Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, Huazhong Agricultural Universit y, Wuhan 430070, China.
Environ Sci Technol. 2011 Nov 15;45(22):9750-7. doi: 10.1021/es202420g. Epub 2011 Oct 21.
The teleost gas bladder is a gas-filled internal organ that processes gas exchange and controls buoyancy. Here we report that an emerging heterocyclic brominated flame retardant, tris(2,3-dibromopropyl) isocyanurate (TBC), causes defects in the inflation of the gas bladder of zebrafish larvae. This could cause impaired motility, which can ultimately lead to their death. Exposure to zebrafish embryos revealed that TBC had the most significant influence on the larvae at 72-96 h postfertilization, which coincided with the time that the gas bladder first inflates. Critical factors involved in early zebrafish gas bladder development remained at normal levels, which indicated that TBC caused defects in the inflation of the gas bladder without disrupting early organogenesis. However, the ultrastructure of the gas bladder was altered in the TBC-treated groups: the electron density of cytoplasmic vesicles was changed and the mitochondria were damaged. We deduce that TBC causes damage to mitochondria that influences the secretion of mucus-like material, resulting in defects in gas bladder inflation. For the first time, we report that the gas bladder could be a primary target organ for TBC, and assessment of the gas bladder should be included in toxicity testing protocols of zebrafish embryos.
硬骨鱼的鳔是一个充满气体的内部器官，它处理气体交换和控制浮力。在这里，我们报告说，一种新兴的杂环溴化阻燃剂三（2,3-二溴丙基）异氰尿酸酯（TBC）会导致斑马鱼幼虫鳔充气缺陷。这可能导致运动能力受损，最终导致它们死亡。对斑马鱼胚胎的暴露表明，TBC 在受精后 72-96 小时对幼虫的影响最大，这与鳔第一次充气的时间相吻合。早期斑马鱼鳔发育中涉及的关键因素仍保持正常水平，这表明 TBC 导致鳔充气缺陷而不破坏早期器官发生。然而，TBC 处理组的鳔的超微结构发生了改变：细胞质囊泡的电子密度发生改变，线粒体受损。我们推断，TBC 对线粒体造成损伤，影响黏液样物质的分泌，导致鳔充气缺陷。我们首次报道鳔可能是 TBC 的主要靶器官，在评估斑马鱼胚胎毒性时，应包括对鳔的评估。
