TY - JOUR
T1 - The anti-estrogenic activity of sediments from agriculturally intense watersheds
T2 - Assessment using in vivo and in vitro assays
AU - Sellin Jeffries, Marlo K.
AU - Conoan, Nicholas H.
AU - Cox, Marc B.
AU - Sangster, Jodi L.
AU - Balsiger, Heather A.
AU - Bridges, Andrew A.
AU - Cowman, Tim
AU - Knight, Lindsey A.
AU - Bartelt-Hunt, Shannon L.
AU - Kolok, Alan S.
N1 - Funding Information:
Partial support for this project was provided by the University of South Dakota, Missouri River Institute, and by NSF grant numbers CBET-1040895 and CBET-0966850 . M.K.S.J. was supported by the University of Nebraska Medical Center Emley Fellowship Program. H.A.B., A.A.B. and M.B.C. were, in part, supported by grant #5G12RR008124 (to the Border Biomedical Research Center (BBRC)/University of Texas at El Paso) from the National Center for Research Resources (NCRR) , a component of the National Institutes of Health (NIH) . Its contents are solely the responsibility of the authors and do not necessarily represent the official views of NCRR or NIH. A.A.B. was supported by the Research Experience for Undergraduates Program funded by NSF-REU grant number DBI-0851881 . J.L.S. was supported by NSF grant #CBET-0966850. Dr. Daniel Snow of the University of Nebraska Water Science Center led the chemical analysis of sediment samples. Kelty Abbott, Kate Oien and Eric Jeffries assisted with sediment and water collections.
PY - 2011/9
Y1 - 2011/9
N2 - The goal of the current study was to determine whether sediments from agriculturally intense watersheds can act as a potential source of anti-estrogenic endocrine-disrupting compounds. The specific objectives of the current study were to determine (1) whether female fathead minnows (Pimephales promelas) experience alterations in endocrine function when exposed to sediments collected from agriculturally intense watersheds and (2) if these sediments display anti-estrogenic activity in an in vitro assay. In addition, sediment samples were analyzed for the presence of steroid hormones and pesticides associated with local agricultural practices. To accomplish this, sediments and water were collected from three sites within two agriculturally intense Nebraska watersheds (Bow Creek and the Elkhorn River). In 2009, minnows were exposed to sediment and/or water collected from the two Bow Creek sites (East Bow Creek and the Confluence) in the laboratory, while in 2010, minnows were exposed to sediment and/or water from East Bow Creek, the Confluence and the Elkhorn River. Following the 7-day exposure period, the hepatic mRNA expression of two-estrogen responsive genes, estrogen receptor α (ERα) and vitellogenin (Vtg) was determined. In 2009, females exposed to Confluence sediments, in the presence of laboratory water or Confluence water, experienced significant reductions in ERα expression relative to unexposed and Confluence water-exposed females. The defeminization of these females suggests the presence of a biologically available anti-estrogenic compound in sediments collected from this site. In 2010, sediments were assessed for anti-estrogenic activity on days 0 and 7 of the exposure period using a 4-h yeast estrogen screen. Lipophilic extracts (LEs) of day 0 sediments collected from the Confluence and the Elkhorn River induced significant reductions in the estrogenic reporter activity of treated yeast cultures suggesting the presence of a lipophilic anti-estrogenic compound in these extracts. Chemical analysis revealed the presence of a variety of steroid hormones, including those associated with the production of beef cattle (i.e. β-trenbolone, α-zearalanol and α-zearalenol), in sediments indicating that compounds utilized by local beef cattle operations are capable of entering nearby watersheds. Overall, the results of this study indicate that an environmentally relevant anti-estrogenic compound is present in sediments from agriculturally intense watersheds and that this compound is bioavailable to fish. Furthermore, the presence of steroid hormones in sediments from these watersheds provides evidence indicating that steroids are capable of sorbing to sediments.
AB - The goal of the current study was to determine whether sediments from agriculturally intense watersheds can act as a potential source of anti-estrogenic endocrine-disrupting compounds. The specific objectives of the current study were to determine (1) whether female fathead minnows (Pimephales promelas) experience alterations in endocrine function when exposed to sediments collected from agriculturally intense watersheds and (2) if these sediments display anti-estrogenic activity in an in vitro assay. In addition, sediment samples were analyzed for the presence of steroid hormones and pesticides associated with local agricultural practices. To accomplish this, sediments and water were collected from three sites within two agriculturally intense Nebraska watersheds (Bow Creek and the Elkhorn River). In 2009, minnows were exposed to sediment and/or water collected from the two Bow Creek sites (East Bow Creek and the Confluence) in the laboratory, while in 2010, minnows were exposed to sediment and/or water from East Bow Creek, the Confluence and the Elkhorn River. Following the 7-day exposure period, the hepatic mRNA expression of two-estrogen responsive genes, estrogen receptor α (ERα) and vitellogenin (Vtg) was determined. In 2009, females exposed to Confluence sediments, in the presence of laboratory water or Confluence water, experienced significant reductions in ERα expression relative to unexposed and Confluence water-exposed females. The defeminization of these females suggests the presence of a biologically available anti-estrogenic compound in sediments collected from this site. In 2010, sediments were assessed for anti-estrogenic activity on days 0 and 7 of the exposure period using a 4-h yeast estrogen screen. Lipophilic extracts (LEs) of day 0 sediments collected from the Confluence and the Elkhorn River induced significant reductions in the estrogenic reporter activity of treated yeast cultures suggesting the presence of a lipophilic anti-estrogenic compound in these extracts. Chemical analysis revealed the presence of a variety of steroid hormones, including those associated with the production of beef cattle (i.e. β-trenbolone, α-zearalanol and α-zearalenol), in sediments indicating that compounds utilized by local beef cattle operations are capable of entering nearby watersheds. Overall, the results of this study indicate that an environmentally relevant anti-estrogenic compound is present in sediments from agriculturally intense watersheds and that this compound is bioavailable to fish. Furthermore, the presence of steroid hormones in sediments from these watersheds provides evidence indicating that steroids are capable of sorbing to sediments.
KW - Agrichemicals
KW - Anti-estrogen
KW - Fathead minnow
KW - Gene expression
KW - Sediment
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UR - http://www.scopus.com/inward/citedby.url?scp=79959654097&partnerID=8YFLogxK
U2 - 10.1016/j.aquatox.2011.04.008
DO - 10.1016/j.aquatox.2011.04.008
M3 - Article
C2 - 21723217
AN - SCOPUS:79959654097
SN - 0166-445X
VL - 105
SP - 189
EP - 198
JO - Aquatic Toxicology
JF - Aquatic Toxicology
IS - 1-2
ER -