title: Postprandial intestinal and whole body nitrogen kinetics and distribution in piglets fed a single meal.
abstract: 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.
authors.affiliation: 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
authors.forename: Cécile
authors.initials: C
authors.lastname: Bos
authors.forename: Barbara
authors.initials: B
authors.lastname: Stoll
authors.forename: Hélène
authors.initials: H
authors.lastname: Fouillet
authors.forename: Claire
authors.initials: C
authors.lastname: Gaudichon
authors.forename: Xinfu
authors.initials: X
authors.lastname: Guan
authors.forename: Michael A
authors.initials: MA
authors.lastname: Grusak
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Reeds
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Burrin
authors.forename: Daniel
authors.initials: D
authors.lastname: Tomé
mesh_terms: 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
chemical_list: D009584:Nitrogen