Toxicokinetics of PCDD, PCDF, and Coplanar PCB Congeners in Baikal Seals, Pusa sibirica: Age-Related Accumulation, Maternal Transfer, and Hepatic Sequestration
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- 作者：Hisato Iwata ; Mafumi Watanabe ; Yuka Okajima ; Shinsuke Tanabe ; Masao Amano ; Nobuyuki Miyazaki ; and Evgeny A. Petrov
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：July 1, 2004
- 年：2004
- 卷：38
- 期：13
- 页码：3505 - 3513
- 全文大小：168K
- 年卷期：v.38,no.13(July 1, 2004)
- ISSN：1520-5851
文摘
To assess the toxicokinetic behavior and potential toxicityof polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinateddibenzofurans (PCDFs), and coplanar polychlorinatedbiphenyls (PCBs) in Baikal seals, congener-specific levelsand tissue distribution were evaluated in the liver andblubber, and the effects of biological factors including sexand growth were assessed. Total 2,3,7,8-TCDD toxicequivalents (TEQs) were in the range of 210-920 pgTEQ/gfat wt (180-800 pgTEQ/g wet wt) in the blubber and 290-7800 pgTEQ/g fat wt (10-570 pgTEQ/wet wt) in the liver. Non-ortho coplanar PCB126 was the most TEQ-contributedcongener accounting for 37-59% of the total TEQs in theliver. From the unique congener profiles, weak metabolicproperties of Baikal seals for 2,3,7,8-TCDF and 1,2,3,7,8-P5CDF are suggested. Concentrations of most congenerslinearly increased with age in male seals, whereas in adultfemales the levels revealed an age-related decline. Theincreasing and declining rates were congener-specific.Maternal transfer rates of 5 representative congeners fromadult female to pup through lactation, which was estimatedfrom male-female differences in the body burden, was1.1 ngTEQ/kg/day for the first pup and decreased with everylactational epoch. The liver-blubber distribution of 1,2,3,4,7,8-H6CDD, 1,2,3,6,7,8-H6CDD, PCB81, PCB126, and PCB169was dependent on the hepatic total TEQ, indicating hepaticsequestration by induced cytochrome P450 (CYP). Theseresults indicate that congener profile in Baikal seals isgoverned by complex factors including sex, tissueconcentration, binding to CYP, and rates of absorptionand metabolism/excretion.