Design of the in vitro model with a cultured intestinal cell monolayer and pseudo lymph and blood streams for assessment of the absorption of a hydrophobic substance

疏水性物质在体内从肠道吸收到血液或淋巴中。本项目旨在设计一个简单的体外模型，该模型可以与体内吸收过程相比较，并利用分化的培养细胞层独立控制血流和淋巴流，本研究的主要部分是分析疏水物质对细胞的吸收和通过细胞层的吸收。发现疏水性物质积累到细胞层中，并且通过添加另一种具有相反电荷的疏水性物质，可以改善易于被消化酶分解并具有电荷的疏水性物质的吸收，因为两种物质之间的静电相互作用防止了物质的酶促水解并加速了吸收速率。并详细分析了抗氧化剂酰基抗坏血酸在细胞层的吸附过程，包括非酶水解过程。结果表明，酰基抗坏血酸酯具有较强的抗氧化能力，能有效地对抗从肠腔侧到肠道吸收细胞Caco-2的氧化剂。三辛酸甘油酯是作为假淋巴组分的良好化合物之一。选择膜过滤器，以便于将疏水物质从亲水溶液（适用于血液）传输到疏水溶液（适用于淋巴）。此外，经验证，可通过输液泵控制溶液流入血液侧隔室的流出量，并确定了小隔室完全混合的搅拌条件。这些发现将使体外模型的建设评估的疏水性物质的吸收。

The hydrophobic substance is absorbed from the intestinal tract into the blood or lymph in vivo. This project intended to design the simple in vitro model which can be compared with the absorption process in vivo and independently control the blood stream and the lymph stream making use of the cultured cell layer which differentiates.Most part of this research was analysis of absorption of the hydrophobic substance to the cells and through the cell layer. It was found that the hydrophobic substances accumulated into the cell layer and that there was a possibility to improve the absorption of a hydrophobic substance, which is easily decomposed by digestive enzymes and possesses an electric charge, by adding another hydrophobic substance which possesses the counter electric charge because the electrostatic interaction between both substances prevented enzymatic hydrolysis of the substance and accelerated the absorption rate. And the absorption of acyl ascorbates, which possess an anti-oxidation property, to the cell layer was also analyzed in detail including the non-enzymatically hydrolytic process. Furthermore, it was found that the acyl ascorbates granted a strong anti-oxidation property against the oxidant from the lumen side to the intestinal tract absorption cell, Caco-2.The various conditions necessary for model construction were examined. Tricaprylin was one of the good compounds as a pseudo lymph component. A membrane filter was selected for the easy transmit of a hydrophobic substance from the hydrophilic solution (suitable to the blood) to the hydrophobic solution (suitable to the lymph). In addition, it was verified that the influx outflow of the solution to the compartment of blood side can be controlled with an infusion pump and was decided the churning condition for complete mixing of the small compartment. These findings would enable the construction of the in vitro model for assessment of the absorption of a hydrophobic substance.