title: Intestinal lysine metabolism is driven by the enteral availability of dietary lysine in piglets fed a bolus meal.
abstract: Previous steady-state continuous-feeding studies have shown that the gut mucosa removes substantial amounts of both dietary and systemic amino acids. However, enteral nutrition is often given under non-steady-state conditions as a bolus meal, and this has been shown to influence systemic metabolism. Therefore, our aim was to quantify the relative metabolism of dietary and systemic lysine by the portal-drained viscera (PDV) under non-steady-state conditions after a single bolus meal. Five 28-day-old piglets implanted with arterial, venous, and portal catheters and with an ultrasonic portal flow probe were given an oral bolus feeding of a milk formula containing a trace quantity of intrinsically 15N-labeled soy protein and a continuous intravenous infusion of [U-13C]lysine for 8 h. Total lysine use by the PDV was maximal 1 h after the meal (891 micromol x kg(-1) x h(-1)) and was predominantly of dietary origin (89%), paralleling the enteral delivery of dietary lysine. Intestinal lysine use returned to a low level after 4 h postprandially and was derived exclusively from the arterial supply until 8 h. Cumulative systemic appearance of dietary lysine reached 44 and 80% of the ingested amount 4 and 8 h after the meal, respectively, whereas the PDV first-pass use of dietary lysine was 55 and 32% of the intake for these two periods, respectively. We conclude that the first-pass utilization rate of dietary lysine by the PDV is directly increased by the enteral lysine availability and that it is higher with a bolus than with continuous oral feeding.
authors.affiliation: Department of Nutrition Physiology and Feeding Control, National Institute for Agricultural Research, Unité Mixte de Recherche, Paris, 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: Daniel
authors.initials: D
authors.lastname: Tomé
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Burrin
mesh_terms: D000222:Adaptation, Physiological; D000601:Amino Acids, Essential / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D000818:Animals; D001682:Biological Availability; D001786:Blood Glucose / Q000032:analysis*; D004032:Diet / Q000379:methods; D004064:Digestive System / Q000098:blood supply / Q000378:metabolism*; D005260:Female; D005527:Food, Fortified; D006499:Hepatic Artery / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply; D008239:Lysine / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D008657:Metabolic Clearance Rate; D009747:Nutritional Physiological Phenomena; D011169:Portal Vein / Q000378:metabolism*; D019518:Postprandial Period / Q000502:physiology; D013552:Swine
chemical_list: D000601:Amino Acids, Essential; D001786:Blood Glucose; D008239:Lysine