癫痫患者CYP2D6~* 10基因多态性分析

目的:通过比较本地区健康人与癫痫患者CYP2D6*10基因多态性的差异,探索CYP2D6*10基因多态性与癫痫易感的关系。方法:应用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法检测健康人和癫痫患者CYP2D6*10的基因型分布及等位基因频率,通过χ2检验来比较健康人和癫痫患者的基因型分布差异和等位基因频率差异。结果:健康人和癫痫患者的基因型分布及等位基因频率差异有显著性和高度显著性(P<0.05和P<0.01)。结论:癫痫病的发生与CYP2D6*10的碱基变异具有相关性。     

CYP2D6*10和CYP2C19*2基因型多态性与接受他莫昔芬治疗乳腺癌患者生存率的相关性研究

目的:研究CYP2D6*10和CYP2C19*2基因型多态性与接受他莫昔芬(tamoxifen,TAM)治疗乳腺癌患者生存率的相关性研究.方法:选择2009至2004年本院甲乳外科和肿瘤内科收治的171名术后服用TAM治疗的雌激素阳性乳腺癌患者,调查TAM使用情况和生存状态等相关资料;收集相关的石蜡组织切片用于DNA提取;用PCR技术检测CYP2D6*10和CYP2C19*2基因型多态性;查明CYP2D6*10和CYP2C19*2基因型多态性与患者生存率的相关性.结果:本次研究中,CYP2D6Wt/Wt、CYP2D6Wt/*10 和CYP2D6*10/*10基因型的总生存率(overall survival,OS)类似,差异无统计学意义(P＞0.05).CYP2C19*2/*2基因型的5年OS明显优于CYP2C19 Wt/Wt,差异具有统计学意义(P＜0.05);CYP2C19*2/*2基因型的10年OS明显优于CYP2C19 Wt/Wt和CYP2C19 Wt/*2,差异具有统计学意义(P＜0.05);但是CYP2C19Wt/Wt与CYP2C19 Wt/*2的5、10年OS差异无统计学意义(P＞0.05).结论:研究结果显示,CYP2D6*10基因型多态性与服用TAM治疗乳腺癌患者的生存率之间不存在相关性;CYP2C19*2基因型多态性与接受TAM治疗乳腺癌患者的生存率之间存在相关性,CYP2C19*2/*2接受TAM治疗乳腺癌患者的生存率最高,CYP2C19 Wt/*2生存率较高,CYP2C19 Wt/Wt较低.     

CYP2D6*10基因多态性与比索洛尔药动学关系研究

目的:研究CYP2D6*10不同基因型对健康志愿者体内比索洛尔药动学的影响。方法:采用实时荧光测序法分析CYP2D6*10基因型。将24例健康志愿者分为CC、CT、TT基因型3组(n=8),受试者单剂量口服富马酸比索洛尔片5 mg后,采用高效液相色谱法测定血药浓度。结果:CC、CT、TT 3种基因型受试者之间主要药动学参数t1/2、cmax、AUC0-32 h分别为(8.25±1.80)、(7.70±1.18)、(8.19±1.86)h,(41.69±11.22)、(37.69±6.53)、(43.14±5.85)μg/L,(394.38±104.70)、(380.04±84.04)、(414.08±104.40)μg·h/L。通过t检验,3种基因型之间无显著性差异(P>0.05)。结论:比索洛尔药动学在个体间的差异与CYP2D6*10基因型无相关性。     

CYP2D6*10基因多态性与泮托拉唑药动学关系研究

目的:研究泮托拉唑在不同CYP2D6*10基因型健康志愿者体内的药动学。方法:24名健康志愿者分为CC组、CT组、TT组;应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析CYP2D6*10基因型。受试者均口服泮托拉唑肠溶胶囊(40mg)后,采用高效液相色谱法测定血药浓度。结果:CC组、CT组、TT组的t1/2分别为(1.78±0.34)、(1.51±0.64)、(2.05±0.37)h,cmax分别为(3.20±0.82)、(3.29±0.74)、(3.13±0.79)mg/L,AUC0-12h分别为(11.18±3.94)、(11.37±4.66)、(14.31±4.77)mg·h/L。通过t检验,t1/2、cmax、AUC0-12h3种基因型之间的差异均无统计学意义(P>0.05)。结论:泮托拉唑药动学在个体间的差异与CYP2D6*10基因型可能不相关。     

