上海地区210名12周岁儿童CYP3A活性分布

目的:了解上海地区12岁儿童CYP3A酶活性的分布。方法:采用HPLC法测定尿液中氢化可的松和6β-羟基氢化可的松的浓度,以6β-羟基氢化可的松/氢化可的松的浓度比来表示CYP3A酶的活性。结果:210名受检者CYP3A酶的活性为(5.0±2.3),其中男性为(4.7±2.3),女性为(5.4±2.4)。结论:12岁儿童CYP3A酶活性无性别差异,正常值范围为0.96~26.55。     

上海市544例学龄儿童CYP3A酶活性分布初探

目的:为儿童个体化给药建立科学的评价依据。方法:采用定量方法,利用氢化可的松探针测定544例健康儿童志愿者CYP3A酶活性。结果:健康儿童志愿者CYP3A酶活性取自然对数时呈正态分布,其平均值为1·69±1·04,其中男性为1·63±0·99,女性为1·75±1·09。结论:CYP3A酶活性在性别方面无显著性差异。     

上海市中小学女生CYP3A酶活性分析

目的:分析女中小学生CYP3A酶活性及其变化趋势。方法:用HPLC梯度洗脱法测定573名女中小学生尿液中6β-羟基氢化可的松和氢化可的松的含量,并通过计算其比值分析CYP3A的活性。结果:在青春期开始发育时CYP3A酶的活性降低,且发育后酶活性个体差异变大。结论:中小学女生年龄跨越大,临床使用经CYP3A酶代谢的药物时应根据身体发育情况适当调整。     

上海地区初中生CYP3A酶活性分布

目的了解上海地区初中生CYP3A酶活性的分布。方法采用HPLC法测定尿液中氢化可的松和6β-羟基氢化可的松的浓度,以6β-羟基氢化可的松/氢化可的松的浓度比来表示CYP3A酶的活性。结果980名受检者CYP3A酶的活性为5.21±2.32,年龄(X)与CYP3A酶的活性(Y)的线性方程为:Y=0.342X 0.900。结论上海地区初中生CYP3A酶活性无性别差异,其正常值范围为1.00~27.16。     

上海地区208名儿童CYP3A活性分布

目的:了解上海地区3岁儿童CYP3A酶活性的分布。方法:采用高效液相色谱法(HPLC)测定尿液中氢化可的松和6β-羟基氢化可的松的浓度,以6β-羟基氢化可的松/氢化可的松的浓度比来表示CYP3A酶的活性。结果:208名受检者CYP3A酶的活性为4.0±1.9,其中男性为4.2±1.9,女性为3.7±1.8。结论:3岁儿童CYP3A酶活性无性别差异,正常值范围为1.13~13.77。     

五酯片提取物对人CYP3A4及CYP3A5重组酶活性的抑制作用及其机制

五酯片是临床上常用的护肝中药单方制剂,常被用来治疗各种原因引起的肝损伤。前期研究表明五酯片可通过抑制CYP3A从而升高移植患者、大鼠体内他克莫司、环孢素、紫杉醇等药物的血药浓度。CYP3A4和CYP3A5是CYP3A的两种重要亚型,但它们在催化活性及对抑制剂敏感性上表现不同。对CYP3A4和CYP3A5抑制作用的差异可能会导致不同的药物相互作用,这种相互作用的风险在体内可能会被进一步放大。可见,研究五酯片对CYP3A4及CYP3A5活性抑制作用的异同具有较好的临床治疗学及经济学意义。然而,目前尚未见五酯片对CYP3A4及CYP3A5活性的抑制作用及作用机制的相关研究。因此,本研究利用人重组CYP3A4 (recombinant human CYP3A4, rhCYP3A4)、人重组CYP3A5 (recombinant human CYP3A5, rhCYP3A5)考察五酯片提取物对CYP3A4、CYP3A5活性的影响及作用特征、机制。结果表明,五酯片提取物对CYP3A4、CYP3A5活性的抑制作用存在NADPH、预孵育时间及浓度依赖性;其与CYP3A4及CYP3A5的结合比较牢固,不...     

环孢素A与CYP3A

环孢霉素A是一种广泛用于器官移植的免疫抑制剂,其生物利用度低且个体差异大,本文从环孢霉素A代谢的影响因素、环孢霉素A与药物和食物的相互作用等方面探讨了环孢霉素A与CYP3A的关系。则时介绍了CYP3A活性的体内测定方法。     

CYP3A4,CYP3A5和MDR1基因多态性对环孢素处置的影响

环孢素是一个广泛用于器官移植患者的免疫抑制剂,具有治疗指数窄,不同个体间药代动力学差异较大的特点。它主要通过肝脏和小肠的CYP3A4和CYP3A5代谢;同时它又是药物转运体的底物。不同个体间药物代谢酶和转运体活性的差异可能是造成不同器官移植患者环孢素药代动力学差异的主要原因。而遗传因素即编码药物代谢酶和转运体基因序列的差异可能是其产生活性差异的分子机制。因此,从编码药物代谢酶和转运体的基因入手,可能会为器官移植患者提供最优的治疗方案。     

