DEALKYLATION OF PENTOXYRESORUFIN - A RAPID AND SENSITIVE ASSAY FOR MEASURING INDUCTION OF CYTOCHROME(S)-P-450 BY PHENOBARBITAL AND OTHER XENOBIOTICS IN THE RAT
DEALKYLATION OF PENTOXYRESORUFIN - A RAPID AND SENSITIVE ASSAY FOR MEASURING INDUCTION OF CYTOCHROME(S)-P-450 BY PHENOBARBITAL AND OTHER XENOBIOTICS IN THE RAT
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DOI：
10.1016/0003-9861(85)90138-9
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发表时间：
1985-01-01
影响因子：
3.9
通讯作者：
GUENGERICH, FP
中科院分区：
文献类型：
--
作者：
LUBET, RA;MAYER, RT;GUENGERICH, FP
本文研究了大鼠肝微粒体对7-戊氧基苯恶酮的O-脱烷基反应。该反应对苯巴比妥诱导的某些形式的细胞色素P-450具有高度的特异性，经苯巴比妥(75 mg/kg/d，4次/d)动物预处理后，该反应增加了95-140倍。注射)和.apprx。50倍Aroclor 1254(500 mg/kg，1 ip.3-甲基胆蒽(50 mg/kg/d，3次/d，ip.注射)导致在对照微粒子中检测到的比率增加不到2倍。Aroclor处理的大鼠微粒体中的这种活性依赖于O2，并被甲替拉酮和SKF525-A[2-二乙基甘油乙基-2，2‘-二苯基戊酸酯]抑制，表明细胞色素(S)P-450参与了这一反应。当针对纯化的细胞色素(S)P-450的抗体抑制戊氧基间苯二酚O-脱烷基反应时，P-450PB-B的抗体对该反应有明显的抑制作用(90%)，而P-450PB-C或P-450PB/PCN-E的抗体对该反应的抑制作用很小。对给予不同剂量苯巴比妥(0.9-75 mg/kg/d，4次/d)处理的大鼠肝微粒体进行测定。注射)表明，在最大剂量(每天75 mg/kg)时，氨基比林-N-脱甲基酶活性仅被诱导2倍，而戊氧基间苯二酚O-脱烷基酶活性被诱导。在这个剂量和.apprx下是140倍。4倍剂量的苯巴比妥低至0.9 mg/kg。
The O-dealkylation of pentoxyresorufin (7-pentoxyphenoxazone) by rat liver microsomes was examined. The reaction appeared highly specific for certain phenobarbital inducible forms of cytochrome P-450 and was increased 95- to 140-fold by animal pretreatment with phenobarbital (75 mg/kg per day, 4 i.p. injections) and .apprx. 50-fold by Aroclor 1254 (500 mg/kg, 1 i.p. injection) while animal pretreatment with 3-methylcholanthrene (50 mg/kg per day, 3 i.p. injections) resulted in less than a 2-fold increase over the rate detected in control microsomes. This activity, in microsomes for Aroclor-pretreated rats, was dependent on O2 and was inhibited by metyrapone and SKF 525-A [2-diethylmanioethyl-2,2''-diphenylvalerate], indicative of cytochrome(s) P-450 mediation in the reaction. When antibodies directed against purified cytochrome(s) P-450 were employed to inhibit the pentoxyresorufin O-dealkylation reaction, antibodies to P-450PB-B greatly inhibited the reaction (> 90%), while antibodies to P-450PB-C or P-450PB/PCN-E had minimal effects. Assay of hepatic microsomes from rats which were pretreated with varying doses of phenobarbital (0.9-75 mg/kg per day, 4 i.p. injections) indicated that while aminopyrine-N-demethylase activity was induced only 2-fold at the maximum dose (75 mg/kg per day), pentoxyresorufin O-dealkylase activity was induced .apprx. 140-fold at this dose and .apprx. 4-fold by a dose of phenobarbital as low as 0.9 mg/kg.