title: Gonadal histology and serum vitellogenin levels of bigeye tuna Thunnus obesus from the Northern Pacific Ocean--absence of endocrine disruption bio-indicators.
abstract: Endocrine disrupting chemicals such as organochlorines have been detected in a large number of marine fish. Histological observation of the gonads, measurement of serum vitellogenin (VTG) level and of liver polychlorinated biphenyl (PCB) content were performed to evaluate the reproductive health and the contamination with endocrine disruptors in bigeye tuna Thunnus obesus, collected in the northern Pacific Ocean in 1999 and 2000. Abnormalities commonly found in species affected by endocrine disruptors such as the presence of oocytes in the testis or elevated serum VTG levels were not found in any of males examined. Both males and females had only small amounts of liver PCB content. The results suggest that currently there is little if any risk of organochlorine contamination or endocrine disruption of gonadal function in bigeye tuna from the northern Pacific Ocean. However, further studies are necessary to evaluate the health status of the open sea fishery resources.
authors.affiliation: Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan. hashimos@u-shizuoka-ken.ac.jp
authors.forename: Shinya
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Ryo
authors.initials: R
authors.lastname: Kurihara
authors.forename: Carlos Augusto
authors.initials: CA
authors.lastname: Strüssmann
authors.forename: Tsugiko
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Soyano
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Morita
mesh_terms: D000818:Animals; D004703:Endocrine System / Q000187:drug effects*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D007306:Insecticides / Q000009:adverse effects; D008297:Male; D010053:Ovary / Q000473:pathology*; D010140:Pacific Ocean; D011078:Polychlorinated Biphenyls / Q000009:adverse effects / Q000493:pharmacokinetics*; D018570:Risk Assessment; D013737:Testis / Q000473:pathology*; D014413:Tuna / Q000502:physiology*; D014819:Vitellogenins / Q000032:analysis* / Q000096:biosynthesis; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
chemical_list: D007306:Insecticides; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls