蝌蚪出现了变态发育延迟的现象。变态发育延迟可能是由于DU在体内的累积量增加，范围为0.98至2.82毫克/千克。