癫痫患者CYP2D6*10基因多态性对丙戊酸钠血药浓度的影响

目的:比较不同基因型与血药浓度之间的关系,为实行个体化用药方案提供参考。方法:采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)法检测癫痫患者CYP2D6*10的基因型,高效液相色谱法测定丙戊酸钠的血药浓度。结果:CC、CT、TT3种基因型基因分别占20.9%、24.4%、54.7%;3种基因型癫痫患者服用丙戊酸钠达稳态血药浓度后测得的血药浓度、标准化血药浓度之间差异无统计学意义(P>0.05)。结论:CYP2D6*10基因多态性对癫痫患者服用丙戊酸钠的血药浓度没有影响。     

CYP2D6*10等位基因在肝癌患者中的分布

目的 考察CYP2D6* 10等位基因在肝癌患者中的分布,探讨*10等位基因与肝癌的易感性.方法 收集50例肝细胞肝癌(HCC组)和50例肝血管瘤患者(对照组)的肝组织和血液标本,进行组织病理学分级,采用聚合酶链反应进行DNA扩增,采用质谱测序进行CYP2D6* 10基因分型.结果 与对照组相比,HCC组CYP2D6*...     

CYP2D6*10基因多态性对喹硫平血药浓度和临床疗效的影响

目的 探讨细胞色素P450 2D6（CYP2D6）基因多态性对精神分裂症患者喹硫平血药浓度和临床疗效的影响,为喹硫平的个体化给药提供参考。方法 选取符合诊断标准的精神分裂症住院患者98例,接受喹硫平单一治疗,剂量范围为100~750 mg·d^-1,观察疗程为4周。采用多重高温连接酶检测反应技术检测CYP2D6*10基因多态性,采用UPLC-MS/MS测定喹硫平血药浓度,以治疗前后阳性和阴性症状量表（PANSS）评分变化评价临床疗效,并比较不同基因型之间喹硫平血药浓度和临床疗效的差异。结果 TT型患者喹硫平血药浓度明显高于CC型和CT型患者（P<0.05）,且喹硫平血药浓度与CYP2D6*10基因型存在相关关系（r=0.558,P<0.001）;TT型患者治疗有效率最高,CT型次之,CC型最低,差异有统计学意义（P<0.05）;治疗后TT型患者PANSS量表总减分值、阳性症状减分值和阴性症状减分值均明显高于CC型患者（P<0.05）。结论 CYP2D6*10基因多态性可影响喹硫平血药浓度和临床疗效,CC型患者用喹硫平治疗时血药浓度偏低且疗效较差,临床医生用药时应予以关注。     

CYP2D6基因多态性及其临床意义

CYP2D6是CYP酶系中重要的一种氧化代谢酶,参与多种药物的代谢.CYP2D6具有基因多态性,使药物代谢在不同种族之间,甚至在同种族不同人群中产生较大的差异,从而影响药物的疗效.因此,深入了解CYP2D6基因的多态性以及对药物代谢的影响,对指导临床合理用药和调整用药方案具有重大意义.     

