Endocrine screening methods workshop report: Detection of estrogenic and androgenic hormonal and antihormonal activity for chemicals that act via receptor or steroidogenic enzyme mechanisms

This workshop evaluated methods to detect chemicals that act as (anti)estrogens and (anti)androgens via alteration of the action of their respective nuclear receptors, as well as alteration of sex steroid hormone synthesis. The benefits and limitations of each endpoint were discussed. Other important mechanisms that can result in endocrine disruption (e.g., antithyroid effects of chemicals) were not discussed at this workshop. Screens should be hazard identification tools designed to detect endocrine activity, not to determine dose-response relationships. No single endpoint can provide results that would allow one to conclude with absolute certainty that a toxicant acted via estrogen receptor (ER), androgen receptor (AR) or inhibition of sex steroid hormone synthesis (steroidogenesis-inhibiting substances, SIS). Workshop participants expressed a high level of confidence that a screen(s) that would identify endocrine disrupters that act via AR, ER, or SIS activity could be developed, but this will require some combination of endpoints discussed at the workshop. It was beyond the scope of this workshop to determine what endocrine mechanisms a screen should detect, or to develop a screening approach.