Biotransformation of polychlorinated biphenyls (PCBs) and bioformation of hydroxylated PCBs in fish
Document Type
Article
Publication Date
6-15-2006
Publication Title
Aquatic Toxicology
Volume
78
Issue
2
First Page
176
Keywords
Chiral, CYP2B-like, Metabolites, Rainbow trout
Last Page
185
Abstract
Hydroxylated PCBs (OH-PCBs) are a class of organic contaminants that have been found recently in the plasma of Great Lakes fish, the source of which is either bioformation from PCBs or accumulation from the environment. To address the potential for fish to biotransform PCBs and bioform OH-PCBs juvenile rainbow trout (Oncorhynchus mykiss; ∼80 g) were exposed to dietary concentrations of an environmentally relevant mixture of PCBs. Eight OH-PCBs were found in the plasma of rainbow trout after 30 days of exposure to the PCBs, the relative pattern of which was similar to those observed in wild lake trout (Salvelinus namaycush) from Lake Ontario. Hydroxylated-PCBs were not found (detection limit 0.02 pg/g) in the food or control (not PCB-exposed) fish. A curvilinear log t1/2-log Kow relationship for recalcitrant PCBs was found, similar to previously reported relationships, although t1/2 values were longer and shorter than studies using smaller fish or cooler temperatures, respectively. A number of PCB congeners fell below the log t1/2-log Kow relationship providing the first estimates of non-chiral PCB biotransformation rates in fish. Enantioselective degradation of the chiral congeners PCBs 91 and 136, also indicated biotransformation. Biotransformation of PCBs was structure-dependent with greater biotransformation of PCBs with vicinal hydrogen atoms in the meta/para positions, suggesting CYP 2B-like biotransformation. Other chiral congeners with a meta/para substitution pattern showed no enantioselective degradation but were biotransformed based on the log t1/2-log Kow relationship. The results of this study demonstrate that laboratory held rainbow trout can biotransform a number of PCB congeners and that bioformation is likely an important source of OH-PCBs in wild salmonids of the Great Lakes. © 2006 Elsevier B.V. All rights reserved.
DOI
10.1016/j.aquatox.2006.02.033
ISSN
0166445X
Recommended Citation
Buckman, Andrea H.; Wong, Charles S.; Chow, Elaine A.; Brown, Scott B.; Solomon, Keith R.; and Fisk, Aaron T.. (2006). Biotransformation of polychlorinated biphenyls (PCBs) and bioformation of hydroxylated PCBs in fish. Aquatic Toxicology, 78 (2), 176-185.
https://scholar.uwindsor.ca/glierpub/421
PubMed ID
16621064