CYP2D6基因多态性及对药物代谢的影响

CYP2D6代谢酶是细胞色素P450家族中的成员之一,是参与Ⅰ相代谢和众多内源性物质和不同药物消除的酶。虽然它在肝脏中的含量大约只占肝脏总量的2%,但在临床上却参与了25%以上的常用药物的代谢活动。在所有参与药物代谢的细胞色素P450基因家族中,CYP2D6是唯一不能被诱导的酶,这种酶具有广泛的多态性,这种多态性对酶的药物代谢功能具有重要影响,CYP2D6的这种多态性和药物代谢功能所表现的对个体活性的差异,在遗传药理学上具有重要意义。本文从CYP2D6基因多态性和它对药物代谢的影响这两方面进行了阐述。     

与CYPOR共表达CYP2D6~*1和CYP2D6~*10及其代谢活性比较

细胞色素P450 2D6(cytochrome P450 2D6,CYP2D6)是一种重要的氧化代谢酶,呈基因多态性,对药物的代谢呈现明显的个体差异和种族差异,CYP2D6*10在中国人群中的发生率高达51.3%。采用杆状病毒昆虫表达系统,采用与细胞色素氧化还原酶(cytochrome oxidoreductase,CYPOR)共表达的方式获得具有代谢活性的CYP2D6*1/CYP2D6*10,并初步研究其催化右美沙芬的代谢活性差异。构建重组质粒pFastBac-CYP2D6*1,pFastBac-CYP2D6*10和pFastBac-CYPOR,并分别转化DH10Bac菌株构建重组Bacmid-CYPOR,Bacmid-CYP2D6*1和Bacmid-CYP2D6*10,转染Sf9昆虫细胞,获得重组杆状病毒用于病毒扩增和感染Sf9昆虫细胞。通过测定混悬蛋白催化右美沙芬的速率来优化重组CYPOR和CYP2D6病毒感染Sf9昆虫细胞的感染复数(multiplicity of infection,MOI)值和其比例,获得活力较高的重组CYP2D6*1和CYP2D6*10。重组CYP2D6*1催化右美沙芬的Km为(...     

Atomoxetine pharmacokinetics in healthy Chinese subjects and effect of the CYP2D6*10 allele

AIMS: To characterize atomoxetine pharmacokinetics, explore the effect of the homozygous CYP2D6*10 genotype on atomoxetine pharmacokinetics and evaluate the tolerability of atomoxetine, in healthy Chinese subjects. METHODS: Twenty-four subjects, all CYP2D6 extensive metabolizers (EM), were randomized to receive atomoxetine (40 mg qd for 3 days, then 80 mg qd for 7 days) or matching placebo (2 : 1 ratio) in a double-blind fashion. Atomoxetine serum concentrations were measured following single (40 mg) and multiple (80 mg) doses. Adverse events, clinical safety laboratory data and vital signs were assessed during the study. RESULTS: Atomoxetine was rapidly absorbed with median time to maximum serum concentrations of approximately 1.5 h after single and multiple doses. Atomoxetine concentrations appeared to decrease monoexponentially with a mean apparent terminal half-life (t(1/2)) of approximately 4 h. The apparent clearance, apparent volume of distribution and t(1/2) following single and multiple doses were similar, suggesting linear pharmacokinetics with respect to time. Homozygous CYP2D6*10 subjects had 50% lower clearances compared with other EM subjects, resulting in twofold higher mean exposures. No clinically significant changes or abnormalities were noted in laboratory data and vital signs. CONCLUSIONS: The pharmacokinetics of atomoxetine in healthy Chinese subjects appears comparable to other ethnic populations. Multiple dosing of 80 mg qd atomoxetine was well tolerated in this study.     

Effect of the CYP2D6*10 genotype on venlafaxine pharmacokinetics in healthy adult volunteers

