RESUMO
OBJECTIVE@#To analyze the clinical phenotype and genetic characteristics of a child with Hereditary spastic paraplegia (HSP).@*METHODS@#A child with HSP who was admitted to the Third Affiliated Hospital of Zhengzhou University on August 10, 2020 due to discovery of tiptoeing for 2 years was selected as the study subject, and relevant clinical data was collected. Peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. And trio-whole exome sequencing (trio-WES) was carried out. Candidate variants were verified by Sanger sequencing. Bioinformatic software was used to analyze the conservation of variant sites.@*RESULTS@#The child was a 2-year-and-10-month-old female with clinical manifestations including increased muscle tone of lower limbs, pointed feet, and cognitive language delay. Trio-WES results showed that she had harbored compound heterozygous variants of c.865C>T (p.Gln289*) and c.1126G>A (p.Glu376Lys) of the CYP2U1 gene. And the corresponding amino acid for c.1126G>A (p.Glu376Lys) is highly conserved among various species. Based on guidelines from the American College of Medical Genetics and Genomics, the c.865C>T was predicted as a pathogenic variant (PVS1+PM2_Supporting), and c.1126G>A was rated as a variant of uncertain significance (PM2_Supporting+PM3+PP3).@*CONCLUSION@#The child was diagnosed with HSP type 56 due to compound variants of the CYP2U1 gene. Above findings have enriched the mutation spectrum of the CYP2U1 gene.
Assuntos
Feminino , Humanos , Lactente , Família 2 do Citocromo P450/genética , Mutação , Linhagem , Fenótipo , Paraplegia Espástica Hereditária/genéticaRESUMO
ABSTRACT Setting: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH).DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. Objective: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. Design: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. Results: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. Conclusion: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p = 0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Tuberculose Pulmonar/tratamento farmacológico , Predisposição Genética para Doença/genética , Doença Hepática Induzida por Substâncias e Drogas/genética , Antituberculosos/efeitos adversos , Polimorfismo Genético , Tuberculose Pulmonar/enzimologia , Estudos Prospectivos , Citocromo P-450 CYP2E1 , Sistema Enzimático do Citocromo P-450/genética , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Família 2 do Citocromo P450 , Genótipo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Antituberculosos/uso terapêuticoRESUMO
Triptolide (TP) is a major active component in Tripterygium root, but its therapeutic window was very narrow due to its severe multi-organ toxicity. In this work, the effect of TP combined with glycyrrhetic acid (GA) on mRNA expression and activity of four cytochrome P450 (CYP) enzymes in rat liver was studied after intragastric administration of TP (0.05, 0.3 and 0.6 mg x kg(-1) x day(-1)) and TP (0.6 mg x kg(-1) x day(-1)) combined with GA (30 mg x kg(-1) x day(-1)) for 7 consecutive days. Compared with the control, the high dose of TP significantly up-regulated the mRNA expression levels of CYP2E1, 1A2, 3A1 and 2C11, the co-administration of TP and GA further up-regulated the mRNA expression levels of CYP3A1, 2C11 and 2E1 as compared with the high dose of TP. Meanwhile, TP at high dose and combined with GA significantly increased CYP3A-associated testosterone 6beta-hydroxylation activity (2.2-fold and 4.1-fold, respectively) as compared with the control. Because TP is mainly metabolized by CYP3A2 in male rats, the present work indicated that TP-induced increase of CYP3A activity might be an important reason for the rapidly metabolic clearance of TP in rat liver, and GA can reduce the hepatotoxicity of TP by promoting its hepatic metabolic clearance. Furthermore, the results also suggest that the drug interactions might be occurred when TP and GA were co-administered with other CYP3A substrate drug.
