Environ. Sci. Technol. 2010, 44, 5781–5786
Tissue Concentrations of
Polybrominated Compounds in
Chinese Sturgeon (Acipenser
sinensis): Origin, Hepatic
Sequestration, and Maternal
Transfer
KUN ZHANG,† YI WAN,‡
J O H N P . G I E S Y , ‡,§,|
MICHAEL H. W. LAM,| STEVE WISEMAN,‡
P A U L D . J O N E S , ‡ A N D J I A N Y I N G H U * ,†
Laboratory for Earth Surface Processes, College of Urban and
Environmental Sciences, Peking University, Beijing 100871, China,
Department of Veterinary Biomedical Sciences and Toxicology
Centre, University of Saskatchewan, Saskatoon,
Saskatchewan, S7J 5B3, Canada, Zoology Department, Center
for Integrative Toxicology, Michigan State University, East
Lansing, Michigan 48824, and Department of Biology and
Chemistry, and State Key Laboratory in Marine Pollution, City
University of Hong Kong, Kowloon, Hong Kong SAR, China
Received January 31, 2010. Revised manuscript received
June 3, 2010. Accepted June 29, 2010.
Information on concentrations of polybrominated compounds
in various tissues of wild fish is limited. Concentrations of
polybrominated diphenyl ethers (PBDEs), methoxylated PBDEs
(MeO-PBDEs), and hydroxylated PBDEs (OH-PBDEs) were
measured in 12 organs and eggs of 17 female Chinese sturgeon
(Acipenser sinensis). The highest concentrations of PBDEs
(42.8 ( 39.4 ng/g ww), and MeO-PBDEs (135 ( 63.6 pg/g ww)
occurred in adipose followed by liver (PBDEs: 25.0 ( 27.0
ng/g ww, MeO-PBDEs: 32.3 ( 29.1 pg/g ww) and eggs (PBDEs:
21.2 ( 19.4 ng/g ww, MeO-PBDEs: 120 ( 119 pg/g ww), and
the highest concentration of OH-PBDEs was observed in liver
(185 ( 174 pg/g ww) and eggs (178 ( 294 pg/g ww). The
lack of in vitro transformation of 6-MeO-BDE47 or BDE47 by
microsomes prepared from Chinese sturgeon liver suggests that
most 6-OH-BDE47 was directly accumulated as a natural
product. Lipid-normalization revealed preferential accumulation
of PBDEs in liver, and ratios of concentrations between eggs
and liver were 0.10 ( 0.11 to 0.22 ( 0.26, which was lower than
that for MeO-PBDEs (6-MeO-BDE47: 0.57 ( 0.60, 2′-MeOBDE68: 0.65 ( 0.85) and 6-OH-BDE47 (0.59 ( 0.51). Concentrations
of PBDEs were negatively correlated with age, but no
significant relationships between concentrations of OH-PBDEs
or MeO-PBDEs and age were observed.
Introduction
Polybrominated diphenyl ethers (PBDEs) are a class of flame
retardants used in a wide range of products such as textiles,
* Corresponding author tel and fax: 86-10-62765520; e-mail:
hujy@urban.pku.edu.cn.
†
Peking University.
‡
University of Saskatchewan.
§
Michigan State University.
|
City University of Hong Kong.
10.1021/es100348g
 2010 American Chemical Society
Published on Web 07/07/2010
construction materials, and electronic equipment (1). Environmental occurrences (2–4), fates (5), and toxicities of
PBDEs (6–9) have been reported. Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are also toxic (10).
The presence of OH-PBDEs in wildlife and humans is of
concern due to their higher toxic potencies relative to PBDEs
and MeO-PBDEs (11). Some OH-PBDEs bind to human
transthyretin with affinities 3-fold higher than the natural
ligand thyroxine (T4) (12). Some OH-PBDEs such as 4′-OHBDE17 can displace 17-β estradiol (E2) from the estrogen
receptor (ER)-R with a relative estrogenic potency approximately 30% higher than that of E2 (13).
OH-PBDEs have been reported to originate from both
anthropogenic and natural sources. They have been reported
to be transformed from PBDEs by female Sprague-Dawley
rats (14) or from MeO-PBDEs by rainbow trout, chicken, and
rat microsomes (15). OH-PBDEs and MeO-PBDEs have also
been reported to be synthesized by marine organisms such
as algae and sponges or their associated microorganisms
(16, 17). There are reports that OH-PBDE can be formed in
vitro and in vivo from PBDE, but the literature is ambivalent
with some authors reporting transformation while others
did not observe transformation. The proportions transformed
are small even when exposures were large (5, 15, 18, 19).
Purity of the exposure mixtures is always an issue in these
sorts of studies and the reported formation of OH-BDEs and
MeO-BDE from PBDE may be an artifact. When the precursor
materials were confirmed to not contain OH-BDE or MeOBDE no transformation was observed (15, 18). OH-PBDEs
and MeO-PBDEs have been reported in many aquatic
organisms including marine and freshwater fish, birds, and
higher trophic level organisms such as marine mammals
including beluga whales, ringed seals, and polar bears (20–22).
However, information on concentrations of OH-PBDEs and
MeO-PBDEs is mainly restricted to blood, adipose, and liver
of wildlife. There have been few studies of the toxicokinetics
of OH-PBDEs, MeO-PBDEs, and PBDEs (23, 24), which could
help clarify the tissue concentration, maternal transfer, and
age-related accumulation of these polybrominated compounds in organisms and help identify possible target organs
to guide monitoring and studies of toxicity.
For oviparous organisms, such as some fish, transfer of
hydrophobic chemicals from females to eggs along with yolk
proteins is a pathway of exposure of eggs (25). Organisms
usually exhibit higher sensitivity to pollutant exposure during
early life stage than adult life stages (26, 27), and various
effects of polybrominated compounds on embryos have been
reported. Exposure of zebrafish embryos to BDE47 resulted
in development of morphological, cardiac, and neural deficits
(7). Bromkal 70-DE, a commercial mixture containing
predominantly BDE47, 99, and 100, delayed and altered
activity level, fright response, predation rates, and learning
ability in subsequent life stages (8). Exposure of zebrafish
embryos to 6-OH-BDE47 caused a wide range of developmental defects, including pericardial edema, yolk sac deformations, reduced pigmentation, and lowered heart rate
as well as delayed development, with an EC50 value of 25 nM
(28).
