Meeting Abstract

P3.68  Sunday, Jan. 6  Comparison of two endocrine disruptor in vitro screening assays and the potential for conflicting measurements DAVIES, R.E.*; BRANDER, S.M.; HE, G.; CONNON, R.E.; DENISON, M.S.; University of California, Davis; University of North Carolina, Wilmington; University of California, Davis; University of California, Davis; University of California, Davis beeka_hd1@hotmail.com

The U.S. Environment Protection Agency has recommended that endocrine disruptor screening be conducted on a variety of chemicals under the Endocrine Disruptor Screening Program, including the pyrethroid insecticide bifenthrin. Another contaminant of emerging concern is ibuprofen, a non-steroidal anti-inflammatory drug. Bifenthrin has been shown to have both estrogenic and anti-estrogenic properties in vitro and in vivo, and ibuprofen is known to mediate levels of prostaglandins, lipid mediators involved in aspects of reproduction. High throughput screening using cell lines to evaluate the potential for estrogenic or androgenic activity is now an established method of prioritizing contaminants for further assessment, but results can differ depending upon the cell lines used. Conflicting findings may be observed depending on the sensitivity and specificity of the system to endocrine responses and interpretation may depend on the complexity, context and design of the screening systems. The majority of previous in vitro assays have used concentrations of bifenthrin and ibuprofen much higher than usually detected in the environment. We will present comparative results from tests conducted on environmentally relevant concentrations in two cell systems, the CALUX and YES/YAS, and consider their potential for assessing endocrine disruption in aquatic ecosystems, and discuss differences in the quantitation of endocrine disrupting potential between the assay types.