title: Effects of 17beta-trenbolone in male eelpout Zoarces viviparus exposed to ethinylestradiol.
abstract: To evaluate the interaction between 17beta-trenbolone (TB) and 17alpha-ethinylestradiol (EE2), male eelpout, Zoarces viviparus, was exposed for 21 days (April to May 2008) to 5 ng l(-1) EE2 and 5 or 20 ng l(-1) TB, separately or in combination in a flow-through SW system. The effects on hepatosomatic (HSI) and gonadosomatic index (GSI), plasma vitellogenin (Vtg) concentration, gonadal histology, hepatic and testicular Vtg mRNA and estrogen receptor (ERalpha) mRNA expression were investigated. No effects on HSI were observed. A significant decrease was observed in the GSI of all males exposed to EE2 (<0.7%) when compared to controls (1.4%). Histological alterations and immature stages were observed in the testis of all exposed males; however, males exposed to EE2 were the most affected. Increased tubule number and proportionally decreased tubule diameter were observed in the testis of all EE2 groups. No effects in Vtg mRNA expression were observed in the testis; however, a significant decrease in testis ERalpha mRNA was observed in males exposed to 20 ng l(-1) TB. The groups exposed to EE2 showed a significant increase in plasma Vtg (>300-fold), hepatic Vtg mRNA (>450-fold), and ERalpha mRNA (>100-fold) when compared to controls. This study shows that lower concentrations of 17beta-trenbolone are unable to counteract the EE2 estrogenic effects when the exposure is simultaneous.
authors.affiliation: Institute of Biology, University of Southern Denmark, Odense, Campusvej 55, 5230 Odense M, Denmark. ymvelascos@biology.sdu.dk
authors.forename: Yohana M
authors.initials: YM
authors.lastname: Velasco-Santamaría
authors.forename: Steffen S
authors.initials: SS
authors.lastname: Madsen
authors.forename: Poul
authors.initials: P
authors.lastname: Bjerregaard
authors.forename: Bodil
authors.initials: B
authors.lastname: Korsgaard
mesh_terms: D000818:Animals; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010473:Perciformes / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D014204:Trenbolone Acetate / Q000494:pharmacology*
chemical_list: D029941:Fish Proteins; D011960:Receptors, Estrogen; D004997:Ethinyl Estradiol; D014204:Trenbolone Acetate