Quan Y S, Hattori K, Lundborg E, Fujita T, Murakami M, Muranishi S, Yamamoto A
Department of Biopharmaceutics, Kyoto Pharmaceutical University, Japan.
Biol Pharm Bull. 1998 Jun;21(6):615-20. doi: 10.1248/bpb.21.615.
We studied the enhancing and toxic effects of five different absorption enhancers on the transport of FITC-dextran with an average molecular weight of 4000 (FD-4) across Caco-2 cell monolayers, and their enhancing effects were also compared with those in rat intestine. The enhancing and cytotoxic properties of these enhancers were characterized using the following tests: measurement of the permeability coefficients of FD-4 and the transepithelial electrical resistance (TEER) in Caco-2, the release of cytosolic lactate dehydrogenase (LDH) and intracellular mitochondrial dehydrogenase (MDH) activity. All the absorption enhancers increased the permeability of FD-4 across Caco-2 cell monolayers and a good relationship was observed between the enhancement and their toxic effects. However, EDTA and Na-Cap were effective for improving the transport of FD-4 across Caco-2 cells without serious cytotoxicity. At concentrations with low cytotoxicity, various absorption enhancers exihibited reversible effects on the TEER values in Caco-2 cell monolayers, except for 50 mM sodium salicylate (Na-Sal). Moreover, we obtained a good correlation between the enhancement of these enhancers in Caco-2 cell monolayers and in rat large intestine. This finding indicated that the effectiveness of absorption enhancers in the Caco-2 monolayer system was similar to an in vivo rat system. Therefore, the screening system using Caco-2 cell monolayers is useful for examining the effectiveness and toxicity of absorption enhancers.
我们研究了五种不同吸收促进剂对平均分子量为4000的异硫氰酸荧光素标记葡聚糖（FD-4）跨Caco-2细胞单层转运的增强作用和毒性作用，并将它们的增强作用与在大鼠肠道中的增强作用进行了比较。使用以下测试来表征这些促进剂的增强特性和细胞毒性：测量FD-4的渗透系数以及Caco-2中的跨上皮电阻（TEER）、胞质乳酸脱氢酶（LDH）的释放和细胞内线粒体脱氢酶（MDH）的活性。所有吸收促进剂均增加了FD-4跨Caco-2细胞单层的通透性，并且在增强作用与其毒性作用之间观察到良好的相关性。然而，乙二胺四乙酸（EDTA）和癸酸钠（Na-Cap）在不产生严重细胞毒性的情况下有效地改善了FD-4跨Caco-2细胞的转运。在低细胞毒性浓度下，除50 mM水杨酸钠（Na-Sal）外，各种吸收促进剂对Caco-2细胞单层的TEER值均表现出可逆作用。此外，我们发现这些促进剂在Caco-2细胞单层和大鼠大肠中的增强作用之间具有良好的相关性。这一发现表明，吸收促进剂在Caco-2单层系统中的有效性与体内大鼠系统相似。因此，使用Caco-2细胞单层的筛选系统可用于检测吸收促进剂的有效性和毒性。
