S. Jobling, J. Sumpter
Dec 1, 1993
Citations
34
Influential Citations
1,002
Citations
Quality indicators
Journal
Aquatic Toxicology
Abstract
Abstract Alkylphenol-polyethoxylates (APnEO, n = 1–40) are a major group of surfactants and are normally present in raw sewage. Many of the products of the biodegradation of these compounds are both persistent and present in substantial quantities in effluent and in river water. We report here on the use of an in vitro bioassay to determine the oestrogenic potencies of these compounds to fish. The bioassay is based on the fact that the synthesis of vitellogenin by hepatocytes is oestrogen dependent. Of the compounds tested, 4-nonylphenol, 4-tert-octylphenol, 4-tert-butylphenol, 4-nonylphenol-diethoxylate, Tergitol-NP9, and 4-nonylphenoxycarboxylic acid were all weakly oestrogenic, with potencies between about 1 × 10−4 to 1 × 10−6 the activity of 17β-oestradiol The oestrogenic activity observed appeared to be confined to para or 4 substituted compounds, because 2-tert-butylphenol and 3-tert-butylphenol were inactive. The polyethoxylate compounds became less oestrogenic with increasing lengh of the ethoxy chain. Thus cells exposed to Tergitol NP40EO (with a chain length of 40) did not secrete vitellogenin. Simultaneous exposure of the hepatocytes to Tamoxifen (an oestrogen antagonist) and effective doses of representative compounds caused an inhibition of the oestrogenic effect in all cases, suggesting that the action of these compounds is mediated by the oestradiol receptor.