Koopman René, Crombach Nico, Gijsen Annemie P, Walrand Stéphane, Fauquant Jacques, Kies Arie K, Lemosquet Sophie, Saris Wim H M, Boirie Yves, van Loon Luc J C
Department of Human Movement Sciences, Nutrition and Toxicology Research Institute Maastricht, Maastricht, Netherlands.
Am J Clin Nutr. 2009 Jul;90(1):106-15. doi: 10.3945/ajcn.2009.27474. Epub 2009 May 27.
It has been suggested that a protein hydrolysate, as opposed to its intact protein, is more easily digested and absorbed from the gut, which results in greater plasma amino acid availability and a greater muscle protein synthetic response.
We aimed to compare dietary protein digestion and absorption kinetics and the subsequent muscle protein synthetic response to the ingestion of a single bolus of protein hydrolysate compared with its intact protein in vivo in humans.
Ten elderly men (mean +/- SEM age: 64 +/- 1 y) were randomly assigned to a crossover experiment that involved 2 treatments in which the subjects consumed a 35-g bolus of specifically produced L-[1-(13)C]phenylalanine-labeled intact casein (CAS) or hydrolyzed casein (CASH). Blood and muscle-tissue samples were collected to assess the appearance rate of dietary protein-derived phenylalanine in the circulation and subsequent muscle protein fractional synthetic rate over a 6-h postprandial period.
The mean (+/-SEM) exogenous phenylalanine appearance rate was 27 +/- 6% higher after ingestion of CASH than after ingestion of CAS (P < 0.001). Splanchnic extraction was significantly lower in CASH compared with CAS treatment (P < 0.01). Plasma amino acid concentrations increased to a greater extent (25-50%) after the ingestion of CASH than after the ingestion of CAS (P < 0.01). Muscle protein synthesis rates averaged 0.054 +/- 0.004% and 0.068 +/- 0.006%/h in the CAS and CASH treatments, respectively (P = 0.10).
Ingestion of a protein hydrolysate, as opposed to its intact protein, accelerates protein digestion and absorption from the gut, augments postprandial amino acid availability, and tends to increase the incorporation rate of dietary amino acids into skeletal muscle protein.
有人提出，与完整蛋白质相比，蛋白质水解产物更容易被肠道消化和吸收，这会使血浆氨基酸可用性更高，肌肉蛋白质合成反应更强。
我们旨在比较在人体内单次摄入蛋白质水解产物与其完整蛋白质后，膳食蛋白质的消化吸收动力学以及随后的肌肉蛋白质合成反应。
10名老年男性（平均±标准误年龄：64±1岁）被随机分配到一项交叉实验中，该实验涉及2种处理，受试者分别摄入35克经特殊生产的L-[1-(13)C]苯丙氨酸标记的完整酪蛋白（CAS）或水解酪蛋白（CASH）。在餐后6小时内采集血液和肌肉组织样本，以评估循环中膳食蛋白质衍生苯丙氨酸的出现率以及随后的肌肉蛋白质分数合成率。
摄入CASH后，外源性苯丙氨酸平均（±标准误）出现率比摄入CAS后高27±6%（P<0.001）。与CAS处理相比，CASH的内脏提取率显著更低（P<0.01）。摄入CASH后血浆氨基酸浓度升高幅度（25 - 50%）大于摄入CAS后（P<0.01）。在CAS和CASH处理中，肌肉蛋白质合成率分别平均为0.054±0.004%/小时和0.068±0.006%/小时（P = 0.10）。
与完整蛋白质相比，摄入蛋白质水解产物可加速肠道蛋白质消化和吸收，增加餐后氨基酸可用性，并倾向于提高膳食氨基酸掺入骨骼肌蛋白质的速率。
