New methods for detection of potential endocrine disruptors

It has been hypothesized that recent adverse trends in humans are linked to an increased exposure to potential endocrine disrupting agents. These incl ude widely used compounds that mimic the action of sex hormones, including bisphenol A, phthalates and parabens. Since the chemical structure is not s ufficient to determine whether a chemical will act as an oestrogen, there i s a need for assays that can determine whether a compound interferes with t he endocrine systems. The Environmental Protection Agency has recently sugg ested a testing scheme, composed of an initial screening followed by a more comprehensive investigation of chemicals that are positive in the screenin g. The screening will use several short-term assays to screen many thousand s of compounds for potential endocrine disrupting properties. However, none of these tests determines compound-induced effects on the expression of en dogenous genes, which is the cause of the adverse effects. We propose to us e a precise quantification of the expression levels of endogenous oestrogen -regulated genes to test whether a chemical has oestrogenic properties, and describe how an endogenous gene expression assay can be established and co nducted. Furthermore, different applications of such an assay are discussed : in cell cultures; in experimental animals; or, optimally, directly in blo od samples from exposed humans.