title: Interaction of 17β-estradiol and ketoconazole on endocrine function in goldfish (Carassius auratus).
abstract: An understanding of the effects of toxic mixtures of endocrine disrupting chemicals (EDCs) on aquatic organisms is challenging as these organisms are exposed to multiple classes of contaminants in their natural habitat. The aim of the present study was to evaluate the interactions of two classes of EDCs, 17β-estradiol (E2) and ketoconazole (KTC), on endocrine function in male goldfish (Carassius auratus), including vitellogenesis, metabolic capability and serum steroid synthesis. Changes in vitellogenin (VTG) concentration, liver 7-ethoxyresorufin-O-deethylase (EROD) activity and circulating serum E2 level were examined. The expression of related genes was also determined using quantitative real-time polymerase chain reaction. Exposure to E2 caused a significant increase in VTG concentrations which corresponded with the gene expression of VTG and estrogen receptor (ER) in males, which were further elevated after combined exposure to E2 and KTC, indicative of a synergetic relationship. Exposure to E2 also resulted in a distinct increase in serum steroid biosynthesis and associated cytochrome P450 (CYP) aromatase expression after 10 days. However, these changes were inhibited by the presence of KTC, which acted as a steroidogenic inhibitor in fish. Moreover, KTC significantly decreased liver EROD activity and increased the related gene expression of CYP1A. However, these KTC-mediated metabolic reactions in goldfish were up-regulated following exposure to KTC in combination with E2. These findings reveal complex interactions on endocrine functions in male goldfish when exposed to multiple contaminations and may provide a better understanding of the effects of toxic mixtures.
authors: Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China.
authors: Zhenhua
authors: Z
authors: Yan
authors: Guanghua
authors: G
authors: Lu
authors: Donghai
authors: D
authors: Wu
authors: Qiuxia
authors: Q
authors: Ye
authors: Zhengxin
authors: Z
authors: Xie
mesh_terms: D000818:Animals; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D052244:Endocrine Disruptors / Q000633:toxicity*; D004958:Estradiol / Q000097:blood*; D029941:Fish Proteins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006054:Goldfish / Q000378:metabolism*; D012739:Gonadal Steroid Hormones / Q000097:blood; D007654:Ketoconazole / Q000633:toxicity*; D008099:Liver / Q000378:metabolism; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D011960:Receptors, Estrogen / Q000378:metabolism; D014818:Vitellogenesis / Q000187:drug effects; D014819:Vitellogenins / Q000097:blood / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D052244:Endocrine Disruptors; D029941:Fish Proteins; D012739:Gonadal Steroid Hormones; D011960:Receptors, Estrogen; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D004958:Estradiol; D019363:Cytochrome P-450 CYP1A1; D007654:Ketoconazole