Regulation of cytochrome P-450j, a high-affinity N-nitrosodimethylamine demethylase, in rat hepatic microsomes.
Regulation of cytochrome P-450j, a high-affinity N-nitrosodimethylamine demethylase, in rat hepatic microsomes.
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细胞色素 P-450j（一种高亲和力 N-亚硝基二甲胺脱甲基酶）在大鼠肝微粒体中的调节。
作者：
P. Thomas;S. Bandiera;S. Maines;D. Ryan;W. Levin
从异烟肼处理的成年雄性大鼠中分离纯化的细胞色素P-450j，在家兔中制备了多克隆抗体。免疫吸附抗体对细胞色素P-450j的单特异性通过Ouchterlony双扩散分析、酶联免疫吸附试验和免疫印迹证实。免疫定量结果显示，雄性和雌性大鼠肝微粒体细胞色素P-450j含量在3 ~ 6周龄均呈下降趋势。几种外源药物，如Aroclor 1254、mirex和3-甲基胆蒽，在给雄性大鼠时抑制细胞色素P-450j水平。异烟肼、二甲基亚砜、吡唑、4-甲基吡唑和乙醇均是大鼠肝脏细胞色素P-450j的诱导剂，但诱导效果不同。与未治疗的动物相比，化学诱导糖尿病的成年雄性大鼠的微粒体也含有更高水平的细胞色素P-450j。细胞色素P-450j水平在肾脏中可测量到，而这种同工酶在肺、卵巢和睾丸中几乎检测不到；异烟肼对肝外细胞色素P-450j有诱导作用。细胞色素P-450j抗体抑制了约80-90%的微粒体n -亚硝基二甲胺去甲基化，无论这些微粒体是从未经处理的大鼠或给予细胞色素P-450j诱导剂或阻遏剂的动物中分离出来的。根据重组体系获得的结果，残余的抗抗体抑制的催化活性可能反映了由于nadph -细胞色素P-450还原酶的干扰，一定量的细胞色素P-450j无法接近。细胞色素P-450j含量与n -亚硝基二甲胺去甲基化酶活性具有良好的相关性（r2 = 0.87）。现有证据表明，细胞色素P-450j是n -亚硝基二甲胺去甲基化的主要（可能是唯一）微粒体催化剂，其底物浓度与n -亚硝基二甲胺诱导的肝癌发生有关。
Polyclonal antibodies were produced in rabbits against purified cytochrome P-450j isolated from isoniazid-treated adult male rats. The monospecificity of immunoadsorbed antibody to cytochrome P-450j was demonstrated by Ouchterlony double diffusion analyses, enzyme-linked immunosorbent assays, and immunoblots. Immunoquantitation results indicated that rat liver microsomal cytochrome P-450j content decreases between 3 and 6 weeks of age in both the male and female animal. Several xenobiotics, such as Aroclor 1254, mirex, and 3-methylcholanthrene, repressed cytochrome P-450j levels when administered to male rats. Isoniazid, dimethyl sulfoxide, pyrazole, 4-methylpyrazole, and ethanol were inducers of cytochrome P-450j in rat liver although these compounds showed different inducing potencies. Microsomes from adult male rats with chemically induced diabetes also contained elevated levels of cytochrome P-450j compared to untreated animals. Cytochrome P-450j levels were measurable in kidney, whereas this isozyme was barely detectable in lung, ovaries, and testes; however, extrahepatic cytochrome P-450j was inducible by isoniazid. Approximately 80-90% of microsomal N-nitrosodimethylamine demethylation was inhibited by antibody to cytochrome P-450j whether the microsomes were isolated from untreated rats or animals administered inducers or repressors of cytochrome P-450j. The residual catalytic activity resistant to antibody inhibition may be a reflection of the inaccessibility of a certain amount of cytochrome P-450j due to interference by NADPH-cytochrome P-450 reductase based on results obtained with the reconstituted system. There was a good correlation (r2 = 0.87) between cytochrome P-450j content and N-nitrosodimethylamine demethylase activity in microsomes from rats of different ages and treated with various xenobiotics. The evidence presented indicates that cytochrome P-450j is the primary, and perhaps sole, microsomal catalyst of N-nitrosodimethylamine demethylation at substrate concentrations relevant to hepatocarcinogenesis induced by N-nitrosodimethylamine.
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DOI：
10.1073/pnas.82.12.4065
发表时间：
1985-01-01
影响因子：
11.1
作者：
KOOP, DR;CRUMP, BL;COON, MJ
通讯作者：
COON, MJ
从乙醇处理的兔子的肝微粒体中分离出的细胞色素 P-450 同工酶 3a 的催化活性。
DOI：
--
发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Morgan,ET;Koop,DR;Coon,MJ
通讯作者：
Coon,MJ
影响因子：
2.9
作者：
WRIGHTON, SA;THOMAS, PE;GUZELIAN, PS
通讯作者：
GUZELIAN, PS
异烟肼诱导的大鼠肝微粒体细胞色素 P-450 主要形式的表征。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ryan,DE;Ramanathan,L;Iida,S;Thomas,PE;Haniu,M;Shively,JE;Lieber,CS;Levin,W
通讯作者：
Levin,W
来自成年雄性大鼠肝微粒体的三种高度纯化的细胞色素 P-450 的表征。
DOI：
--
发表时间：
1984
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ryan,DE;Iida,S;Wood,AW;Thomas,PE;Lieber,CS;Levin,W
通讯作者：
Levin,W