The Chinese sturgeon (Acipenser sinensis) is a predatory
fish that can live for 40 years or longer and weigh as much
as 500 kg (29). Previous studies have shown that Chinese
sturgeon can be exposed to pollutants and accumulate
especially high concentrations into their eggs (27, 30). In this
study, concentrations of 9 OH-PBDEs, 12 MeO-PBDEs, and
11 PBDEs were measured in thirteen organs, including 8
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liver, 8 muscle, 6 heart, 7 gonad, 5 stomach, 7 intestine, 5
adipose, 6 gill, 2 pancreas, 1 kidney, 1 gallbladder, 1 spleen,
and 15 egg samples from 17 Chinese sturgeon. Tissuedependent accumulations of the three classes of compounds
were examined and hepatic sequestration and maternal
transfer rates were calculated. Finally, age-related accumulation was compared among PBDEs, OH-PBDEs, and
MeO-PBDEs.
Materials and Methods
Sample Collection. Because the Chinese sturgeon has been
listed as a grade I protected animal in China since the 1980s,
the capture of Chinese sturgeon was authorized strictly for
scientific purposes only. Artificial propagation has been
implemented to save this endangered species. This program
captures adult Chinese sturgeon from the Yangtze River.
Chinese sturgeon migrate from the East Sea and spend
approximately one year in the river before spawning. After
propagation, sturgeon were released back into the Yangtze
River, but some did not survive. Eggs were collected before
propagation and the other organs and tissues came from the
17 sturgeon that died during artificial propagation in the
period between 2003 and 2006. To avoid contamination of
stomach and intestine with gut contents, only the inner layer
of the stomach and intestine were collected. This was possible
because of their large body size and because the muscle
layer of the stomach and intestine are very thick. After
collection, tissues were frozen immediately at -20 °C until
analysis. The ages of fish were determined by counting growth
layers in the cleithrum, as described previously (29). The
total number of sturgeon samples was 72, and the detailed
information about the samples is given in Supporting
Information Table S1.
In Vitro Microsomal Incubations. Microsomes were
isolated from cultured two-year-old Chinese sturgeon, according to the method improved by Benedict et al. (31) and
included dithiothreitol (DTT) in the homogenization, wash
and resuspension buffers to preserve catalytic activity of
reductases and deiodinases. Ethoxyresorunfin O-deethylase
(EROD) activity and protein content of microsomes were
determined simultaneously by use of a fluorescence kit
(Genmed Scientific Inc., USA). The final reaction volume
was 100 µL and contained either 50 µL of the microsomal
preparation and 3 µL of exposure chemicals. Individual
congeners (BDE47, BDE99, BDE154, BDE183, and 6-MeOBDE47) were used, and the concentration in the incubation
mixture was 150 ng/mL. The protein concentration in the
reaction vial was 5.2 mg/mL and the CYP1A1-catalyzed EROD
activity was 3.5 pmol/mg/min. Reactions were performed at
37 °C for 20 h with constant agitation. Incubations without
chemicals and without microsomes were used as negative
controls to assess background contaminants and the possibility of nonenzyme-mediated changes in chemical structure. After the incubation, the samples were extracted
immediately for chemical analysis.
Quantification of Target Analytes and Transformation
Products in Tissues and Microsomes. The method used to
quantify PBDEs, OH-PBDEs, and MeO-PBDEs has been
described previously (15) and details specific to this study
are given in Supporting Information.
Quality Assurance and Quality Control (QA/QC). Details
of the QA/QC of the method have been described previously
(15). Concentrations of all congeners were quantified by the
internal standard isotope-dilution method with mean relative
response factors determined from standard calibration runs.
PBDEs and MeO-PBDEs were quantified in sample extracts
relative to 13C-PBDEs, and OH-PBDEs were quantified relative
to 6′-OH-BDE17. Recoveries of 13C-PBDEs and 6′-OH-BDE17
were 74.9 ( 38.8% to 130 ( 60.0% and 98.5 ( 33.7%,
respectively. All equipment rinses were carried out with
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FIGURE 1. Concentrations of ΣOH-PBDEs, ΣMeO-PBDEs, and
ΣPBDEs in tissues of Chinese sturgeon. Due to the limited
number of samples, kidney, spleen, and gallbladder are not
presented. The horizontal line represents the median
concentration. The 25th and 75th percentiles define the boxes
and the whiskers represent the 10th and 90th percentiles. Of
the five stomach samples, concentrations of PBDEs in one
sample exceeded three times the standard deviation so that
data point was not included in calculating the median.
acetone and hexane to avoid sample contamination. A
laboratory blank was incorporated in the analytical procedures for every batch of 12 samples. The method detection
limits (MDLs) were set to be the mean of the concentration
plus three times the standard deviation in the blank samples
in which BDE28, BDE47, BDE85, BDE154, BDE153, and
BDE138 were detected. The MDLs for the other compounds,
which were not detected in blank samples, were set to the
instrumental minimum detectable amounts. Based on an
average sample with a wet mass of 10 g, the detection limits
were 0.4 pg/g ww for MeO-PBDEs; 2.0 pg/g ww for 2′-OH6′-Cl-BDE7; 4.0 pg/g ww for 3-OH-BDE47, 5-OH-BDE47,
2′OH-BDE68, 6-OH-BDE47, 4′-OH-BDE49, 2′-OH-6′-ClBDE68, 6-OH-BDE90, and 2-OH-BDE123; 1.6 pg/g ww for
BDE28; 26.8 pg/g ww BDE47; 48.8 pg/g ww for BDE85; 22.4
pg/g ww for BDE154; 3.2 pg/g ww for BDE153; 11.2 pg/g ww
for BDE138; and 0.4 pg/g ww for BDE66, BDE77, BDE100,
BDE99, and BDE183. Purity of stock chemicals was checked
by measuring, and concentrations of potential transformation
products in stocks were determined by quantification of
concentrated standards.
Statistical Analysis. In this study, for those results lower
than the MDL, half of the MDL was assigned to avoid missing
values in statistical analyses. The average liver/adipose and
egg/liver ratios calculated on a lipid weight basis were
calculated for individual PBDE and MeO-PBDE congener
and the egg/liver ratios base on wet weight was calculated
for the 6-OH-BDE47 in Chinese sturgeon. All data analyses
such as linear regression were performed with SPSS 15.0.
Statistical significance was defined as p < 0.05.