Assuntos
Animais , Masculino , Ratos , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Citocromo P-450 CYP1A2 , Genética , Metabolismo , Citocromo P-450 CYP2E1 , Genética , Metabolismo , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Genética , Metabolismo , Família 2 do Citocromo P450 , Diterpenos , Farmacologia , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Interações Medicamentosas , Ativação Enzimática , Compostos de Epóxi , Farmacologia , Ácido Glicirretínico , Farmacologia , Fígado , Fenantrenos , Farmacologia , Raízes de Plantas , Química , Plantas Medicinais , Química , RNA Mensageiro , Metabolismo , Ratos Wistar , Esteroide 16-alfa-Hidroxilase , Genética , Metabolismo , Tripterygium , QuímicaRESUMO
The paper is to report the study of the effect of Shenfu injection on the enzyme activity of liver CYP450 and its mRNA level of rat liver. Microsome of rat liver was prepared after intravenous administration of Shenfu injection for 7 days. The enzyme activity was quantified by Cocktail method. Meanwhile, the mRNA expression of CYP1A2, CYP2B1/2, CYP2C11 and CYP3A1 in the liver was detected by RT-PCR. Shenfu injection obviously induced the enzyme activities of CYP2B and CYP2C. Meantime Shenfu injection decreased the enzyme activities of CYP1A2 and CYP3A. The mRNA levels of CYP2B and CYP2C were also induced in rats treated with Shenfu injection. But it obviously inhibited the mRNA level of CYP1A2 and CYP3A. Since the enzyme activity and mRNA level were obviously changed after administration, the potential effect of drug-drug interaction should be concerned.
Assuntos
Animais , Masculino , Ratos , Aconitum , Química , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Citocromo P-450 CYP1A2 , Genética , Metabolismo , Citocromo P-450 CYP2B1 , Genética , Metabolismo , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Genética , Metabolismo , Família 2 do Citocromo P450 , Combinação de Medicamentos , Medicamentos de Ervas Chinesas , Farmacologia , Injeções , Microssomos Hepáticos , Panax , Química , Plantas Medicinais , Química , RNA Mensageiro , Metabolismo , Ratos Sprague-Dawley , Esteroide 16-alfa-Hidroxilase , Genética , MetabolismoRESUMO
<p><b>OBJECTIVE</b>To examine the expression of cytochrome P450 related genes in oral submucous fibrosis tissue and to investigate the possible role of the genes in pathogenesis of oral submucous fibrosis (OSF).</p><p><b>METHODS</b>Buccul mucosa tissues were obtained from OSF patients in early, medium and advanced stages, with each stage including 10 patients. Normal buccul mucosa tissues were collected from 10 patients undergoing oral and maxillofacial surgery as control. Oral submucous fibrosis-related genes were analysed by cDNA chips, and the results were submitted to the gene network database. Differentially expressed genes related to the pathway of CYP metabolism were indentifyed by the database analysis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to verify the results from cDNA chips by increasing sample volume.</p><p><b>RESULTS</b>There were eight genes [CYP2B6, CYP2C18, CYP2F1, CYP3A5, microsomal glutathione S-transferase 2 (MGST2), alcohol dehydrogenase (ADH), UDP glucuronosyl transferase 2B15 (UGT2B15), ADH1C] which were related to the pathway of CYP metabolism. These genes were low expressed in all stages of OSF (P < 0.001).There were no differences in genes expression among the three stages of OSF (P > 0.05).</p><p><b>CONCLUSIONS</b>There were down-regulated genes related to the pathway of CYP metabolism in oral submucous fibrosis tissue. The ability of the pathway of CYP to metabolize and clear betel nut ingredients was reduced in OSF patients, which may play a role in the pathogenesis of OSF.</p>
Assuntos
