SUN-LB670: Branched-Chain Amino Acid and Branched-Chain Ketoacid Ingestion Increase Muscle Protein Synthesis Rates in Vivo in Older Adults

2019 ◽  
Vol 38 ◽  
pp. S308
Author(s):  
C.J. Fuchs ◽  
W.J.H. Hermans ◽  
A.M. Holwerda ◽  
J.S.J. Smeets ◽  
J.M. Senden ◽  
...  
Keyword(s):  
Older Adults ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain

scholarly journals Amino acid infusion increases the sensitivity of muscle protein synthesis in vivo to insulin. Effect of branched-chain amino acids

1988 ◽  
Vol 254 (2) ◽  
pp. 579-584 ◽  
Author(s):  
P J Garlick ◽  
I Grant
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Branched Chain Amino Acids ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Branched Chain

Rates of muscle protein synthesis were measured in vivo in tissues of post-absorptive young rats that were given intravenous infusions of various combinations of insulin and amino acids. In the absence of amino acid infusion, there was a steady rise in muscle protein synthesis with plasma insulin concentration up to 158 mu units/ml, but when a complete amino acids mixtures was included maximal rates were obtained at 20 mu units/ml. The effect of the complete mixture could be reproduced by a mixture of essential amino acids or of branched-chain amino acids, but not by a non-essential mixture, alanine, methionine or glutamine. It is concluded that amino acids, particularly the branched-chain ones, increase the sensitivity of muscle protein synthesis to insulin.

scholarly journals Branched-chain amino acid and branched-chain ketoacid ingestion increases muscle protein synthesis rates in vivo in older adults: a double-blind, randomized trial

2019 ◽  
Vol 110 (4) ◽  
pp. 862-872 ◽  
Author(s):  
Cas J Fuchs ◽  
Wesley J H Hermans ◽  
Andrew M Holwerda ◽  
Joey S J Smeets ◽  
Joan M Senden ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Myofibrillar Protein ◽  
Postprandial Phase ◽  
Branched Chain ◽  
Myofibrillar Protein Synthesis ◽  
Older Males

ABSTRACTBackgroundProtein ingestion increases muscle protein synthesis rates. However, limited data are currently available on the effects of branched-chain amino acid (BCAA) and branched-chain ketoacid (BCKA) ingestion on postprandial muscle protein synthesis rates.ObjectiveThe aim of this study was to compare the impact of ingesting 6 g BCAA, 6 g BCKA, and 30 g milk protein (MILK) on the postprandial rise in circulating amino acid concentrations and subsequent myofibrillar protein synthesis rates in older males.MethodsIn a parallel design, 45 older males (age: 71 ± 1 y; BMI: 25.4 ± 0.8 kg/m2) were randomly assigned to ingest a drink containing 6 g BCAA, 6 g BCKA, or 30 g MILK. Basal and postprandial myofibrillar protein synthesis rates were assessed by primed continuous l-[ring-13C6]phenylalanine infusions with the collection of blood samples and muscle biopsies.ResultsPlasma BCAA concentrations increased following test drink ingestion in all groups, with greater increases in the BCAA and MILK groups compared with the BCKA group (P < 0.05). Plasma BCKA concentrations increased following test drink ingestion in all groups, with greater increases in the BCKA group compared with the BCAA and MILK groups (P < 0.05). Ingestion of MILK, BCAA, and BCKA significantly increased early myofibrillar protein synthesis rates (0–2 h) above basal rates (from 0.020 ± 0.002%/h to 0.042 ± 0.004%/h, 0.022 ± 0.002%/h to 0.044 ± 0.004%/h, and 0.023 ± 0.003%/h to 0.044 ± 0.004%/h, respectively; P < 0.001), with no differences between groups (P > 0.05). Myofibrillar protein synthesis rates during the late postprandial phase (2–5 h) remained elevated in the MILK group (0.039 ± 0.004%/h; P < 0.001), but returned to baseline values following BCAA and BCKA ingestion (0.024 ± 0.005%/h and 0.024 ± 0.005%/h, respectively; P > 0.05).ConclusionsIngestion of 6 g BCAA, 6 g BCKA, and 30 g MILK increases myofibrillar protein synthesis rates during the early postprandial phase (0–2 h) in vivo in healthy older males. The postprandial increase following the ingestion of 6 g BCAA and BCKA is short-lived, with higher myofibrillar protein synthesis rates only being maintained following the ingestion of an equivalent amount of intact milk protein. This trial was registered at Nederlands Trial Register (www.trialregister.nl) as NTR6047.

Isoleucine increases muscle mass through promoting myogenesis and intramyocellular fat deposition

2021 ◽  
Author(s):  
Shuge Liu ◽  
Yunmei Sun ◽  
Rui Zhao ◽  
Yingqian Wang ◽  
Wanrong Zhang ◽  
...  
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vital Role ◽  
Fat Deposition ◽  
Branched Chain Amino Acid ◽  
Branched Chain

Isoleucine (Ile), as a branched-chain amino acid (BCAA), has a vital role in regulating body weight and muscle protein synthesis.

