Developmental differences in elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during Xenopus laevis development.
Developmental differences in elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during Xenopus laevis development.
复制标题
非洲爪蟾发育过程中消除 2,3,7,8-四氯二苯并-对二恶英 (TCDD) 的发育差异。
DOI：
10.1016/j.marenvres.2006.04.027
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发表时间：
2006
影响因子：
3.3
通讯作者：
Powell,WadeH
中科院分区：
文献类型：
--
作者：
Philips,BlytheH;Susman,ThomasC;Powell,WadeH
尽管 2,3,7,8 四氯二苯并二恶英 (TCDD) 对大多数脊椎动物来说是一种有效的发育毒物，但一些青蛙物种对 TCDD 不敏感，尤其是在生命早期阶段。先前对蛙类进行的实验表明，TCDD 不敏感主要是由于快速消除所致。最近对非洲爪蛙（Xenopus laevis；Pipidae 科）的研究将低 TCDD 毒性与芳基烃受体的低结合亲和力联系起来，芳基烃受体介导了二恶英类化合物的毒性作用。本研究旨在检查非洲青蛙胚胎和蝌蚪中 TCDD 的消除情况，从而能够综合评估单个青蛙物种内 TCDD 消除的相对作用和 AHR 相关机制在 TCDD 不敏感性中的作用。使用暴露于 [3H]TCDD 的蝌蚪（52-55 阶段；∼1 个月大），我们观察到 TCDD 的半衰期相对较短，为 102.6 小时，与其他青蛙一致，并且比报道的发育中鱼类的清除率快得多。相比之下，TCDD 的消除在早期发育过程中要慢得多。在初级器官发生期间（从第 31-41 阶段，受精后约 36 小时开始）暴露的胚胎在随后的 96 小时内几乎没有表现出 TCDD 消除。在发育后期，TCDD 清除率增强可能伴随着功能性消化道的出现和进食的开始。这些结果表明，在心血管系统发育过程中，快速消除不太可能从机制上导致 TCDD 不敏感，而心血管系统在鱼胚胎中受到 TCDD 的显着干扰。
Although 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a potent developmental toxicant in most vertebrates, several frog species are insensitive to TCDD, especially during early life stages. Previous experiments with ranid frogs suggest that TCDD insensitivity results largely from rapid elimination. Recent studies in the African clawed frog (Xenopus laevis; family Pipidae) link low TCDD toxicity with the low binding affinity of aryl hydrocarbon receptors, which mediate the toxic effects of dioxin-like compounds. The present study sought to examine TCDD elimination in X. laevis embryos and tadpoles, enabling an integrated assessment of the relative roles of TCDD elimination and AHR-related mechanisms in TCDD insensitivity within a single frog species. Using tadpoles (stage 52–55; ∼1 month old) exposed to [3H]TCDD, we observed that TCDD has a relatively short half life of 102.6h, consistent with other frogs and much faster than reported clearance rates in developing fish. In contrast, TCDD elimination is much slower during early development. Embryos exposed during primary organogenesis (from stage 31–41, beginning ∼36h after fertilization) exhibited little TCDD elimination during the subsequent 96h. Enhanced TCDD clearance in later developmental stages may follow the appearance of a functional digestive tract and the onset of feeding. These results suggest that rapid elimination is unlikely to contribute mechanistically to TCDD insensitivity during development of the cardiovascular system, which is significantly perturbed by TCDD in fish embryos.