Results and Discussion
Concentrations among Tissues. Higher concentrations of
ΣPBDEs were observed in adipose (42.8 ( 44.0 ng/g ww),
liver (25.0 ( 27.0 ng/g ww), and eggs (21.2 ( 19.4 ng/g ww)
(Figure 1). Detailed information on concentrations of PBDEs,
OH-PBDEs, and MeO-PBDEs in tissues of 17 Chinese sturgeon
are shown in Supporting Information Tables S2 and S3.
Concentrations of ΣPBDEs in eggs of Chinese sturgeon (21.3
( 19.4 ng/g ww) were higher than those of sturgeons from
Azerbaijan (Acipenser Huso huso), Bulgaria (Acipenser gueldenstaedti), and Russia (Acipenser stellatus) (0.010-0.27 ng/g
ww) (32). Concentrations of PBDEs in skipjack tuna from the
East China Sea were relative high compared to other areas
of the world (33). This is consistent with the concentrations
of PBDEs observed in the Chinese sturgeon which is an
anadromous fish that spends its first 14 years of life in the
East China Sea (29).
The highest concentrations of MeO-PBDEs were found
in adipose (135 ( 63.6 pg/g ww), eggs (120 ( 119 pg/g ww),
and liver (32.3 ( 29.1 pg/g ww). Concentrations of 6-MeOBDE47 in liver of Chinese sturgeon were lower than those in
beluga whales from Eastern Hudson Bay and the Hudson
Strait (34) and in tuna (Katsuwonus pelamis) from the North
Pacific Ocean (15).
Both PBDEs and MeO-PBDEs were preferentially accumulated in organs with higher lipid contents such as
adipose (65.9 ( 13.8%), egg (35.1 ( 8.5%), and liver (12.7 (
6.6%). When concentrations of PBDEs and MeO-PBDEs were
expressed on a lipid weight basis, differences in concentrations among tissues were less (Supporting Information Figure
S1). But, concentrations of PBDEs were still higher in liver
(157 ( 114 ng/g lw) than in other tissues, which suggests that
the lipid of tissues is not the sole factor influencing the tissue
concentrations of PBDEs in Chinese sturgeon.
The highest concentrations of OH-PBDEs occurred in liver
(185 ( 174 pg/g ww) and eggs (178 ( 294 pg/g ww).
Concentrations of 6-OH-BDE47, a major congener of OHPBDEs, in liver (166 ( 182 pg/g ww) of Chinese sturgeon
were higher than those (17.8-44.0 pg/g ww) in liver of tuna
(Katsuwonus pelamis) collected from the North Pacific Ocean
(15). The tendency of OH-PBDEs to associate with liver may
be due to their biotransformation formation in this tissue
and/or competitive binding to the major thyroid hormone
transport protein (TTR) (12), which is mainly produced and
expressed in liver (35). Among target tissues, gonad and heart
could be classified as richly perfused tissues, and adipose
and muscle as poorly perfused tissues (36). Concentrations
of OH-PBDEs in two richly perfused tissues (gonad: 42.8 (
39.4 pg/g ww, heart: 46.1 ( 26.5 pg/g ww) were higher than
those in poorly perfused tissues (adipose: 35.0 ( 40.1 pg/g
ww, muscle: 11.1 ( 14.3 pg/g ww). This observation indicates
that blood flow could be an important factor to influence the
tissue concentrations of OH-PBDEs. OH-PBDEs have been
shown to bind competitively to TTR leading to their accumulation in blood (12, 37).
Relatively high concentrations of PBDEs (28.5 ng/g ww,
n ) 1) and OH-PBDEs (138 pg/g ww) were observed in gall
bladder. This indicates possible preferential disposition of
PBDEs and OH-PBDEs in bile, which could facilitate excretion
of these compounds from Chinese sturgeon.
Patterns of Relative Concentrations. All of identifiable
tri- to hepta-BDE congeners (BDE28, 47, 66, 77, 99, 100, 85,
153, 154, and 183) were detected, and the patterns of relative
concentrations were similar among tissues except for stomach (Figure 2). BDE47 (52.5 ( 13.8%) was the predominant
congener, followed by BDE154 (16.7 ( 8.4%), BDE100 (12.2
( 2.8%), BDE28 (6.1 ( 2.1%), BDE153 (4.1 ( 2.3%), and BDE99
(2.4 ( 2.2%). In the stomach, the profile of PBDEs was
dominated by BDE183, accounting for 27.7 ( 27.5%, which
is largely different from those in the extra-hepatic tissues.
While such a different pattern observed in stomach could be
attributed to the molecule size of BDE183, which makes it
difficult to pass through the stomach wall or intestines into
the bloodstream and further to other tissues (38), an exposure
experiment with Juvenile lake trout (Salvelinus namaycush)
showed that the assimilation efficiency of BDE183 (22.8%)
was similar to those of BDE153 (33.3%), BDE 154 (47.0%),
BDE47(21.8%), BDE99(31.3%), and BDE100 (41.9%) (39).
Thus, the most likely explanation for the concentration of
BDE 183 observed in other organs would be biotransformation. To better understand the potential biotransformation
of BDE183 in Chinese sturgeon, in vitro studies of BDE183,
BDE154, and BDE99 were conducted in microsomal fractions
of Chinese sturgeon liver (Supporting Information Table S4).
FIGURE 2. Relative contribution (%) of seven major PBDE
congeners (% congener contribution on a mass per mass basis)
in tissues of Chinese sturgeon.
After a 20-h exposure, 94 ( 1% of BDE183 and 78 ( 1% of
BDE99 were biotransformed while concentrations of BDE154
were comparable to the starting concentrations indicating
that BDE183 is readily metabolized in Chinese sturgeon. A
significant amount of BDE154 was formed by conversion of
BDE183 (73 ( 1.2%), while BDE47 was formed from BDE99
(52 ( 2%). This result demonstrated that part of the BDE99
and BDE183 were transformed to unquantified products or
becoming unextractable. This result is similar to those
observed when common carp (Cyprinus carpio) were exposed
to BDE99 and BDE183 (40). Thus, it is likely that biotransformation was responsible for the relatively large BDE183/
154 and BDE99/47 ratios in stomach and intestine relative
to other tissues (Supporting Information and Figure 2).
Furthermore, application of these two ratios can be used to
estimate the extent of biotransformation in other tissues.
