Low hepatic 7-ethoxyresorufin-O-deethylase (EROD) activity and minor alterations in retinoid and thyroid hormone levels in flounder (Platichthys flesus) exposed to the polychlorinated biphenyl (PCB) mixture, Clophen A50

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Abstract

The effect of the polychlorinated biphenyl (PCB) mixture Clophen A50 on hepatic cytochrome P4501A1 dependent EROD (7-ethoxyresorufin-O-deethylase) activity, plasma thyroid hormone levels and plasma, kidney and liver retinoid concentrations of the euryhaline flatfish flounder (Platichthys flesus) was determined 2 and 10 days after i.p. (intraperitoneal) injection with 20, 100 and 500 mg Clophen A50/kg body weight. No effect of Clophen A50 on total cytochrome P450 content in flounder liver was observed at both time points. A six-fold, dose-dependent, significant increase in EROD activity was found at exposure day 10 in flounder receiving 100 or 500 mg Clophen A50/kg body weight. Plasma retinol concentrations were not altered at both time points after Clophen A50 administration, whereas renal retinol levels showed a minor dose-related increase at day 2 and day 10 of exposure. Significant alterations in hepatic retinoid concentrations were observed, which were not dependent on the dose of PCB administered. In addition Clophen A50 administration did not result in a dose-related alteration of total T4 concentrations in plasma. Total T3 concentrations in plasma were only significantly increased at day 2 after exposure, whereas free T4 concentrations were increased at both time points after Clophen A50 administration. These data indicate that with regard to the parameters investigated and in contrast to other fish species studied, the flounder is not a sensitive species to PCB exposure.

References (50)

  • H. Hektoen et al.

    Response of hepatic xenobiotic metabolizing enzymes in rainbow trout (Oncorhynchus mykiss) and cod (Gadus morhua) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)

    Aquat. Toxicol.

    (1994)
  • Y. Inui et al.

    Effects of bovine TSH on the tissue thyroxine level and metamorphosis in prometamorphic flounder larvae

    Gen. Comp. Endocrin.

    (1989)
  • R.K. Jensen et al.

    Vitamin A metabolism in rats chronically treated with 3,3′,4,4′,5,5′-hexabromobiphenyl

    Biochem. Biophys. Acta

    (1987)
  • M.C. Lans et al.

    Structure dependent competitive interaction of hydroxychlorobiphenyls, dipenzo-p-dioxins and dibenzofurans with human transthyretin

    Chem. Biol. Inter.

    (1993)
  • D.C. Malins et al.

    Neoplastic and other diseases in fish in relation to toxic chemicals: an overview

    Aquat. Toxicol.

    (1988)
  • D.C. Morse et al.

    Interference of polychlorinated biphenyls in hepatic and brain thyroid metabolism in fetal and neonatal rats

    Toxicol. Appl. Pharmacol.

    (1993)
  • R.A. Prough et al.

    Direct fluorometric methods for measuring mixed function oxidase activity

    Meth. Enzymol.

    (1978)
  • P. Prunet et al.

    Smoltification and seawater adaptation in atlantic salmon (Salmo salar): plasma prolactin, growth hormone, and thyroid hormones

    Gen. Comp. Endocrinol.

    (1989)
  • J.J. Stegeman

    Polynuclear aromatic hydrocarbons and their metabolism in the marine environment

  • A. Brouwer

    Interference of 3,4,3′,4′-tetrachlorobiphenyl in vitamin A (retinoids) metabolism

  • A. Brouwer

    Inhibition of thyroid hormone transport in plasma of rats by polychlorinated biphenyls

    Arch. Toxicol. Suppl.

    (1989)
  • D.P. Chopra

    Cell dynamics in explants derived from tracheas of hamsters fed normal and vitamin D deficient diets

    Cell Tissue Kinet.

    (1983)
  • M.E. Hahn et al.

    Regulation of cytochrome P4501A1 in teleost: sustained induction of CYP1A1 mRNA, protein, and catalytic activity by 2,3,7,8-tetrachlorodibenzofuran in the marine fish Stenotomus chrysops

    Toxicol. Appl. Pharmacol.

    (1994)
  • C. Ishida et al.

    Metabolism in vitro of 3,4,3′,4′- and 2,5,2′,5′-tetrachlorobiphenyl by rat liver microsomes and highly purified cytochrome P-450

    J. Pharmacobio-Dyn.

    (1991)
  • J.P. Landers et al.

    The Ah receptor and the mechanism of dioxin toxicity

    Biochem. J.

    (1991)
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