Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.chemosphere.2015.04.084
Title (Primary) Understanding the implications of dissolved organic carbon when assessing antagonism in vitro: An example with an estrogen receptor assay
Author Neale, P.A.; Escher, B.I.; Leusch, F.D.L.
Source Titel Chemosphere
Year 2015
Department ZELLTOX
Volume 135
Page From 341
Page To 346
Language englisch
Supplements https://ars.els-cdn.com/content/image/1-s2.0-S0045653515004300-mmc1.docx
Keywords Antagonism; Dissolved organic carbon; Estrogen receptor; In vitro
UFZ wide themes RU3;
Abstract Both estrogenic and anti-estrogenic activity has been observed in water samples. Some studies have suggested that dissolved organic carbon (DOC), which can be co-extracted during sample enrichment, contributes to the apparent antagonistic effect. DOC has a high sorption capacity for the estrogen receptor (ER) agonist 17β-estradiol, which may reduce the available 17β-estradiol concentration in the antagonist testing mode and potentially lead to apparent antagonism. The aim of the study was to determine the influence of DOC when assessing antagonism in an ER reporter gene assay. The presence of DOC shifted the 17β-estradiol concentration-effect curve to higher concentrations, increasing the nominal EC50 value by up to 0.3 log units. However, this shift was within the usual variability associated with repeated measurements of concentration-effect curves. This shift was not due to DOC being an antagonist itself or interfering with fluorescence measurements, but was due to DOC reducing the bioavailability of 17β-estradiol. This was demonstrated by modelling the DOC sorption corrected 17β-estradiol concentration using experimental DOC-water partition coefficients (KDOC). While the shift in the 17β-estradiol concentration-effect curve was minor, sorption of 17β-estradiol to DOC can have an impact when assessing antagonism. At the EC50 agonist concentration, both modelled and experimental results showed that DOC at concentrations similar to that co-extracted in water samples caused suppression of the agonist at levels that would be classified as antagonism. The suppression was less pronounced at the EC80 agonist concentration, hence this is recommended when assessing antagonism of DOC rich samples, such as surface water and wastewater.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=16326
Neale, P.A., Escher, B.I., Leusch, F.D.L. (2015):
Understanding the implications of dissolved organic carbon when assessing antagonism in vitro: An example with an estrogen receptor assay
Chemosphere 135 , 341 - 346 10.1016/j.chemosphere.2015.04.084