AIMS: Interindividual differences in the pharmacokinetics of venlafaxine, a new antidepressant, were shown during early clinical trials in Japan. Venlafaxine is metabolized mainly by CYP2D6 to an active metabolite, O-desmethylvenlafaxine (ODV). Therefore, the influence of the CYP2D6 genotypes on venlafaxine pharmacokinetics was examined in a Japanese population. METHODS: Twelve adult Japanese men in good health participated in this study. Genomic DNA was isolated from peripheral lymphocytes, and the CYP2D6 genotypes were determined by codon 188C/T, 1934G/A, 2938G/A and 4268G/C mutations using endonuclease tests based on PCR and by Xba I-RFLP analysis. Subjects were categorized into the following 3 groups (n=4 in each group); Group1: CYP2D6*10/*10, *5/*10, Group2: CYP2D6*1/*10, *2/*10 and Group3: CYP2D6*1/*1, CYP2D6*1/*2. Venlafaxine (25 mg, n=6; 37.5 mg, n=6) was administered orally at 09.00 h following an overnight fast. Plasma concentrations of venlafaxine and ODV were monitored by h.p.l.c. for 48 h. RESULTS: The Cmax and AUC of venlafaxine were 184% and 484% higher in the group 1 subjects than in the group 3 subjects, and 101% and 203% higher in the group 1 than in the group 2, respectively. CONCLUSIONS: These results suggest that CYP2D6*10 influences the pharmacokinetics of venlafaxine in a Japanese population.     

Frequencies of CYP2D6 mutant alleles in a normal Japanese population and metabolic activity of dextromethorphan O-demethylation in different CYP2D6 genotypes

AIMS: To determine the frequencies of 11 CYP2D6 mutant alleles (CYP2D6*2, *3, *4, *5, *8, *10, *11, *12, *14, *17 and *18), and their relation to the metabolic capacity of CYP2D6 in Japanese subjects. METHODS: One hundred and sixty-two unrelated healthy Japanese subjects were genotyped with the polymerase chain reaction amplification method and 35 subjects were phenotyped with dextromethorphan. RESULTS: The frequencies of CYP2D6*2,*5, *10 and *14 were 12.9, 6.2, 38.6 and 2.2% in our Japanese subjects, respectively. CYP2D6*3, *4, *8, *11, *12, *17 and *18 were not detected. The mean log metabolic ratio of dextromethorphan in subjects with genotypes predicting intermediate metabolizers was significantly greater than that of heterozygotes for functional and defective alleles. CONCLUSIONS: CYP2D6*5 and CYP2D6*14 are the major defective alleles found in Japanese subjects. In addition, CYP2D6*10 may play a more important role than previously thought for the treatment of Japanese patients with drugs metabolized by CYP2D6.     

Influence of the CYP2D6*10 allele on the metabolism of mexiletine by human liver microsomes

AIMS: To study the influence of CYP2D6*10 on the formation of p-hydroxymexiletine (PHM) and hydroxymethylmexiletine (HMM) using microsomes from human liver of known genotypes. METHODS: Microsomes from human livers of genotype CYP2D6*1/*1 (n = 5), *1/*10 (n = 6) and *10/*10 (n = 6) were used in this study. The formation of PHM and HMM was determined by high-performance liquid chromatography. RESULTS: The formation rates of PHM and HMM were decreased by more than 50% and 85% in CYP2D6*1/*10 and *10/*10 microsomes, respectively, compared with *1/*1 microsomes. CONCLUSIONS: The metabolism of mexiletine to form PHM and HMM appears to be impaired to a significant extent in human liver microsomes from hetero- and homozygotes of CYP2D6*10.     

肾功能不全患者细胞色素P4502D6酶的基因多态性分析

目的研究肾功能不全患者细胞色素P4502D6酶的CYP2D6＊10等位基因的基因多态性。方法采用5引物单管聚合酶链反应扩增CYP2D6＊10等位基因,对103例肾功能不全患者的细胞色素P4502D6酶基因型进行分析。结果 103例肾功能不全患者的CYP2D6＊10等位基因频率为49.51%,其中33例（32.04%）为野生型（C/C）,32例（31.07%）为突变型（T/T）,其余38例（36.89%）为杂合子型（C/T）,与健康汉族人群比较差异有显著意义（P〈0.05）。C等位基因频率为50.5%,T等位基因频率为49.5%。结论 CYP2D6＊10等位基因是影响肾功能不全的一个因素。     

