Postprandial intestinal and whole body nitrogen kinetics and distribution in piglets fed a single meal.
Our aim was to characterize the postprandial total and dietary N fluxes in the portal drained viscera (PDV) and whole body after administration of a single meal in young pigs. Seven 4-wk-old piglets, implanted with a portal flow probe and portal, arterial and venous catheters, received a primed constant [(18)O]urea intravenous infusion and were studied for 8 h after a bolus mixed meal ingestion (46 mmol N/kg body wt) intrinsically labeled with (15)N to trace dietary N fluxes. The real cecal digestibility of the formula was 94.3% (SD 1.8). PDV output of dietary N was found principally in the pool of circulating protein (51% of the measured dietary N PDV output), in the free alpha-amino N pool (44%), and to a lesser extent in ammonia (5%). Dietary N release in alpha-amino N and ammonia mainly occurred during the first 3 h. Total and exogenous postprandial urea productions were 5.8 and 2.0 mmol N/kg body wt, respectively. At the end of the postprandial period, losses of dietary N amounted to 10.3% of the dose: 5.7% through ileal losses and 4.6% by deamination and transfer to urea. Net postprandial retention of dietary N was 90.4% (SD 1.3), of which 20% was found in splanchnic zone (small intestine 10%, liver 5%, and plasma protein 3%) and 42% in peripheral zone (muscle 31%, skin 6%). In conclusion, our results show a high efficiency of dietary N utilization for muscular uptake and anabolic utilization. However, the results obtained point out the necessity to further explore the form of dietary N released into the portal blood.
Bos
Cécile
C
Institut National Agronomique Paris-Grignon, UMR INRA-INAPG 914, Physiologie de la Nutrition et du Comportement Alimentaire, 16 rue Claude Bernard, 75231 Paris cedex 05, France. bos@inapg.inra.fr
Stoll
Barbara
B
Fouillet
Hélène
H
Gaudichon
Claire
C
Guan
Xinfu
X
Grusak
Michael A
MA
Reeds
Peter J
PJ
Burrin
Douglas G
DG
Tomé
Daniel
D
D000222:Adaptation, Physiological / Q000502:physiology; D000284:Administration, Oral; D000818:Animals; D007413:Intestinal Mucosa / Q000378:metabolism*; D007700:Kinetics; D008657:Metabolic Clearance Rate; D009584:Nitrogen / Q000008:administration & dosage* / Q000378:metabolism*; D009747:Nutritional Physiological Phenomena; D009928:Organ Specificity; D019518:Postprandial Period / Q000502:physiology*; D013552:Swine; D014018:Tissue Distribution
D009584:Nitrogen