title: Histological alternation and vitellogenin induction in adult rare minnow (Gobiocypris rarus) after exposure to ethynylestradiol and nonylphenol.
abstract: Adult rare minnow (Gobiocypris rarus) were exposed to 0, 1, 5, and 25 ng/l (nominal concentrations) of 17alpha-ethynylestradiol (EE2) and 3, 10, and 30 microg/l (nominal concentrations) of 4-nonylphenol (NP) under flow-through conditions for a period of 28 d. Low mortality was observed at 5 and 25 ng/l EE2 and the growth of fish reduced significantly at 25 ng/l EE2 compared to controls. However, the gonadosomatic indices (GSI) of male fish were significantly higher in 1 ng/l EE(2) treatments and in 10 and 30 microg/l NP treatments (p<0.05). Renal somatic indices (RSI) of male fish in EE2 treatments were significantly higher than those in controls (p<0.05). In contrast, significantly decreased GSI and RSI of female fish could only be observed in 5 and 25 ng/l EE(2) treatments (p<0.05). Hepatosomatic indices (HSI) of male fish were significantly higher in 25 ng/l EE(2) treatments. However, significantly increased of HSI of female fish could only be observed in 1 ng/l EE(2) treatments. Plasma vitellogenin (VTG) induction could be observed in males after exposed to different concentrations of EE2 and NP, and plasma VTG concentrations in females exposed to 5 and 25 ng/l EE(2) were also significantly higher than in controls (p<0.05). At level higher than 5 ng/l EE2 or 30 microg/l NP, hepatic tissue and renal tissue impairment of males could be observed. The pathological male liver was associated with a hypertrophy of hepatocytes and damages to cellar structure and accumulated eosinophilic material. Renal tissue showed different pathological effects which was reflected by accumulated eosinophilic material, hemorrhages within the kidney tubules and hypertrophy of the tubular epithelia. Also at these levels of exposure, feminization of male fish could be noticed and parts of males manifested the testis-ova phenomenon. Ovaries of female rare minnow in 25 ng/l EE2 treatment group were degenerated. Therefore when exposed to EE2 and NP even at environmental observed concentrations, adverse effects could occur in the reproductive system of adult fishes. The observed hepatic tissue and renal tissue impairment should be due to the induction and accumulation of VTG in organs, especially in males.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China.
authors.forename: Jinmiao
authors.initials: J
authors.lastname: Zha
authors.forename: Zijian
authors.initials: Z
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Chris
authors.initials: C
authors.lastname: Ingersoll
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000254:growth & development / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004997:Ethinyl Estradiol / Q000633:toxicity*; D005260:Female; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000473:pathology; D010636:Phenols / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects; D013737:Testis / Q000187:drug effects / Q000473:pathology; D014819:Vitellogenins / Q000097:blood / Q000378:metabolism*
chemical_list: D010636:Phenols; D014819:Vitellogenins; D004997:Ethinyl Estradiol; C025256:nonylphenol