Silk D B, Fairclough P D, Clark M L, Hegarty J E, Marrs T C, Addison J M, Burston D, Clegg K M, Matthews D M
JPEN J Parenter Enteral Nutr. 1980 Nov-Dec;4(6):548-53. doi: 10.1177/0148607180004006548.
Previous studies have shown that amino acid (AA) residues are absorbed more rapidly from di- tripeptides than from free AA. In the present study, an intestinal perfusion technique has been used in normal human subjects to compare absorption of AA residues and total alpha-amino nitrogen (N) from 4 partial enzymic hydrolysates of protein (50--80% of the N contents present as small peptides) and their respective equimolar free AA mixtures. alpha-Amino N absorption was greater from 2 casein hydrolytes and a lactalbumin hydrolysate than from the respective free AA mixtures but similar to that from a fish protein hydrolysate and its AA mixture. The considerable variation in absorption of individual AA residues from the AA mixtures was much reduced when the protein hydrolysates were perfused, as a number of AA which were poorly absorbed from the AA mixtures were absorbed to a greater extent from the protein hydrolysates. The casein and lactalbumin hydrolysates had a stimulatory effect on jejunal absorption of water and electrolytes. In contrast, the fish protein hydrolysate appeared to cause a mean net secretion of fluid and electrolytes. The findings indicate that when absorption is limited by diminished luminal hydrolysis or absorptive capacity, serious consideration might be given to using partial enzymic hydrolysates of whole protein rather than free AA mixtures as the N source in "elemental" diets. Care should be taken, however, in ensuring that the preparation of choice does not promote a net secretion of fluid and electrolytes for such a property could have a deleterious effect in the clinical setting.
以往的研究表明，氨基酸（AA）残基从二肽和三肽中的吸收速度比从游离氨基酸中更快。在本研究中，已在正常人类受试者中使用肠道灌注技术，以比较蛋白质的4种部分酶解产物（50%-80%的氮含量以小肽形式存在）及其各自等摩尔游离氨基酸混合物中氨基酸残基和总α-氨基氮（N）的吸收情况。2种酪蛋白水解产物和1种乳白蛋白水解产物的α-氨基氮吸收量高于各自的游离氨基酸混合物，但与鱼蛋白水解产物及其氨基酸混合物的吸收量相似。当灌注蛋白质水解产物时，氨基酸混合物中单个氨基酸残基吸收的显著差异大大降低，因为一些从氨基酸混合物中吸收较差的氨基酸从蛋白质水解产物中的吸收程度更高。酪蛋白和乳白蛋白水解产物对空肠水分和电解质的吸收有刺激作用。相反，鱼蛋白水解产物似乎导致液体和电解质的平均净分泌。研究结果表明，当吸收因肠腔水解减少或吸收能力降低而受到限制时，在“要素”饮食中作为氮源，可能应认真考虑使用全蛋白的部分酶解产物而非游离氨基酸混合物。然而，应注意确保所选制剂不会促进液体和电解质的净分泌，因为这种特性在临床环境中可能产生有害影响。
