Polymorphic debrisoquine 4-hydroxylase activity in the rat is due to differences in CYP2D2 expression.
Polymorphic debrisoquine 4-hydroxylase activity in the rat is due to differences in CYP2D2 expression.
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大鼠体内的多态异喹啉 4-羟化酶活性是由于 CYP2D2 表达的差异造成的。
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
R. Edwards
中科院分区：
文献类型：
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作者：
T. Schulz;A. Bennett;S. Ellis;G. Tucker;A. Boobis;R. Edwards
雌性Dark Agti大鼠被广泛用作CYP2D6代谢物表型的动物模型，其他品系的雄性大鼠如SpragueDawley或Wistar被用作广泛代谢物表型的模型。为了确定雌性和雄性Dark Agti、SpragueDawley和Wistar大鼠肝脏中细胞色素P450酶的相对表达水平，用兔抗代表大鼠P450酶的C端的短肽进行了抗肽抗体的制备。在免疫印迹研究中，发现Dark Agti大鼠肝脏中CYP2D1的表达高于SpragueDawley或Wistar大鼠。相比之下，雌性Dark Agti大鼠肝脏中的CYP2D2含量比雌性SpragueDawley或Wistar大鼠低30-40倍，而雄性Dark Agti大鼠肝脏中的CYP2D2含量比雄性SpragueDawley或Wistar大鼠低6-8倍。在三个品系的雌雄中均未检测到肝脏细胞色素P450 2D3。雄性大鼠肝脏细胞色素P450 2 D4的表达普遍高于雌性大鼠，与SpragueDawley或Wistar品系大鼠相比，Dark Agti大鼠肝脏中的表达更高。在雌性和雄性Dark Agti大鼠的肝脏中均有表达，而在雌性SpragueDawley和Wistar大鼠肝脏中不表达。这种形式在雄性SD大鼠和Wistar大鼠的肝脏中有不同程度的表达。与SD大鼠和Wistar大鼠相比，雌性和雄性Dark Agti大鼠肝脏Debrisquine 4-羟基酶活性均显著降低，且与肝脏细胞色素P450_2含量呈正相关(r=0.88；P<；0.001)。在催化脱氢异喹的4-羟基化反应中，重组CYP2D2的催化活性是CYP2D2的18倍。此外，奎宁能显著抑制细胞色素P450 2D2介导的去氢异喹和美托洛尔的氧化反应，而其非对映异构体奎尼丁的抑制作用较小。综上所述，这些结果表明雌性Dark Agti大鼠的脱氢异喹4-羟基酶活性受损是由于低水平的CYP2D2所致。
The female Dark Agouti rat is widely used as an animal model for the CYP2D6 poor metabolizer phenotype, males of other strains such as Sprague Dawley or Wistar serving as models for the extensive metabolizer phenotype. To determine the relative level of expression of CYP2D enzymes in the liver of female and male Dark Agouti, Sprague Dawley and Wistar rats, anti-peptide antibodies were raised in rabbits against short synthetic peptides representing the C-termini of the rat P450 enzymes CYP2D1, CYP2D2, CYP2D3, CYP2D4 and CYP2D5. In immunoblotting studies, it was found that the hepatic expression of CYP2D1 was greater in Dark Agouti rats than Sprague Dawley or Wistar rats. In contrast, hepatic CYP2D2 was 30-40-fold less abundant in female Dark Agouti than female Sprague Dawley or Wistar rats and six- to eightfold less abundant in male Dark Agouti than male Sprague Dawley or Wistar rats. No hepatic CYP2D3 could be detected in either sex of any of the three strains. Hepatic CYP2D4 expression was generally greater in male than female rats, and higher in Dark Agouti compared with Sprague Dawley or Wistar strains. CYP2D5 was expressed in the livers of female and male Dark Agouti rats but not in female Sprague Dawley or Wistar rats. This form was variably expressed in livers of male Sprague Dawley and Wistar rats. Hepatic debrisoquine 4-hydroxylase activity was markedly reduced in female and male Dark Agouti rats as compared to Sprague Dawley or Wistar rats and correlated (r = 0.88; P < 0.001) with the hepatic CYP2D2 content. Recombinant CYP2D2 was 18-fold more active at catalysing the 4-hydroxylation of debrisoquine than CYP2D1. Furthermore, quinine markedly inhibited CYP2D2-mediated debrisoquine and metoprolol oxidation, while quinidine, its diastereoisomer, inhibited the reactions to a lesser extent. In conclusion, these results show that impaired debrisoquine 4-hydroxylase activity in the female Dark Agouti rat is due to low levels of CYP2D2.