title: Differential accumulation of low-chlorinated (Delor 103) and high-chlorinated (Delor 106) biphenyls in human placental tissue and opposite effects on conversion of DHEA to E2.
abstract: OBJECTIVE
  Polychlorinated biphenyls (PCBs) and related compounds elicit a diverse spectrum of toxic responses. Additionally, they are able to pass through the human placenta. The aim of the presented data was to compare the action of low-chlorinated (Delor 103) and (Delor 106) high-chlorinated biphenyls on placental steroidogenesis.
  
  
  METHODS
  Explants of human placental tissue were used to test differences in PCBs accumulation and influence on placental steroidogenesis. Delor 103 or 106, were added daily for six days at a dose of 200 pg from day 0 to day 6 of culture. The media in the control and experimental groups were changed every day, and collected and frozen for steroid analysis by RIA. Determinations of PCBs of tissue and medium were analysed by GC/MS/MS.
  
  
  RESULTS
  Delor 103 was found at a higher level in the tissue than Delor 106. The first day of exposure to Delor 103 had no effect on the conversion of dehydroepiandrosterone (DHEA) to estradiol (E2) while there was a 2-fold decrease in E2 secretion from days 3 to 6. Conversely, Delor 106 caused an immediate increase in E2 secretion, which was maintained at higher levels throughout the exposure period.
  
  
  CONCLUSIONS
  Differences between the accumulation of lower chlorinated and higher chlorinated biphenyls in human placental tissue and in the properties of the congeners can have multiple effects that may intensify or counteract the effects on uterine contraction by PCBs.
authors.affiliation: Institute of Public Health in Ostrava, National Reference Laboratory for Analysis of POPs, Ministry of Health CR, Partyzanske nam. 7, 702 00 Ostrava, Czech Republic.
authors.forename: R
authors.initials: R
authors.lastname: Grabic
authors.forename: L G
authors.initials: LG
authors.lastname: Hansen
authors.forename: A
authors.initials: A
authors.lastname: Ptak
authors.forename: S
authors.initials: S
authors.lastname: Crhova
authors.forename: E Ł
authors.initials: EŁ
authors.lastname: Gregoraszczuk
mesh_terms: D001141:Aromatase / Q000378:metabolism; D003687:Dehydroepiandrosterone / Q000378:metabolism; D004785:Environmental Pollutants / Q000493:pharmacokinetics* / Q000494:pharmacology; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D010920:Placenta / Q000187:drug effects / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics* / Q000494:pharmacology; D011247:Pregnancy
chemical_list: D004785:Environmental Pollutants; C015550:2,4',5-trichlorobiphenyl; D003687:Dehydroepiandrosterone; D004958:Estradiol; C073236:Delor 106; D011078:Polychlorinated Biphenyls; D001141:Aromatase