α1-antitrypsin and antichymotrypsin in human milk:: origin, concentrations, and stability
α1-antitrypsin and antichymotrypsin in human milk:: origin, concentrations, and stability
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DOI：
10.1093/ajcn/76.4.828
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发表时间：
2002-10-01
影响因子：
7.1
通讯作者：
Lönnerdal, B
中科院分区：
文献类型：
--
作者：
Chowanadisai, W;Lönnerdal, B
背景：蛋白水解酶抑制剂α(1)-抗胰蛋白酶和抗凝乳凝乳酶存在于母乳中，但对它们在婴儿时期蛋白质消化中的作用知之甚少。已有假说认为α(1)-抗胰蛋白酶和抗凝乳糜蛋白酶可能调节婴儿肠道的消化。目的：我们确定乳腺是否表达α(1)-抗胰蛋白酶和抗糜乳蛋白酶，测量整个哺乳期的α(1)-抗胰蛋白酶和抗糜乳蛋白酶，评估α(1)-抗胰蛋白酶对蛋白分解的抵抗力，并确定α(1)-抗胰蛋白酶影响其他磨坊蛋白质存活的可能性。设计：用聚合酶链式反应分析人乳腺的互补DNA池，以检测α(1)-抗胰蛋白酶和抗糜乳蛋白酶的基因。α(1)-从8名妇女的纵向(4-47天)采集的乳样中测量了抗胰蛋白酶和抗凝乳凝乳酶的浓度。采用婴幼儿体外消化模型，评价α(1)-抗胰蛋白酶对胃酶和胰酶的消化稳定性。结果：乳铁蛋白中α(1)-抗胰凝乳酶和α(1)-抗胰凝乳酶在乳汁中含量较高，在整个哺乳期呈下降趋势。对两种基因的聚合酶链式反应产物进行检测。在体外消化后，大部分α(1)-抗胰蛋白酶仍然完好无损，而许多其他乳蛋白被消化。大部分乳铁蛋白在消化后仍保持完整，但只有在添加α(1)-抗胰蛋白酶的情况下才能保持完整。结论：结果表明，α(1)-抗胰蛋白酶和抗凝乳蛋白酶是由乳腺产生的，并且在哺乳早期以相对较高的数量存在于牛奶中。α(1)-抗胰蛋白酶可能在消化过程中存活，并可能影响其他蛋白质的存活。
Background: The protease inhibitors alpha(1)-antitrypsin and antichymotrypsin are present in human milk, but little is known about their roles in protein digestion during infancy. It has been hypothesized that alpha(1)-antitrypsin and antichymotrypsin may modulate digestion in the infant gut.Objective: We determined whether the mammary gland expresses alpha(1)-antitrypsin and antichymotrypsin, measured alpha(1)-antitrypsin and antichymotrypsin throughout lactation, assessed the resistance of alpha(1)-antitrypsin to proteolysis, and determined the potential of alpha(1)-antitrypsin to affect the survival of other mill, proteins.Design: A pool of complementary DNA from the human mammary gland was analyzed with polymerase chain reaction to detect genes for alpha(1)-antitrypsin and antichymotrypsin. alpha(1)-Antitrypsin and antichymotrypsin concentrations were measured in milk samples obtained longitudinally (days 4-47) from 8 women. An in vitro model of infant digestion was used to assess the digestive stability of alpha(1)-antitrypsin against pepsin and pancreatin. Lactoferrin, with alpha(1)-antitrypsin present, was digested by pancreatin, and the digested proteins were separated.Results: alpha(1)-Antitrypsin and antichymotrypsin concentrations were high in early milk and decreased throughout lactation. Polymerase chain reaction products were detected for both genes. After in vitro digestion, much of the alpha(1)-antitrypsin was still intact, whereas many other milk proteins were digested. Much of the lactoferrin was still intact after digestion, but only when alpha(1)-antitrypsin was added.Conclusions: The results suggest that alpha(1)-antitrypsin and antichymotrypsin are produced by the mammary gland and are present in milk in relatively high amounts in early lactation. alpha(1)-Antitrypsin may survive digestion and may affect the survival of other proteins.