A new study published in the April 2015 issue of the peer-reviewed journal Environmental Health Perspectives (EHP) describes a new in vivo screen designed to identify potential endocrine disrupting chemicals (EDCs) with estrogenic properties. In the EHP news article about the study, science writer Carrie Arnold highlights that 84,000 chemicals are currently listed in the U.S. Toxic Substances Control Act (TSCA) inventory. Yet, toxicological data for many of these chemicals are lacking. As a result, it is difficult to pick out potential EDCs, Arnold stresses. Therefore, in the new study, Hewitt and colleagues developed an in vivo screen that enables researchers to determine whether a chemical has estrogenic effects and also gives them the ability to classify the substance as a short- or long-acting estrogen. The screen uses the uterus of an ovariectomized mouse. As there is no circulating estrogen, the model allows researchers to isolate the effects of the investigated compound. High-throughput in vitro assays, such as the U.S. Environmental Protection Agency’s ToxCast™, help with preliminary screening. However, they cannot identify how a compound may affect the body, explains study’s first author Sylvia Hewitt of the U.S. National Institute of Environmental Health Sciences (NIEHS). Therefore, the researchers wanted to have a screen that goes beyond in vitro. The next big challenge for EDC research will be to figure out how to translate the results of these and other assays into risk assessments.

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Arnold, C. (2015). “New tool for EDC research: In vivo assay screens for estrogenic effects.Environmental Health Perspectives 123, A95 (open access).

Hewitt, S.C. et al. (2015). ”Development of phenotypic and transcriptional biomarkers to evaluate relative activity of potentially estrogenic chemicals in ovariectomized mice.Environmental Health Perspectives 123, 344–352 (open access).