Next Article in Journal
Comparative Metabolomic Analysis of Dendrobium officinale under Different Cultivation Substrates
Previous Article in Journal
Metabolomic Signature of Amino Acids, Biogenic Amines and Lipids in Blood Serum of Patients with Severe Osteoarthritis
Review

Branched-Chain Amino Acids and Branched-Chain Keto Acids in Hyperammonemic States: Metabolism and as Supplements

Department of Physiology, Charles University, Faculty of Medicine in Hradec Králové, 500 03 Hradec Kralove, Czech Republic
Metabolites 2020, 10(8), 324; https://doi.org/10.3390/metabo10080324
Received: 25 July 2020 / Revised: 6 August 2020 / Accepted: 7 August 2020 / Published: 9 August 2020
(This article belongs to the Section Nutrition and Metabolism)
In hyperammonemic states, such as liver cirrhosis, urea cycle disorders, and strenuous exercise, the catabolism of branched-chain amino acids (BCAAs; leucine, isoleucine, and valine) is activated and BCAA concentrations decrease. In these conditions, BCAAs are recommended to improve mental functions, protein balance, and muscle performance. However, clinical trials have not demonstrated significant benefits of BCAA-containing supplements. It is hypothesized that, under hyperammonemic conditions, enhanced glutamine availability and decreased BCAA levels facilitate the amination of branched-chain keto acids (BCKAs; α-ketoisocaproate, α-keto-β-methylvalerate, and α-ketoisovalerate) to the corresponding BCAAs, and that BCKA supplementation may offer advantages over BCAAs. Studies examining the effects of ketoanalogues of amino acids have provided proof that subjects with hyperammonemia can effectively synthesize BCAAs from BCKAs. Unfortunately, the benefits of BCKA administration have not been clearly confirmed. The shortcoming of most reports is the use of mixtures intended for patients with renal insufficiency, which might be detrimental for patients with liver injury. It is concluded that (i) BCKA administration may decrease ammonia production, attenuate cataplerosis, correct amino acid imbalance, and improve protein balance and (ii) studies specifically investigating the effects of BCKA, without the interference of other ketoanalogues, are needed to complete the information essential for decisions regarding their suitability in hyperammonemic conditions. View Full-Text
Keywords: glutamine; α-ketoglutarate; urea-cycle disorders; liver cirrhosis; exercise glutamine; α-ketoglutarate; urea-cycle disorders; liver cirrhosis; exercise
Show Figures

Graphical abstract

MDPI and ACS Style

Holeček, M. Branched-Chain Amino Acids and Branched-Chain Keto Acids in Hyperammonemic States: Metabolism and as Supplements. Metabolites 2020, 10, 324. https://doi.org/10.3390/metabo10080324

AMA Style

Holeček M. Branched-Chain Amino Acids and Branched-Chain Keto Acids in Hyperammonemic States: Metabolism and as Supplements. Metabolites. 2020; 10(8):324. https://doi.org/10.3390/metabo10080324

Chicago/Turabian Style

Holeček, Milan. 2020. "Branched-Chain Amino Acids and Branched-Chain Keto Acids in Hyperammonemic States: Metabolism and as Supplements" Metabolites 10, no. 8: 324. https://doi.org/10.3390/metabo10080324

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop