Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, P.O. Box 8888, Succursale Centre-ville, Montreal, QC, Canada H3C 3P8.
Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, P.O. Box 8888, Succursale Centre-ville, Montreal, QC, Canada H3C 3P8.
Environ Res. 2018 May;163:108-114. doi: 10.1016/j.envres.2018.01.001. Epub 2018 Feb 22.
Studies have shown that debromination of the major component in the deca-brominated diphenyl ether mixture (deca-BDE), BDE-209, occurs in vivo in birds. Recent work from our laboratory on breeding ring-billed gulls (Larus delawarensis) exposed to elevated PBDE concentrations in the densely-populated metropolis of Montreal (Canada) further suggests that BDE-209 debromination is potentially catalyzed by deiodinases in liver microsomes. The first objective of this study was to determine if type 1 deiodinase (D1) was involved in the in vitro debromination of BDE-209 in liver microsomes of ring-billed gulls. The second objective was to determine if there was an interaction between D1 and BDE-209 using an in vitro D1 activity assay. No depletion of BDE-209 was observed in gull liver microsomes. A significant 42% increase in total D1 activity was found in gull liver microsomes at the medium BDE-209 concentration (1.0 nM), although not at the low (0.5 nM) or high (2.5 nM) concentrations, suggesting potential non-dose related interaction with D1. Moreover, no correlation was found between total D1 activity in liver microsomes and plasma thyroid hormone levels, although there was a negative relationship between plasma BDE-209 concentrations and FT levels. Results from this study suggest that debromination of BDE-209 did not occur using present in vitro assay conditions, although indicated potential interaction with D1 that may have implication on circulating thyroid hormone status.
研究表明，十溴二苯醚混合物（十溴二苯醚）中的主要成分 BDE-209 在鸟类体内会发生脱溴反应。我们实验室最近对在人口密集的加拿大蒙特利尔市暴露于高浓度多溴二苯醚的圈养环嘴鸥（Larus delawarensis）进行的研究进一步表明，BDE-209 的脱溴反应可能是由肝微粒体中的脱碘酶催化的。本研究的第一个目的是确定 1 型脱碘酶（D1）是否参与了环嘴鸥肝微粒体中 BDE-209 的体外脱溴反应。第二个目的是使用体外 D1 活性测定来确定 D1 和 BDE-209 之间是否存在相互作用。在环嘴鸥的肝微粒体中没有观察到 BDE-209 的耗尽。在中浓度 BDE-209（1.0 nM）下，发现环嘴鸥肝微粒体中的总 D1 活性显著增加了 42%，尽管在低浓度（0.5 nM）或高浓度（2.5 nM）下没有增加，这表明与 D1 存在潜在的非剂量相关相互作用。此外，肝微粒体中的总 D1 活性与血浆甲状腺激素水平之间没有相关性，尽管血浆 BDE-209 浓度与 FT 水平之间存在负相关关系。本研究结果表明，在目前的体外测定条件下，BDE-209 没有发生脱溴反应，尽管表明与 D1 存在潜在的相互作用，这可能对循环甲状腺激素状态有影响。
