title: Identification of metabolites of trenbolone acetate in androgenic runoff from a beef feedlot.
abstract: Little is known concerning the potential ecological effects of hormonally active substances associated with discharges from animal feeding operations. Trenbolone acetate is a synthetic anabolic steroid that is widely used in the United States to promote growth of beef cattle. Metabolites of trenbolone acetate include the stereoisomers 17alpha- and 17beta-trenbolone, both of which are stable in animal wastes and are relatively potent androgens in fish and mammals. Our purpose in this study was to evaluate the occurrence of 17alpha- and 17beta-trenbolone in a beef cattle feedlot discharge and in river water upstream and downstream from the discharge. In conjunction with that effort, we measured in vitro androgenic activity of the discharge using CV-1 cells that had been transiently cotransfected with human androgen receptor and reporter gene constructs. Samples were collected on nine different occasions during 2002 and 2003. Whole-water samples from the discharge caused a significant androgenic response in the CV-1 cells and contained detectable concentrations of 17alpha- and 17beta-trenbolone. Further work is needed to ascertain the degree to which synthetic androgens such as trenbolone contribute to androgenic activity of feedlot discharges.
authors.affiliation: Mid-Continent Ecology Division, National Health and Environmental Effects Laboratory, U.S. Environmental Protection Agency, Duluth, Minnesota 55804, USA. durhan.elizabeth@epa.gov
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Durhan
authors.forename: Christy S
authors.initials: CS
authors.lastname: Lambright
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Makynen
authors.forename: James
authors.initials: J
authors.lastname: Lazorchak
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Hartig
authors.forename: Vickie S
authors.initials: VS
authors.lastname: Wilson
authors.forename: L Earl
authors.initials: LE
authors.lastname: Gray
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Ankley
mesh_terms: D045930:Anabolic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D000728:Androgens / Q000008:administration & dosage / Q000009:adverse effects*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D008401:Gas Chromatography-Mass Spectrometry; D045483:Rivers / Q000737:chemistry; D014204:Trenbolone Acetate / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D045930:Anabolic Agents; D000728:Androgens; D014874:Water Pollutants, Chemical; D014204:Trenbolone Acetate