Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Finland.
Int J Pharm. 2010 Jan 4;383(1-2):24-9. doi: 10.1016/j.ijpharm.2009.08.044. Epub 2009 Sep 4.
The human intestinal cell line, Caco-2, was used to study compounds - indomethacin, paracetamol and 1-naphthol - that undergo intestinal phase II metabolism followed by apical and/or basolateral efflux of the metabolites and/or parent compounds. The interplay was studied during permeability experiments across fully differentiated Caco-2 cell monolayers. The parent compounds and their glucuronide and/or sulfate metabolites were detected by LC-MS/MS. Conjugation of the model compounds and effluxes of their metabolites were observed. The efflux of indomethacin glucuronide was apical, but complementary basolateral efflux was observed at the highest indomethacin concentration (500 microM), probably due to apical saturation. Paracetamol glucuronide was not formed in these experiments, but apical and basolateral effluxes of paracetamol sulfate were observed. A typical bell-shaped inhibition curve was observed for the formation of 1-naphthol glucuronides, indicating substrate or product inhibition of the UGT enzyme(s) at higher 1-naphthol concentrations (200 microM and 500 microM). Based on these results, the fully differentiated Caco-2 cell monolayers can be applied as a platform for qualitative in vitro studies, where phase II metabolism and efflux activities are ongoing simultaneously.
人肠道细胞系 Caco-2 用于研究在经历肠内二期代谢后，其代谢物和/或母体化合物通过顶端和/或基底外侧外排的化合物 - 吲哚美辛、扑热息痛和 1-萘酚。在跨完全分化的 Caco-2 细胞单层的渗透实验中研究了这种相互作用。母体化合物及其葡萄糖醛酸和/或硫酸盐代谢物通过 LC-MS/MS 检测。观察到模型化合物的缀合和代谢物的外排。吲哚美辛葡萄糖醛酸的外排是顶端的，但在最高吲哚美辛浓度（500μM）下观察到互补的基底外侧外排，可能是由于顶端饱和。在这些实验中未形成对乙酰氨基酚葡萄糖醛酸，但观察到对乙酰氨基酚硫酸盐的顶端和基底外侧外排。1-萘酚葡萄糖醛酸的形成呈典型的钟形抑制曲线，表明在较高的 1-萘酚浓度（200μM 和 500μM）下，UGT 酶的底物或产物抑制。基于这些结果，完全分化的 Caco-2 细胞单层可作为同时进行二期代谢和外排活动的定性体外研究平台。
