Xenoestrogenic activity in blood of European and Inuit populations.
BACKGROUND
Human exposure to persistent organic pollutants (POPs) is ubiquitous and found in all individuals. Studies have documented endocrine disrupting effects and impact on reproduction. The aim of the present study was to compare the level of xenoestrogenic activity in serum of groups with varying POP exposure, and to evaluate correlations to the POP biomarkers, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE).


METHODS
The study included 358 men: Greenlandic Inuit's, Swedish fishermen, and Warsaw (Poland) and Kharkiv (Ukraine) inhabitants. Xenoestrogenicity of serum extracts alone (XER) and XER competitive (XERcomp) effect on 17beta-estradiol induced estrogen receptor (ER) transactivity were assessed in the hormone free, lipophilic serum fraction containing the POPs using the MVLN human breast cancer cell line.


RESULTS
No agonistic XER activity was exhibited for Inuit serum samples, while 12 - 24% of the European samples had detectable agonistic XER activity. On the contrary, 71% of Inuit serum samples antagonized XERcomp compared to 7 - 30 % in the other regions. XER and XERcomp were not or weakly correlated to the two POP markers. XER activity of Inuit samples was negatively associated to levels of CB-153 and p,p'-DDE. For the Warsaw group a positive and negative correlation between XER and p,p'-DDE and estradiol equivalence level and CB-153 levels was found.


CONCLUSIONS
No strong consistent association between xenoestrogenic net activity and the two POP markers was found. The results showed that the selected POP markers alone can not predict the integrated xenoestrogenic serum activity. Correlations to the POP markers were found at the extreme edge; the Inuit's and Warsaw study groups eliciting high frequency of samples with ER antagonistic and agonistic activity, respectively. We suggest that the variation in xenoestrogenic serum activity reflects differences in POP exposure mixture, genetic factors and/or life style factors.
Bonefeld-Jorgensen
Eva C
EC
Unit of Cellular and Molecular Toxicology, Department of Environmental and Occupational Medicine, Institute of Public Health, Vennelyst Boulevard 6, Build, 1260, University of Aarhus, DK-8000 Aarhus, Denmark. ebj@mil.au.dk
Hjelmborg
Philip S
PS
Reinert
Thayaline S
TS
Andersen
Birgitte S
BS
Lesovoy
Vladimir
V
Lindh
Christian H
CH
Hagmar
Lars
L
Giwercman
Aleksander
A
Erlandsen
Mogens
M
Manicardi
Gian-Carlo
GC
Spanò
Marcello
M
Toft
Gunnar
G
Bonde
Jens Peter
JP