Adulto , Humanos , Masculino , Adulto Jovem , Álcool Desidrogenase , Genética , Metabolismo , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Genética , Metabolismo , Família 2 do Citocromo P450 , Regulação para Baixo , Glucuronosiltransferase , Genética , Metabolismo , Glutationa Transferase , Genética , Metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Fibrose Oral Submucosa , Metabolismo , Patologia , RNA Mensageiro , Metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Effects of constituents from Schisandra chinensis (Wuweizi) on six liver microsomal CYP450 isozymes (CYP1A2, CYP2C6, CYP2C11, CYP2D2, CYP2E1 and CYP3A1/2) were studied in rats in vivo and in vitro. The in vitro incubation was conducted using liver microsomes of rats after multiple dosing of alcoholic/water extract from Schisandra chinensis. A HPLC-MS method was applied to determine the metabolites formation of six CYP450s probe substrates (phenacetin-CYP1A2, dextromethorphan-CYP2D2, diclofenac sodium-CYP2C6, mephenytoin-CYP2C11, chlorzoxazone-CYP2E1 and midazolam-CYP3A1/2) in rat liver microsomal incubations. The activity of CYP450 isozymes were represented by the formation of metabolites. Alcoholic extract of Schisandra chinensis (28-120 microg x mL(-1)) showed significant inhibitory effect on six CYP450 isozymes to a certain extent in vitro. Multiple dosing of Schisandra chinensis alcoholic extract (1.5 g x kg(-1), qd x 7d) had significant induction on CYP2E1 and CYP3A1/2, inhibition on CYP2D2 and CYP2C11, and no effect on CYP2C6 and CYP1A2. Water extract of Schisandra chinensis (100-500 microg x mL(-1)) also exhibited inhibition on the activity of CYP450 isozymes in vitro, whereas multiple administrations (1.5 g x kg(-1), qd x 7d) had significant induction of CYP2E1 and inhibition on CYP2D2, no effect on CYP2C6, CYP3A1/2, CYP1A2 or CYP2C11. The results suggested that the constituents from Schisandra chinensis exhibited the inhibition and induction on six rat liver microsomal CYP450 isozymes to a certain extent in vivo and in vitro. The possibility of interaction between Schisandra chinensis and coadministrative drugs will be considered base on the levels and subtype of CYP450 involved in the drug metabolism.
Assuntos
Animais , Ratos , Hidrocarboneto de Aril Hidroxilases , Metabolismo , Citocromo P-450 CYP1A2 , Metabolismo , Citocromo P-450 CYP2E1 , Metabolismo , Citocromo P-450 CYP3A , Metabolismo , Sistema Enzimático do Citocromo P-450 , Metabolismo , Família 2 do Citocromo P450 , Medicamentos de Ervas Chinesas , Farmacologia , Isoenzimas , Metabolismo , Lignanas , Farmacologia , Microssomos Hepáticos , Plantas Medicinais , Química , Ratos Sprague-Dawley , Schisandra , Química , Esteroide 16-alfa-Hidroxilase , Metabolismo , Esteroide 21-Hidroxilase , Metabolismo , Especificidade por SubstratoRESUMO
The present study was performed to investigate the effect of bicyclol on hepatic microsomal cytochrome P450 (CYP) activity, as well as gene and protein expressions in rats after partial hepatectomy (PH). Bicyclol (300 mg x kg(-1)) was given to rats subjected to 70% hepatectomy three times before operation. At 6 and 48 h after PH, blood and liver tissue samples were collected for the measurement of serum alanine aminotransferase (ALT), hepatic microsomal malondialdehyde (MDA) and total hepatic CYP content. The activities of four CYP isozymes were detected with liquid chromatography-mass spectrometry (LC-MS) and the gene and protein expressions were determined by RT-PCR and Western blotting assay. As a result, bicyclol pretreatment markedly inhibited the elevation of serum ALT and hepatic microsomal MDA, and prevented the decrease of total hepatic CYP content in PH rats. In addition, bicyclol significantly attenuated the reduction of CYP2C6 activity and mRNA expression, as well as the reduction of CYP2C11 activity in PH rats. Bicyclol can inhibit the decrease of CYP3A1/2 activity, and up-regulate the mRNA and protein expressions of CYP3A1 and CYP2E1. These results showed that bicyclol pretreatment might ameliorate abnormality in CYP450 isoforms during liver regeneration after PH, and this protective effect was likely due to its anti-oxidative property and enzyme induction.
Assuntos
Animais , Masculino , Ratos , Alanina Transaminase , Sangue , Antioxidantes , Farmacologia , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Compostos de Bifenilo , Farmacologia , Citocromo P-450 CYP2E1 , Genética , Metabolismo , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Metabolismo , Família 2 do Citocromo P450 , Ativação Enzimática , Indução Enzimática , Hepatectomia , Malondialdeído , Metabolismo , Proteínas de Membrana , Genética , Metabolismo , Microssomos Hepáticos , Metabolismo , RNA Mensageiro , Metabolismo , Ratos Sprague-Dawley , Esteroide 16-alfa-Hidroxilase , Genética , Metabolismo , Esteroide 21-Hidroxilase , Genética , MetabolismoRESUMO
Abstract: The activities of four CYP450 enzymes (CYP3A, 1A2, 2El and 2C) and the mRNA expression levels of CYP1A2, 2El, 2Cll and 3A1 in rat liver were determined after Wistar rats were orally administered with brucine (BR) at three dosage levels (3, 15 and 60 mg.kg-1 per day) and the high dose of BR combined with glycyrrhetinic acid (GA, 25 mg.kg-1 per day) or liquiritin (LQ, 20 mg.kg-1 per day) for 7 consecutive days. Compared with the control, brucine caused 24.5% and 34.6% decrease of CYP3A-associated testosterone 6beta-hydroxylation (6betaTesto-OH) and CYP2C-associated tolbutamide hydroxylation (Tol-OH), respectively, and 146.1% increase of CYP2El-associated para-nitrophenol hydroxylation (PNP-OH) at the high dose level. On the other hand, (BR+GA) caused 51.4% and 33.5% decrease, respectively, of CYP2El-associated PNP-OH and CYP1A2-associated ethoxyresorufin-O-de-ethylation (EROD) as compared with the high dose of BR group. Meanwhile, (BR+LQ) caused 41.1% decrease of CYP2El-associated PNP-OH and 37.7% increase of CYP2C-associated Tol-OH. The results indicated that the co-administration of BR with GA or LQ had effect on mRNA expression and activities of the CYP450 enzymes mentioned above to some extent, and the in vivo antagonism of LQ on BR-induced CYPs adverse effects and the in vivo inhibitory action of GA on CYP2E1 and 1A2 might play an important role in the detoxification of Radix Glycyrrhizae against Strychnos nux-vomica L.
Assuntos
Animais , Masculino , Ratos , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Citocromo P-450 CYP1A1 , Metabolismo , Citocromo P-450 CYP1A2 , Genética , Metabolismo , Citocromo P-450 CYP2E1 , Genética , Metabolismo , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Genética , Metabolismo , Família 2 do Citocromo P450 , Flavanonas , Farmacologia , Regulação Enzimológica da Expressão Gênica , Glucosídeos , Farmacologia , Ácido Glicirretínico , Farmacologia , Hidroxilação , Fígado , Metabolismo , Nitrofenóis , Metabolismo , Plantas Medicinais , Química , RNA Mensageiro , Metabolismo , Ratos Wistar , Esteroide 16-alfa-Hidroxilase , Genética , Metabolismo , Esteroide Hidroxilases , Metabolismo , Estricnina , Farmacologia , Strychnos nux-vomica , Química , Tolbutamida , MetabolismoRESUMO
This paper is aimed to study the metabolic kinetics of nicousamide in rat liver microsomes and cytosol and to identify the major metabolite and drug metabolizing enzymes involved in the metabolism of nicousamide in rat and human liver microsomes by selective inhibitors in vitro. The concentration of nicousamide was determined by HPLC-UV method. The metabolite of nicousamide in rat and human liver microsomes was isolated and identified by LC-MS/MS. The major metabolite of nicousamide in rat and human liver microsomes was identified to be 3-(3'-carboxy-4'-hydroxy-anilino-carbo-)-6-amino-7-hydroxy-8-methyl-coumarin (M1). The metabolite of nicousamide in rat plasma, urine, bile and liver was consistent with M1. The metabolism of nicousamide can be catalyzed by several reductases, including CYP450 reductases, cytochrome b5 reductases and CYP2C6 in rat liver microsomes, as well as xanthine oxidase and DT-diaphorase in rat liver cytosol.
Assuntos
Animais , Feminino , Humanos , Masculino , Ratos , Monofosfato de Adenosina , Farmacologia , Alopurinol , Farmacologia , Compostos de Anilina , Metabolismo , Cimetidina , Farmacologia , Cumarínicos , Metabolismo , Inibidores das Enzimas do Citocromo P-450 , Família 2 do Citocromo P450 , Citocromo-B(5) Redutase , Citosol , Metabolismo , Dicumarol , Farmacologia , Inibidores Enzimáticos , Farmacologia , Fígado , Biologia Celular , Metabolismo , Microssomos Hepáticos , Metabolismo , Mitocôndrias Hepáticas , Metabolismo , NAD(P)H Desidrogenase (Quinona) , Propiltiouracila , Farmacologia , Ratos Sprague-Dawley , Esteroide 21-Hidroxilase , Xantina OxidaseRESUMO
<p><b>OBJECTIVE</b>To investigate the effects of the ethyl acetate extract of Semen Hoveniae (ESH) on liver microsomal cytochrome P450 isoenzyme in rats.</p><p><b>METHOD</b>The rats were given orally the ESH in the doses of 0.14, 0.17, 0.2 g x kg (equivalent to the crude herb) for 10 days respectively. Rat liver microsomal cytochrome P450, NADPH-Cyt C reductase, erythromycin N-demethylase (ERD), Aniline hydroxylase (ANH), aminopyrine N-demethylase (ADM) activities were quantitated by UV chromatography. The levels of mRNA expression of CYP1A1, CYP2C11, CYP2E1 and CYP3A1 were detected by semi-quantitative reverse transcripatase-polymerase chain reaction (RT-PCR).</p><p><b>RESULT</b>The cytochrome P450 content, NADPH-Cyt C reductase activities and erythromycin N-demethylase (ERD) activities were not affected. Aniline hydroxylase (ANH) activities in liver were decreased by up to35.1%; aminopyrine N-demethylase (ADM) activitiesin liver were increased by up to 42.4%. The mRNA expression of CYP1A1, CYP2C11 and CYP3A1 were found to be increased markedly.</p><p><b>CONCLUSION</b>A specific effect of ESH on liver microsomal cytochrome P450 isoenzyme in rats was observed in this investigation. ESH had various effects on liver microsomal cytochrome P450 isoenzyme.</p>
Assuntos
Animais , Masculino , Ratos , Acetatos , Química , Aminopirina N-Desmetilase , Metabolismo , Anilina Hidroxilase , Genética , Metabolismo , Hidrocarboneto de Aril Hidroxilases , Genética , Metabolismo , Citocromo P-450 CYP1A1 , Genética , Metabolismo , Citocromo P-450 CYP2E1 , Genética , Metabolismo , Citocromo P-450 CYP3A , Genética , Metabolismo , Sistema Enzimático do Citocromo P-450 , Genética , Metabolismo , Família 2 do Citocromo P450 , Medicamentos de Ervas Chinesas , Química , Farmacologia , Regulação Enzimológica da Expressão Gênica , Microssomos Hepáticos , NADPH-Ferri-Hemoproteína Redutase , Genética , Metabolismo , Plantas Medicinais , Química , RNA Mensageiro , Genética , Metabolismo , Distribuição Aleatória , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rhamnaceae , Química , Sementes , Química , Esteroide 16-alfa-Hidroxilase , Genética , MetabolismoRESUMO
The present study utilized LC-MS and HPLC approaches to characterize the metabolites of neferine in rat liver after an oral administration of 20 mg x kg(-1), and investigated the involvement of CYP450 isoforms in the metabolism of neferine by their selective inhibitors in vitro, separately. In positive ionization mode, besides neferine, four metabolites (M1-M4) were detected. M2 (the major metabolite) and M4 were identified as liensinine and isoliensinine by comparison with reference substances. Moreover, according to the analysis of metabolic rule of parent drug (neferine), M1 and M3 may be desmethylliensinine and desmethyl-isoliensinine, respectively. Furthermore, the metabolism of neferine in rat liver microsomes showed that the percentage inhibition of the major metabolism (liensinine) formation was 80.5% by quinidine (10 micromol x L(-1), selective CYP2D1 inhibitor) and 25.7% by ketoconazole (1 micromol x L(-1), selective CYP3A1 inhibitor). Neferine was mainly metabolized by CYP2D1 or CYP3A1 to liensinine, isoliensinine, desmethyl-liensinine and desmethyl-isoliensinine.
