Carver J D, Pimentel B, Cox W I, Barness L A
Department of Pediatrics, University of South Florida College of Medicine, Tampa 33612-4799.
Pediatrics. 1991 Aug;88(2):359-63.
Nucleotide (NT) nitrogen, a component of nonprotein nitrogen, accounts for approximately 0.1% to 0.15% of the total nitrogen content of human milk. The results of studies in animals indicate that dietary NTs may be required for maintenance of normal immune function. Thirty-seven healthy term infants were either breast-fed (n = 9) or fed SMA formula supplemented with 33 mg of NTs per liter (n = 13, NT+) or standard SMA formula (n = 15; NT-). At 2 months of age, natural killer cell percent cytotoxicity was significantly higher in the breast-fed and NT+ groups compared with the NT- group (41.7 +/- 4.7, 32.2 +/- 3.4, 21.7 +/- 2.2%, respectively). Interleukin-2 production by stimulated mononuclear cells was higher in the NT+ compared with the NT- group at 2 months of age (0.90 +/- 0.28 U/mL, 0.27 +/- 0.11 U/mL, respectively); neither formula-fed group differed significantly from the breast-fed group. Rate of growth and incidence and severity of infections did not differ significantly among dietary groups. Nucleotides may be a component of human milk that contributes to the enhanced immunity of the breast-fed infant.
核苷酸（NT）氮作为非蛋白氮的一个组成部分，约占人乳总氮含量的0.1%至0.15%。动物研究结果表明，维持正常免疫功能可能需要膳食核苷酸。37名足月健康婴儿，其中9名母乳喂养，13名喂食每升添加33毫克核苷酸的惠氏金装爱儿乐奶粉（NT+组），15名喂食标准惠氏金装爱儿乐奶粉（NT-组）。在2月龄时，母乳喂养组和NT+组的自然杀伤细胞细胞毒性百分比显著高于NT-组（分别为41.7±4.7%、32.2±3.4%、21.7±2.2%）。2月龄时，NT+组受刺激的单核细胞产生的白细胞介素-2高于NT-组（分别为0.90±0.28 U/mL、0.27±0.11 U/mL）；两组配方奶喂养组与母乳喂养组相比均无显著差异。各饮食组间的生长速率、感染发生率和严重程度无显著差异。核苷酸可能是人乳中的一种成分，有助于提高母乳喂养婴儿的免疫力。
