Enhanced Glutamine Availability Exerts Different Effects on Protein and Amino Acid Metabolism in Skeletal Muscle From Healthy and Septic Rats
Language English Country United States Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
24906686
DOI
10.1177/0148607114537832
PII: 0148607114537832
Knihovny.cz E-resources
- Keywords
- branched-chain amino acids, glutamine, leucine oxidation, nutrition,
- MeSH
- Amino Acids metabolism MeSH
- Glutamine administration & dosage deficiency pharmacokinetics MeSH
- Muscle, Skeletal drug effects metabolism MeSH
- Rats MeSH
- Leucine metabolism MeSH
- Methylhistidines metabolism MeSH
- Rats, Wistar MeSH
- Dietary Supplements MeSH
- Proteins metabolism MeSH
- Protein Biosynthesis drug effects MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- 3-methylhistidine MeSH Browser
- Amino Acids MeSH
- Glutamine MeSH
- Leucine MeSH
- Methylhistidines MeSH
- Proteins MeSH
BACKGROUND: Enhanced glutamine (GLN) intake may affect the catabolism of branched-chain amino acids (BCAAs; valine, leucine, and isoleucine), which play a regulatory role in protein turnover. We examined the effects of enhanced GLN availability on leucine oxidation, amino acid concentrations, and protein metabolism in muscles from healthy and septic rats. METHODS: Cecal ligation and puncture were used as a model of sepsis. Twenty-four hours after surgery, the soleus (SOL, red muscle) and the extensor digitorum longus (EDL, white muscle) were incubated in medium containing 0.5 or 2.0 mM GLN. Protein breakdown, protein synthesis, and leucine oxidation were determined via 3-methylhistidine release, muscle L-[1-(14)C]leucine radioactivity, and the radioactivity of released (14)CO2, respectively. RESULTS: In muscles from septic animals, increased proteolysis and leucine oxidation and decreased protein synthesis were detected. These effects were more pronounced in the EDL. In septic muscles, the addition of GLN decreased leucine oxidation in both muscles and increased protein synthesis in the EDL. In muscles from untreated animals, decreased leucine oxidation after the addition of GLN to the medium was associated with decreased protein synthesis in the SOL and decreased concentrations of serine, glycine, histidine, alanine, arginine, proline, and lysine in both muscles. CONCLUSIONS: White muscle fibers are more sensitive to septic stimuli than red fibers are. In sepsis, enhanced GLN intake may ameliorate GLN deficiency, inhibit BCAA catabolism, and stimulate protein synthesis. In the healthy state, surplus of GLN may lead to severe alterations in the intramuscular concentration of several amino acids and impair protein synthesis.
Department of Physiology Charles University Prague Faculty of Medicine Hradec Kralove Czech Republic
References provided by Crossref.org
Aspartic Acid in Health and Disease
Influence of Histidine Administration on Ammonia and Amino Acid Metabolism: A Review