Assuntos
Animais , Masculino , Ratos , Administração Oral , Oxirredutases do Álcool , Hidrocarboneto de Aril Hidroxilases , Benzilisoquinolinas , Metabolismo , Cromatografia Líquida de Alta Pressão , Citocromo P-450 CYP3A , Família 2 do Citocromo P450 , Isoquinolinas , Metabolismo , Cetoconazol , Farmacologia , Microssomos Hepáticos , Metabolismo , Nelumbo , Química , Fenóis , Metabolismo , Plantas Medicinais , Química , Quinidina , Farmacologia , Sementes , Química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
<p><b>OBJECTIVE</b>To investigate the genetic polymorphism of CYP2F1 gene, a member of CYP450 gene family in the healthy population and the patients with nasopharyngeal carcinoma (NPC) of Guangdong province, and furthermore analyze the relationship between CYP2F1 genetic polymorphism and the risk of developing NPC.</p><p><b>METHODS</b>By direct gene sequencing, all of 10 exons of CYP2F1 gene were detected in 40 peripheral blood specimens of patients with primary NPC. For the genetic polymorphism with high allelic frequency, mismatch PCR-RFLP technique was developed to identify the different frequency between 368 NPC cases and 344 cancer-free controls.</p><p><b>RESULTS</b>There were totally 35 SNPs identified in all of 10 exons and exon-intron junctions of CYP2F1 gene from 40 NPC patients, which included 10 missense mutations and 1 frame shift mutation. The most important mutation was C insertion located in 15-16 bp, which caused the frame shift. The allelic frequency of C insertion was 25%. However, there was no significant difference found between 368 NPC cases and 344 controls in allelic frequency of 15-16 bp C insertion mutation (P>0.05).</p><p><b>CONCLUSION</b>A lot of genetic polymorphism of CYP2F1 gene is found in Guangdong population of China. However, no single genetic polymorphism associated with the individual susceptibility to NPC can be identified. The cooperated operations with multiple genetic polymorphisms of one or more genes may be critical factors contributing to the development and progression of NPC.</p>
Assuntos
Humanos , Povo Asiático , Genética , Sequência de Bases , China , Sistema Enzimático do Citocromo P-450 , Genética , Família 2 do Citocromo P450 , Frequência do Gene , Predisposição Genética para Doença , Genética , Neoplasias Nasofaríngeas , Genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
<p><b>AIM</b>To evaluate the effect of in vitro and in vivo treatment with mitomycin C (MMC) on activities of CYP2D1/2, CYP2C1 , and CYP1A2 in the liver of male rats.</p><p><b>METHODS</b>Using HPLC to determine the activities of the three isoenzymes in rat liver microsomes by detecting the specific metabolites of their substrates after treatment with inducers in vivo or inhibitors in vitro.</p><p><b>RESULTS</b>In vitro, MMC inhibited the activity of CYP2D1/2, CYP2C11, and CYP1A2 in dexamethasone-induced microsomes by (19 +/- 6)% (P < 0.05), (85 +/- 10)% (P < 0.01), and (36 +/- 6)% (P < 0.05), respectively, and decreased the activity of CYP1A2 in beta-naphthoflavone-induced microsomes by (58 +/- 6)% (P < 0.01). Rats were injected intraperitoneally with 20% of the LD50 of MMC for 3 or 6 d. The treatment showed no significant effect on microsomal activities of CYP2D1/2, CYP2C11 or CYP1A2.</p><p><b>CONCLUSION</b>MMC can inhibit the activities of CYP2D1/2, CYP2C11, and CYP1A2 in rat liver microsomes in vitro, but it showed no significant effect on the activities of the three isoenzymes in vivo.</p>