Polychlorinated biphenyl (PCB) effects, PCB congener distributions, and cytochrome P-450 regulation in fish
PCB studies were conducted in gonadally mature winter flounder (Pseudopleuronectes americanus) collected from spawning grounds with different degrees of PCB contamination. Flounder from Fox Is., RI, Gaspee Pt., RI and New Bedford, MA (US) had mean hepatic PCB concentrations between 1.6-10.6, 3.8-17.7, and 58-333 {mu}g PCB/g dry liver, respectively. PCB congener distributions in these flounder indicated that PCB disposition was not influenced by reproductive condition, that these migratory fish accumulate a significant portion of their PCB body burden during residence in their spawning grounds, and that flounder selectively metabolize congeners with adjacent meta-, para-unsubstituted carbon atoms. The most significant reproductive effect of PCBs in flounder was a 32 to 52% decrease in the mean ovarian size of highly contaminated females from New Bedford. Plasma levels of the sex hormones, estradiol and testosterone, and of the egg yolk precursor, vitellogenin, as well as hepatic estradiol metabolism (measured as estradiol 2-hydroxylase), showed no relationship to hepatic PCB concentration. PCB effects on flounder P4501A indicated that hepatic PCB concentrations as low as 0.9 {mu}g PCB/g were associated with decreased P4501A catalytic efficiency. Additional suppression of flounder P4501A by estrogens was suggested by depressed levels of P4501A messenger RNA, protein and catalytic activity in highly contaminated female fish with high estradiol titers. The mechanism of P4501A suppression by estrogens was studied in killifish (Fundulus heteroclitus) treated wit {beta}-napthoflavone ({beta}-NF), a P4501A inducer, and/or estradiol.
- Research Organization:
- Boston Univ., MA (United States)
- OSTI ID:
- 5109278
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHLORINATED AROMATIC HYDROCARBONS
TOXICITY
FISHES
SENSITIVITY
MIXED-FUNCTION OXIDASES
ENZYME ACTIVITY
BODY BURDEN
ESTRADIOL
METABOLISM
REPRODUCTION
TISSUE DISTRIBUTION
WATER POLLUTION
ANIMALS
AQUATIC ORGANISMS
AROMATICS
DISTRIBUTION
ENZYMES
ESTRANES
ESTROGENS
HALOGENATED AROMATIC HYDROCARBONS
HORMONES
HYDROXY COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDOREDUCTASES
OXYGENASES
POLLUTION
PROTEINS
STEROID HORMONES
STEROIDS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology