Influence of protein intake on whole body and splanchnic leucine kinetics in humans
Cayol, M.; Boirie, Y.; Rambourdin, F.; Prugnaud, J.; Gachon, P.; Beaufrère, B.; Obled, C.
American Journal of Physiology 272(4 Pt 1): E584-E591
1997
ISSN/ISBN: 0002-9513 PMID: 9142878 Document Number: 472798
The influence of the protein content of the meal on protein turnover was investigated in the splanchnic bed and in the remaining parts of the body in humans. Two groups of five subjects consumed every 20 min a liquid formula providing either 1.5 g protein cntdot kg-1 cntdot day-1 (P) or no protein (PF). L-(1-13C)leucine and L-(5,5,5-2H-3)leucine were administered by vein and gut, respectively. An open two-pool model was developed to calculate leucine kinetics in both compartments, with the assumption that the enrichment of the tracers incorporated into very low density lipoprotein apolipoprotein B100 at isotopic steady state could reflect the leucine labeling in the splanchnic region. Nonsplanchnic uptake and release of leucine were not significantly different in the two groups. Within the splanchnic area, leucine uptake was 2.1 times higher in the P than in the PF group (P lt 0.01), whereas leucine release was reduced but not significantly (-19%) in the P group compared with the PF group. Moreover, data derived from this model showed that protein intake induced an increase in whole body protein synthesis and no change in whole body protein breakdown. Albumin synthesis, as well as its contribution to whole body protein synthesis, was significantly enhanced by protein intake.