title: Cytochrome p450 induction and gonadal status alteration in common carp (Cyprinus carpio) associated with the discharge of dioxin contaminated effluent to the Hikiji River, Kanagawa Prefecture, Japan.
abstract: Accumulations of polychlorinated dibenzo-p-dioxins, dibenzofurans and coplanar polychlorinated biphenyls were analyzed in common carp (Cyprinus carpio) collected in the Hikiji River, Kanagawa Prefecture, Japan in which dioxin contaminated effluent was released during the period starting from November 1992 to March 2000. Higher levels of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin toxic equivalents were observed in carps collected downstream to the dioxin release site (contaminated site) than the reference site. Modulations of cytochrome p450 (CYP) enzyme in liver, serum estrogen concentration and gonadal somatic index (GSI) were also measured as biomarkers for the contaminants. Total CYP content in livers was markedly higher in male and female carps from the contaminated site relative to the reference site fish. The expression level of the cytochrome p450 1A and Ethoxyresorufin O-deethylase activity were significantly higher in female carps from the contaminated site than from the reference site. A lower level of plasma estrogen was observed in carps from the contaminated site. The GSI in female carps from the contaminated site was smaller than that recorded at the reference site. The present study indicates that dioxins released to the Hikiji River might induce the CYP enzyme and inhibit the reproductive functions in common carps dwelling downstream from the release site.
authors.affiliation: Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita-ku N18W9 North Ward, Sapporo 060-0818, Japan.
authors.forename: Kentaro Q
authors.initials: KQ
authors.lastname: Sakamoto
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Nakai
authors.forename: Takahiro
authors.initials: T
authors.lastname: Aoto
authors.forename: Aiko
authors.initials: A
authors.lastname: Yokoyama
authors.forename: Ryoko
authors.initials: R
authors.lastname: Ushikoshi
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hirose
authors.forename: Mayumi
authors.initials: M
authors.lastname: Ishizuka
authors.forename: Akio
authors.initials: A
authors.lastname: Kazusaka
authors.forename: Shoichi
authors.initials: S
authors.lastname: Fujita
mesh_terms: D000818:Animals; D002347:Carps / Q000502:physiology*; D019363:Cytochrome P-450 CYP1A1 / Q000494:pharmacology; D004147:Dioxins / Q000009:adverse effects* / Q000493:pharmacokinetics; D004790:Enzyme Induction; D004967:Estrogens / Q000097:blood; D005260:Female; D007564:Japan; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D012737:Sex Factors; D013737:Testis / Q000187:drug effects / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000493:pharmacokinetics
chemical_list: D004147:Dioxins; D004967:Estrogens; D014874:Water Pollutants, Chemical; D019363:Cytochrome P-450 CYP1A1