SUCROSE-ABSORPTION BY RAT SMALL-INTESTINE INVIVO AND INVITRO
SUCROSE-ABSORPTION BY RAT SMALL-INTESTINE INVIVO AND INVITRO
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DOI：
10.1113/jphysiol.1977.sp011810
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发表时间：
1977-01-01
影响因子：
5.5
通讯作者：
LEESE, HJ
中科院分区：
文献类型：
--
作者：
DAVIDSON, RE;LEESE, HJ
使用大鼠空肠的体外和体内环研究了来自蔗糖的葡萄糖和果糖的吸收。在低蔗糖浓度（1 和 10 mM）下，葡萄糖以比果糖更快的速度出现在体外制剂的浆膜区室中，但在高蔗糖浓度（50 和 100 mM）下，两种糖的浆膜转移速率相似。在所有研究的蔗糖浓度下，葡萄糖和果糖出现在粘膜区室中，果糖出现的速率超过葡萄糖。添加到体外制剂的粘膜介质中的根皮苷(5×10-5M)消除了源自50mM蔗糖的葡萄糖的浆膜转移，并将果糖的浆膜转移减少了75%。在没有 Na 离子的情况下，体外制剂无法将源自 50 mM 蔗糖的葡萄糖和果糖转移到浆膜室中。葡萄糖在体内制剂的整个肠壁中积极积累，其浓度在 50 和 100 mM 时高于血浆中的浓度，但在 10 mM 蔗糖浓度下则不然。在每个蔗糖浓度下，果糖的积累量约为葡萄糖的一半，但达到的组织浓度高于血浆中的浓度。当体内制剂的血液供应终止时，添加到管腔中的源自蔗糖的葡萄糖和果糖的全壁浓度继续升高。当蔗糖与足以使单糖转运系统饱和的葡萄糖浓度一起添加到管腔中时，没有检测到体内全壁葡萄糖和果糖浓度的增加。二糖水解和产生的己糖转移是连续的、独立的事件。
The absorption of glucose and fructose derived from sucrose was studied using in vitro and in vivo loops of the rat jejunum. At low sucrose concentrations (1 and 10 mM) glucose appeared in the serosal compartment of the in vitro preparation at a faster rate than fructose, but at high sucrose concentrations (50 and 100 mM) the rates of serosal transfer of the 2 sugars were similar. Glucose and fructose appeared in the mucosal compartment, with the rate of fructose appearance exceeding that of glucose, at all the sucrose concentrations studied. Phlorizin (5 .times. 10-5 M) added to the mucosal medium of the in vitro preparation abolished the serosal transfer of glucose derived from 50 mM sucrose, and reduced that of fructose by 75%. In the absence of Na ions, the in vitro preparation failed to transfer glucose and fructose derived from 50 mM sucrose, into the serosal compartment. Glucose was actively accumulated in the whole gut wall of the in vivo preparation to concentrations higher than those in the plasma at 50 and 100 mM, but not at 10 mM sucrose concentrations. Fructose was actively accumulated to about half the extent of glucose, but reached tissue concentrations greater than those in the plasma, at each sucrose concentration. The whole wall concentrations of glucose and fructose derived from sucrose added to the lumen continued to rise when the blood supply to the in vivo preparation was terminated. No increase in the in vivo whole wall concentrations of glucose and fructose were detected when sucrose was added to the lumen together with concentrations of glucose sufficient to saturate the monosaccharide transport systems. Disaccharide hydrolysis and resulting hexose transfer are sequential, separate events.