Measurement of the Rate of Protein Synthesis in Muscle of Postabsorptive Young Men by Injection of a ‘Flooding Dose’ of [1-13C]leucine

1989 ◽  
Vol 77 (3) ◽  
pp. 329-336 ◽  
Author(s):  
Peter J. Garlick ◽  
Jan Wernerman ◽  
Margaret A. McNurlan ◽  
Pia Essen ◽  
Gerald E. Lobley ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Isotopic Enrichment ◽  
Plasma Leucine ◽  
Convenient Technique ◽  
Tissue Compartments ◽  
Muscle Biopsies

1. The ‘flooding dose’ technique for measuring the rate of protein synthesis in tissues in vivo involves the injection of a large amount of unlabelled amino acid together with the tracer to minimize differences in isotopic enrichment of the free amino acid in plasma and tissue compartments. This approach has been investigated in human muscle by taking biopsies from postabsorptive male volunteers given [1-13C]leucine. 2. Intravenous injection of 4 g of unlabelled leucine resulted in a rapid rise in free leucine concentration of seven- to eleven-fold in plasma and five-fold in muscle. Values were still elevated by two-fold after 2 h. 3. Five minutes after injection of [1-13C]leucine (0.05 g/kg) the isotopic enrichment of plasma leucine was 82% that of the injected material, falling to 44% at 120 min. The enrichment of free leucine in sequential muscle biopsies was close to that in plasma and almost identical to that for plasma α-ketoisocaproate. 4. The rate of protein synthesis was determined from the increase in leucine enrichment in protein of muscle biopsies taken before and 90 min after injection of [1-13C]leucine (0.05 g/kg; 19 or 39 atom% excess) and the average plasma α-ketoisocaproate enrichment over this period (taken to represent muscle free leucine). The mean rate of muscle protein synthesis in 10 subjects was 1.95 (sem 0.12)%/day. Rates of protein synthesis calculated from plasma leucine as precursor enrichment were only 5% lower than those calculated from plasma α-ketoisocaproate. 5. It is concluded that a ‘flooding dose’ of 13C-labelled amino acid is a useful and convenient technique for determining the rate of protein synthesis in tissues of human volunteers and patients.

Dietary protein considerations for muscle protein synthesis and muscle mass preservation in older adults

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Eunice T. Olaniyan ◽  
Fiona O’Halloran ◽  
Aoife L. McCarthy
Keyword(s):  
Older Adults ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Mass ◽  
Protein Intake ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Adult Population ◽  
Anabolic Resistance

Abstract Amino acid bioavailability is critical for muscle protein synthesis (MPS) and preservation of skeletal muscle mass (SMM). Ageing is associated with reduced responsiveness of MPS to essential amino acids (EAA). Further, the older adult population experiences anabolic resistance, leading to increased frailty, functional decline and depleted muscle mass preservation, which facilitates the need for increased protein intake to increase their SMM. This review focuses on the role of proteins in muscle mass preservation and examines the contribution of EAA and protein intake patterns to MPS. Leucine is the most widely studied amino acid for its role as a potent stimulator of MPS, though due to inadequate data little is yet known about the role of other EAA. Reaching a conclusion on the best pattern of protein intake has proven difficult due to conflicting studies. A mixture of animal and plant proteins can contribute to increased MPS and potentially attenuate muscle wasting conditions; however, there is limited research on the biological impact of protein blends in older adults. While there is some evidence to suggest that liquid protein foods with higher than the RDA of protein may be the best strategy for achieving high MPS rates in older adults, clinical trials are warranted to confirm an association between food form and SMM preservation. Further research is warranted before adequate recommendations and strategies for optimising SMM in the elderly population can be proposed.

Effect of Infused Branched-Chain Amino Acids on Muscle and Whole-Body Amino Acid Metabolism in Man

1990 ◽  
Vol 79 (5) ◽  
pp. 457-466 ◽  
Author(s):  
Rita J. Louard ◽  
Eugene J. Barrett ◽  
Robert A. Gelfand
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Branched Chain Amino Acids ◽  
Whole Body ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Branched Chain Amino Acid ◽  
Branched Chain

1. Using the forearm balance method, together with systemic infusions of l-[ring-2,6-3H]phenylalanine and l-[1-14C]leucine, we examined the effects of infused branched-chain amino acids on whole-body and skeletal muscle amino acid kinetics in 10 postabsorptive normal subjects; 10 control subjects received only saline. 2. Infusion of branched-chain amino acids caused a four-fold rise in arterial branched-chain amino acid levels and a two-fold rise in branched-chain keto acids; significant declines were observed in circulating levels of most other amino acids, including phenylalanine, which fell by 34%. Plasma insulin levels were unchanged from basal levels (8 ± 1 μ-units/ml). 3. Whole-body phenylalanine flux, an index of proteolysis, was significantly suppressed by branched-chain amino acid infusion (P < 0.002), and forearm phenylalanine production was also inhibited (P < 0.03). With branched-chain amino acid infusion total leucine flux rose, with marked increments in both oxidative and non-oxidative leucine disposal (P < 0.001). Proteolysis, as measured by endogenous leucine production, showed a modest 12% decrease, although this was not significant when compared with saline controls. The net forearm balance of leucine and other branched-chain amino acids changed from a basal net output to a marked net uptake (P < 0.001) during branched-chain amino acid infusion, with significant stimulation of local leucine disposal. Despite the rise in whole-body non-oxidative leucine disposal, and in forearm leucine uptake and disposal, forearm phenylalanine disposal, an index of muscle protein synthesis, was not stimulated by infusion of branched-chain amino acids. 4. The results suggest that in normal man branched-chain amino acid infusion suppresses skeletal muscle proteolysis independently of any rise of plasma insulin. Muscle branched-chain amino acid uptake rose dramatically in the absence of any apparent increase in muscle protein synthesis, as measured by phenylalanine disposal, or in branched-chain keto acid release. Thus, an increase in muscle branched-chain amino acid concentrations and/ or local branched-chain amino acid oxidation must account for the increased disposal of branched-chain amino acids.

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