CYP3A4与CYP3A5基因多态性与中国汉族急性白血病易感性的相关性研究

目的检测中国汉族急性白血病(AL)患者和健康受试者中CYP3A4*18和CYP3A5*3基因型分布特征,探讨CYP3A4和CYP3A5基因多态性与中国汉族AL易感性的相关性。方法病例对照研究,用聚合酶链反应(PCR)后直接测序的方法,检测中国汉族AL患者91例,健康受试者200例的CYP3A4*18B和CYP3A5*3位点的基因型分布及等位基因频率。结果中国汉族AL患者和健康受试者CYP3A4*18B和CYP3A5*3基因型分布均符合Hardy-Weinberg平衡。与健康受试者比较,AL患者CYP3A4*18B基因型及等位基因频率差异均无统计学意义(P>0.05),CYP3A5*3基因型及等位基因分布频率差异均有统计学意义(P<0.05)。结论 CYP3A4*18B多态性与中国汉族AL的易感性可能无关,CYP3A5*3多态性与中国汉族AL的易感性可能相关。     

重组肝CYP3A4与CYP3A29细胞微粒体药物代谢动力学比较

目的 比较巴马小型猪CYP3A29和人CYP3 A4稳定表达重组肝癌细胞株微粒体的药物代谢特征,在分子水平为巴马小型猪作为临床前药物代谢实验动物提供科学依据.方法 以CYP3A特异性代谢底物硝苯地平、睾酮及其抑制药酮康唑为探针药物,将探针药物与重组CYP3A4、CYP3A29细胞微粒体在优化的微粒体浓度、药物浓度、孵育时间等条件下进行体外孵育,高效液相色谱法检测其药物代谢(抑制)动力学参数,并将二者进行比较分析.结果 巴马小型猪CYP3A29与CYP3A4在硝苯地平和睾酮代谢差异无统计学意义(P＞0.05).酮康唑的抑制活性为:当代谢底物为硝苯地平时,酮康唑对CYP3A29和CYP3A4的半数抑制浓度分别为0.090,0.132 μmol·L-1(P＜0.05);当代谢底物为睾酮时,酮康唑对CYP3A29和CYP3A4的半数抑制浓度分别为0.056,0.032 μmol·L-1(P＜0.05).结论 重组CYP3A29与CYP3 A4细胞微粒体对硝苯地平和睾酮活性差异不显著;酮康唑对重组CYP3A29与CYP3A4细胞微粒体硝苯地平和睾酮代谢活性有差异.     

Pharmacokinetics of midazolam in CYP3A4- and CYP3A5-genotyped subjects

Objective We investigated whether differences in pharmacokinetics of midazolam, a CYP3A probe, could be demonstrated between subjects with different CYP3A4 and CYP3A5 genotypes.Methods Plasma concentrations of midazolam, and of total (conjugated + unconjugated) 1OH-midazolam, and 4OH-midazolam were measured after the oral administration of 7.5 mg or of 75 µg of midazolam in 21 healthy subjects.Results CYP3A5*7, CYP3A4*1E, CYP3A4*2, CYP3A4*4, CYP3A4*5, CYP3A4*6, CYP3A4*8, CYP3A4*11, CYP3A4*12, CYP3A4*13, CYP3A4*17 and CYP3A4*18 alleles were not identified in the 21 subjects. CYP3A5*3, CYP3A5*6, CYP3A4*1B and CYP3A4*1F alleles were identified in 20, 1, 4 and 2 subjects, respectively. No statistically significant differences were observed for the AUC_inf values between the different genotypes after the 75-µg or the 7.5-mg dose.Conclusion Presently, CYP3A4 and CYP3A5 genotyping methods do not sufficiently reflect the inter-individual variability of CYP3A activity.     

CYP3A5~*3和CYP3A4~*18B基因多态性对肾移植患者环孢素药代动力学的影响

目的回顾性研究肾脏移植后1mon,CYP3A5*3和CYP3A4*18B基因多态性对CsA药代动力学参数的影响。方法采用PCR-RFLP方法分析了63名肾脏移植患者CYP3A5*3和CYP3A4*18B基因型;荧光偏正免疫法用于检测肾移植患者静脉全血中的CsA浓度。结果在63名肾移植患者中,CYP3A5*3和CYP3A4*18B突变等位基因发生频率分别为0.770(95CI:0.767～0.773),0.235(95CI:0.235～0.241),而且这些等位基因表现出完全连锁不平衡。在移植术后1mon内,携带CYP3A4*1/*1野生型纯合子患者的C0以及剂量校正谷血浓度(C0/D)均明显高于携带CYP3A4*1/*18B杂合子或CYP3A4*18B/*18B突变型纯合子患者(P<0.05,Mann-WhitneyUtest);CYP3A5*1/*1基因型组的给药剂量明显高于CYP3A5*1/*3或CYP3A5*3/*3基因型组(P=0.004<0.01,Kruakal-Wallistest);CYP34*18B和CYP3A5*3联合考虑,对于CYP3A5表达组,同样发现C0、C0/D在CYP3A4*1/*1组C0以及C0/D均明显高于CYP3A4*1/*18B或CYP3A4*18B/*18B组(P<0.05,Mann-WhitneyUtest);而其他药动学参数在CYP3A5*3及CYP3A4*18B各组间相比差异则没有统计学意义。结论CYP3A5*3和(或)CYP3A4*18B基因多态性对肾移植后1monCsA药代动力学有一定影响,移植前CYP3A5*3基因型的分析仍需进一步研究。     

Development of template systems for ligand interactions of CYP3A5 and CYP3A7 and their distinctions from CYP3A4 template

Starting from established CYP3A4 Template (DMPK. 2019, and 2020), CYP3A5 and CYP3A7 Templates have been constructed to be reliable tools for verification of their distinct catalytic properties. A distinct occupancy was observed on CYP3A4-selective ligands, but not on the non-selective ligands, in simulation experiments. These ligands often invade into Bay-1 region during the migration from Entrance to Site of oxidation in simulation experiments. These results offered an idea of the distinct localization of Bay-1 residue on CYP3A5 Template, in which the Bay-1 residue stayed closely to Template border. The idea also accounted for the higher oxidation rates of CYP3A5, than of CYP3A4, of noscapine and schisantherin E through their enhanced sitting-stabilization. Typical CYP3A7 substrates such as zonisamide and retinoic acids took their placements without occupying a left side region of Template for their metabolisms. In turn, the occupancies of the left-side region were inevitably observed among poor ligands of CYP3A7. Altered extent of IJK-Interaction or localization of a specific residue at the left-side would thus explain distinct catalytic properties of CYP3A7 on Template. These data suggest the alteration of each one of Template region, from CYP3A4 Template, led to the distinct catalytic properties of CYP3A5 and CYP3A7 forms.     

Comparative analysis of substrate and inhibitor interactions with CYP3A4 and CYP3A5

To evaluate the role that cytochrome (CYP) 3A5 plays in hepatic drug metabolism, the substrate selectivity and inhibitory potential of over 60 compounds towards CYP3A4 and CYP3A5 were assessed using Escherichia coli recombinant cell lines. CYP3A4-mediated metabolism predominated for many of the compounds studied. However, a number of drugs gave similar CL_int estimates using CYP3A5 compared with CYP3A4 including midazolam (CL_int?=?3.4 versus 3.3?µl?min^–1?pmol^–1). Significant CYP3A5-mediated metabolism was also observed for several drugs including mifepristone (CL_int?=?10.3 versus 2.4?µl?min^–1?pmol^–1), and ritonavir (CL_int?=?0.76 versus 0.47?µl?min^–1?pmol^–1). The majority of compounds studied showed a greater inhibitory potential (IC₅₀) towards CYP3A4 compared with CYP3A5 (eightfold lower on average). A greater degree of time-dependent inhibition was also observed with CYP3A4 compared with CYP3A5. The range of compounds investigated in the present study extends significantly previous work and suggests that CYP3A5 may have a significant role in drug metabolism particularly in populations expressing high levels of CYP3A5 and/or on co-medications known to inhibit CYP3A4.     

内源性氢化可的松为探针的体内CYP3A活性测定

目的建立测定精神病患者体内CYP3A酶活性的方法。方法直接收集20例精神病住院患者晨尿液,测定尿液中内源性氢化可的松与6β-羟基氢化可的松的含量,以6β-羟基氢化可的松/氢化可的松来评估CYP3A酶的活性。结果患者尿液中6β-羟基氢化可的松与氢化可的松的比值为(8.12±4.36)。结论CYP3A酶的活性可以通过测定6β-羟基氢化可的松与氢化可的松的比值进行预测。     

Differential expression of CYP3A12 and CYP3A26 mRNAs in canine liver and intestine

The cytochrome P450 (CYP) 3A family is often considered the most important CYP subfamily with regard to drug metabolism in people. Certainly, CYP3A4 contributes to poor oral bioavailability of a number of drugs, and a tremendous amount of effort has been made in attempting to find an appropriate model system to predict the oral bioavailability of candidate drugs. The dog is a species widely used as a preclinical model for the evaluation of drug safety and pharmacokinetics. Compared with other species, little information is available on the tissue distribution of CYP enzymes. The purpose of this study was to determine the level of messenger RNA (mRNA) expression of the canine CYP3A subfamily (CYP3A12 and CYP3A26) in the liver and duodenum. Overall, expression of CYP3A mRNA was greater in the liver than in the duodenum. Hepatic expression of CYP3A26 was greater than CYP3A12 in all dogs, with CYP3A26 comprising 75.2% of the hepatic mRNA CYP3A pool. Conversely, duodenal expression of CYP3A12 was greater than CYP3A26 in all dogs, with CYP3A12 comprising 99.8% of the duodenal mRNA CYP3A pool. In summary, these results represent an important step toward the systematic comparison of human and canine CYP3A enzymes, particularly in relation to oral bioavailability of substrate drugs.