Insulin and amino acids both strongly participate to the regulation of protein metabolism
作者:
Magali Prod'homme,
Isabelle Rieu,
Michele Balage,
Dominique Dardevet,
Jean Grizard,
期刊:
Current Opinion in Clinical Nutrition and Metabolic Care
(OVID Available online 2004)
卷期:
Volume 7,
issue 1
页码: 71-77
ISSN:1363-1950
年代: 2004
出版商: OVID
关键词: amino acids;insulin;leucine;protein metabolism;skeletal muscle
数据来源: OVID
摘要:
Purpose of reviewThe application of tracer kinetic methods, combined with measurements of the activity of components of the cellular signaling pathways involved in protein synthesis and degradation, affords new insights into the regulation of skeletal muscle protein metabolismin vivoin humans. Feeding is associated with an increase in protein synthesis and a decrease in proteolysis. These changes are mediated by feeding-induced increases in plasma concentrations of both nutrients and hormones.Recent findingsRecent studies definitely demonstrated that insulin and amino acids directly interacted in promoting postprandial anabolism. However, the contribution of amino acids was abolished in old individuals in whom only insulin action persisted. There was a line of evidence that the effect of amino acids originates from leucine, which should not be viewed simply as a building block for protein synthesis, but as a signal in the regulation of cell functions. Although their cellular signaling pathways do not completely overlap, insulin and amino acids both activate the translation initiation of protein synthesis. Insulin presumably inhibits skeletal muscle protein degradation through a decrease in the activity of the ubiquitin proteasome-dependent pathway.SummaryWhether or not amino acids modify insulin action and have specific effects on proteolysis has not yet been documented. At the molecular level, amino acids such as insulin modulate gene expression. Such studies are needed to gain a better understanding of the interactions between insulin and amino acids in the regulation of skeletal muscle protein anabolism.
点击下载:
PDF
(120KB)
返 回