title: Effects of combined exposure to 17α-ethynylestradiol and dibutyl phthalate on the growth and reproduction of adult male zebrafish (Danio rerio).
abstract: To evaluate the combined effects of 17α-ethynylestradiol (EE2) and dibutyl phthalate (DBP) on the growth and reproduction of male zebrafish, three-month-old fish were exposed to 0.005 or 0.020µg/L EE2, 100 or 500µg/L DBP or their binary mixtures under semi-static conditions. Investigated parameters include the length, weight, condition factor, vitellogenin (VTG) induction, acyl-CoA oxidase (AOX) protein level, histopathological alteration of testis, liver and gill, and reproductive capacity. After 21d exposure, no statistical difference was found among the weights, lengths and condition factors of different treatment groups. In all binary mixture groups, decreased VTG levels were detected compared to EE2-only groups; and the AOX levels were significantly lower than DBP-only treatments while both chemicals can individually induce AOX synthesis. Therefore, EE2 and DBP may act additively on VTG and antagonistically on AOX induction in males. After 45d exposure, delayed gametogenesis was observed for the DBP-only groups, indicated by fewer spermatozoa and more spermatocytes, which was further aggravated with the addition of EE2. The developmental delay of testis partially recovered after a 30d depuration in clean water. Combined exposure also caused liver and gill lesions, which were not alleviated during the 30d depuration, suggesting a nonreversible harmful effect the same as single exposure. Mixed EE2 and DBP were observed to impair the reproductive capability (the fecundity and fertilization rate) of males, while single exposure did not. Co-exposed to 0.020µg/L EE2 and 100µg/L DBP promoted the early hatching of offspring (F1 generation) at 48h post-fertilization (hpf), but the survival rates of the F1 generation were similar in all treatments. Our findings indicate that the effects of mixed EE2 and DBP at environmentally relevant levels can be either antagonistic or additive relying on the specific toxicological endpoints and the respective doses of each chemical.
authors.affiliation: Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China. Electronic address: xunan@pkusz.edu.cn.
authors.forename: Nan
authors.initials: N
authors.lastname: Xu
authors.affiliation: Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Chen
authors.affiliation: Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Yaqiong
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China. Electronic address: lisong@pkusz.edu.cn.
authors.forename: Song
authors.initials: S
authors.lastname: Li
mesh_terms: D042962:Acyl-CoA Oxidase / Q000378:metabolism; D000818:Animals; D003993:Dibutyl Phthalate / Q000633:toxicity*; D052244:Endocrine Disruptors / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity*; D005260:Female; D005298:Fertility / Q000187:drug effects; D005306:Fertilization / Q000187:drug effects; D005718:Gametogenesis / Q000187:drug effects; D005880:Gills / Q000187:drug effects; D006801:Humans; D008099:Liver / Q000187:drug effects; D008297:Male; D012098:Reproduction / Q000187:drug effects*; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000187:drug effects; D014819:Vitellogenins / Q000378:metabolism; D015027:Zebrafish / Q000254:growth & development
chemical_list: D052244:Endocrine Disruptors; D014819:Vitellogenins; D003993:Dibutyl Phthalate; D004997:Ethinyl Estradiol; D042962:Acyl-CoA Oxidase
keywords: 17α-Ethynylestradiol (EE2); Acyl-CoA oxidase; Dibutyl phthalate (DBP); Male zebrafish; Vitellogenin