Sanchez-Pozo A, Lopez Morales J, Izquierdo A, Martinez-Valverde A, Gil A
Hum Nutr Clin Nutr. 1987 Mar;41(2):115-25.
In the past few years there has been a resurgence of interest in the protein composition of human milk. Up to now the influence of maternal diet and of the mothers' nutritional status on the protein composition of human milk have not been fully clarified. We have evaluated the relationship between the mothers' socioeconomic status and weight and the protein composition of human milk. Protein fractions were determined by a polyacrylamide gel electrophoresis method in 181 samples of human milk obtained from voluntary donors. Samples were classified according to the time of lactation and in relation to the socioeconomic status and to the weight of the lactating women. Total protein and non-protein nitrogen decreased with advancing lactation but there were no differences among the socioeconomic and weight groups of mothers who were considered. beta- and kappa-caseins fell during lactation and beta-casein was significantly increased in the milk of the upper socioeconomic class with respect to that of the low one. alpha-lactalbumin increased from transitional to mature milk (16-30 d) and then declined. The milk from the low socioeconomic group presented the lowest levels of this protein. Lysozyme increased during lactation, whereas lactoferrin decreased. Both proteins were significantly influenced by the mothers' socioeconomic status; the highest concentrations for these proteins were found in the milk of the low socioeconomic group. Deficit or excess of mothers' weight did not influence the levels of the different protein fractions of human milk.
在过去几年里，人们对人乳的蛋白质组成重新产生了兴趣。到目前为止，母亲饮食和营养状况对人乳蛋白质组成的影响尚未完全阐明。我们评估了母亲的社会经济地位和体重与人乳蛋白质组成之间的关系。采用聚丙烯酰胺凝胶电泳法测定了从自愿捐赠者处获得的181份人乳样本中的蛋白质组分。样本根据哺乳期时间以及与社会经济地位和哺乳期妇女体重的关系进行分类。总蛋白和非蛋白氮随着哺乳期的推进而下降，但在所考虑的母亲社会经济和体重组之间没有差异。β-酪蛋白和κ-酪蛋白在哺乳期下降，并且与低社会经济阶层相比，高社会经济阶层的乳汁中β-酪蛋白显著增加。α-乳白蛋白从过渡乳到成熟乳（16 - 30天）增加，然后下降。低社会经济组的乳汁中该蛋白水平最低。溶菌酶在哺乳期增加，而乳铁蛋白减少。这两种蛋白均受母亲社会经济地位的显著影响；这些蛋白的最高浓度出现在低社会经济组的乳汁中。母亲体重不足或超重并不影响人乳中不同蛋白质组分的水平。
