Glycerol absorption by Na+-dependent carrier-mediated transport in the closed loop of the rat small intestine
Glycerol absorption by Na+-dependent carrier-mediated transport in the closed loop of the rat small intestine
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DOI：
10.1248/bpb.28.553
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发表时间：
2005-03-01
影响因子：
2
通讯作者：
Yuasa, H
中科院分区：
文献类型：
--
作者：
Kato, T;Hayashi, Y;Yuasa, H
利用原位小肠闭合环检测甘油的吸收，以阐明其转运机制。甘油的吸收，通过其从肠腔中消失来评估，在无Na+的条件下是饱和的和减少的，这表明Na+依赖载体介导的运输系统的参与。此外，几种醇选择性地抑制了甘油的吸收，其中1,3-丙二醇的抑制作用最大，甘油-3-磷酸和voglibose也是类似于甘油的醇相关化合物。其他几种不抑制甘油吸收的化合物包括d -葡萄糖和l -抗坏血酸，已知它们是通过特定载体运输的。因此，这两种化合物的载体似乎不参与甘油的吸收。参与甘油吸收的载体介导的转运系统很可能只针对甘油，也可能针对一些类似的羟基化合物。因此，本研究为大鼠小肠中存在Na+依赖性载体介导的甘油转运系统提供了原位证据。研究载体介导的甘油运输系统参与药物吸收的可能性以及它可用于口服药物递送的可能性将是很有趣的。
The absorption of glycerol was examined using the closed loop of the rat small intestine in situ to clarify the transport mechanism. The absorption of glycerol, evaluated by its disappearance from the intestinal lumen, was saturable and reduced under the Na+-free conditions, suggesting the involvement of an Na+-dependent carrier-mediated transport system. Furthermore, glycerol absorption was selectively inhibited by several alcohols, among which 1,3-propanediol caused the greatest inhibition, and also by glycerol-3-phosphate and voglibose, which are alcohol-related compounds analogous to glycerol. Several other compounds that did not inhibit glycerol absorption included D-glucose and L-ascorbate, which are known to be transported by specific carriers. Therefore, the carriers for these two compounds do not seem to be involved in glycerol absorption. It is likely that the carrier-mediated transport system involved in glycerol absorption is specific to glycerol and, possibly, some analogous compounds with hydroxyl groups. Thus, the present study has provided in situ evidence for the presence of an Na+-dependent carrier-mediated transport system for glycerol in the rat small intestine. It would be interesting to examine the possibility that the carrier-mediated glycerol transport system could be involved in drug absorption and also that it could be used for oral drug delivery.