当前位置： SCI文献检索 > Journal of the American Medical Directors Association期刊下所有文献 > Protein redistribution from skeletal muscle to splanchnic tissue on fasting and refeeding in young and older healthy individuals.

Protein redistribution from skeletal muscle to splanchnic tissue on fasting and refeeding in young and older healthy individuals.

Abstract：

BACKGROUND:During aging, a shift of protein metabolism from muscle to splanchnic tissue contributes to increased muscle protein loss after a period of metabolic stress (eg, fasting). OBJECTIVE:To study the adaptation of protein metabolism in the whole body and tissue (ie, skeletal muscle and splanchnic area) to metabolic stress, such as short-term fasting and refeeding, in aged people. DESIGN AND PARTICIPANTS:We studied splanchnic and muscle protein metabolism after 38 hours of fasting and refeeding in 7 young (5 men/2 women, 24.4 ± 2.0 years) and 8 elderly individuals (6 men/2 women, 70.6 ± 3.1 years). MEASUREMENTS:We used intravenous (IV) L-[(13)C6]phenylalanine, IV L-[(2)H3]leucine, and oral L-[(13)C1]leucine to obtain (1) whole-body protein kinetics, (2) muscle and albumin fractional synthesis rate (FSR, %/d; (13)C6-Phe, and (13)C1-Leu), and (3) splanchnic extraction during fasting and refeeding (%, (2)H3- and (13)C1-Leu). RESULTS:Whole-body protein breakdown was activated during fasting in young and older individuals (P < .01 vs fasted state). Muscle FSR remained unchanged in both groups and not stimulated by refeeding in either group with either IV (13)C Phe or oral (13)C Leu, probably because of high plasma levels of essential amino acids (EAAs) and branched-chain amino acids (BCAAs). Splanchnic extraction of leucine was 42% higher in the elderly individuals (P = .03 vs young) and was associated with an increased albumin synthesis rate in elderly individuals in the fed state (P < .05 vs young). CONCLUSION:Splanchnic protein metabolism is modified by age, but this metabolic change is not associated with a lower synthesis rate of muscle protein, provided high plasma levels of essential EAAs are maintained. Our data also suggest that splanchnic protein synthesis is a metabolic priority during recovery after metabolic stress in healthy elderly persons and that it might be even more affected in polymedicated older individuals having chronic diseases.

journal_name

J Am Med Dir Assoc

journal_title

Journal of the American Medical Directors Association

authors

Moreau K,Walrand S,Boirie Y

doi

10.1016/j.jamda.2013.06.005

subject

Has Abstract

pub_date

2013-09-01 00:00:00

pages

696-704

issue

eissn

1525-8610

issn

1538-9375

pii

S1525-8610(13)00348-4

journal_volume

pub_type

杂志文章

在线工具

Protein redistribution from skeletal muscle to splanchnic tissue on fasting and refeeding in young and older healthy individuals.