Abstract
Evidence has recently been presented for variation in the inducibility of various 7-alkoxycoumarin-O-dealkylase activities in liver microsomes from a number of mammalian species by β-naphthoflavone (βNF). In the present study we have investigated the inducibility of hepatic microsomal 7-methoxycoumarin-O-demethylase, 7-ethoxycoumarin-O-deethylase, 7-propoxycoumarin-O-depropylase and 7-butoxycoumarin-O-debutylase activities in rainbow trout by βNF. O-demethylase activity was increased approximately 17-fold, O-deethylase and O-depropylase activities approximately 9-fold and O-debutylase activity approximately 25-fold. The kinetics of the various hepatic microsomal 7-alkoxycoumarin-O-dealkylase activities were investigated in control and βNF-treated rainbow trout. The O-demethylase-, O-depropylase- and O-debutylase activities exhibited monophasic Michaelis-Menten kinetics in liver microsomes from both control and βNF-treated rainbow trout, whereas the O-deethylase activity exhibited biphasic Michaelis-Menten kinetics in control liver microsomes and monophasic Michaelis-Menten kinetics in liver microsomes from βNF-treated rainbow trout.
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References cited
Åström, A. and DePierre, J.W. 1986. Rat-liver microsomal cytochrome P-450: purification, characterization, multiplicity and induction. Biochim. Biophys. Acta. 853: 1–27.
Boobis, A.R., Whyte, C. and Davies, D.S. 1986. Selective induction and inhibition of the components of 7-ethoxycoumarin O-deethylase activity in the rat. Xenobiotica, 16: 233–238.
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 treated municipal wastewater on the hepatic, xenobiotic and steroid metabolism in trout. Ecotoxicol. Environ. Safety 6: 41–48.
Goksøyr, A. 1985. Purification of hepatic microsomal cytochromes P-450 from β-naphthoflavone-treated Atlantic cod (Gadus morhua), a marine teleost fish. Biochim. Biophys. Acta., 840: 409–417.
Greenlee, W.F., and Poland, A. 1978. An improved assay of 7-ethoxycoumarin O-deethylase activity: induction of hepatic enzyme activity in C57BL/6J and DBA/2J mice by phenobarbital, 3-methylcholanthrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin. J. Pharmacol. Exp. Ther. 205: 596–605.
Guengerich, F.P. 1978. Separation and purification of multiple forms of microsomal cytochrome P-450. Partial characterization of three apparently homogenous cytochromes P-450 prepared from livers of phenobarbital- and 3-methylcholanthrene-treated rats. J. Biol. Chem. 253: 7931–7939.
Guengerich, F.P. 1979. Isolation and purification of cytochrome P-450, and the existence of multiple forms. Pharmac. Ther. 6: 99–121.
Guengerich, F.P., Dannan, G.A., Wright, S.T., Martin, M.V. and Kaminsky, L.S. 1982. Purification and characterization of liver microsomal cytochromes P-450: electrophoretic, spectral, catalytic, and immunochemical properties and inducibility of eight isozymes isolated from rat treated with phenobarbital or β-naphthoflavone. Biochemistry 21: 6019–6030.
Kamataki, T., Ando, M., Yamazoe, Y., Ishii, K. and Kato, R. 1980. Sex difference in the O-dealkylation activity of 7-hydroxycoumarin O-derivatives in liver microsomes of rats. Biochem. Pharmacol. 29: 1015–1022.
Kleinow, K.M., Melancon, M.J. and Lech, J.J. 1987. Biotransformation and induction: implications for toxicity, bioaccumulation and monitoring of environmental xenobioties in fish. Environ, Health Perspec. 71: 105–119.
Klotz, A.V., Stegeman, J.J. and Walsh, C. 1983. An aryl hydrocarbon hydroxylating hepatic cytochrome P-450 from the marine fishStenotomus chrysops. Arch. Biochem. Biophys. 226: 578–592.
Leaver, M.J., Burke, M.D., George, S.G., Rafaelli, D. and Davies, J.M. 1988. Differential induction of cytochrome P-450 mixed function oxidase in plaice by 3MC, Aroclor and isosaffrole. Mar. Environ. Res. (In press).
Lowry, O.H., Rosebrough, N.J., Farr, A.L. and Randall, R.J. 1951. Protein measurements with the Folin phenol reagent. J. Biol. Chem. 193: 265–275.
Matsubara, T., Yoshihara, E., Iwata, T., Tochino, Y. and Hachino, Y. 1982. Biotransformation of coumarin derivatives (1) 7-alkoxycoumarin O-dealkylase in liver microsomes. Jap. J. Pharmacol. 32: 9–21.
Matsubara, T., Otsubo, S., Yoshihara, E. and Touchi, A. 1983. Biotransformation of coumarin derivatives (2) oxidative metabolism of 7-alkoxycoumarin by microsomal enzymes and a simple assay procedure for 7-alkoxycoumarin O-dealkylase. Jap. J. Pharmacol. 33: 41–56.
Sladek, N.E. and Mannering, G.J. 1966. Evidence for a new P-450 hemoprotein in hepatic microsomes from methylcholanthrene treated rats. Biochem. Biophys. Res. Commun. 24: 668–674.
Snegaroff, J. 1982. 7-Ethoxycoumarin deethylation in rainbow trout (Salmo gairdneri). Bull. Environ. Contam. Toxicol. 29: 492–497.
Stegeman, J.J. 1981. Polynuclear aromatic hydrocarbons and their metabolism in the marine environment.In Polycyclic Hydrocarbons and Cancer. Vol. 3, pp. 1–47. Edited by H.V. Gelboin and P.O.T. T'so. Academic Press, New York.
Stegeman, J.J. and Kloepper-Sams, P.J. 1987. Cytochrome P-450 isozymes and monooxygenase activity in aquatic animals. Environ. Health Perspec 71: 87–96.
Ullrich, V. and Weber, P. 1972. The O-dealkylation of 7-ethoxycoumarin by liver microsomes. A direct fluorometric test. Physiol. Chem. 353: 1171–1177.
Waterman, M.R., John, M.E. and Simpson, E.R. 1986. Regulation of synthesis and activity of cytochrome P-450 enzymes in physiological pathways.In Cytochrome P-450: Structure, Mechanism, and Biochemistry, pp. 345–386. Edited by P. R. Ortiz de Montellano. Plenum Press, New York.
White, R.E. and Coon, M.J. 1980. Oxygen activation by cytochrome P-450. Ann. Rev. Biochem. 49: 315–356.
Williams, D.E. and Buhler, D.R. 1982. Purification of cytochrome P-448 from β-naphthoflavone-treated rainbow trout. Biochim. Biophys. Acta. 717: 398–404.
Williams, D.E. and Buhler, D.R. 1984. Benzo(a)pyrene-hydroxylase catalyzed by purified isozymes of cytochrome P-450 from β-naphthoflavone-fed rainbow trout. Biochem. Pharmacol. 33: 3743–3753.
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Celander, M., Förlin, L. & Andersson, T. Cytochrome P-450 mediated O-dealkylation of 7-alkoxycoumarins in liver microsomes from rainbow trout (Salmo gairdneri). Fish Physiol Biochem 6, 199–205 (1989). https://doi.org/10.1007/BF01875022
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DOI: https://doi.org/10.1007/BF01875022