Toxicity and accumulation of 6-OH-BDE-47 and newly synthesized 6,6 '-diOH-BDE-47 in early life-stages of Zebrafish (Danio rerio)
Toxicity and accumulation of 6-OH-BDE-47 and newly synthesized 6,6 '-diOH-BDE-47 in early life-stages of Zebrafish (Danio rerio)
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6-OH-BDE-47 和新合成的 6,6'-diOH-BDE-47 在斑马鱼（斑马鱼）生命早期阶段的毒性和积累
DOI：
10.1016/j.scitotenv.2020.143036
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发表时间：
2021
影响因子：
9.8
通讯作者：
Cai Zongwei
中科院分区：
文献类型：
--
作者：
Zhang Mengtao;Zhao Feng;Zhang Jiawei;Shi Jianghong;Tao Huanyu;Ge Hui;Guo Wei;Liu Dong;Cai Zongwei
二羟基化多溴联苯醚（diOH-PBDEs）似乎是某些海洋生物体内的天然产物或多溴联苯醚的代谢物，但其毒性仍在很大程度上未知。本研究首次比较了6-羟基-2，2 ′，4 ′4′-四溴二苯醚（6-OH-BDE-47）和6，6 ′-二羟基-2，2 ′，4 ′4′-四溴二苯醚（6，6 ′-diOH-BDE-47）对斑马鱼幼鱼的急性毒性、蓄积和甲状腺激素水平。利用真实的时间PCR技术，对受精后96 h（96 hpf）发育中的仔鱼进行了下丘脑-垂体-甲状腺轴相关基因的转录检测。显然，6，6 ′-diOH-BDE-47的毒性低于6-OH-BDE-47：6-OH-BDE-47和6，6 ′-diOH-BDE-47的96小时半致死浓度分别为235 nM和516 nM; 2）虽然在高暴露剂量下观察到斑马鱼幼体严重的发育迟缓和形态畸形，在接触浓度为1-50 nM时，在处理过的幼虫中，6-OH-BDE-47和6，6 ′-diOH-BDE-47的累积量介于226-2279 nmol/g和123-539 nmol/g之间; 6-OH-BDE-47的生物浓缩系数（BCF）是6，6 ′-diOH-BDE-47的1.83 ~ 4.30倍，表明6，6 ′-diOH-BDE-47的内接触浓度较低，毒性较低。1 nM的6-OH-BDE-47和20 nM的6，6 ′-diOH-BDE-47会导致甲状腺激素水平升高，这两种接触都会显著增加甲状腺特异性的甲状腺球蛋白基因转录，表明与HPT轴相关的不利影响。因此，6，6 ′-diOH-BDE-47虽然毒性低于6-OH-BDE-47，但仍具有一定的危害和环境风险。
Dihydroxylated polybrominated diphenyl ethers (diOH-PBDEs) appear to be natural products or metabolites of PBDEs in some marine organisms, yet its toxicity is still largely unknown. With a newly lab-synthesized diOH-PBDE, 6,6′-dihydroxy-2,2′,4′4′-tetrabromodiphenyl ether (6,6′-diOH-BDE-47) in hand, the present study has provided the first data set to compare 6-hydroxy-2,2′,4′4′- tetrabromodiphenyl ether (6-OH-BDE-47) and 6,6′-diOH-BDE-47 for their acute toxicity and accumulation, and thyroid hormone levels in treated zebrafish larvae. By real time-PCR technique, transcripts of hypothalamic-pituitary-thyroid axis associated genes were also investigated in developing larvae at 96 h post fertilization (96 hpf). Apparently, 6,6′-diOH-BDE-47 was less toxic than that of 6-OH-BDE-47: 1) the 96-h LC50(96-h median lethal concentration) of 6-OH-BDE-47 and 6,6′-diOH-BDE-47 were 235 nM and 516 nM, respectively; 2) although severe developmental delays and morphological deformities were observed in zebrafish larvae in high exposure doses, at the exposure concentration of 1–50 nM, the accumulated 6-OH-BDE-47 and 6,6′-diOH-BDE-47 is ranged between 226–2279 nmol/g and 123–539 nmol/g in treated larvae; and 3) for 6-OH-BDE-47, its bioconcentration factor (BCF) were 1.83- to 4.30-fold more than that of 6,6′-diOH-BDE-47, suggesting that the lower internal exposure concentration of 6,6′-diOH-BDE-47 may lead to lower toxicity. The increased thyroid hormone levels were recorded for 1 nM of 6-OH-BDE-47 and 20 nM of 6,6′-diOH-BDE-47, and the exposures both significantly increased thyroid gland-specific transcription of thyroglobulin gene, indicating an adverse effect associated with the HPT axis. Therefore, 6,6′-diOH-BDE-47, with lower toxicity compared to that of 6-OH-BDE-47, still possesses hazards and environmental risk.