Document Detail


The effect of cytochromes P4501A induction and inhibition on the disposition of the cognition activator tacrine in rat hepatic preparations.
MedLine Citation:
PMID:  8893040     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. The disposition of tacrine 1,2,3,4-tetrahydro-9-acridinamine monohydrochloride monohydrate (THA, Cognex), was studied using livers obtained from control, phenobarbital (PB), isosafrole (ISO), and 3-methycholanthrene (3-MC) treated rats. 2. Pretreatment of rats with PB, ISO, and 3-MC reduced AUC(10-120 min) of THA in liver perfusates by 28, 32, and 86% respectively. 3. Elimination of [14C]-THA-derived radioactivity into bile was 7.6 +/- 1.2%, 11.7 +/- 2.9%, 14.8 +/- 2.0%, and 46.3 +/- 9.7% (mean +/- SD) of the infusion dose for control PB, ISO, and 3-MC pretreated isolated perfused rat livers, respectively. 4. In perfusion experiments using 3-MC pretreated livers, a marked increase in irreversible protein binding of 3-, 7-, and 8-fold was observed to microsomal, cytosolic and total liver proteins, respectively, compared to control. Only a slight effect was observed on protein binding in perfusion experiments using PB and ISO pretreated animals. 5. Co-incubations of [14C]-THA with the metabolic inhibitors enoxacin, ethimizol, and furafylline in hepatocyte preparations obtained from 3-MC pretreated rats markedly inhibited THA-derived irreversible protein binding. Furafylline, a specific inhibitor of cytochrome P4501A2, had the greatest inhibitory effect (approximately 70%). 6. These results are consistent with a major role of cytochrome P4501A in the metabolism and irreversible protein binding of THA in rat liver and demonstrate the utility of isolated liver perfusion and hepatocyte models for examining the effect of metabolic modulators.
Authors:
S Bezek; M Kukan; W F Pool; T F Woolf
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Xenobiotica; the fate of foreign compounds in biological systems     Volume:  26     ISSN:  0049-8254     ISO Abbreviation:  Xenobiotica     Publication Date:  1996 Sep 
Date Detail:
Created Date:  1997-02-07     Completed Date:  1997-02-07     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  1306665     Medline TA:  Xenobiotica     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  935-46     Citation Subset:  IM    
Affiliation:
Pharmacokinetics and Drug Metabolism Department, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, MI 48106, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Cholinesterase Inhibitors / metabolism*
Chromatography, High Pressure Liquid
Cytochrome P-450 CYP1A1 / metabolism*
Cytochrome P-450 CYP1A2 / metabolism*
Enoxacin / pharmacology
Enzyme Induction
Etimizol / pharmacology
Glucuronidase / metabolism
Glutathione / pharmacology
Liver / drug effects,  enzymology
Male
Methylcholanthrene / pharmacology
Rats
Rats, Wistar
Tacrine / metabolism*
Theophylline / analogs & derivatives,  pharmacology
Chemical
Reg. No./Substance:
0/Cholinesterase Inhibitors; 321-64-2/Tacrine; 56-49-5/Methylcholanthrene; 58-55-9/Theophylline; 64-99-3/Etimizol; 70-18-8/Glutathione; 74011-58-8/Enoxacin; 80288-49-9/furafylline; EC 1.14.14.1/Cytochrome P-450 CYP1A1; EC 1.14.14.1/Cytochrome P-450 CYP1A2; EC 3.2.1.31/Glucuronidase

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