Format

Send to

Choose Destination
Mech Ageing Dev. 2016 Jul;157:7-16. doi: 10.1016/j.mad.2016.05.007. Epub 2016 Jun 18.

Differential effects of leucine supplementation in young and aged mice at the onset of skeletal muscle regeneration.

Author information

1
Exercise Muscle Biology Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, United States.
2
Integrative Muscle Metabolism Laboratory, Human Performance Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, United States.
3
Department of Food Science, University of Arkansas, Fayetteville AR 72701, United States.
4
Exercise Muscle Biology Laboratory, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR 72701, United States. Electronic address: tawashin@uark.edu.

Abstract

Aging decreases the ability of skeletal muscle to respond to injury. Leucine has been demonstrated to target protein synthetic pathways in skeletal muscle thereby enhancing this response. However, the effect of aging on leucine-induced alterations in protein synthesis at the onset of skeletal muscle regeneration has not been fully elucidated. The purpose of this study was to determine if aging alters skeletal muscle regeneration and leucine-induced alterations in markers of protein synthesis. The tibialis anterior of young (3 months) and aged (24 months) female C57BL/6J mice were injected with either bupivacaine or PBS, and the mice were given ad libitum access to leucine-supplemented or normal drinking water. Protein and gene expression of markers of protein synthesis and degradation, respectively, were analyzed at three days post-injection. Following injury in young mice, leucine supplementation was observed to elevate only p-p70S6K. In aged mice, leucine was shown to elicit higher p-mTOR content with and without injury, and p-4EBP-1 content post-injury. Additionally in aged mice, leucine was shown to elicit higher content of relative p70S6K post-injury. Our study shows that leucine supplementation affects markers of protein synthesis at the onset of skeletal muscle regeneration differentially in young and aged mice.

KEYWORDS:

Aging; BCAAs; Injury; Protein synthesis; mTOR

PMID:
27327351
PMCID:
PMC5002371
DOI:
10.1016/j.mad.2016.05.007
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center