title: Endocrine disrupters with (anti)estrogenic and (anti)androgenic modes of action affecting reproductive biology of Xenopus laevis: I. Effects on sex steroid levels and biomarker expression.
abstract: Adult Xenopus laevis were exposed in vivo to ethinylestradiol, tamoxifen, methyldihydrotestosterone and flutamide as (anti)estrogenic and (anti)androgenic compounds, respectively, for four weeks at a concentration of 10(-8) M and to Lambro river water, a polluted river from Italy. Effects of the treatments were analysed by mRNA expression of retinol-binding protein (RBP), transferrin (TF), transthyretin (TTR) and vitellogenin (VTG) in the liver of male and female X. laevis, to analyse the potential of these genes to detect endocrine disrupting compounds (EDC) with different modes of action. In addition, plasma VTG and sex steroid levels, estradiol-17beta (E(2)) and testosterone (T), were analysed. Sex steroids were depressed by ethinylestradiol in both sexes whereas tamoxifen increased E(2) in females. The induction of VTG protein plasma levels was more pronounced at the protein level compared to hepatic VTG mRNA expression in response to estrogenic treatment but VTG mRNA expression detected both, estrogenic and antiestrogenic EDC. The mRNA expression of TF was decreased by estrogenic and increased by antiestrogenic treatment while TTR mRNA expression was down-regulated and RBP mRNA up-regulated by estrogenic exposure. The other treatments did not affect the mRNA expression of the examined genes.
authors.affiliation: Department of Inland Fisheries, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Urbatzka
authors.forename: Sergio
authors.initials: S
authors.lastname: Bottero
authors.forename: Alberta
authors.initials: A
authors.lastname: Mandich
authors.forename: Ilka
authors.initials: I
authors.lastname: Lutz
authors.forename: Werner
authors.initials: W
authors.lastname: Kloas
mesh_terms: D000726:Androgen Antagonists / Q000633:toxicity; D000728:Androgens / Q000633:toxicity; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D013196:Dihydrotestosterone / Q000031:analogs & derivatives / Q000633:toxicity; D052244:Endocrine Disruptors / Q000633:toxicity*; D004958:Estradiol / Q000097:blood; D004965:Estrogen Antagonists / Q000633:toxicity; D004967:Estrogens / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity; D005260:Female; D005485:Flutamide / Q000633:toxicity; D007558:Italy; D008297:Male; D011228:Prealbumin / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D012177:Retinol-Binding Proteins / Q000235:genetics; D054839:Retinol-Binding Proteins, Plasma; D045483:Rivers; D013629:Tamoxifen / Q000633:toxicity; D013739:Testosterone / Q000097:blood; D014168:Transferrin / Q000235:genetics; D014819:Vitellogenins / Q000097:blood / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014982:Xenopus laevis
chemical_list: D000726:Androgen Antagonists; D000728:Androgens; D015415:Biomarkers; D052244:Endocrine Disruptors; D004965:Estrogen Antagonists; D004967:Estrogens; D011228:Prealbumin; D012333:RNA, Messenger; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014168:Transferrin; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D013196:Dihydrotestosterone; D013629:Tamoxifen; D013739:Testosterone; D004997:Ethinyl Estradiol; D004958:Estradiol; D005485:Flutamide; C008376:mestanolone