Effect of aging on the availability of amino acids from an immune-enhancing diet (IED) after a surgical stress in rats.
Aging
/ physiology
Amino Acids
/ administration & dosage
Animals
Arginine
/ administration & dosage
Biological Availability
Enteral Nutrition
/ methods
Immunity
/ physiology
Male
Models, Animal
Postoperative Care
/ methods
Rats
Rats, Sprague-Dawley
Stress, Physiological
/ physiology
Surgical Procedures, Operative
/ adverse effects
Aging
Amino acid availability
Arginine
Immunonutrition
Journal
Clinical nutrition (Edinburgh, Scotland)
ISSN: 1532-1983
Titre abrégé: Clin Nutr
Pays: England
ID NLM: 8309603
Informations de publication
Date de publication:
09 2020
09 2020
Historique:
received:
03
07
2019
revised:
25
11
2019
accepted:
06
12
2019
pubmed:
31
12
2019
medline:
7
8
2021
entrez:
30
12
2019
Statut:
ppublish
Résumé
Dietary amino acid (AA) requirements increase after a surgical stress while the systemic AA availability from the diet decreases with age, due to splanchnic sequestration. While immune-enhancing diets (IEDs) have been recommended for the nutritional management of surgical patients, the systemic bioavailability of their AA supply has not been evaluated in elderly surgical patients. This was determined in surgically-stressed IED-fed aged rats. Thirty-four 5-month- or 21-month-old male Sprague-Dawley rats were used. After a gastrostomy and placement of a jugular vein catheter and a one-week recovery period, the animals underwent two 24 h-enteral feedings with an arginine-enriched IED (Impact®, Nestlé Health Science) before (healthy state) and 18 h after a standardized laparotomy, used as a model of surgical stress. During enteral nutrition, blood samples were repeatedly collected to measure plasma AA bioavailability (incremental areas under the curve) at 2, 5 and 24 h. Surgical stress was evaluated from urinary catecholamines and plasma protein profile. Whatever the age or stress situation, IED feeding was associated with decreased plasma glycine and increased alanine, proline and arginine. Aging was mainly associated with a delayed plasma AA accumulation in the first hours after the initiation of enteral nutrition. Stress was associated with higher plasma arginine increase and lower histidine, methionine, phenylalanine and tyrosine accumulation. Age and stress interactions seem limited. AA bioavailability from an arginine-enriched IED seems to be maintained whatever age and stress situation. Aging appears to be mainly associated with a delay in plasma AA accumulation probably related to age-associated splanchnic sequestration of AAs. Additional effects of surgical stress per se seem limited.
Sections du résumé
BACKGROUND & AIMS
Dietary amino acid (AA) requirements increase after a surgical stress while the systemic AA availability from the diet decreases with age, due to splanchnic sequestration. While immune-enhancing diets (IEDs) have been recommended for the nutritional management of surgical patients, the systemic bioavailability of their AA supply has not been evaluated in elderly surgical patients. This was determined in surgically-stressed IED-fed aged rats.
METHODS
Thirty-four 5-month- or 21-month-old male Sprague-Dawley rats were used. After a gastrostomy and placement of a jugular vein catheter and a one-week recovery period, the animals underwent two 24 h-enteral feedings with an arginine-enriched IED (Impact®, Nestlé Health Science) before (healthy state) and 18 h after a standardized laparotomy, used as a model of surgical stress. During enteral nutrition, blood samples were repeatedly collected to measure plasma AA bioavailability (incremental areas under the curve) at 2, 5 and 24 h. Surgical stress was evaluated from urinary catecholamines and plasma protein profile.
RESULTS
Whatever the age or stress situation, IED feeding was associated with decreased plasma glycine and increased alanine, proline and arginine. Aging was mainly associated with a delayed plasma AA accumulation in the first hours after the initiation of enteral nutrition. Stress was associated with higher plasma arginine increase and lower histidine, methionine, phenylalanine and tyrosine accumulation. Age and stress interactions seem limited.
CONCLUSIONS
AA bioavailability from an arginine-enriched IED seems to be maintained whatever age and stress situation. Aging appears to be mainly associated with a delay in plasma AA accumulation probably related to age-associated splanchnic sequestration of AAs. Additional effects of surgical stress per se seem limited.
Identifiants
pubmed: 31883944
pii: S0261-5614(19)33176-0
doi: 10.1016/j.clnu.2019.12.007
pii:
doi:
Substances chimiques
Amino Acids
0
Arginine
94ZLA3W45F
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
2793-2801Informations de copyright
Copyright © 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Déclaration de conflit d'intérêts
Conflict of Interest LC received honorarium from Nestlé Health Science.