Fouillet Hélène, Gaudichon Claire, Bos Cécile, Mariotti François, Tomé Daniel
Unité Mixte de Recherche de Physiologie de la Nutrition et du Comportement Alimentaire, Institut National de la Recherche-Agronomique-Institut National Agronomique Paris-Grignon, France.
Am J Physiol Endocrinol Metab. 2003 Jul;285(1):E88-97. doi: 10.1152/ajpendo.00469.2002. Epub 2003 Mar 18.
Splanchnic tissues are largely involved in the postprandial utilization of dietary amino acids, but little is yet known, particularly in humans, about the relative contributions of different splanchnic protein pools to splanchnic and total postprandial anabolism. Our aim was to develop a compartmental model that could distinguish dietary nitrogen (N) incorporation among splanchnic constitutive, plasma (splanchnic exported), and peripheral proteins after a mixed-protein meal in humans. Eight healthy subjects were fed a single mixed meal containing 15N-labeled soy protein, and dietary N postprandial kinetics were measured in plasma free amino acids, proteins, and urea and urinary urea and ammonia. These experimental data and others previously obtained for dietary N kinetics in ileal effluents under similar experimental conditions were used to develop the compartmental model. Six hours after the mixed-meal ingestion, 31.5, 7.5, and 21% of ingested N were predicted to be incorporated into splanchnic constitutive, splanchnic exported, and peripheral proteins, respectively. The contribution of splanchnic exported proteins to total splanchnic anabolism from dietary N was predicted to be approximately 19% and to remain steady throughout the simulation period. Model behavior and its predictions were strongly in line with current knowledge of the system and the scarce, specific data available in the literature. This model provides the first data concerning the anabolism of splanchnic constitutive proteins in the nonsteady postprandial state in humans. By use of only slightly invasive techniques, this model could help to assess how the splanchnic anabolism is modulated under different nutritional or pathophysiological conditions in humans.
内脏组织在餐后膳食氨基酸的利用中起主要作用，但对于不同内脏蛋白库对内脏和餐后总合成代谢的相对贡献，人们知之甚少，尤其是在人类中。我们的目标是建立一个房室模型，该模型能够区分人类摄入混合蛋白餐后，膳食氮（N）在内脏组成蛋白、血浆（内脏输出）蛋白和外周蛋白中的掺入情况。给8名健康受试者喂食一顿含有15N标记大豆蛋白的单一混合餐，并在血浆游离氨基酸、蛋白质、尿素以及尿尿素和氨中测量餐后膳食氮动力学。这些实验数据以及之前在类似实验条件下获得的回肠流出物中膳食氮动力学的其他数据被用于建立房室模型。摄入混合餐后6小时，预计分别有31.5%、7.5%和21%的摄入氮掺入内脏组成蛋白、内脏输出蛋白和外周蛋白中。预计内脏输出蛋白对膳食氮在内脏总合成代谢中的贡献约为19%，并且在整个模拟期间保持稳定。模型行为及其预测结果与该系统的现有知识以及文献中稀少的具体数据高度一致。该模型提供了有关人类餐后非稳态内脏组成蛋白合成代谢的首批数据。通过仅使用轻微侵入性技术，该模型有助于评估在不同营养或病理生理条件下人类内脏合成代谢是如何被调节的。
