甲基莲心碱在大鼠肝微粒体CYP450系统中的代谢特征  

Metabolic characteristics of neferine in the cytochrome P450 of rat liver microsomes

作　　者：姜敏[1] 梁先明 熊玉卿 

机构地区：[1]江西医学院临床药理研究所,江西南昌330006 [2]中国兽药品监察所,北京100081

出　　处：《中国药理学通报》2006年第6期739-743,共5页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金资助项目(No30060092)

摘　　要：目的研究甲基莲心碱(Nef)在大鼠肝微粒体系的代谢特性,探明参与Nef代谢的CYP450亚酶种类及其在Nef代谢中的作用。方法应用CYP3A特异性诱导剂地塞米松(DEX)、CYP2B诱导剂苯巴比妥(PB)、CYP1A诱导剂β-萘黄酮(β-NF)分别对W istar大鼠进行在体诱导,建立肝微粒体温孵及NADPH再生体系,HPLC紫外检测法测定Nef及其代谢产物。观察Nef代谢消失率与代谢特征,研究上述各诱导剂和CYP3A特异性抑制剂三乙酰竹桃霉素(TAO)对Nef体外代谢的影响。结果Nef在大鼠微粒体系代谢呈饱和现象;温孵液中代谢产物生成的量与底物Nef的浓度具有良好的相关性(r=0.993);Nef在DEX、PB诱导组大鼠肝微粒体温孵液中的生物转化较对照组明显加快(P<0.01),DEX组又较PB组的Nef药物代谢率差异有显著性(P<0.01),而β-NF组未显现诱导作用,其药物代谢率分别为:DEX组80.6%±9.5%;PB组61.5%±6.7%;β-NF组20.7%±1.5%;对照组19.9%±1.6%;TAO呈量效依赖性抑制Nef在肝微粒体温孵液中的代谢。结论研究结果提示Nef具有酶促动力学代谢特性;CYP3A及CYP2B是介导Nef在大鼠体内生物转化的CYP450亚酶,其中主要参与Nef代谢的为CYP3A。Aim The metabolic character of neferine （Nef） in rat liver microsomes was studied in vitro to identify which isoforms of eytoehrome P450 were responsible for Nef metabolism in rats. Methods ① Wistar rats were untreated or treated with various inducers including dexamethasone （DEX,50 mg .kg^-1, ig×4 d）, phenobarbital （PB, 75 mg. kg^-1, ip × 3 d） and β-naphthoflavone （ β-NF, 80 mg . kg ^- 1, ip × 3 d）. Liver mierosomes were obtained from these rats and incubated with Nef in the presence of reduced form of nicotinamide adenine dinucleotide phosphate. A HPLC-UV method was developed to determine Nef and its metabolites. ②The enzyme kinetics of the metabolism of Nef was investigated in rat liver microsomes. ③ Troleandomycin, a CYP3A selective inhibitor, was used to study its inhibitory effect on the metabolism of Nef in vitro. Results ① The metabolism of Nef in rat liver＇ microsomes showed the characteristic of enzyme kinetics. ② The correlation between peak area of a metabolite and original concentration of Nef in rat liver microsomes solution was significant （ r = 0. 993 ）. ③ The disappearing rate of Nef in the incubation solutions of the rats liver microsomes, which treated with DEX or PB, were markedly quicker than that of control group （ P 〈 0. 01 ） and the rate of DEX group was quicker than that of PB group （ P 〈 0. 01 ）. No obvious difference between the disappearing rates of β-NF group and control group was observed （P 〉 0. 05 ）. The average disappearing rates of Nef in rat liver microsomes after incubation with different inducers were as follows： DEX, 80.6%± 9. 5%; PB,61.5% ± 6. 7%;β-NF, 20.7%± 1.5%;Control, 19. 9%±1.6%. ④ Troleandomycin could significantly inhibit the metabolism of Nef in rat liver microsomes. Conclusion Our results suggest that both CYP3A and CYP2B are involved in Nef metabolism in rats liver microsomes, and CYP3A probably play a major role.

关 键 词：甲基莲心碱 高效液相色谱法 微粒体 细胞色素P450 药物代谢 

分 类 号：R-332[医药卫生] R284.1