Reis B L, Keen C L, Lönnerdal B, Hurley L S
Department of Nutrition, University of California, Davis 95616.
J Nutr. 1991 May;121(5):687-99. doi: 10.1093/jn/121.5.687.
We studied changes in the mineral composition of milk of lactating Swiss-Webster mice and the relationship of those changes to mineral metabolism of suckling mouse pups. Concentrations of Zn, Cu, Mg and Ca were analyzed in maternal and neonatal tissues and in milk; Zn metabolism was studied using 65Zn. Although Cu, Ca and Mg concentrations in milk declined during the first 2 d of lactation, only the concentration of Zn decreased progressively throughout 30 d. Various pup tissues were characterized by developmental changes in concentrations of some elements. Turnover of Zn in neonatal tissues was studied by radiolabeling litters in utero and fostering them at birth to nonradiolabeled lactating dams. The turnover of whole-body 65Zn in suckling mice decreased during development, and, at 20 d of age, the biological half-life of 65Zn in the neonate was approximately the same as for a nonpregnant, nonlactating adult female (20 d). The decreased turnover of 65Zn in lactating dams that characterized progressive lactation and was reflected in the Zn concentration of milk is in agreement with changes in whole-body 65Zn turnover observed for the suckling mouse. These findings demonstrate that the metabolism of the suckling neonate is directly related to longitudinal changes in the composition of maternal milk.
我们研究了哺乳期瑞士 Webster 小鼠乳汁矿物质组成的变化，以及这些变化与哺乳幼鼠矿物质代谢的关系。分析了母体和新生儿组织以及乳汁中锌、铜、镁和钙的浓度；使用 65Zn 研究锌代谢。尽管哺乳期前 2 天乳汁中铜、钙和镁的浓度下降，但仅锌的浓度在整个 30 天内逐渐降低。各种幼鼠组织的特点是某些元素浓度的发育变化。通过在子宫内对窝仔进行放射性标记并在出生时将它们寄养给未进行放射性标记的哺乳期母鼠，研究了新生儿组织中锌的周转率。哺乳小鼠全身 65Zn 的周转率在发育过程中下降，在 20 日龄时，新生儿体内 65Zn 的生物半衰期与未怀孕、未哺乳的成年雌性小鼠大致相同（20 天）。哺乳期母鼠体内 65Zn 周转率的下降是渐进性哺乳的特征，并反映在乳汁的锌浓度中，这与哺乳小鼠全身 65Zn 周转率的变化一致。这些发现表明，哺乳新生儿的代谢与母体乳汁成分的纵向变化直接相关。