Of the 11 MeO-PBDEs congeners monitored, 4-MeOBDE17, 2′-MeO-BDE68, 6-MeO-BDE47, 5-MeO-BDE47, and
5′-MeO-BDE100 were detected in eggs and liver, but their
concentrations were lower than the detection limit in
stomach, pancreas, and spleen. 6-MeO-BDE47 was the
predominant congener, followed by 2′-MeO-BDE68 (Supporting Information Table S3). A similar pattern of relative
concentrations was observed in organisms from the Canadian
Arctic marine food web and pike (Esox lucius) from the
Swedish coast (34, 41). Generally, MeO-PBDEs are detected
in marine organisms at concentrations sometimes higher
than those of PBDEs, and concentrations of OH-PBDEs are
lower than those of MeO-PBDEs (42–44). But in the tissue
samples of Chinese sturgeons, the concentration of MeOPBDEs was 100-1000 times lower than those of PBDEs and
comparable to those of OH-PBDEs. A recent study found
that concentrations (31 ng/g lw) of MeO-PBDEs in the
anadromous anchovy (Coilia nasus) from the Yangtze River
estuary were higher than those (9.1 and 14 ng/g lw) farther
upstream in the Yangtze River near the city of Nanjing (45).
The Chinese sturgeon is an anadromous fish in the Yangtze
River Basin. Chinese sturgeon were collected from their
spawning habitat in the middle-stem of the Yangtze River.
The fact that Chinese sturgeon may have been in the river
for as much as a year may have resulted in the lower
concentrations of OH-PBDE and MeO-PBDEs.
Of the 9 OH-PBDEs monitored, 2′-OH-BDE68, 6-OHBDE47, 5-OH-BDE47, and 4-OH-BDE49 were detected (Supporting Information Table S3). 6-OH-BDE47 was the predominant compound in all tissues. This result is similar to
the pattern observed in blood plasma of bottlenose dolphin
from Indian River Lagoon, Florida and fish collected from
the Detroit River and Hudson Bay region of northeastern
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FIGURE 3. Correlations among concentrations (pg/g ww) of PBDEs, OH-PBDEs, and MeO-PBDEs in eggs as a function of age.
Canada (21, 34, 43). Relatively high 6-OH-BDE47 concentrations and comparable 2′-OH-BDE68 concentrations were
detected in eggs. 5-OH-BDE47 and 4-OH-BDE49 with higher
frequencies of detection were observed in liver (Supporting
Information Table S3). It was reported that OH-PBDEs with
a hydroxyl moiety at the meta or para position have been
hypothesized to be biotransformation products of PBDEs
based on the results of in vivo exposures while OH-PBDEs
of natural origin all have a hydroxyl group at the ortho position
(14, 18). Since the hydroxyl groups in 5-OH-BDE47 and 4-OHBDE49 are at the meta and para positions, respectively, they
likely would originate from biotransformation of PBDEs in
liver rather than from accumulation of natural products (15).
2′-OH-BDE68 and 6-OH-BDE47 which have a hydroxyl group
at the ortho position would be derived from natural products.
There was a significant correlation between concentrations
of 6-OH-BDE47 and 6-MeO-BDE47 (R2 ) 0.534, p ) 0.003)
(Supporting Information Figure S3) in the eggs of Chinese
sturgeon. Such correlation was also observed in albatross
(Thalassarche chlororhynchos, Phoebetria palpebrata, Thalassarche chrysostoma, Thalassarche cauta, and Thalassarche
melanophrys), and polar bear (Ursus maritimus) (15). This
result suggested that 6-OH-BDE47 would be from metabolic
demethoxylation of MeO-PBDEs as demonstrated by a recent
study based on in vitro metabolism using rainbow trout
(Oncorhynchus mykiss), chicken (Gallus gallus), and rat
(Rattus norvegicus) microsomes (15). On the other hand,
6-OH-BDE47 has also been observed in rats exposed to BDE47
as metabolite (18). To further understand the origin of 6-OHBDE47 in Chinese sturgeon, in vitro metabolism of 6-MeOBDE47 and various PBDE individual congeners by microsomal fractions of Chinese sturgeon was conducted (Table S4
in Supporting Information). Concentrations of 6-OH-BDE47
were lower than the MDL when dosing with PBDEs and
6-MeO-BDE47 at concentration of 150 ng/mL. Considering
that 6-OH-BDE47 and 6-MeO-BDE47 have been reported in
the marine environment (from formation in algae/sponges)
and Chinese sturgeons spend most of their life in the sea, a
large proportion of 6-OH-BDE47 in Chinese sturgeons would
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result from direct bioaccumulation of OH-PBDEs from
natural sources.
Liver/Adipose Ratios. Ratios of lipid-normalized concentrations in liver and adipose (liver/adipose) have been
used as in some physiologically based pharmacokinetic (PBPK) models (46). The liver/adipose ratios based on lipid
normalized concentrations were 1.1 ( 1.0 for MeO-PBDEs
and 2.6 ( 1.7 for PBDEs, indicating preferential deposition
of PBDEs in liver. This result is similar to the hepatic
sequestration of PCDD/Fs that has been observed in birds
(47). Hepatic sequestration of PCDD/Fs is due to binding to
proteins such as cytochrome P450 (CYP) enzymes (48, 49)
via the aromatic hydrocarbon receptor (AhR) mediated
pathway. A statistically significant correlation (Supporting
Information Figure S4) was also observed between liver/
adipose ratios of individual PBDEs and their reported AhR
binding affinities (r 2 ) 0.934, p < 0.001), suggesting that AhR
might be involved in the hepatic sequestrations. However,
PBDEs are relatively weak AhR agonists relative to PCDD/Fs
or nonortho, 2,3,7,8-substituted, PCB (50, 51), the actual
mechanism(s) responsible for hepatic sequestrations of
PBDEs should be further studied.
