Methadone metabolism by human placenta
Methadone metabolism by human placenta
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DOI：
10.1016/j.bcp.2004.04.011
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发表时间：
2004-08-01
影响因子：
5.8
通讯作者：
Ahmed, MS
中科院分区：
文献类型：
--
作者：
Nanovskaya, TN;Deshmukh, SV;Ahmed, MS
美沙酮药物治疗被认为是治疗怀孕海洛因/阿片类药物成瘾者的标准方法。影响阿片类药物通过人胎盘转移动力学及其在胎儿循环中的水平的因素之一是它们在组织中的代谢。本研究的目的是确定负责美沙酮代谢的酶，确定反应的动力学和利用足月健康妊娠获得的胎盘组织形成的代谢物。滋养细胞组织匀浆的微粒体部分催化美沙酮代谢的活性最高。产物经HPLC-UV鉴定为2乙基吡咯烷-1,5-二甲基-3,3-二苯基吡咯烷（EDDP）。细胞色素P450 （CYP）同工酶选择性抑制剂用于鉴定催化美沙酮生物转化的酶。氨基甲硫胺和4-羟基雄烯二酮对EDDP形成的抑制作用分别为88%和70%，表明CYP19/芳香化酶是催化该反应的酶。针对CYP19的单克隆抗体的作用证实了这一点，该抗体对该反应有80%的抑制作用。CYP19催化美沙酮代谢EDDP的表观K-m和V-max值分别为424 +/- 92 muM和420 +/- 89 mumol (mg protein)(-1) min（-1）。dna表达的CYP19对美沙酮到EDDP代谢的动力学分析与胎盘微粒体的代谢相同。综上所述，这些数据表明，CYP19/芳香化酶是健康妊娠足月胎盘中美沙酮代谢为EDDP的主要酶。(C) 2004爱思唯尔公司版权所有。
Methadone pharmacotherapy is considered the standard for treatment of the pregnant heroin/opioid addict. One of the factors affecting the transfer kinetics of opioids across human placenta and their levels in the fetal circulation is their metabolism by the tissue. The aim of this investigation is to identify the enzyme(s) responsible for the metabolism of methadone, determine the kinetics of the reaction and the metabolites formed utilizing placental tissue obtained from term healthy pregnancies. Microsomal fractions of trophoblast tissue homogenates had the highest activity in catalyzing the metabolism of methadone. The product formed was identified by HPLC-UV as 2ethylidine-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP). Inhibitors selective for cytochrome P450 (CYP) isozymes were used to identify the enzyme catalyzing the biotransformation of methadone. Aminoglutethimide and 4-hydroxyandrostenedione inhibited EDDP formation by 88 and 70%, respectively, suggesting that CYP19/aromatase is the enzyme catalyzing the reaction. This was confirmed by the effect of monoclonal antibodies raised against CYP19 that caused an 80% inhibition of the reaction. The apparent K-m and V-max values for the CYP19 catalyzed metabolism of methadone to EDDP were 424 +/- 92 muM and 420 +/- 89 mumol (mg protein)(-1) min(-1), respectively. Kinetic analysis of a cDNA-expressed CYP19 for the metabolism of methadone to EDDP was identical to that by placental microsomes. Taken together, these data indicate that CYP19/aromatase is the major enzyme responsible for the metabolism of methadone to EDDP in term human placentas obtained from healthy pregnancies. (C) 2004 Elsevier Inc. All rights reserved.