Liver Cytochrome

Gradelet, S. et al., Beta-apo-8-carotenal, but not beta-carotene, is a strong inducer of liver cytochromes P4501A1 and 1A2 in rat, Xenobiotica, 26, 909, 1996. 

Shimada, T. et al. (1994). Interindividual variations in human liver cytochrome P-450 enzymes involved in the oxidation of drugs, carcinogens and toxic chemicals studies with liver micro-somes of 30 Japanese and 30 Caucasians. /. Pharmacol. Exp. Ther., 270,414-23. 

Microsomal oxidation of amines and phenols may proceed by different ways. For example, it has been shown [42] that phentermine (2-methyl-l-phenyl-2-propylamine) is hydro-xylated to /V-hydroxyphcntcrminc by rat liver cytochrome P-450 system through a normal cytochrome P-450 way ... 

Moody, G.C. et al. 1999. Fully automated analysis of activities catalysed by the major human liver cytochrome P450 (CYP) enzymes. Xenobiotica. 29 53. 

Oda Y, Hamaoka N, Hiroi T, et al. Involvement of human liver cytochrome P4502B6 in the metabolism of propofol. Br J Clin Pharmacol 2001 51(3) 281-285. 

Veronese ME, Mackenzie PI, Doecke CJ, et al. Tolbutamide and phenytoin hydroxylations by cDNA-expressed human liver cytochrome P4502C9. Biochem Biophys Res Commun 1991 175(3) 1112-1118. 

Ahr HJ, King LJ, Nastainczyk W, et al. The mechanism of reductive dehalogenation of halothane by liver cytochrome P450. Biochem Pharmacol 1982 31 (3) 383—390. 

Shimada, T., Yamazaki, H., Mimura, M., Inui, Y. and Guengerich, F.P. (1994) Interindividual variations inhuman liver cytochrome P-450 enzymes involved in... 

Shin, J.G., Soukhova, N. and Flockhart, D.A. (1999) Effect of antipsychotic drugs on human liver cytochrome P-450 (CYP) isoforms in vitro preferential inhibition of CYP2 D6. Drug Metabolism and Disposition, 27 (9), 1078-1084. 

Moody, G.C., Griffin, S.J., Mather, A.N., McGinnity, D.F. and Riley, R.J. (1999) Fully automated analysis of activities catalysed by the major human liver cytochrome P450 (CYP) enzymes assessment of human CYP inhibition potential. Xenobiotica, 29 (1), 53-75. 

He, K., Falick, A.M., Chen, B., Nilsson, F. and Correia, M.A. (1996) Identification of the heme adduct and an active site peptide modified during mechanism-based inactivation of rat liver cytochrome P450 2B1 by secobarbital. Chemical Research in Toxicology, 9 (3), 614-622. 

Waxman DJ, Light DR, Walsh C. 1982. Chiral sulfoxidations catalyzed by rat liver cytochromes P-450. Biochemistry 21 2499-2507. 

Recently Bend et al. have succeeded to solubilize and partially purify little skate liver microsomal cytochrome P-l+50 and have thus been able to record the absolute spectra of fish cytochrome P-l+50 (25.). The spectra are very similar to those of rat liver microsomal cytochrome P-l+50 and purified rat liver cytochrome P-1+50 and P-1+1+8 (Table II). 

Table II. Comparison of the spectral properties of partially purified little skate liver cytochrome P-l+50 with partially purified rat liver cytochrome P-l+50 and highly purified rat liver cytochro-me P-l+50 and P-1+1+8. ...

Partially purified Little Skate liver cytochrome P-l+50. The data is from (25.) and is as accurate as can be read from published... 

