+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Alterations in protein and amino acid metabolism in rats fed a branched-chain amino acid- or leucine-enriched diet during postprandial and postabsorptive states



Alterations in protein and amino acid metabolism in rats fed a branched-chain amino acid- or leucine-enriched diet during postprandial and postabsorptive states



Nutrition and Metabolism 13: 12



Many people believe in favourable effects of branched-chain amino acids (BCAAs; valine, leucine, and isoleucine), especially leucine, on muscle protein balance and consume BCAAs for many years. We determined the effects of the chronic intake of a BCAA- or leucine-enriched diet on protein and amino acid metabolism in fed and postabsorptive states. Rats were fed a standard diet, a diet with a high content of valine, leucine, and isoleucine (HVLID), or a high content of leucine (HLD) for 2 months. Half of the animals in each group were sacrificed in the fed state on the last day, and the other half were sacrificed after overnight fast. Protein synthesis was assessed using the flooding dose method (L-[3,4,5-(3)H]phenylalanine), proteolysis on the basis of chymotrypsin-like activity (CHTLA) of proteasome and cathepsin B and L activities. Chronic intake of HVLID or HLD enhanced plasma levels of urea, alanine and glutamine. HVLID also increased levels of all three BCAA and branched-chain keto acids (BCKA), HLD increased leucine, ketoisocaproate and alanine aminotransferase and decreased valine, ketovaline, isoleucine, ketoisoleucine, and LDL cholesterol. Tissue weight and protein content were lower in extensor digitorum longus muscles in the HLD group and higher in kidneys in the HVLID and HLD groups. Muscle protein synthesis in postprandial state was higher in the HVLID group, and CHTLA was lower in muscles of the HVLID and HLD groups compared to controls. Overnight starvation enhanced alanine aminotransferase activity in muscles, and decreased protein synthesis in gastrocnemius (in HVLID group) and extensor digitorum longus (in HLD group) muscles more than in controls. Effect of HVLID and HLD on CHTLA in muscles in postabsorptive state was insignificant. The results failed to demonstrate positive effects of the chronic consumption of a BCAA-enriched diet on protein balance in skeletal muscle and indicate rather negative effects from a leucine-enriched diet. The primary effects of both diets are an activated catabolism of BCAAs, which leads to an enhanced production of BCKA, alanine and glutamine and their utilization in visceral tissues and an impaired protein synthesis in postabsorptive state, particularly in fast-twitch (white) muscles.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 057162854

Download citation: RISBibTeXText

PMID: 26877757

DOI: 10.1186/s12986-016-0072-3


Related references

Pharmacological studies of branched chain amino acid and arginine enriched amino acid solution mhs 2 for the treatment of hepatic encephalopathy effect on the ammonia metabolism in pca rats. Japanese Journal of Pharmacology 52(Suppl. 1): 336P, 1990

The effect of enriched branched chain amino acid solution with hypocaloric TPN on acute phase protein, plasma amino acid profile metabolism in postoperative children. Zhonghua Wai Ke Za Zhi 29(5): 283-6 333, 1991

Tryptophan metabolism of rats fed on an amino acid diet devoid of one branched chain amino acid. Agricultural and Biological Chemistry. 35: 7, 1033-1038, 1971

Tryptophan metabolism of rats fed on an amino acid diet devoid of 1 branched chain amino acid. Agricultural & Biological Chemistry 35(7): 1033-1038, 1971

Short- and long-term effects of leucine and branched-chain amino acid supplementation of a protein- and energy-reduced diet on muscle protein metabolism in neonatal pigs. Amino Acids 50(7): 943-959, 2018

Branched-chain amino acid interactions with reference to amino acid requirements in adult men: valine metabolism at different leucine intakes. American Journal of Clinical Nutrition 54(2): 395-401, 1991

Branched-chain amino acid interactions with reference to amino acid requirements in adult men: leucine metabolism at different valine and isoleucine intakes. American Journal of Clinical Nutrition 54(2): 402-407, 1991

Effects of branched chain amino acid and arginine enriched amino acid solution on brain regional amine metabolism. Japanese Journal of Pharmacology 49(Suppl.): 110P, 1989

The effect of enriched branched chain amino acid solution on amino acid metabolism during perioperative total parenteral nutrition support. Zhonghua Wai Ke Za Zhi 27(12): 756-9 782, 1989

Effects of branched chain amino acid-enriched total parenteral nutrition on amino acid utilization in rats bearing Yoshida sarcoma. Cancer Research 48(10): 2698-2702, 1988

Obesity-related elevations in plasma leucine are associated with alterations in enzymes involved in branched-chain amino acid metabolism. American Journal of Physiology. Endocrinology and Metabolism 293(6): E1552-E1563, 2007

Effect of a keto acid-amino acid supplement on the metabolism and renal elimination of branched-chain amino acids in patients with chronic renal insufficiency on a low protein diet. Wiener Klinische Wochenschrift 112(20): 876-881, 2000

Alterations in protein metabolism and amino acid concentrations in rats fed by a high-protein (casein-enriched) diet - effect of starvation. Food and Chemical Toxicology 49(12): 3336-3342, 2011

A kinetic study of leucine metabolism in severely burned patients. Comparison between a conventional and branched-chain amino acid-enriched nutritional therapy. Annals of Surgery 207(4): 421-429, 1988

In vivo measurement of leucine metabolism with stable isotopes in normal subjects and in those with cirrhosis fed conventional and branched-chain amino acid-enriched diets. Surgery 98(3): 405-413, 1985