Erdman S H, Hart M H, Park J H, Vanderhoof J A
Section of Pediatric Gastroenterology and Nutrition, University of Nebraska Medical Center, Omaha.
J Pediatr Gastroenterol Nutr. 1991 Nov;13(4):360-6. doi: 10.1097/00005176-199111000-00005.
The in vivo absorption of 3-O-methyl-D-glucose (3MG) as a marker of intestinal function has not been studied in an animal model. We evaluated the use of 3MG as a marker of intestinal absorption when given enterally to rats recovering from small bowel mucosal injury induced by methotrexate (MTX). Radiolabeled 3MG was administered into the duodenum of control (CON) and MTX-treated rats and blood samples were obtained at specified intervals. Mucosal permeability was also assessed using radiolabeled mannitol and polyethylene glycol 900 (PEG). Concentration time points were plotted, and area under the curve was calculated as an approximation of absorbed dose. Mucosal weight, maltase activity, and protein content were determined on mucosal scrapings. During the acute phase (day 5), 3MG absorption and maltase-specific activity were significantly decreased in the MTX group when compared to the CON group (p less than 0.001). The MTX group showed a trend toward greater permeability to mannitol when compared to the CON group; however, this was not statistically significant. Mucosal permeability to PEG was similar in both groups. During a later stage in the recovery process (day 12), the area under the curve calculations for 3MG absorption were the same for both CON and MTX animals, with maltase activity in the MTX group recovering to control values. Changes in 3MG absorption paralleled total maltase activities following severe injury. These results suggest that the combined active and passive transport of 3MG in vivo could be of use as a marker of intestinal absorption in states where the small intestine has sustained major damage resulting in compromised absorption as well as brush border digestion.
作为肠功能标志物的3 - O - 甲基 - D - 葡萄糖（3MG）的体内吸收情况尚未在动物模型中进行研究。我们评估了给从甲氨蝶呤（MTX）诱导的小肠黏膜损伤中恢复的大鼠经肠给予3MG作为肠吸收标志物的用途。将放射性标记的3MG注入对照（CON）组和MTX处理组大鼠的十二指肠，并在特定时间间隔采集血样。还使用放射性标记的甘露醇和聚乙二醇900（PEG）评估黏膜通透性。绘制浓度时间点图，并计算曲线下面积作为吸收剂量的近似值。测定黏膜刮片的黏膜重量、麦芽糖酶活性和蛋白质含量。在急性期（第5天），与CON组相比，MTX组的3MG吸收和麦芽糖酶比活性显著降低（p小于0.001）。与CON组相比，MTX组对甘露醇的通透性有增加趋势；然而，这在统计学上不显著。两组对PEG的黏膜通透性相似。在恢复过程的后期（第12天），CON组和MTX组动物的3MG吸收曲线下面积计算结果相同，MTX组的麦芽糖酶活性恢复到对照值。严重损伤后3MG吸收的变化与总麦芽糖酶活性平行。这些结果表明，在小肠遭受重大损伤导致吸收以及刷状缘消化受损的状态下，3MG在体内的主动和被动联合转运可作为肠吸收的标志物。
