Kotler D P, Levine G M, Shiau Y F
Am J Physiol. 1981 Jun;240(6):G432-6. doi: 10.1152/ajpgi.1981.240.6.G432.
Luminal nutrients, but not metabolic status, maintain active glucose transport by the rat intestine in vitro. The present study was designed to examine the effects of these factors on the in vivo absorption of glucose and 3-O-methylglucose. Rats were fed either intraluminally or by total parenteral nutrition (TPN) for 7 days or fasted for 72 h. Sugar absorption was measured under pentobarbital sodium (Nembutal) anesthesia at concentrations from 7 to 28 mM. Luminally fed rats had a significantly greater mucosal mass and absorption rates per centimeter of both sugars than either TPN or fasted animals. However, TPN rats had significantly greater absorption per milligram protein (i.e., specific activity) for both glucose and 3-O-methylglucose than luminally fed rats. In addition, TPN rats absorbed significantly more glucose per milligram protein, but not 3-O-methylglucose, than fasted animals. These data indicate: 1) luminal nutrients maintain glucose absorption by their trophic effects on mucosal mass; 2) the increase in specific activity for sugar absorption after TPN is unrelated to caloric balance; and 3) intestinal glucose metabolism affects its rate of absorption of glucose, but not 3-O-methylglucose.
肠腔营养物质而非代谢状态维持大鼠离体肠的活性葡萄糖转运。本研究旨在检测这些因素对葡萄糖和3 - O - 甲基葡萄糖体内吸收的影响。大鼠通过肠腔内喂养或全胃肠外营养（TPN）喂养7天，或禁食72小时。在戊巴比妥钠（戊巴比妥）麻醉下，测量7至28 mM浓度下的糖吸收情况。与TPN喂养或禁食的动物相比，肠腔内喂养的大鼠具有显著更大的黏膜质量和两种糖每厘米的吸收速率。然而，TPN喂养的大鼠对葡萄糖和3 - O - 甲基葡萄糖的每毫克蛋白质吸收量（即比活性）显著高于肠腔内喂养的大鼠。此外，TPN喂养的大鼠每毫克蛋白质吸收的葡萄糖显著多于禁食动物，但3 - O - 甲基葡萄糖并非如此。这些数据表明：1）肠腔营养物质通过对黏膜质量的营养作用维持葡萄糖吸收；2）TPN后糖吸收比活性的增加与热量平衡无关；3）肠道葡萄糖代谢影响其葡萄糖吸收速率，但不影响3 - O - 甲基葡萄糖的吸收速率。
