Linked Life Data

8461258

Source:http://linkedlifedata.com/resource/pubmed/id/8461258

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-4-30
pubmed:abstractText
We describe here an in vitro technique to assess the estrogenic activity of chemicals. This technique is based on rainbow trout hepatocytes incubated in a basic medium free of any additional growth factors or estrogenic chemicals and uses the production of vitellogenin (VTG) as a marker for the estrogenic potency of the compounds tested. The system allows at least some of the metabolic transformations which are undertaken by the liver cells in vivo and could therefore be used for xenobiotic compounds which exhibit estrogenic activities after liver metabolic transformation. A dose-response curve was always consistently obtained using estradiol-17 beta (E2), with a mid point at around 100 nM E2 and a maximum response at around 1000 nM. Established estrogens such as 17 a 1 ethynylestradiol (EE2) or diethylstilboestrol (DES) were also tested. EE2 appeared to be equipotent with E2 and DES slightly less potent. E2 conjugates were, perhaps surprisingly, also very potent. Estradiol-3-sulfate was equipotent with E2 and estradiol-17 beta-glucuronide approx. 10% as potent. Other steroids such as androgens and progesterone, though active in the bioassay, were 3 orders of magnitude less potent than E2. Of the various steroids tested, only cortisol, at concentrations up to 50 microM, was completely inactive. Six different phytoestrogens were tested in the assay. All were weakly estrogenic, possessing approximately one thousandth the potency of E2 (they were as potent as the androgens and progesterone). All six phytoestrogens, as well as the androgens and progesterone, were tested in the presence of tamoxifen. In all cases tamoxifen reduced the production of VTG significantly, demonstrating that the estrogenic action of all of these compounds was most likely mediated by the E2 receptor. The potencies determined here may not reflect the situation in vivo but can provide complementary results about the activity of chemicals which need an hepatic metabolization to be estrogenic. Hepatocyte cultures would profitably be developed in other species to sustain these results.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Diethylstilbestrol, http://linkedlifedata.com/resource/pubmed/chemical/Estradiol, http://linkedlifedata.com/resource/pubmed/chemical/Estrogens, http://linkedlifedata.com/resource/pubmed/chemical/Estrogens, Non-Steroidal, http://linkedlifedata.com/resource/pubmed/chemical/Ethinyl Estradiol, http://linkedlifedata.com/resource/pubmed/chemical/Isoflavones, http://linkedlifedata.com/resource/pubmed/chemical/Phytoestrogens, http://linkedlifedata.com/resource/pubmed/chemical/Plant Preparations, http://linkedlifedata.com/resource/pubmed/chemical/Progesterone, http://linkedlifedata.com/resource/pubmed/chemical/Tamoxifen, http://linkedlifedata.com/resource/pubmed/chemical/Testosterone, http://linkedlifedata.com/resource/pubmed/chemical/Vitellogenins, http://linkedlifedata.com/resource/pubmed/chemical/estradiol-3-sulfate
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0960-0760
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
263-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Vitellogenin synthesis in cultured hepatocytes; an in vitro test for the estrogenic potency of chemicals.
pubmed:affiliation
Department of Biology and Biochemistry, Brunel University, Uxbridge, Middlesex, England.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't