Initiation of muscle protein synthesis was unrelated to simultaneously upregulated local production of IGF-1 by amino acids in non-proliferating L6 muscle cells.

ABSTRACT:

Background

IGF-1 is considered an important regulator of muscle protein synthesis. However, its role in stimulation of muscle protein synthesis by amino acids (AA) is not clear, despite pronounced alterations in IGF-1 mRNA expression and signaling in muscle tissues by feeding. This study evaluates the role of locally produced IGF-1 and IGF-1 signaling when skeletal muscle protein synthesis is activated by increased amino acid availability in confluent, non-proliferating cells.

Methods

L6 skeletal muscle cells were subjected to amino acid starvation (24 h, 0.14 mM) followed by 18 h amino acid refeeding in Low AA (0.28 mM) or High AA concentrations (9 mM). Protein synthesis rates were estimated by L-[U-14C]-phenylalanine incorporation into cellular proteins. IGF-1 and IGF-1 re

SUBMITTER: Iresjo BM 

PROVIDER: S-EPMC9269383 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature