Iizuka T, Sasaki M, Oishi K, Uemura S, Koike M, Shinozaki M
Department of Pediatrics, Kihoku Hospital, Wakayama Medical College, Japan.
Acta Paediatr. 1999 Oct;88(10):1053-5. doi: 10.1080/08035259950168063.
Human breast milk contains high concentrations of nitrate and nitrite in the early postpartum period. The acidification of nitrite leads to the generation of nitric oxide (NO) in the gastric lumen. NO reportedly plays an important role in adult stomachs. The objective of the present study was to determine whether NO is generated in the stomach of breastfed neonates. We examined (i) the concentrations of nitrite and nitrate in human breast milk and formula milk, according to the method based on the Griess reaction; (ii) the concentration of NO in gases collected from the lumen of the neonatal stomach; and (iii) NO generation in acidified milks in vitro, using a NO chemiluminescence analyser. We found that breast milk contained high levels of nitrite, the NO level in the stomach gas of neonates fed only breast milk peaked on days 2 to 5, and NO was present on the milk surface in vitro. These findings suggest that a high concentration of nitrite in the stomachs of breastfed neonates enables a high production of NO. We propose that breast milk is important in regulating the mucosal blood flow and gastric motility and in achieving bacteriostasis via induction of NO generation in the neonatal stomach.
产后早期，人母乳中含有高浓度的硝酸盐和亚硝酸盐。亚硝酸盐的酸化会导致胃腔内生成一氧化氮（NO）。据报道，NO在成人胃中起重要作用。本研究的目的是确定母乳喂养的新生儿胃中是否会生成NO。我们按照基于格里斯反应的方法，检测了（i）人母乳和配方奶中的亚硝酸盐和硝酸盐浓度；（ii）从新生儿胃腔收集的气体中的NO浓度；以及（iii）使用NO化学发光分析仪检测酸化奶体外的NO生成情况。我们发现母乳中含有高水平的亚硝酸盐，仅母乳喂养的新生儿胃气体中的NO水平在第2至5天达到峰值，且体外奶液表面存在NO。这些发现表明，母乳喂养的新生儿胃中高浓度的亚硝酸盐能够大量生成NO。我们认为，母乳在调节黏膜血流和胃动力以及通过诱导新生儿胃中生成NO来实现抑菌方面具有重要作用。