Maternal Transfer of PBDEs to Eggs. Hydrophobic
chemicals can be transferred from the female to eggs along
with yolk proteins formed in the liver of the female parent
(25). Ratios of lipid-normalized concentrations of PBDEs and
MeO-PBDEs egg to those in liver (E/L) were used to assess
maternal transfer in Chinese sturgeon. Since lipid is not a
major factor affecting concentrations of OH-PBDEs in
different tissues, wet weight concentrations were used to
calculate egg to liver ratios. The E/L ratios of PBDEs ranged
from 0.10 ( 0.11 for BDE153 to 0.22 ( 0.26 for BDE28. Ratios
of 6-OH-BDE47 (0.59 ( 0.51), 6-MeO-BDE47 (0.57 ( 0.60),
and 2′-MeO-BDE68 (0.65 ( 0.85) were higher. Previous
investigations of maternal transfer of organochlorines in
Chinese sturgeon (30) provide an opportunity to compare
the E/L ratios of the polybrominated compounds with other
chemicals. The E/L ratios of PBDEs were low than those of
p,p-DDD (0.27 ( 0.15), p,p-DDE (0.30 ( 0.19), and HCB (0.98
( 0.46), but those of 6-OH-BDE47, 6-MeO-BDE47, and 2′MeO-BDE68 were higher than the E/L ratios of DDTs. It was
found that the more PBDEs were hepatic sequestrated in the
liver, the lower the ratio of E/L, indicating that hepatic
sequestration of PBDEs would affect their maternal transfer
in Chinese sturgeon.
Maternal transfer can influence accumulation of pollutants in females, and generally higher transfer ratios will result
in lower accumulation by females than males (52). While
there is no correlation between age and concentrations of
OH-PBDEs or MeO-PBDEs, the concentration of ΣPBDEs
significantly decreased with age (Figure 3a). As shown in
Figure 3b, c, and d the lipid normalized concentrations of
six major PBDEs congeners (BDE28, BDE47, BDE99, BDE100,
BDE153, and BDE154) also show a negative trend with age
of female Chinese sturgeon (p < 0.05 except for BDE99 and
BDE154, Supporting Information Table S5). This result is
different from those for DDE and HCB which were positively
correlated with age of Chinese sturgeon (30). A similar
negative correlation between concentrations of PBDEs with
age was observed in tissues of both male and female Harbour
seals (Phocoena phocoena) (53). Since maternal transfer ratios
(E/L) of HCB and DDE were higher than those of PBDEs,
maternal transfer would not be the primary factor resulting
in accumulation of PBDEs in Chinese sturgeon. The higher
metabolism of PBDEs such as BDE99 and 183 is a more likely
factor. In addition, rapid excretion could be another potential
factor since higher concentrations were observed in gall
bladder as discussed above.
Acknowledgments
Financial support for this study was obtained from the
National Basic Research Program of China (2007CB407304)
and the National Natural Science Foundation of China
(40632009). We thank Qiwei Wei, Yangtze River Fisheries
Research Institute, Chinese Academy of Fisheries Science,
Ministry of Agriculture of China, for providing samples of
eggs and tissues from Chinese sturgeon. Portions of this
research were supported by a Discovery Grant from the
National Science and Engineering Research Council of
Canada (Project 326415-07) and a grant from Western
Economic Diversification Canada (Projects 6578 and 6807).
J.P.G. was supported by the Canada Research Chair program
and an at large Chair Professorship at the Department of
Biology and Chemistry and State Key Laboratory in Marine
Pollution, City University of Hong Kong.
Supporting Information Available
Text, figures, and tables addressing (1) chemicals and
standards used in the analysis; (2) extraction and cleanup of
tissues; (3) instrumental conditions; (4) details of Chinese
sturgeon samples; (5) mean concentrations and ranges of
OH-PBDEs, MeO-PBDEs, and PBDEs in tissues of Chinese
sturgeon; (6) percentages of brominated compounds relative
to the dosing concentration after metabolism with Chinese
sturgeon microsomes exposed to PBDEs and 6-MeO-BDE47;
(7) association of concentrations of PBDE congeners with
age of Chinese sturgeon; (8) levels of MeO-PBDEs and ΣPBDEs
in various tissues in Chinese sturgeon after lipid normalization; (9) ratios of concentrations of BDE99 to BDE47 (BDE99/
47) and BDE183 to BDE154 (BDE183/154) in Chinese sturgeon
tissues; (10) relationships between the concentrations of
6-OH-BDE47 and the concentration of 6-MeO-BDE47; (11)
ratios of lipid-normalized ratio of concentration in liver to
that in adipose of Chinese sturgeon plotted versus Ah receptor
binding affinities. This material is available free of charge via
the Internet at http://pubs.acs.org.
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ES100348G
1
2
3
SUPPORTING INFORMATION
For:
Tissue concentrations of Polybrominated compounds in Chinese Sturgeon (Acipenser
4
sinensis): Origin, Hepatic Sequestration, and Maternal Transfer
5
Kun Zhang1, Yi Wan2, John P. Giesy2,3,4, Michael H. W. Lam4, Steve Wiseman2,
6
Paul D. Jones2, and Jianying Hu1*
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
1
Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences,
Peking University, Beijing 100871, China
2
Department of Veterinary Biomedical Sciences and Toxicology Centre, University of
Saskatchewan, Saskatoon, Saskatchewan, S7J 5B3, Canada
3
Zoology Department, Center for Integrative Toxicology, Michigan State University, East
Lansing, MI 48824, USA
4
Department of Biology and Chemistry, and State Key Laboratory in Marine Pollution, City
University of Hong Kong, Kowloon, Hong Kong SAR, China
Tables
Figures
5
4
Words
819
This supporting information provides detailed descriptions of chemicals and standards used in
22
the analysis, extraction and cleanup of tissue samples and instrument condition. Figures, and
23
tables addressing: details of Chinese sturgeon samples (Table S1); Mean concentrations and
24
ranges of OH-PBDEs and MeO-PBDEs in tissues of Chinese sturgeon (Table S2); Mean
25
concentrations and ranges of PBDEs in tissues of Chinese sturgeon (Table S3); Percentages of
26
brominated compounds relative to the dosing concentration after metabolism with Chinese
27
sturgeon microsomes exposed to PBDEs and 6-MeO-BDE47 (Table S4); Association of
28
concentrations of PBDE congeners with age of Chinese sturgeon (Table S5); Tissue
29
distribution of MeO-PBDEs and ∑PBDEs in Chinese sturgeon after lipid normalization
30
(Figure S1); Ratios of concentrations of BDE99 to BDE47 (BDE99/47) and BDE183 to
31
BDE154 (BDE183/154) in Chinese sturgeon tissues (Figure S2); Relationships between the
32
concentrations of 6-OH-BDE47 and the concentration of 6-MeO-BDE47 (Figure S3); Lipid
33
normalized liver to adipose concentration ratios in Chinese sturgeon plotted versus Ah
34
35
receptor binding affinities (Figure S4).
