Uauy R, Stringel G, Thomas R, Quan R
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235-9063.
J Pediatr Gastroenterol Nutr. 1990 May;10(4):497-503. doi: 10.1097/00005176-199005000-00014.
Dietary nucleoside (DN) as a precursor for nucleic acid synthesis may be important for rapidly dividing cells, since gut epithelial cells have limited capacity for de novo purine and pyrimidine synthesis. We evaluated in a controlled blinded study the effect of added nucleosides, 0.8% by weight, given for 2 weeks, on gut growth and maturation in 20 weanling rats. Mucosal protein and DNA in the proximal intestinal segment were 50% and 77% higher, respectively, in the DN-supplemented group (n = 10; p less than 0.05). Villus height based on cell count was 25% greater in the DN group (p less than 0.05). Maltase activity was significantly greater in proximal, middle, and distal intestinal segments, and the largest increase, 87%, was seen in the proximal gut mucosa. The maltase/lactase ratio was also higher in this segment. Increases in sucrase were less prominent. Lactase was minimally affected. The pattern of change in disaccharidase activity suggests that DN may enhance gut growth and maturation of the intestine in the weanling rat, the effects being more pronounced in the proximal segment. Diets free of nucleosides and nitrogenous bases may have adverse effects on the gut.
膳食核苷（DN）作为核酸合成的前体，对于快速分裂的细胞可能很重要，因为肠道上皮细胞从头合成嘌呤和嘧啶的能力有限。我们在一项对照双盲研究中评估了添加0.8%（按重量计）核苷、持续给予2周对20只断奶大鼠肠道生长和成熟的影响。在补充DN的组（n = 10；p < 0.05）中，近端肠段的黏膜蛋白和DNA分别高出50%和77%。基于细胞计数的绒毛高度在DN组中高出25%（p < 0.05）。近端、中部和远端肠段的麦芽糖酶活性显著更高，在近端肠黏膜中增幅最大，达87%。该段的麦芽糖酶/乳糖酶比值也更高。蔗糖酶的增加不太明显。乳糖酶受影响最小。双糖酶活性的变化模式表明，DN可能促进断奶大鼠肠道的生长和成熟，在近端肠段效果更明显。不含核苷和含氮碱基的饮食可能对肠道有不良影响。
