IMPORTANCE OF CYP2D3 IN POLYMORPHISM OF DIAZEPAMP-HYDROXYLATION IN RATS
| Autor: | Hyung-Sub Kim, Akio Kazusaka, Shoichi Fujita, Yoshihiko Funae, Noriaki Sakai, Konomu Saito, Mayumi Ishizuka |
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| Rok vydání: | 2005 |
| Předmět: |
Male
Gene isoform medicine.drug_class Molecular Sequence Data Pharmaceutical Science Biology Pharmacology Hydroxylation Mixed Function Oxygenases Hypnotic chemistry.chemical_compound Cytochrome P-450 Enzyme System Species Specificity medicine Animals heterocyclic compounds Amino Acid Sequence Rats Wistar Cytochrome P450 Family 2 chemistry.chemical_classification Diazepam Polymorphism Genetic digestive oral and skin physiology Metabolism Recombinant Proteins Rats Amino acid Alcohol Oxidoreductases Kinetics Enzyme chemistry Microsomes Liver Microsome medicine.drug |
| Zdroj: | Drug Metabolism and Disposition. 33:1657-1660 |
| ISSN: | 1521-009X 0090-9556 |
| DOI: | 10.1124/dmd.105.004242 |
| Popis: | Diazepam was metabolized to three primary metabolites, 3-hydroxy-diazepam, N-desmethyl-diazepam, and p-hydroxy-diazepam. Our previous studies reported metabolic position-specific inter- or intrastrain differences in diazepam metabolism among Sprague-Dawley, Brown Norway, Dark Agouti, and Wistar rats. Especially, there were marked ( approximately 300 fold) inter- or intrastrain differences in diazepam p-hydroxylation activity at low concentration of substrate. In this study, we investigated the enzyme that catalyzes diazepam p-hydroxylation. The activity toward diazepam p-hydroxylation was inhibited by anti-cytochrome P450 2D (CYP2D) antibody, suggesting that this activity was catalyzed by CYP2D isoforms. Comparing the expression levels of the CYP2D subfamily in liver microsomes from various strains of rats using anti-CYP2D2 antibody, we found that there was a band of protein that was consistent with the phenotype of diazepam p-hydroxylation. N-terminal amino acid sequences of the specific protein exactly corresponded to those of CYP2D3, indicating that CYP2D3 might be involved in diazepam p-hydroxylation. Moreover, using rat CYP2D isoforms expressed in yeast, we tested CYP2Ds to catalyze diazepam p-hydroxylation. CYP2D1 and CYP2D2 practically did not participate in diazepam metabolism. On the other hand, diazepam p-hydroxylation was catalyzed by CYP2D3. CYP2D4 had high activity toward diazepam N-desmethylation, but not p-hydroxylation. In conclusion, the polymorphic expression of CYP2D3 caused the inter- or intrastrain differences in diazepam p-hydroxylation among rat strains or individuals. |
| Databáze: | OpenAIRE |
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