36
Chemicals and Standards. Eleven PBDEs (BDE28, BDE47, BDE66, BDE77, BDE100,
37
BDE99, BDE85, BDE154, BDE153, BDE138 and BDE183), twelve MeO-PBDEs
38
(6-MeO-BDE17,
39
4’-MeO-BDE49, 5’-MeO-BDE100, 4’-MeO-BDE103, 4’-MeO-BDE99, 4’-MeO-BDE101,
40
6-MeO-BDE90,
and
41
6-OH-BDE47,
3-OH-BDE47,
42
2’-OH-6’-Cl-BDE68, 6-OH-BDE90 and 2-OH-BDE123) were selected as target compounds.
43
PBDEs,
44
Laboratories
45
2’-OH-BDE68 were obtained from AccuStandard (New Haven, Connecticut, USA).
46
6-MeO-BDE17, 4-MeO-BDE17, 6-MeO-BDE90, 6-MeO-BDE85, 2’-OH-6’-Cl-BDE7,
47
6-OH-BDE47, 4’-OH-BDE49, 2’-OH-6’-Cl-BDE68, 6-OH-BDE90 and 2-OH-BDE123 were
48
synthesized in the Department of Biology and Chemistry, City University of Hong Kong, and
49
purities of all metabolites were >98%.
50
tert-butyl ether (MTBE), acetonitrile and methanol were pesticide residue grade obtained
51
from OmniSolv (EM Science, Lawrence, KS, USA). Sodium sulfate, silica gel (60-100
52
mesh size), aluminum oxide (neutral, 150 mesh size), pyridine (anhydrous, 99.8%), methyl
53
chloroformate (MCF), potassium hydroxide (KOH) and hydrochloric acid (HCl) were
54
purchased from Sigma-Aldrich (St. Louis, MO, USA).
55
fluorescence kit was obtained from (Genmed Scientific Inc, USA), sodium phosphate dibasic
56
(Na2HPO4), sodium phosphate monobasic (NaH2PO4) and potassium phosphate monobasic
57
(KH2PO4), resorufin, ethylenediaminetetraacetic acid (EDTA), and dithiothreitol (DTT) were
58
obtained from Sigma-Aldrich (St. Louis, MO, USA). All other biochemical reagents,
59
including NADPH, were obtained from Sigma-Aldrich and were reagent grade or better
60
unless stated otherwise.
13
4-MeO-BDE17,
2’-MeO-BDE68,
6-MeO-BDE85),
and
nine
5-OH-BDE47,
6-MeO-BDE47,
OH-PBDEs
5-MeO-BDE47,
(2’-OH-6’-Cl-BDE7,
2’-OH-BDE68,
4’-OH-BDE49,
C-PBDEs, and eight MeO-PBDEs standards were obtained from Wellington
Inc. (Guelph, Ontario, Canada).
3-OH-BDE47, 5-OH-BDE47 and
Dichloromethane (DCM), n-hexane, methyl
For biochemical analyses, the
61
Extraction and Cleanup of Tissue Samples Details of our methods for identifying and
62
quantifying PBDE, OH-PBDEs and MeO-PBDEs have been described previously (26).
63
Tissues were freeze-dried, then approximately 1-3 g dry weight (dw) subsamples were spiked
64
with a mixture of
65
13
66
accelerated solvent extraction (Dionex ASE-200, Sunnyvale, CA).
67
two 10 min cycles, the first cycle was performed with n-hexane/dichloromethane (DCM) (1:1)
68
at 100 °C and 1500 psi, followed by a second cycle with n-hexane/methyl tert-butyl ether
69
(MTBE) (1:1) at of 60°C and pressure of 1000 psi.
70
combined and rotary evaporated to near dryness.
71
glass tubes by 8 mL hexane, and 4 mL 0.5 M KOH in 50% ethanol was added.
72
layer (KOH) was extracted with 8 mL of n-hexane three times (neutral fraction).
73
extraction, 1.5 mL of 2 M HCl was added to 15 ml tubes and the phenolic compounds were
74
extracted with n-hexane/MTBE (9:1; v/v) three times (phenolic fraction).
13
C-labeled PBDE (13C-BDE28,
13
C-BDE47,
13
C-BDE99,
13
C-BDE100,
C-BDE153, 13C-BDE154 and 13C-BDE183) and 6-OH-BDE17 surrogates, and extracted by
The extraction employed
The two extraction fractions were
The extract was then transferred to 15 ml
The aqueous
After
75
The neutral fraction was concentrated to approximately 2 mL and loaded onto a column
76
of 1 g Na2SO4 and 8 g acidified silica (48% H2SO4) and eluted with 15 mL of n-hexane and
77
10 mL of DCM.
78
sulfate, 4 g of neutral alumina, 4 g of sodium sulfate).
79
alumina column with 20 mL of hexane was discarded.
80
PBDEs and MeO-PBDEs, was obtained by elution with 25 mL of 60% DCM in n-hexane.
81
The eluate was evaporated to dryness under a gentle stream of nitrogen, then 30 µl nonane
82
and 10 µl internal standards (13C-BDE138) were added for analysis of PBDEs and
83
MeO-PBDEs.
The eluate was further purified on a neutral alumina column (4 g of sodium
The first fraction eluted from the
The second fraction, which contained
84
After dried by a gentle stream of nitrogen, the phenolic fraction was re-dissolved in 480
85
µL of derivatization solvent (acetonitrile/methanol/water/pyridine (5:2:2:1; v/v/v/v)) and then
86
40 µL of methyl chloroformate (MCF) was added.
The reaction mixture was shaken on a
87
vortex at room temperature for 1 h and then diluted with 1.2 mL of pure water.
88
solution was extracted three times with 6 mL volumes of n-hexane.
89
concentrated and subjected to acidified silica gel chromatography as described above, eluted
90
with 30 mL of n-hexane and 30 mL of DCM. The eluate was concentrated to 40 µL for
91
OH-PBDE analysis.
The aqueous
Extracts were
92
Instrumental Conditions. Identification and quantification of PBDEs congeners were
93
performed using a Hewlett-Packard 5890 series II high-resolution gas chromatograph
94
interfaced to a Micromass® Autospec® high-resolution mass spectrometer (HRGC-HRMS)
95
(Micromass®, Beverly, MD).
96
capillary column (30 m length, 0.25 mm ID, 0.1 µm film thickness, Agilent, Carlsbad, CA).
