Lange R, Balny C, Maurel P
Biochem Pharmacol. 1984 Sep 1;33(17):2771-6. doi: 10.1016/0006-2952(84)90694-4.
New Zealand White rabbits were treated with rifampicin at a dose of 50 mg/kg for 4 days. The total amount of microsomal hepatic cytochrome P-450 was not modified in treated, with respect to control, animals. However, further studies involving SDS-PAGE analysis, monooxygenase activity measurements and radial immunodiffusion assays indicated that rifampicin strongly affects the level of two P-450 isoenzymes. An LM3 form was induced; this form, apparently associated with erythromycine demethylase activity and hydroxylation of progesterone preferentially in position 6 beta, was shown to be immunologically and functionally different from LM3a and LM3b. On the other hand, an LM4 form, typically induced by beta-naphthoflavone, was repressed. The concomitant inductive/repressive effect of rifampicine on two cytochrome P-450 isoenzymes makes this drug a very atypical inducer, at least in the rabbit.
给新西兰白兔按50毫克/千克的剂量使用利福平，持续4天。与对照动物相比，经处理的动物肝脏微粒体细胞色素P - 450的总量未发生改变。然而，进一步涉及十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳分析、单加氧酶活性测量和放射免疫扩散测定的研究表明，利福平强烈影响两种P - 450同工酶的水平。诱导出了一种LM3形式；这种形式显然与红霉素脱甲基酶活性以及孕酮优先在6β位的羟基化有关，在免疫学和功能上与LM3a和LM3b不同。另一方面，一种典型地由β - 萘黄酮诱导的LM4形式受到了抑制。利福平对两种细胞色素P - 450同工酶的这种同时诱导/抑制作用，使得这种药物成为一种非常非典型的诱导剂，至少在兔子中是这样。
