scholarly journals Benzobarbital and fluorbenzobarbital - hepatic monooxygenase system phenobarbital-like inducers

2011 ◽  
Vol 10 (5) ◽  
pp. 78-81 ◽  
Author(s):  
T. P. Novozheyeva ◽  
M. I. Smagina ◽  
N. A. Cherevko ◽  
S. N. Fateyeva
Keyword(s):  
Large Degree ◽  
Major Metabolite ◽  
Monooxygenase System ◽  
Oxidation Activity ◽  
Hepatic Monooxygenase ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Benzobarbital and fluorbenzobarbital as monooxygenase system inductors increase the hepatic cytochrome P-450 level and the content of its isoenzymes 2B6, 2C9, 2Å1, accelerate aminopyrine, 7-ethoxyresorufine, 7-pentoxyresorufine, aniline and androstendione oxidation. Activity of benzobarbital and fluorbenzobarbital as inductors is to a large degree due to the action of their major metabolite — phenobarbital. Benzobarbital and fluorbenzobarbital unlike phenobarbital induce isoenzyme 3A4, responsible for androstendione 16b-OH-hydroxylation. PCN-type induction activity posses also native molecules of benzobarbital and fluorbenzobarbital.

scholarly journals Effects of Bromocriptine on Hepatic Cytochrome P-450 Monooxygenase System

1989 ◽  
Vol 49 (2) ◽  
pp. 285-291
Author(s):  
Shabbir M. MOOCHHALA ◽  
Edmund J.D. LEE ◽  
Gwendolene T.M. HU ◽  
O.S. KOH ◽  
Gordon BECKET
Keyword(s):  
Monooxygenase System ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

scholarly journals Effects of bromocriptine on hepatic cytochrome P-450 monooxygenase system.

1989 ◽  
Vol 49 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Shabbir M. MOOCHHALA ◽  
Edmund J.D. LEE ◽  
Gwendolene T.M. HU ◽  
O.S. KOH ◽  
Gordon BECKET
Keyword(s):  
Monooxygenase System ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

scholarly journals Cyclization reactions of IMM-125 and oxidation of cyclosporin A amino-acid 1 in theαposition of the double bond lead to the loss ofin vitroimmunosuppressive activity

2000 ◽  
Vol 14 (4) ◽  
pp. 215-228
Author(s):  
R. Dieden ◽  
D. Latinne ◽  
C. Baldari ◽  
N. Maton ◽  
A. Aubry ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cyclosporin A ◽  
Parent Drug ◽  
Nucleophilic Attack ◽  
Monooxygenase System ◽  
Cyclization Reactions ◽  
Perbenzoic Acid ◽  
Jurkat T Cell ◽  
Cytochrome P 450 ◽  
Hepatic Cytochrome

Cyclosporin A (CsA) and IMM-125, a hydroxyethyl derivative of D-serine CsA, are cyclic undecapeptides of molecular weight 1201.8 and 1261.8, respectively. The main metabolites still possessing the undecapeptide structure were found to be compounds resulting from the biotransformation of amino acids 4, 9 and 1.Under the influence of the hepatic cytochrome P-450-dependent monooxygenase system, CsA and IMM-125 amino acid 1 are metabolized to a mono-hydroxylated compound (metabolite M-17) and to a dihydrodiol. A metabolite M18 was found to be the result of a non-enzymic intramolecular formation of a tetrahydrofuran derivative from metabolite M17. Since the existence of a CsA dihydrodiol was reported and since epoxides are considered as the dihydrodiol precursors, the aim of the present work was to prove that the same non-enzymic intramolecular formation of a tetrahydrofuran ring could occur by nucleophilic attack of the amino-acid 1β-hydroxy group at theɛ-position of the freshly formed epoxide by reaction of IMM-125 with m-chloro-perbenzoic acid and cyclosporin A with selenium oxide. The immunosuppressive activity of the compounds, as measured by the mixed lymphocyte reaction and by the luciferase activity of a Jurkat-T-cell line stably transfected with the NF-AT/luc reporter plasmid, was found negligible for IMM-125 compared to the parent drug as well as for the cyclosporin A derivative. Structures of the IMM-125 and CsA derivatives were elucidated by electrospray mass‒spectrometry and NMR spectroscopy.

Growth hormone depresses ethylmorphine demethylase activity: correlation with decreased levels of fast-turnover cytochrome P-450 in hypophysectomized female rats

1988 ◽  
Vol 66 (7) ◽  
pp. 868-872
Author(s):  
Birgit M. Vockentanz ◽  
Bruce B. Virgo
Keyword(s):  
Growth Hormone ◽  
Cytochrome C ◽  
Female Rats ◽  
Monooxygenase System ◽  
Demethylase Activity ◽  
Hepatic Monooxygenase ◽  
Cytochrome P 450 ◽  
Slow Turnover ◽  
Nadph Cytochrome C Reductase

The hepatic monooxygenase system was studied in hypophysectomized female rats infused for 5 days with ovine growth hormone (GH). At 7.5 μg∙h−1 GH decreased the total cytochrome P-450 by 16%; at 10 μg∙h−1 it reduced both cytochrome P-450 (31%) and the activity of ethylmorphine demethylase (31%). GH did not alter the activities of NADPH cytochrome c reductase or aniline hydroxylase. The lower GH dose decreased the amount of fast- and slow-turnover P-450 by 11 and 38%, respectively, while the higher dose decreased both by 49%. The loss of demethylase activity therefore correlates with the loss of fast-tumover P-450. This component is relatively more abundant in the female (fast: slow turnover of 4.3) than the male (fast: slow turnover of 2.5). GH did not affect the half-lives of the P-450 components, suggesting that it decreases their synthesis. The P-450 concentration in microsomes from GH-treated animals did not increase after incubation with hemin, suggesting that in vivo the hormone does not lower P-450 synthesis via depression of heme. Puromycin mimicked the effect of GH and when given with the hormone their effects on the P-450 levels were multiplicative (p < 0.05), suggesting different modes of action and that GH does not decrease P-450 by acting at translation.

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