BETA-CAROTENE IN HUMAN MILK: QUANTITATION AND TRANSPORT

这项研究的长期目标是对生物化学的理解， β-胡萝卜素从血清到乳汁的转运及其调节 过程该项目将分两个阶段进行。详述 关于人乳中类维生素A和类胡萝卜素的定量信息， 缺乏，我们在第一阶段的目标是确定主要的类胡萝卜素， 成熟乳和初乳的混合样品中的类维生素A。日变化 β-胡萝卜素和视黄醇的含量将在成熟的牛奶样品中测定。在 此外，由于牛奶类胡萝卜素和类维生素A与血清的关系， 水平，饮食摄入量和/或脂肪储存是未知的，我们也将 鉴定并定量混合物中的主要类胡萝卜素和类维生素A 这些组织样本来自同一个人。饮食摄入量将是 通过结合饮食史/饮食记录方法进行评估。在第二阶段 通过补充正常（美国）与不足（危地马拉）， 母亲与β-胡萝卜素，我们将跟踪动力学转移 膳食β-胡萝卜素对血清、脂肪组织和/或乳汁和婴儿 血清的由于β-胡萝卜素可以代谢为视黄醇，特别是在 缺乏的母亲，视黄醇（和/或视黄醇酯）也将监测， 本研究像以前与血清、脂肪储存和 将研究饮食摄入量。缺乏维生素A的儿童， 特别是母乳喂养的婴儿，死亡的风险增加， 呼吸道和胃肠道疾病，这些研究的结果将 对儿童健康有重要的实际应用。

The long-term goal of this research is the biochemical understanding of the transport of beta-carotene from serum to milk and the regulation of this process. This project will be conducted in two phases. As detailed quantitative information about retinoids and carotenoids in human milk is lacking, our objective in Phase I is to identify the major carotenoids and retinoids in pooled samples of mature milk and colostrum. Diurnal variation of beta-carotene and retinal will be determined in mature milk samples. In addition, as the relationship of milk carotenoids and retinoids with serum levels, dietary intake and/or adipose stores is not known, we will also identify and quantitate the major carotenoids and retinoids in pooled samples of these tissues from the same individuals. Dietary intake will be assessed through a combined diet history/diet record approach. In Phase II of the project, by supplementing normal (US) vs. deficient (Guatemalan) mothers with beta-carotene, we will trace the kinetics of transfer of dietary beta-carotene to serum, adipose tissue and/or milk and infant serum. As beta-carotene may be metabolized to retinol, particularly in deficient mothers, retinol (and/or retinylesters) will also be monitored in this study. As before. the relationship to serum, adipose stores and dietary intake will be studied. As vitamin A-deficient children, and in particular breastfed infants, are at increased risk for death due to respiratory and gastrointestinal disease, the results of these studies will have significant practical application to child health.