Review of In Vitro Endocrine Disruptor Screening Assays

ICCVAM conducted a review of four types of in vitro tests to identify potential endocrine disruptors:

  • Estrogen receptor (ER) binding
  • Androgen receptor (AR) binding
  • ER transcriptional activation
  • AR transcriptional activation

The results of this review were published in a 2003 test method evaluation report that included the following recommendations for these types of tests:

  • Tests should use artificial ERs and ARs instead of animal proteins
  • More detailed research and study was needed of methods for making statistical conclusions with the test data
  • Research was needed into what extent metabolism affects estrogenic and androgenic activity in a living organism

This report also listed 78 substances that should be used to validate these tests. A 2006 addendum to the report revised this list due to the high cost and limited availability of some of the original substances.

Nomination and Expert Panel Meeting

In 2000, the U.S. Environmental Protection Agency (EPA) nominated four types of in vitro test methods for ICCVAM to review. These test methods were proposed for use in the EPA Endocrine Disruptor Screening Program.

NICEATM gathered relevant data and prepared a review document of the four types of tests. An independent expert panel review concluded that there were no adequately validated in vitro endocrine disruptor screening tests.

ICCVAM considered the panel's conclusions and recommendations, along with comments from the public, as it developed its final test method evaluation report.