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Article: Time-dependent transcriptional profiles of genes of the hypothalamic-pituitary-gonadal axis in medaka (Oryzias latipes) exposed to fadrozole and 17β-trenbolone

TitleTime-dependent transcriptional profiles of genes of the hypothalamic-pituitary-gonadal axis in medaka (Oryzias latipes) exposed to fadrozole and 17β-trenbolone
Authors
Issue Date2008
PublisherSociety of Environmental Toxicology and Chemistry. The Journal's web site is located at http://etc.allenpress.com/
Citation
Environmental Toxicology And Chemistry, 2008, v. 27 n. 12, p. 2504-2511 How to Cite?
AbstractBoth the anabolic androgen 17β-trenbolone (TRB) and the aromatase inhibitor fadrozole (FAD) can cause decreased plasma concentrations of estrogen (E2) and reduce fecundity of fish. However, the underlying mechanisms and the molecular pathways involved are largely unknown. The present study was designed to assess time-dependent effects of FAD and TRB on the transcriptional responses of the hypothalamic-pituitary-gonadal (HPG) axis of Japanese medaka (Oryzias latipes). Fourteen-week-old Japanese medaka were exposed to 50 μg FAD/L or 2 μg TRB/L in a 7-d static renewal test, and the expression profiles of 36 HPG axis genes were measured by means of a medaka HPG real-time reverse- transcription polymerase chain reaction array after 8 h, 32 h, or 7 d of exposure. Exposure to TRB or FAD caused lesser fecundity of Japanese medaka and down-regulated transcription of vitellogenin and choriogenin (CHG) gene expression in the liver of females. Exposure to FAD for 8 h resulted in an 8-fold and 71-fold down-regulation of expression of estrogen receptor α and choriogenin L (CHG L), respectively, in female liver. 17β-Trenbolone caused similar down-regulation of these genes, but the effects were not observed until 32 h of exposure. These results support the hypothesis that FAD reduces plasma E2 more quickly by inhibiting aromatase enzyme activity than does TRB, which inhibits the production of the E2 precursor testosterone. Exposure to FAD and TRB resulted in rapid (after 8 h) down-regulation of luteinizing hormone receptor and low-density-lipoprotein receptor in the testis to compensate for excessive androgen levels. Overall, the molecular responses observed in the present study differentiate the mechanisms of the reduced fecundity by TRB and FAD. © 2008 SETAC.
Persistent Identifierhttp://hdl.handle.net/10722/179107
ISSN
2015 Impact Factor: 2.763
2015 SCImago Journal Rankings: 1.523
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorZhang, Xen_US
dc.contributor.authorHecker, Men_US
dc.contributor.authorPark, JWen_US
dc.contributor.authorTompsett, ARen_US
dc.contributor.authorJones, PDen_US
dc.contributor.authorNewsted, Jen_US
dc.contributor.authorAu, DWTen_US
dc.contributor.authorKong, Ren_US
dc.contributor.authorWu, RSSen_US
dc.contributor.authorGiesy, JPen_US
dc.date.accessioned2012-12-19T09:52:02Z-
dc.date.available2012-12-19T09:52:02Z-
dc.date.issued2008en_US
dc.identifier.citationEnvironmental Toxicology And Chemistry, 2008, v. 27 n. 12, p. 2504-2511en_US
dc.identifier.issn0730-7268en_US
dc.identifier.urihttp://hdl.handle.net/10722/179107-
dc.description.abstractBoth the anabolic androgen 17β-trenbolone (TRB) and the aromatase inhibitor fadrozole (FAD) can cause decreased plasma concentrations of estrogen (E2) and reduce fecundity of fish. However, the underlying mechanisms and the molecular pathways involved are largely unknown. The present study was designed to assess time-dependent effects of FAD and TRB on the transcriptional responses of the hypothalamic-pituitary-gonadal (HPG) axis of Japanese medaka (Oryzias latipes). Fourteen-week-old Japanese medaka were exposed to 50 μg FAD/L or 2 μg TRB/L in a 7-d static renewal test, and the expression profiles of 36 HPG axis genes were measured by means of a medaka HPG real-time reverse- transcription polymerase chain reaction array after 8 h, 32 h, or 7 d of exposure. Exposure to TRB or FAD caused lesser fecundity of Japanese medaka and down-regulated transcription of vitellogenin and choriogenin (CHG) gene expression in the liver of females. Exposure to FAD for 8 h resulted in an 8-fold and 71-fold down-regulation of expression of estrogen receptor α and choriogenin L (CHG L), respectively, in female liver. 17β-Trenbolone caused similar down-regulation of these genes, but the effects were not observed until 32 h of exposure. These results support the hypothesis that FAD reduces plasma E2 more quickly by inhibiting aromatase enzyme activity than does TRB, which inhibits the production of the E2 precursor testosterone. Exposure to FAD and TRB resulted in rapid (after 8 h) down-regulation of luteinizing hormone receptor and low-density-lipoprotein receptor in the testis to compensate for excessive androgen levels. Overall, the molecular responses observed in the present study differentiate the mechanisms of the reduced fecundity by TRB and FAD. © 2008 SETAC.en_US
dc.languageengen_US
dc.publisherSociety of Environmental Toxicology and Chemistry. The Journal's web site is located at http://etc.allenpress.com/en_US
dc.relation.ispartofEnvironmental Toxicology and Chemistryen_US
dc.subject.meshAnimalsen_US
dc.subject.meshAromatase Inhibitors - Toxicityen_US
dc.subject.meshFadrozole - Toxicityen_US
dc.subject.meshFemaleen_US
dc.subject.meshGene Expression Profilingen_US
dc.subject.meshHypothalamo-Hypophyseal Systemen_US
dc.subject.meshMaleen_US
dc.subject.meshOryziasen_US
dc.subject.meshOvary - Metabolismen_US
dc.subject.meshReverse Transcriptase Polymerase Chain Reactionen_US
dc.subject.meshTestis - Metabolismen_US
dc.subject.meshTranscription, Genetic - Drug Effectsen_US
dc.subject.meshTrenbolone Acetate - Toxicityen_US
dc.titleTime-dependent transcriptional profiles of genes of the hypothalamic-pituitary-gonadal axis in medaka (Oryzias latipes) exposed to fadrozole and 17β-trenboloneen_US
dc.typeArticleen_US
dc.identifier.emailWu, RSS: rudolfwu@hku.hken_US
dc.identifier.authorityWu, RSS=rp01398en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1897/08-082.1en_US
dc.identifier.pmid18693774-
dc.identifier.scopuseid_2-s2.0-57649118742en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-57649118742&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume27en_US
dc.identifier.issue12en_US
dc.identifier.spage2504en_US
dc.identifier.epage2511en_US
dc.identifier.isiWOS:000262399300012-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridZhang, X=8606600100en_US
dc.identifier.scopusauthoridHecker, M=35247848500en_US
dc.identifier.scopusauthoridPark, JW=8414402800en_US
dc.identifier.scopusauthoridTompsett, AR=12244509300en_US
dc.identifier.scopusauthoridJones, PD=34771015600en_US
dc.identifier.scopusauthoridNewsted, J=6603677236en_US
dc.identifier.scopusauthoridAu, DWT=7004909228en_US
dc.identifier.scopusauthoridKong, R=7005290687en_US
dc.identifier.scopusauthoridWu, RSS=7402945079en_US
dc.identifier.scopusauthoridGiesy, JP=35459135300en_US

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