Castro G A, Copeland E M, Dudrick S J, Johnson L R
J Nutr. 1975 Jun;105(6):776-81. doi: 10.1093/jn/105.6.776.
The importance of the presence of food in the gastointestinal (GI) tract in maintaining normal enzyme activity in the small intestine was investigated in rats that were kept from eating for as long as 2 weeks. During this time animals were sustained on a nutrient solution administered intravenously. Enzyme activity and small bowel mass in these animals and similiar parameters in rats that were administered the same solution orally were compared with control groups fed an essentially isoenergetic diet of stock rat food and water. Disaccharidase and peroxidase levels in mucosal scrapings expressed as activity/milligram protein, activity/intestine, and activity/100 g body weight, were significantly reduced in intravenously nourished rats but not in rats receiving the solution orally. In addition to changes in enzyme activities, parenteral feeding was accompanied by a significant reduction in the small bowel weight:body weight ratio as compared with that of rats fed the stock diet or nutrient solution orally. Results support the conclusion that normal activity of intestinal enzymes spatially distributed with regard to depth within the mucosa depends on the presence of food in theGI tract and cannot be maintained at normal levels by total intravenous nutrition.
在禁食长达2周的大鼠中，研究了胃肠道（GI）中食物的存在对于维持小肠正常酶活性的重要性。在此期间，通过静脉注射营养液维持动物生存。将这些动物的酶活性和小肠质量以及口服相同溶液的大鼠的类似参数，与喂食基本等能量的标准大鼠食物和水的对照组进行比较。以活性/毫克蛋白质、活性/肠和活性/100克体重表示的粘膜刮片中的双糖酶和过氧化物酶水平，在静脉营养的大鼠中显著降低，但在口服溶液的大鼠中未降低。除了酶活性的变化外，与口服标准饮食或营养液的大鼠相比，肠外营养还伴随着小肠重量与体重比的显著降低。结果支持以下结论：在粘膜内深度上空间分布的肠道酶的正常活性取决于胃肠道中食物的存在，并且不能通过全静脉营养维持在正常水平。
