PREDICTION OF DRUG INTERACTION IN VITRO -FOCUSING ON CYTOCHROME P-450 3A AND P-GLYCOPROTEIN-

体外药物相互作用的预测 - 重点关注细胞色素 P-450 3A 和 P-糖蛋白 -

• 批准号: 10672153
• 负责人: SUGIMOTO Koichi
• 金额: $ 1.92万
• 依托单位: JICHI MEDICAL SCHOOL
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10672153/
• 关键词: Caco-2 cell; P-glycoprotein; cytochrome P-450 3A4; drug interaction; phenobarbital; rifampicin; digoxin; チトクロムP-450 3A4; Caco2; シクロスポリン; プロブコール

Using cultured Caco-2 cell monolayers, we tried to investigate the involvement of cytochrome P-450 (CYP) 3A4 and P-glycoprotein (P-gp) and to predict drug interaction of orally administered agents in vitro. Probucol, a lipid-lowering drug, caused P-gp-independent suppression of cyclosporine A (a substrate of CYP3A4 and P-gp) transport across Caco-2 cell monolayers. Pretreatment with various inducers failed to augment the P-gp-induced drug extrusion into the apical side of Caco-2 cell monolayers. Microsome fraction from Caco-2 cells even treated with CYP inducers did not demonstrate oxidization of nifedipine which is mediated by CYP3A4.We thus performed ex vivo experiments using intact rats. Microsome fractions from the intestinal epithelium and liver showed oxidation of nifedipine (averaged production rate ; 35 and 160 pmol/min/mg protein, respectively). We constructed ex vivo intestinal perfusion system and examined the absorption and secretion of P-gp substrate drug. P-gp inhibitor (verapamil, ketoconazole) increased the transport of digoxin, a P-gp substrate, to the adventitial side, and decreased the secretion into the luminal perfusate, indicating that this system can be used to assess the involvement of P-gp in the drug absorption at the intestinal tract. Treatment with phenobarbital, a CYP inducer, increased CYP3A4 activity in the liver (+ 130 %), but not intestinal epithelium. Another inducer, rifampicin, elevated CYP3A4 activity in the intestinal epithelium (+ 32 %) without affecting the activity in the liver. Rifampicin also enhanced the P-gp activity in the intestine. These results from ex vivo study suggest that CYP inducers may cause tissue-specific induction of CYP or P-gp activity. The mechanism of tissue-specific induction of drug metabolism or drug extrusion needs to be clarified. It may be helpful to understand the mechanism of drug interaction.

使用培养的CACO-2细胞单层，我们试图研究细胞色素P-450（CYP）3A4和P-糖蛋白（P-GP）的参与，并预测体外口服药物的药物相互作用。 Procucol是一种降脂药物，在跨CACO-2细胞单层跨CACO-2细胞单层抑制了P-gp非依赖性抑制环孢菌素A（CYP3A4和P-GP的底物）。用各种诱导剂进行预处理未能将P-gp诱导的药物挤出到Caco-2细胞单层的顶端。甚至用CYP诱导剂处理的CACO-2细胞的微粒体馏分并未证明由CYP3A介导的硝苯地平的氧化。因此，我们使用完整的大鼠进行了离体实验。肠上皮和肝脏的微粒体馏分显示硝苯地平的氧化（平均产量;分别为35 pmol/min/mg蛋白）。我们构建了体内肠道灌注系统，并检查了P-gp底物药物的吸收和分泌。 P-GP抑制剂（Verapamil，酮康唑）增加了地高辛（P-gp底物）的转运，并减少了向腔灌注液中的分泌，表明该系统可用于评估P-gp在肠道中吸收P-gp的参与。用苯巴比妥治疗CYP诱导剂，肝脏中CYP3A4的活性增加（+ 130％），但没有肠上皮。另一种诱导剂利福平升高的CYP3A4活性升高（+ 32％），而不会影响肝脏的活性。利福平还增强了肠中的P-gp活性。来自体内研究的这些结果表明，CYP诱导剂可能引起组织特异性CYP或P-gp活性的诱导。需要澄清组织特异性诱导药物代谢或药物挤出的机制。了解药物相互作用的机制可能会有所帮助。