97
A splitless injector was used and the injector was held at 285°C.
98
was 320°C, and ion temperature was 285°C.
99
ionization energy was 37 eV and the ion current was 750 µA.
Chromatographic separation was achieved on a DB-5MS
The interface temperature
The carrier gas was helium.
The electron
Data acquisition was
100
conducted in selected ion monitoring mode. For PBDEs, the temperature program was from
101
110°C (10min) to 250°C at the rate of 25°C/min, then increased to 260°C at the rate of
102
1.5°C/min, and then to 323°C (15 min) at a rate of 25°C/min.
103
temperature program was from 150°C (2min) to 320°C (2min) at the rate of 10°C/min.
104
MeO-PBDEs, the temperature program was from 150°C (2 min) to 245°C (2 min) at 2°C/min,
105
and then increased to 320°C (2 min) at 30°C/min.
For OH-PBDEs, the
For
106
107
108
SUPPORTING INFORMATION TABLE S1. Details of Chinese Sturgeon Samples.
Sample
date of
age
wt
body
Tissue collecteda
Code
collection (year) (kg) length (cm)
E
A0403
2005
24
260
280
E, L, M, H, Go, St, P
A0406
2004
18
174
245
E
A0408
2004
22
230
258
E, L, M, H, Go, St, I, A, Gb
246
A0410
2004
17
140
E, L, M, H, Go, St, I, Gi, P
A0412
2004
24
230
287
E, L, M, I, A, Gi
285
A0414
2004
25
263
E
A0438
2006
26
334
290
E, L, M, H, Go, St, I, A, Gi, S
262
A0439
2006
21
223
E
A0440
2006
18
176
250
E
300
A0441
2006
25
240
E
A0444
2005
23
224
270
A0445
2005
18
187
237
L, M, H, Go, I, Gi
E, L, M, H, Go, I, A, Gi
A0447
2005
19
192
247
E
275
A0449
2005
22
252
E
282
A0452
2005
23
207
E
261
A0500
2005
22
227
L, M, Go, St, I, A, Gi, K
A0466
2003
24
254
285
a) E: egg; L: liver; M: muscle; H: heart; Go: gonad; St: stomach; I: intestine; A: adipose; Gi:
gill; K: kidney; Gb: gallbladder; P: pancreas; S: spleen;
109
110
SUPPORTING INFORMATION TABLE S2. Mean Concentrations and Ranges of OH-PBDEs and MeO-PBDEs (pg/g ww) in Tissues of
Chinese Sturgeon.
Eggs
Liver
Gonad
Adipose
Heart
muscle
Intestine
Stomach
Gill
Pancreas
Gall bladder
Spleen
Kidney
n=15
n=8
n=7
n=5
n=6
n=8
n=7
n=5
n=6
n=2
n=1
n=1
n=1
23
3.3
32
58
64
19
Chemicals
lipid content (%)
6-OH-BDE47
2-OH-BDE68
35
13
3.5
66
3.8
1.9
2.6
1.2
2.2
6.8
(24-50)
(7.1-29)
(1.2-6.3)
(46-89)
(2.3-5.9)
(0.5-3.6)
(1.0-5.4)
(0.8-1.7)
(1.4-3.4)
(5.1-8.6)
180
170
35
17
38
5.2
15
7.7
8.5
7.1
(17-1200)
(35-580)
(18-54)
(N.D.-38)
(9.3-81)
(N.D.-18)
(N.D.-41)
(N.D.-20)
(N.D.-26)
(5.4-8.8)
N.D.
2.9
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
14
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
22
N.D.
N.D.
4.4
N.D.
N.D.
N.D.
N.D.
N.D.
56
N.D.
N.D.
(N.D.-7.7)
5-OH-BDE47
4-OH-BDE49
4-MeO-BDE17
2'-MeO-BDE68
6-MeO-BDE47
5-MeO-BDE47
5'-MeO-BDE100
111
112
113
114
a
3.2
16
(N.D.-17)
(N.D.-39)
8.8
15
4.2
(N.D.-75)
(N.D.-59)
(N.D.-17)
0.6
1.2
0.3
(N.D.-3.2)
(N.D.-4.1)
(N.D.-0.7)
14
4.5
(1.5-45)
(N.D.-62)
N.D.
(N.D.-16)
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
0.8
16
0.6
0.4
0.4
N.D.
N.D.
N.D.
N.D.
N.D.
1.9
(N.D.-12)
(N.D.-2.4)
(7.1-29)
(N.D.-2.4)
(N.D.-0.9)
(N.D.-1.4)
110
25
6.3
120
3.3
1.3
1.5
N.D.
2.2
N.D.
12
N.D.
12
(15-370)
(N.D.-69)
(1.3-24)
(36-210)
(N.D.-9.5)
(N.D.-3.7)
(N.D.-6.9)
N.D.
1.1
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
0.5
0.7
(N.D.-4.9)
(N.D.-2.0)
1.2
1.4
(N.D.-3.6)
(N.D.-3.1)
ND, not detected.
(N.D.-6.7)
(N.D.-4.8)
N.D.
1.8
(N.D.-4.8)
115
116
SUPPORTING INFORMATION TABLE S3. Mean Concentrations and Ranges of PBDEs (ng/g ww) in tissues of Chinese Sturgeon.
