Abstract
The cytochrome P-450 content in liver cells from rainbow trout was not affected by starvation for 12 weeks whereas the rate of cytochrome P-450-dependent deethylation of 7-ethoxycoumarin in liver cells from 6 or 12 weeks starved fish was 60% of the rate in fed fish. Treatment of fish with β-naphthoflavone increased the 7-ethoxycoumarin metabolism several-fold in both starved and fed fish.
Optimal cytochrome P-450 monooxygenation in liver cells from fed or starved fish was not affected by addition of glucose or 2-bromooctanoate, an inhibitor of fatty acid β-oxidation which is the main source of metabolic fuel in trout liver. The cellular content of NADPH, an obligatory cofactor for cytochrome P-450 monooxygenation, was not affected by addition of substrate to cytochrome P-450, inhibition of fatty acid β-oxidation or inhibition of the oxidative phosphorylation. This indicates a great capacity of rainbow trout liver cells to retain high NADPH/NADP+ ratios. These results suggest that the cytochrome P-450 mediated metabolism of xenobiotics in liver cells from fed or starved trout is not limited by the availability of reducing equivalents.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References cited
Andersson, T. and Förlin, L. 1985. Spectral properties of substrate-cytochrome P-450 interaction and catalytic activity of xenobiotic metabolizing enzymes in isolated rainbow trout liver cells. Biochem. Pharmacol. 34: 1407–1413.
Bend, J.R., Pohl, R.J. and Fouts, J.R. 1973. Further studies of the microsomal mixed-function oxidase system of the little skate,Raja erinacea, including its response to some xenobiotics. Bull. Mt Desert Island Biol. 13: 9–13.
Bilinski, E. 1968. Lipid catabolism in fish muscle.In Fish in Research. pp 135–151. Edited by O.W. Neuhaus and J.E. Halver. Academic Press. New York.
Carlsson, L.A. 1963. Determination of serum triglycerides. J. Atheroscler. Res. 3: 334–336.
Danis, M., Kauffman, F.C., Evans, R.K. and Thurman, R.G. 1981. Role of reducing equivalents from fatty acid oxidation in mixed function oxidation: studies with 2-bromooctanoate in the perfused rat liver. J. Pharmacol. Exp. Ther. 219: 383–388.
Dewaide, J.H. 1980. Species differences in hepatic drug oxidation in mammals and fishes in relation to thermal acclimation. Comp. Gen. Pharmacol. 1: 375–384.
Elcombe, C.R. and Lech, J.J. 1979. Induction and characterization of hemoprotein(s) P-450 and monooxygenation in rainbow trout (Salmo gairdneri). Toxicol. Appl. Pharmacol. 49: 437–450.
Estabrook, R.W., Peterson, J., Baron, J. and Hildebrant, A.G. 1972. The spectrophotometric measurement of turbid suspensions of cytochromes associated with drug metabolism.In Methods in Pharmacology vol 2, pp 303–350. Edited by C.F. Chignell. Appleton-Century Crofts, New York.
Förlin, L. 1980. Effects of Clophen A50, 3-methylcholanthrene, pregnenolone-16α-carbonitrile, and phenobarbital on the hepatic microsomal cytochrome P-450-dependent monooxygenase system in rainbow trout,Salmo gairdneri, of different age and sex. Toxicol. Appl. Pharmacol. 54: 420–430.
Förlin, L. and Hansson, T. 1982. Effects of estradiol-17β and hypophysectomy on hepatic mixed function oxidases in rainbow trout. J. Endocrinol. 95: 245–252.
Hansson, T. and Gustafsson, J.-A. 1981.In vitro metabolism of 4-androstene 3,17 dione by hepatic microsomes from rainbow trout (Salmo gairdneri): Effects of hypophysectomy and estradiol-17β. J. Endocrinol. 90: 103–112.
Jezierska, B., Hazel, J.R. and Gerking, S.D. 1982. Lipid mobilization during starvation in the rainbow trout,Salmo gairdneri Richardson, with attention to fatty acids. J. Fish Biol. 21:681–692.
Klingenberg, M. 1974. Nicotinamide-adenine dinucleotides (NAD, NADP, NADH, NADPH). Spectrophotometric and fluorometric methods.In Methods of Enzymatic analysis. pp 2045–2072. Edited by H.U. Bergemeyer. Academic Press, London.
Koivusaari, U. 1983. Thermal acclimatization of hepatic polysubstrate monooxygenase and UDP glucuronosyltransferase of mature rainbow trout (Salmo gairdneri). J. Exp. Zool. 227: 35–42.
Krebs H.A. and Veech, R.L. 1969. Pyridine nucleotides interrelations.In The energy Level and Metabolic Control in Mitochondria. pp 329–382. Edited by S. Papa, J. Tager, M. Quagliariello and E.C. Slater. Academic Press, London.
Lidman, U., Förlin, L., Molander, O. and Axelsson, G. 1976. Induction of the drug metabolizing system in rainbow trout (Salmo gairdneri) liver by polychlorinated biphenyls (PCBs). Acta Pharmacol. Toxicol. 39: 262–272.
Mellanby, J. and Williams, D.H. 1963. Acetoacetate.In Methods of Enzymatic Analysis. pp 454–458. Edited by H.U. Bergemeyerk, Academic Press, London.
Moldéus, P., Grundin, R., Vadi, H. and Orrenius, S. 1974. A study of drug metabolism linked to cytochrome P-450 in isolated rat-liver cells. Eur. J. Biochem. 46: 351–360.
Payne, J.F. and Penrose W.R. 1975. Induction of aryl hydrocarbon (Benzo(a)pyrene) hydroxylase in fish by petroleum. Bull. Environ. Contamin. Tox. 14: 112–116.
Stegeman, J.J., Pajor, A.M. and Thomas, P. 1982. Influence of estradiol and testosterone on cytochrome P-450 and mono-oxygenase activity in immature brook trout,Salvelinus fontanalis. Biochem. Pharmacol. 31: 3979–3989.
Thurman, R.G. and Kauffman, F.C. 1980. Factors regulating drug metabolism in intact hepatocytes. Pharmacol. Rev. 31: 229–251.
Van Handel, E. 1965. Estimation of glycogen in small amounts of tissue. Analyt. Biochem. 11: 256–265.
Walton, M.J. and Cowey, C.B. 1977. Aspects of aminogenesis in rainbow trout.Salmo gairdneri. Comp. Biochem. Physiol. 578: 143–149.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Andersson, T. Cytochrome P-450-dependent metabolism in isolated liver cells from fed and starved rainbow trout,Salmo gairdneri . Fish Physiol Biochem 1, 105–111 (1986). https://doi.org/10.1007/BF02290210
Issue Date:
DOI: https://doi.org/10.1007/BF02290210