title: The role of P450 metabolism in the estrogenic activity of bifenthrin in fish.
abstract: Bifenthrin, a pyrethroid pesticide, is estrogenic in vivo in fishes. However, bifenthrin is documented to be anti-estrogenic in vitro, in the ER-CALUX (estrogen receptor) cell line. We investigated whether metabolite formation is the reason for this incongruity. We exposed Menidia beryllina (inland silversides) to 10ng/l bifenthrin, 10ng/l 4-hydroxy bifenthrin, and 10ng/l bifenthrin with 25μg/l piperonyl butoxide (PBO) - a P450 inhibitor. Metabolite-exposed juveniles had significantly higher estrogen-mediated protein levels (choriogenin) than bifenthrin/PBO-exposed, while bifenthrin alone was intermediate (not significantly different from either). This suggests that metabolites are the main contributors to bifenthrin's in vivo estrogenicity.
authors.affiliation: The University of North Carolina at Wilmington, Wilmington, NC, USA. Electronic address: bcd3861@alum.uncw.edu.
authors.forename: Breanna C
authors.initials: BC
authors.lastname: DeGroot
authors.affiliation: The University of North Carolina at Wilmington, Wilmington, NC, USA. Electronic address: branders@uncw.edu.
authors.forename: Susanne M
authors.initials: SM
authors.lastname: Brander
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004965:Estrogen Antagonists / Q000633:toxicity; D029941:Fish Proteins / Q000378:metabolism; D005399:Fishes / Q000378:metabolism; D011722:Pyrethrins / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D004965:Estrogen Antagonists; D029941:Fish Proteins; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C099952:bifenthrin; D003577:Cytochrome P-450 Enzyme System
keywords: 4-hydroxy bifenthrin; ELISA; Endocrine disruption; Environmental estrogen; Menidia beryllina; Pyrethroid