title: Tamoxifen disrupts the reproductive process in gilthead seabream males and modulates the effects promoted by 17α-ethynylestradiol.
abstract: 17α-Ethynylestradiol (EE2), which is used in oral contraceptives and hormone replacement therapy, is a well documented estrogenic endocrine disruptor and an aquatic contaminant. In the present study, adult male specimens of the marine hermaphrodite teleost gilthead (Sparus aurata L.) were fed a diet containing tamoxifen (Tmx), an estrogen receptor ligand used in cancer therapy, alone or combined with EE2, for 25 days and then fed a commercial diet for a further 25 days (recovery period). The effects of short (5days) and long (25 days) treatments on several reproductive and gonad immune parameters and the reversibility of the disruptive effects after the recovery period were examined. Our data showed that Tmx acted as an estrogenic endocrine disruptor as revealed by the increase in the hepatic transcription of the vitellogenin gene in males, the serum levels of 17β-estradiol and the gonad expression levels of the estrogen receptor α and G protein-coupled estrogen receptor genes, and the recruitment of leukocytes into the gonad, a well known estrogenic-dependent process in gilthead seabream males. On the other hand, Tmx also increased sperm concentration and motility as well as the serum levels of androgens and the expression levels of genes that codify for androgenic enzymes, while decreasing the expression levels of the gene that code for gonadal aromatase. When applied simultaneously, Tmx and EE2 could act in synergy or counteract, each other, depending on the parameter measured. The disruptive effect of EE2 and/or Tmx was not reversible after a 25 day recovery period.
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: García-Hernández
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Rodenas
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Cabas
authors.affiliation: Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), Carretera de la Azohía s/n, Puerto de Mazarrón, 30860 Murcia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: García-Alcázar
authors.affiliation: Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), Carretera de la Azohía s/n, Puerto de Mazarrón, 30860 Murcia, Spain. Electronic address: elena.chaves@mu.ieo.es.
authors.forename: E
authors.initials: E
authors.lastname: Chaves-Pozo
authors.affiliation: Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: García-Ayala
mesh_terms: D000818:Animals; D052244:Endocrine Disruptors / Q000097:blood / Q000633:toxicity*; D004965:Estrogen Antagonists / Q000097:blood / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000097:blood / Q000633:toxicity*; D008297:Male; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology; D021541:Sea Bream; D013091:Spermatogenesis / Q000187:drug effects* / Q000502:physiology; D013629:Tamoxifen / Q000097:blood / Q000633:toxicity*; D013737:Testis / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure
chemical_list: D052244:Endocrine Disruptors; D004965:Estrogen Antagonists; D013629:Tamoxifen; D004997:Ethinyl Estradiol
keywords: 17α-Ethynylestradiol; Endocrine disruption reversibility; Gilthead seabream; Spermatogenesis; Steroidogenesis; Tamoxifen