Impact of CYP2D6*10 on mexiletine pharmacokinetics in healthy adult volunteers

Objective In vitro studies with human liver microsomes have suggested that the oxidative conversion of mexiletine (MX) to its metabolites is catalyzed by CYP2D6 and is significantly impaired in microsomes with the CYP2D6*10/*10 genotype. Therefore, we examined the influence of the CYP2D6*10 allele on MX pharmacokinetics in Japanese subjects.Methods Subjects with CYP2D6*1/*1 (group*1/*1; n=5), CYP2D6*10/*10 (group*10/*10; n=6) and CYP2D6*5/*10 (group*5/*10; n=4) genotypes received a single 200-mg dose of MX. Plasma and urinary levels of MX and its metabolites (p-hydroxymexiletine (PHM), hydroxymethylmexiletine (HMM) and N-hydroxymexiletine (NHM)) were determined by means of high-performance liquid chromatography.Results Mean area under the concentration–time curve (AUC) and t_1/2 of MX were significantly (P<0.05) higher in the CYP2D6*10/*5 group (AUC 11.23±3.05 µg·h/ml; t_1/2 15.5±3.2 h) than in the CYP2D6*1/*1 (AUC 5.53±1.01 µg·h/ml; t_1/2 8.1±1.6 h) and CYP2D6*10/*10 (AUC 7.32±2.36 µg·h/ml; t_1/2 10.8±2.8 h) groups, but there was no significant difference between the CYP2D6*1/*1 and CYP2D6*10/*10 groups. The maximum plasma concentration of MX was not significantly different among the three groups. The values of urinary excretion of PHM and HMM in the CYP2D6*1/*1 group were significantly (P<0.05) higher than those in the CYP2D6*10/*10 and CYP2D6*5/*10 groups, but there was no significant difference in that of NHM among the three groups. Clearance of MX in the CYP2D6*5/*10 subjects was comparable to that in the poor metabolizers described previously.Conclusion The present findings demonstrated that carriers of the CYP2D6*10 allele showed a decreased clearance of MX. Subjects with CYP2D6*5/*10 showed significantly (P<0.05) increased plasma levels of MX, and homozygotes for CYP2D6*10 also showed an increase, although to a lesser extent. Thus, the CYP2D6*10 allele plays an important role in MX pharmacokinetics.     

Effect of CYP2D6*10 on pharmacokinetic variability of routinely administered metoprolol in middle-aged and elderly Japanese patients

Objective This study was performed to evaluate the effect of mutant alleles CYP2D6*2 and CYP2D6*10 on the pharmacokinetics of routinely administered metoprolol in middle-aged and elderly Japanese patients.Methods We determined the genotypes of CYP2D6 in 34 patients aged from 56 years to 83 years, and analyzed the plasma concentration of metoprolol at steady state after repetitive administration. The pharmacokinetic parameters of metoprolol in individual patients were obtained from population estimates according to Bayes' theorem.Results The plasma concentrations of metoprolol in the patients with CYP2D6*1/*1 (group 1a) were similar to those in the patients with CYP2D6*1/*2 (group 1b). The plasma concentrations in the patients with CYP2D6*1/*10 (group 2a) were also similar to those in the patients with CYP2D6*2/*10 (group 2b) but were higher than those in group 1 (group 1a plus 1b). The plasma concentrations of metoprolol in the patients with CYP2D6*10/*10 (group 3) were significantly higher than those in group 1 and group 2 (group 2a plus 2b). Mean values of oral clearance (in l/h/kg) in Groups 1, 2, and 3 were estimated to be 1.2, 1.0, and 0.49, respectively. These oral clearance values of metoprolol estimated in middle-aged and elderly Japanese patients were lower than those estimated in healthy young Chinese reported previously.Conclusion The present study indicated that CYP2D6*10 is mainly responsible for the large pharmacokinetic variability of routinely administered metoprolol in middle-aged and elderly Japanese patients. In addition, the pharmacokinetics of repetitively administered metoprolol in middle-aged and elderly patients may be different from that of a single dose in younger patients. These results suggested that a lower dose of metoprolol may be used in middle-aged and elderly patients with CYP2D6*10.