Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China.
Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China.
Sci Total Environ. 2019 Jan 10;647:992-999. doi: 10.1016/j.scitotenv.2018.08.099. Epub 2018 Aug 7.
With regulations on the manufacture and usage of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and related compounds, short-chain perfluoroalkyl acids (PFAAs) are increasingly being used as alternatives. However, there are limited studies on their bioaccumulation mechanisms, especially for short-chain PFAAs. In this study, we examined the binding affinity of PFAAs with fish serum proteins and tissue distributions of perfluoroalkyl carboxylates (C7-C11 PFCAs) and perfluoroalkyl sulfonates (C4, C6, and C8 PFSAs) in carp (Cyprinus carpio), including the isomers of PFOS and perfluorohexane sulfonate (PFHxS). For both PFCAs and PFSAs, the fish serum protein binding constant (K) and bioconcentration factor (BCF) increased with an increase in the carbon chain length. PFHxS (C6 PFSA) had a much higher K but displayed a much lower BCF than those of C7-C11 PFCAs. It indicated that not only fish blood proteins, but also other proteins in the liver and kidney, mediated the accumulation of PFAAs in fish. The lowest concentration ratios of PFHxS in liver to blood and in kidney to blood suggested that it could not be effectively transported to liver and kidney by fatty acid binding proteins and organic anion transporters. PFOS and PFHxS displayed different elimination pathways, although their linear (n-) isomers were accumulated more in fish than the corresponding branched (br-) isomers. The n-PFOS was eliminated more via the feces but br-PFOS was eliminated more via the urine; while the opposite trend was observed for PFHxS isomers.
随着关于全氟辛烷磺酸（PFOS）和相关化合物以及 全氟辛酸（PFOA）制造和使用的法规的出台，短链全氟烷基酸（PFAAs）作为替代品被越来越多地使用。然而，关于它们的生物积累机制，特别是对于短链 PFAAs，研究有限。在这项研究中，我们研究了 PFAAs 与鱼类血清蛋白的结合亲和力，以及在鲤鱼（Cyprinus carpio）中全氟烷基羧酸（C7-C11 PFCAs）和全氟烷基磺酸盐（C4、C6 和 C8 PFSAs）的组织分布，包括 PFOS 和全氟己烷磺酸盐（PFHxS）的异构体。对于 PFCAs 和 PFSAs，鱼血清蛋白结合常数（K）和生物浓缩因子（BCF）均随碳链长度的增加而增加。PFHxS（C6 PFSA）的 K 高得多，但 BCF 比 C7-C11 PFCAs 低得多。这表明不仅鱼类血液中的蛋白质，而且肝脏和肾脏中的其他蛋白质，也介导了 PFAAs 在鱼类中的积累。PFHxS 在肝脏与血液以及肾脏与血液中的浓度比最低，表明它不能被脂肪酸结合蛋白和有机阴离子转运蛋白有效地转运到肝脏和肾脏。PFOS 和 PFHxS 显示出不同的消除途径，尽管它们的线性（n-）异构体比相应的支链（br-）异构体在鱼类中积累更多。n-PFOS 更多地通过粪便排出，但 br-PFOS 更多地通过尿液排出；而对于 PFHxS 异构体则观察到相反的趋势。
