Human protein metabolism: its measurement and regulation.
The body's protein mass not only provides architectural support for cells but also serves vital roles in maintaining their function and survival. The whole body protein pool, as well as that of individual tissues, is determined by the balance between the processes of protein synthesis and degradation. These in turn are regulated by interactions among hormonal, nutritional, neural, inflammatory, and other influences. Prolonged changes in either the synthetic or degradative processes (or both) that cause protein wasting increase morbidity and mortality. The 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 both protein synthesis and breakdown in vivo. These insights, including those from studies of insulin, insulin-like growth factor I, growth hormone, and amino acid-mediated regulation of muscle and whole body protein turnover, provide opportunities to develop and test therapeutic approaches with promise to minimize or prevent these adverse health consequences.
Liu
Zhenqi
Z
Division of Endocrinology and Metabolism, Department of Internal Medicine, and the General Clinical Research Center, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA.
Barrett
Eugene J
EJ
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism / Q000502:physiology; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007554:Isotopes / Q000032:analysis / Q000378:metabolism; D009928:Organ Specificity; D011506:Proteins / Q000378:metabolism*; D011849:Radioactive Tracers; D051381:Rats; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism
D000596:Amino Acids; D007328:Insulin; D007554:Isotopes; D011506:Proteins; D011849:Radioactive Tracers; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D038762:Ribosomal Protein S6 Kinases, 70-kDa