α-Lactalbumin Hydrolysate Stimulates Glucagon-Like Peptide-2 Secretion and Small Intestinal Growth in Suckling Rats
α-Lactalbumin Hydrolysate Stimulates Glucagon-Like Peptide-2 Secretion and Small Intestinal Growth in Suckling Rats
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DOI：
10.3945/jn.109.106401
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发表时间：
2009-07-01
影响因子：
4.2
通讯作者：
Hara, Hiroshi
中科院分区：
文献类型：
--
作者：
Izumi, Hirohisa;Ishizuka, Satoshi;Hara, Hiroshi
我们研究了牛乳成分是否影响乳鼠胰高血糖素样肽（GLP）-2分泌和肠道生长。雄性Sprague-Dawley大鼠（14日龄）接受i.g.乳蛋白级分、乳糖溶液或乳的奶油级分的输注液。在给药后60至120 min，与给予乳糖溶液或奶油组分的大鼠相比，给予乳蛋白的大鼠中GLP-2的血清浓度显著升高，但GLP-1的血清浓度未升高。在另一个实验中，酪蛋白（CN）和乳清蛋白分离物在给药后120分钟刺激GLP-2分泌，但大豆蛋白和卵清蛋白没有。在单独的实验中，几种乳蛋白对GLP-2分泌的刺激相似，包括α-CN、α-乳白蛋白（α-La）和β-乳球蛋白。由于完整的α-La和其他α-La水解产物，通过与从曲霉（Aspergillus）提取的蛋白酶A（LaHPA）孵育获得的α-La水解产物引起几乎两倍的GLP-2释放。游离氨基酸浓度和分子大小分布没有不同的α-La水解产物，包括LaHPA。在用含有α-La或LaHPA的配方奶喂养的幼鼠中，与含有完整α-La的配方奶相比，LaHPA显著促进小肠伸长并增加隐窝上皮细胞的数量。LaHPA给药还增加了麦芽糖酶：乳糖酶活性比，这是肠粘膜成熟的标志。总之，乳蛋白刺激GLP-2分泌，并有助于乳大鼠小肠的生长和成熟。J.营养139：1322-1327，2009年。
We investigated whether bovine milk constituents influenced glucagon-like peptide (GLP)-2 secretion and intestinal growth in suckling rats. Male Sprague-Dawley rats (14 d old) received i.g. infusions of a milk protein fraction, a lactose solution, or the cream fraction of milk. The serum concentration of GLP-2, but not GLP-1, markedly increased in rats administered milk protein compared with those given the lactose solution or the cream fraction from 60 to 120 min after administration. In another experiment, both casein (CN) and whey protein isolate stimulated GLP-2 secretion at 120 min after administration, but soy protein and ovalbumin did not. Stimulation of GLP-2 secretion by several milk proteins was similar, including alpha-CN, alpha-lactalbumin (alpha-La), and beta-lactoglobulin, in a separate experiment. A hydrolysate of alpha-La obtained by incubation with protease A extracted from Aspergillus oryzae (LaHPA) caused almost twice the GLP-2 release due to intact alpha-La and other alpha-La hydrolysates. Free aminoacid concentrations and molecular size distributions did not differ among alpha-La hydrolysates, including LaHPA. In rat pups reared with milk formulae containing alpha-La or LaHPA, LaHPA significantly promoted small intestinal elongation and increased the number of crypt epithelial cells compared with a formula containing intact alpha-La. LaHPA administration also increased the maltase:lactase activity ratio, a marker of maturation of the intestinal mucosa. In conclusion, milk proteins stimulate GLP-2 secretion and contribute to growth and maturation of the small intestine in suckling rats. J. Nutr. 139: 1322-1327, 2009.