Energy nutrients modulate the splanchnic sequestration of dietary nitrogen in humans: a compartmental analysis

Abstract

We used a previously developed compartmental model to assess the postprandial distribution and metabolism of dietary nitrogen (N) in the splanchnic and peripheral areas after the ingestion of a single meal containing milk protein either alone (MP) or with additional sucrose (SMP) or fat (FMP). The addition of fat was predicted to enhance splanchnic dietary N anabolism only transiently, without significantly affecting the global kinetics of splanchnic retention and peripheral uptake. In contrast, the addition of sucrose, which induced hyperinsulinemia, was predicted to enhance dietary N retention and anabolism in the splanchnic bed, thus leading to reduced peripheral dietary amino acid availability and anabolism. The incorporation of dietary N into splanchnic proteins was thus predicted to reach 18, 24, and 35% of ingested N 8 h after MP, FMP, and SMP, respectively. Such a model provides insight into the dynamics of the system in the nonsteady postprandial state and constitutes a useful, explanatory tool to determine the region-specific utilization of dietary N under different nutritional conditions.

Amino acid absorption and subsequent muscle protein accretion following graded intakes of whey protein in elderly men

“…4A). No other macronutrients were included because we aimed to assess the postprandial response of different amounts of whey protein without possible confounding effects of carbohydrate and/or fat intake on protein digestion and absorption kinetics (10,17). Consequently, nonisocaloric protein drinks were compared, and, as a result, different insulin responses were observed between experiments (Fig.…”

Intestinal lysine metabolism is driven by the enteral availability of dietary lysine in piglets fed a bolus meal

“…This phenomenon can decrease the systemic availability of essential amino acids to the body (39,45,49). However, the gut can also be considered as a buffer, sequestering dietary amino acids through protein synthesis during feeding when they are available in excess, and then releasing them in the fasted state to the peripheral pools when their availability is decreased (12,33).Nonessential amino acids are used by the intestine in synthetic pathways and energy production. They also undergo several metabolic interconversions (in particular, glutamate removal and arginine and alanine synthesis), producing a different pattern of amino acids released in the portal circulation than that of dietary protein (28,29,39,41,43,48).…”

The challenge of diabetes in Asia

“…The model calculations are fairly complex but allow one to predict the kinetics of dietary nitrogen in the body (Juillet et al, 2006). Both the amino acid profi le of the protein and the kinetics of amino acid delivery to the blood can affect the postprandial splanchnic and peripheral uptake of amino acid in humans (Deglaire et al, 2009b;Fouillet et al, 2000Fouillet et al, , 2001Fouillet et al, , 2002bFouillet et al, , 2003Fouillet et al, , 2009Juillet et al, 2008). Increasing protein intake increases splanchnic catabolic use while splanchnic catabolic use and peripheral anabolic use are inversely affected (Fouillet et al, 2009).…”