In addition to the 2 nm shift in the absorption maximum, the two cytochromes can be distinguished by the use of ethyl isocyanide interaction spectra (6, 7) and various inhibitors of the monooxygenase activity (Figure 2 and Table III). The relative magnitude of the ethyl isocyanide-cytochrome P-1+50 interaction spectral peaks at —1+30 and —1+55 nm is pH dependent (6j and if the absorbance differences are plotted as functions of pH, there is a cross-over point at a certain pH which is characteristic for a particular form of cytochrome P-1+50 pH 6.9 for cytochrome P-1+1+8 and pH 7-5-7.6 for PB induced or control cytochrome P-1+50 (6, 21). The cytochrome P-1+50 of apparently uninduced trout species (Salmo trutta lacustris) has been shown by us to have the pH cross-over point for ethyl isocyanide interaction spectrum at pH 7.8 (2l) and the absorption maximum of the reduced trout liver cytochrome P-1+50. 00 complex is 1+50 nm, nevertheless its catalytic and inhibitory properties (2l)(Table III) are similar to those of cytochrome P-1+1+8. 

Figure 3. Preferential routes of metabolism of 2-AAF, biphenyl, and BP (from top to bottom) by different forms of rat liver microsomal Cytochrome P-450. Trout has been reported to metabolize 2-AAF (65) and biphenyl (37) like rat liver Cytochrome P-450 and BP like rat liver Cytochrome P-448 (69,70).

Haugen, D.A., Coon, M.J. and Nebert, D.W. Induction of multiple forms of mouse liver cytochrome P-450. J. Biol. Chem. 

Schuetz EG, Schuetz JD, Strom SC, Thompson MT, Fisher RA, Molowa DT, Li D, Guzelian PS (1993) Regulation of human liver cytochromes P-450 in family 3A in primary and continuous culture of human hepatocytes. Hepatology 18 1254— 1262. 

N. Yumibe, K. Huie, K. J. Chen, M. Snow, R. P. Clement, M. N. Cayen, Identification of Human Liver Cytochrome P450 Enzymes That Metabobze the Nonsedating Antihistamine Loratadine , Biochem. Pharmacol. 1995, 51, 163- 172. 

Strobl GR, von Kruedener S, Stockigt J, Guengerich FP, Wolff T. 1993. Development of a pharmacophore for inhibition of human liver cytochrome P-450 2D6 molecular modeling and inhibition studies. J Med Chem 36 1136-1145. 

Zeldin DC, Moomaw CR, Jesse N, Tomer KB, Beetham J, et al. 1996. Biochemical characterization of the human liver cytochrome P450 arachidonic acid epoxygenase pathway. Arch Biochem Biophys 330 87-96. 

Hakooz N, Hamdan I (2007) Effects of dietary broccoli on human in vivo caffeine metabolism a pilot study on a group of Jordanian volunteers. Curr Drug Metab 8 9-15 Hammond DK, Bjercke RJ, Langone 11, Strobel HW (1991) Metabolism of nicotine by rat liver cytochromes P-450. Assessment utilizing monoclonal antibodies to nicotine and cotinine. Drug Metab Dispos 19 804-808... 

Branchflower RV, Schulick RD, George JW, et al. 1983. Comparison of the effects of methyl-n-butyl ketone and phenobarbital on rat liver cytochromes P-450 and the metabolism of chloroform to phosgene. Toxicol AppI Pharmacol 71 414-421. 

Poli-Scaife, S., Attias, R., Dansette, P. M., and Mansuy, D. (1997) The substrate binding site of human liver cytochrome P450 2C9 an NMR study. Biochemistry 36, 12,672-12,682. 

Mancy, A., Dijols, S., Poli, S., Guengerich, P., and Mansuy, D. (1996) Interaction of sulfaphenazole derivatives with human liver cytochromes P450 2C molecular origin of the specific inhibitory effects of sulfaphenazole on CYP 2C9 and consequences for the substrate binding site topology of CYP 2C9. Biochemistry 35, 16,205-16,212. 

Wolff, T., Distlerath, L. M., Worthington, M. T., et al. (1985) Substrate specificity of human liver cytochrome P-450 debrisoquine 4-hydroxylase probed using immunochemical inhibition and chemical modeling. Cancer Res. 45, 2116-2122. 

Pichard, L., Domergue, J., Fourtanier, G., Koch, P., Schran, H. F., and Maurel, P. (1996) Metabolism of the new immunosuppressor cyclosporin G by human liver cytochromes P450. Biochem. Pharmacol. 51, 591-598. 

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