Jones B J, Higgins B E, Silk D B
Clin Sci (Lond). 1987 Apr;72(4):409-14. doi: 10.1042/cs0720409.
The jejunal absorption of glucose from (1-4)-linked glucose oligomers including maltotriose has been compared with that from free glucose and sucrose in normal subjects. A steady-state perfusion technique in vivo was used to study proximal jejunal assimilation of isotonic sugar-saline solutions isocaloric with 140 mmol/l glucose. Endogenous alpha-amylase was excluded from the test segment by proximal balloon occlusion. The glucose oligomer mixture consisted mainly of maltotriose, maltotetraose, maltopentaose and maltoheptaose. Glucose absorption was significantly faster from maltotriose alone and from the glucose oligomer mixture than from 140 mmol/l glucose controls, whereas glucose absorption from 70 mmol/l sucrose was similar to that from 70 mmol/l glucose plus 70 mmol/l fructose. Hydrolysis in vivo of maltotriose, the oligomer mixture and sucrose were similar, indicating that capture of glucose released by brush border sucrose hydrolysis was less efficient than that associated with (1-4)-linked oligomer hydrolysis. This suggests that the stoichiometric relationship of the active hydrolysis sites for sucrose to the glucose transport system is less advantageous than that of active sites for maltose hydrolysis. Hydrolysis of oligomers larger than maltohexaose may be rate limiting for glucose absorption in the absence of luminal amylase activity.
在正常受试者中，已将包括麦芽三糖在内的（1-4）连接的葡萄糖寡聚物中葡萄糖的空肠吸收与游离葡萄糖和蔗糖的空肠吸收进行了比较。采用体内稳态灌注技术研究等渗糖盐溶液与140 mmol/L葡萄糖等热量的近端空肠同化作用。通过近端气囊闭塞将内源性α-淀粉酶排除在测试段之外。葡萄糖寡聚物混合物主要由麦芽三糖、麦芽四糖、麦芽五糖和麦芽七糖组成。单独的麦芽三糖和葡萄糖寡聚物混合物中的葡萄糖吸收明显快于140 mmol/L葡萄糖对照组，而70 mmol/L蔗糖的葡萄糖吸收与70 mmol/L葡萄糖加70 mmol/L果糖的葡萄糖吸收相似。麦芽三糖、寡聚物混合物和蔗糖在体内的水解相似，这表明刷状缘蔗糖水解释放的葡萄糖捕获效率低于与（1-4）连接的寡聚物水解相关的捕获效率。这表明蔗糖活性水解位点与葡萄糖转运系统的化学计量关系不如麦芽糖水解活性位点的化学计量关系有利。在缺乏腔内淀粉酶活性的情况下，大于麦芽六糖的寡聚物水解可能是葡萄糖吸收的限速因素。
