Levels and enantiomeric signatures of methyl sulfonyl PCB and DDE metabolites in livers of harbor porpoises (Phocoena phocoena) from the Southern North Sea.
The concentration of 26 methyl sulfonyl metabolites of polychlorinated biphenyls (MeSO2-PCBs) and of p,p'-DDE (MeSO2-DDE) were determined in 19 liver samples from harbor porpoises (Phocoena phocoena) stranded between 1997 and 2000 on the Belgian and French North Sea Coasts. The total concentration of MeSO2-PCBs ranged from 39 to 4221 ng/g lipid weight (lw) and were generally higher in adults (age > 2 yr, range 969-4,221 ng/g lw) than in juveniles (age < 2 yr, range 39-1815 ng/g lw). The concentrations of MeSO2-DDE were generally also higher in adults (21-96 ng/g lw) than in juveniles (0.5-60 ng/g lw). Congeners 3- and 4-MeSO2-CB101 were the dominating metabolites in all samples. Due to their preferential retention in the liver, the MeSO2-PCB congeners could be divided into two groups. The first group was dominated by the 3-MeSO2-PCB congeners and consisted of MeSO2-CB31, -CB49, -CB52, -CB87, and -CB101, which all have a 2,5-chlorine substitution in the phenyl ring containing the methyl sulfonyl group. The second group was dominated by the 4-MeSO2-PCB congeners and consisted of MeSO2-CB64, -CB91, -CB110, and -CB132, which all have a 2,3,6-chlorine substitution. The ratios of sum of PCBs/sum of MeSO2-PCBs and p,p'-DDE/MeSO2-DDE differed greatly between individual subjects and ranged from 15 to 419 and from 17 to 1088, respectively. The ratio between the precursor PCB congeners and their corresponding metabolites ranged from 0.6 (CB49) to 175 (CB174). Enantiomeric fractions (EFs) for MeSO2-PCB atropisomers, which include 3-MeSO2-CB132, 3-MeSO2-CB149, 4-MeSO2-CB149, 3-MeSO2-CB174, and 4-MeSO2-CB174, were also measured in 8 out of the 19 subjects. High enantiomeric excess (EF > 0.73 or EF < 0.23) for the measured chiral MeSO2-PCB congeners was found in all samples. This result may suggest that one atropisomer may be preferentially formed in harbor porpoises or that the atropisomers are retained in a highly selective manner.
Toxicological Center, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Shaogang
S
Chu
Adrian
A
Covaci
Koichi
K
Haraguchi
Stefan
S
Voorspoels
Kristin
K
Van de Vijver
Krishna
K
Das
Jean-Marie
JM
Bouquegneau
Wim
W
De Coen
Ronny
R
Blust
Paul
P
Schepens
D000818:Animals; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics; D005260:Female; D007306:Insecticides / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics; D008099:Liver / Q000737:chemistry; D008297:Male; D009659:North Sea; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics; D019576:Porpoises; D013329:Structure-Activity Relationship; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics
D007306:Insecticides; D014874:Water Pollutants, Chemical; D003633:Dichlorodiphenyl Dichloroethylene; D011078:Polychlorinated Biphenyls