Premium
Postprandial urea‐nitrogen production and salvage are modulated by the dietary protein source in humans
Author(s) -
Fouillet Helene,
Juillet Barbara,
Bos Cecile,
Mariotti François,
Gaudichon Claire,
Tome Daniel
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a333-b
Subject(s) - postprandial , urea , ingestion , chemistry , meal , kinetics , excretion , food science , biochemistry , zoology , medicine , endocrinology , biology , insulin , physics , quantum mechanics
The influence of the meal protein source on postprandial urea kinetics remains poorly known, despite its nutritional significance with respect to protein quality. Besides, traditional tracer infusion study has been reported to underestimate acute postprandial change in urea kinetics. In this work, we combined mathematical modeling with robust clinical data on nitrogen (N) postprandial distribution in some accessible pools in humans. This allowed to determine postprandial, non‐steady urea kinetics and their modulation by qualitative factors of protein intake. Dietary and total N kinetics were measured for 8h in plasma proteins, body and urinary urea after ingestion of a mixed meal containing [ 15 N]‐labeled milk, soy or wheat protein. These data were analyzed using a 4‐compartment model that allowed to predict the postprandial kinetics of urea N production (UP), urinary excretion (UE) and intestinal hydrolysis (UH). Results are expressed in mg N/kg at 8h postmeal: In contrast to UE, both UP and UH increased when ingesting plant vs . animal proteins, and so did the relative hydrolysis (UH:UP, 50–60 vs. 25%). This constituted an acute N‐sparing mechanism, which counterbalanced the higher UP occurring after ingestion of plant proteins.