Eggs
Liver
Gonad
Adipose
Heart
Muscle
Intestine
Stomach
Gill
Pancreas
Gall bladder
Spleen
Kidney
n=15
n=8
n=7
n=5
n=6
n=8
n=7
n=5
n=6
n=2
n=1
n=1
n=1
1.6
1.2
0.2
2.4
0.1
0.05
0.03
0.01
0.05
0.04
1.2
0.02
0.1
(0.2-4.0)
(0.1-3.2)
(0.05-0.5)
(0.8-4.8)
(0.05-0.3)
(0.02-0.1)
(0.01-0.1)
(N.D.-0.01)
(0.01-0.1)
(0.03-0.1)
14
15
1.7
29
1.7
0.5
0.3
0.1
0.4
0.5
20
0.2
0.7
(1.6-48)
(0.3-49)
(0.5-4.2)
(4.1-85)
(0.5-4.1)
(0.2-1.3)
(0.03-0.8)
(N.D.-0.1)
(0.04-0.8)
(0.4-0.7)
0.3
0.2
0.04
0.4
0.03
0.01
0.01
0.001
0.01
0.01
0.1
0.01
0.03
(0.04-1.0)
(0.01-0.8)
(0.0-0.1)
(0.1-0.9)
(0.01-0.1)
(N.D.-0.03)
(N.D.-0.02)
(N.D.-0.004)
(N.D.-0.03)
(N.D.-0.02)
0.005
0.01
0.002
0.009
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
0.002
(N.D.-0.1)
(N.D.-0.03)
(N.D.-0.005)
(N.D.-0.03)
2.5
3.8
0.3
5.7
0.4
0.1
0.1
0.02
0.1
0.1
4.4
0.1
0.2
(0.3-10)
(0.1-13)
(0.1-0.8)
(1.0-16)
(0.1-0.8)
(0.1-0.3)
(0.01-0.2)
(N.D.-0.03)
(0.01-0.2)
(0.1-0.2)
0.3
0.2
0.03
0.5
0.03
0.03
0.02
0.02
0.02
0.02
0.2
0.02
0.02
(0.02-0.7)
(0.03-0.7)
(0.01-0.1)
(0.2-1.0)
(0.02-0.1)
(0.01-0.1)
(0.01-0.04)
(N.D.-0.04)
(0.01-0.03)
(0.01-0.02)
0.2
N.D.
N.D.
N.D.
N.D.
0.05
N.D.
0.1
N.D.
N.D.
N.D.
N.D.
N.D.
2.2
3.6
0.4
3.5
0.4
0.1
0.1
0.1
0.1
0.2
1.7
0.04
0.2
(0.3-5.1)
(0.1-11)
(0.1-1.0)
(1.7-5.6)
(0.1-0.8)
(0.1-0.2)
(0.02-0.2)
(0.02-0.2)
(0.02-0.3)
(0.1-0.4)
0.5
1.0
0.1
1.1
0.1
0.04
0.03
0.1
0.03
0.1
1.0
0.02
0.04
(0.1-1.3)
(0.02-2.6)
(0.03-0.2)
(0.2-2.4)
(0.04-0.2)
(0.01-0.1)
(N.D.-0.1)
(N.D.-0.1)
(N.D.-0.1)
(0.03-0.1)
N.D.
0.03
N.D.
N.D.
N.D.
0.01
0.05
1.3
0.01
0.04
N.D.
N.D.
N.D.
(N.D.-0.1)
(N.D.-0.2)
(N.D.-6.1)
(N.D.-0.02)
(N.D.-0.1)
Chemicals
BDE28
BDE47
BDE66
BDE77
BDE100
BDE99
BDE85
(N.D.-0.7)
BDE154
BDE153
BDE183
(N.D.-0.2)
(N.D.-0.2)
117
a
ND, not detected.
(N.D.-0.2)
118
SUPPORTING INFORMATION TABLE S4. Percentages of brominated compounds
119
relative to the dosing concentration after metabolism with Chinese sturgeon microsomes
120
exposed to PBDEs and 6-MeO-BDE47 (%)
6-OH-BDE47
6-MeO-BDE47
5-MeO-BDE47
4′-MeO-BDE49
5′-MeO-BDE100
4′-MeO-BDE103
4′-MeO-BDE99
4′-MeO-BDE101
BDE28
BDE47
BDE66
BDE100
BDE119
BDE99
BDE85
BDE154
BDE153
BDE183
BDE47a
N.D.b
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
99 ± 5
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Exposed group (chemicals)
BDE99 a BDE154 a BDE183 a 6- MeO-BDE47 a
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
106 ± 7
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
52 ± 2
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
28 ± 1
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
109 ± 6
73 ± 5
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
6±1
N.D.
121
a
122
than the detection limit; dosing concentration was 150 ng/mL for BDE47, BDE99, BDE154,
123
BDE183 and 6-MeO-BDE47 as described in materials and methods..
Data represent mean±standard deviation of technical triplicates. N.D.: concentrations less
124
SUPPORTING INFORMATION TABLE S5. Association of concentrations of PBDE
125
Congeners (pg/g ww) with age of Chinese sturgeon: Ln [PBDE concentration] = a× age+ b
126
(R2, p value).
a
BDE28
BDE47
BDE100
BDE99
BDE154
BDE153
∑PBDEs
-0.115
-0.163
-0.161
-0.175
-0.098
-0.164
-0.158
b
9.49
12.7
10.9
8.86
9.51
9.10
13.0
R2
0.51
0.66
0.69
0.45
0.37
0.56
0.65
p
0.03
0.01
0.01
0.05
0.08
0.02
0.01
MeO-PBDE
PBDE
900
300
600
200
300
100
Concentrations of PBDEs (ng/g lw)
Concentrations of MeO-PBDEs (pg/g lw)
127
0
0
Egg Liver Adipose Muscle Gonad Heart Intestine Stomach Gill
N=15
N=8
N=5
N=8
N=7
N=6
N=7
N=4
N=6
Poorly perfused organs Richly perfused organs
128
129
130
131
132
SUPPORTING INFORMATION FIGURE S1. Levels of MeO-PBDEs and ∑PBDEs in
various tissues in Chinese sturgeon after lipid normalization. The horizontal line represents
the median concentration. The 25th and 75th centiles define the boxes and the whiskers
represent the 10th and 90th centiles.
6
BDE99/47
BDE183/154
Ratios
4
2
Gill
Stomach
Intestine
Muscle
Heart
Gonad
Adipose
133
134
135
136
Liver
Egg
0
SUPPORTING INFORMATION FIGURE S2. Ratios of concentrations of BDE99 to
BDE47 (BDE99/47) and BDE183 to BDE154 (BDE183/154) in Chinese sturgeon tissues.
137
100000
6-MeO-BDE47
Log(Conc.) (pg/g ww)
BDE47
10000
1000
100
10
1
1
10
100
1,000
10,000
Log(Conc.) of 6-OH-BDE47 (pg/g ww)
138
139
140
141
SUPPORTING INFORMATION FIGURE S3. Relationships between the concentrations of
6-OH-BDE47 and the concentration of 6-MeO-BDE47 (R2=0.534, p=0.003) and BDE47
(R2=0.25, p=0.069).
Liver/adipose ratio
5
4
3
2
0
142
143
10
20
30
40
50
AhR EC50 (μM)
SUPPORTING INFORMATION FIGURE S4. Lipid normalized liver to adipose
concentration ratios in Chinese sturgeon plotted versus Ah receptor binding affinities.