Advance Access publication

Polychlorinated biphenyls are persistent environmental pollu-tants that elicit a wide range of effects in humans and wildlife, mediated by the aryl hydrocarbon receptor. 3,3#,4,4#,5-pentachlorobiphenyl (PCB126) is the most potent congener with relative effect potencies ranging from 0.0026 to 0.857, and a toxic equivalency factor (TEF) of 0.1 set by an expert panel of the World Health Organization. In this study, the hepatic effects elicited by 300 mg/kg PCB126 were compared with 30 mg/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in immature, ovari-ectomized female C57BL/6 mice. Comprehensive hepatic gene expression analyses with complementary histopathology, high-resolution gas chromatograph/high-resolution mass spectrometer tissue analysis, and clinical chemistry were examined. For temporal analysis, mice were orally gavaged with PCB126 or sesame oi