Laboratory of Animal Science, Kyoto Prefectural University, Hanngi-cho 1-5, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
Histochem Cell Biol. 2011 Feb;135(2):183-94. doi: 10.1007/s00418-011-0779-1. Epub 2011 Jan 28.
Hexose transporters play a pivotal role in the absorption of food-derived monosaccharides in the gastrointestinal tract. Although a basic knowledge of the hexose transporters has already been gained, their detailed distribution and comparative intensities of expression throughout the gastrointestinal tract have not been fully elucidated. In this study, we quantitatively evaluated the expression of SGLT1, GLUT1, GLUT2, and GLUT5 by in situ hybridization and real-time PCR techniques using a total of 28 segments from the gastrointestinal tract of 9-week-old mice. GLUT2 and GLUT5 mRNA expressions were detected predominantly from the proximal to middle parts of the small intestine, showing identical expression profiles, while SGLT1 mRNA was expressed not only in the small intestine but also in the large intestine. Notably, GLUT1 mRNA was expressed at a considerable level in both the stomach and large intestine but was negligible in the small intestine. Immunohistochemistry demonstrated the polarized localization of hexose transporters in the large intestine: SGLT1 on the luminal surface and GLUT1 on the basal side of epithelial cells. The present study provided more elaborate information concerning the localization of hexose transporters in the small intestine. Furthermore, this study revealed the significant expression of glucose transporters in the large intestine, suggesting the existence of the physiological uptake of glucose in that location in mice.
己糖转运体在胃肠道中对食物来源的单糖的吸收起着关键作用。尽管已经对己糖转运体有了基本的了解，但它们在胃肠道中的详细分布和相对表达强度尚未完全阐明。在这项研究中，我们使用原位杂交和实时 PCR 技术，对来自 9 周龄小鼠胃肠道的 28 个部位进行了 SGLT1、GLUT1、GLUT2 和 GLUT5 的定量表达评估。GLUT2 和 GLUT5 mRNA 的表达主要从小肠的近端到中部检测到，表达模式相同，而 SGLT1 mRNA 的表达不仅在小肠中，而且在大肠中。值得注意的是，GLUT1 mRNA 在胃和大肠中有相当水平的表达，但在小肠中则可以忽略不计。免疫组织化学显示了己糖转运体在大肠中的极化定位：SGLT1 在腔面，GLUT1 在上皮细胞的基底侧。本研究提供了关于小肠中己糖转运体定位的更详细信息。此外，本研究还揭示了葡萄糖转运体在大肠中的显著表达，表明在小鼠的大肠中存在葡萄糖的生理摄取。
