scholarly journals Branched-Chain Amino Acid Fortification Does Not Restore Muscle Protein Synthesis Rates following Ingestion of Lower- Compared with Higher-Dose Mycoprotein

2020 ◽  
Vol 150 (11) ◽  
pp. 2931-2941 ◽  
Author(s):  
Alistair J Monteyne ◽  
Mariana O C Coelho ◽  
Craig Porter ◽  
Doaa R Abdelrahman ◽  
Thomas S O Jameson ◽  
...  

ABSTRACT Background We have shown that ingesting a large bolus (70 g) of the fungal-derived, whole food mycoprotein robustly stimulates muscle protein synthesis (MPS) rates. Objective The aim of this study was to determine if a lower dose (35 g) of mycoprotein enriched with branched-chain amino acids (BCAAs) stimulates MPS to the same extent as 70 g of mycoprotein in resistance-trained young men. Methods Nineteen men [aged 22 ± 1 y, BMI (kg/m2): 25 ± 1] took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of l-[ring-2H5]phenylalanine and ingested either 70 g mycoprotein (31.5 g protein; MYCO; n = 10) or 35 g BCAA-enriched mycoprotein (18.7 g protein: matched on BCAA content; ENR; n = 9) following a bout of unilateral resistance exercise. Blood and bilateral quadriceps muscle samples were obtained before exercise and protein ingestion and during a 4-h postprandial period to assess MPS in rested and exercised muscle. Two- and 3-factor ANOVAs were used to detect differences in plasma amino acid kinetics and mixed muscle fractional synthetic rates, respectively. Results Postprandial plasma BCAA concentrations increased more rapidly and to a larger degree in ENR compared with MYCO. MPS increased with protein ingestion (P ≤ 0.05) but to a greater extent following MYCO (from 0.025% ± 0.006% to 0.057% ± 0.004% · h−1 in rested muscle, and from 0.024% ± 0.007% to 0.072% ± 0.005% · h−1 in exercised muscle; P < 0.0001) compared with ENR (from 0.031% ± 0.003% to 0.043% ± 0.005% · h−1 in rested muscle, and 0.027% ± 0.005% to 0.052% ± 0.005% · h−1 in exercised muscle; P < 0.01) ingestion. Postprandial MPS rates were greater in MYCO compared with ENR (P < 0.01). Conclusions The ingestion of lower-dose BCAA-enriched mycoprotein stimulates resting and postexercise MPS rates, but to a lesser extent compared with the ingestion of a BCAA-matched 70-g mycoprotein bolus in healthy young men. This trial was registered at clinicaltrials.gov as 660065600.

2020 ◽  
Vol 112 (2) ◽  
pp. 303-317 ◽  
Author(s):  
Tyler A Churchward-Venne ◽  
Philippe J M Pinckaers ◽  
Joey S J Smeets ◽  
Milan W Betz ◽  
Joan M Senden ◽  
...  

ABSTRACT Background Protein ingestion increases skeletal muscle protein synthesis rates during recovery from endurance exercise. Objectives We aimed to determine the effect of graded doses of dietary protein co-ingested with carbohydrate on whole-body protein metabolism, and skeletal muscle myofibrillar (MyoPS) and mitochondrial (MitoPS) protein synthesis rates during recovery from endurance exercise. Methods In a randomized, double-blind, parallel-group design, 48 healthy, young, endurance-trained men (mean ± SEM age: 27 ± 1 y) received a primed continuous infusion of l-[ring-2H5]-phenylalanine, l-[ring-3,5-2H2]-tyrosine, and l-[1-13C]-leucine and ingested 45 g carbohydrate with either 0 (0 g PRO), 15 (15 g PRO), 30 (30 g PRO), or 45 (45 g PRO) g intrinsically l-[1-13C]-phenylalanine and l-[1-13C]-leucine labeled milk protein after endurance exercise. Blood and muscle biopsy samples were collected over 360 min of postexercise recovery to assess whole-body protein metabolism and both MyoPS and MitoPS rates. Results Protein intake resulted in ∼70%–74% of the ingested protein-derived phenylalanine appearing in the circulation. Whole-body net protein balance increased dose-dependently after ingestion of 0, 15, 30, or 45 g protein (mean ± SEM: −0.31± 0.16, 5.08 ± 0.21, 10.04 ± 0.30, and 13.49 ± 0.55 μmol phenylalanine · kg−1 · h−1, respectively; P < 0.001). 30 g PRO stimulated a ∼46% increase in MyoPS rates (%/h) compared with 0 g PRO and was sufficient to maximize MyoPS rates after endurance exercise. MitoPS rates were not increased after protein ingestion; however, incorporation of dietary protein–derived l-[1-13C]-phenylalanine into de novo mitochondrial protein increased dose-dependently after ingestion of 15, 30, and 45 g protein at 360 min postexercise (0.018 ± 0.002, 0.034 ± 0.002, and 0.046 ± 0.003 mole percentage excess, respectively; P < 0.001). Conclusions Protein ingested after endurance exercise is efficiently digested and absorbed into the circulation. Whole-body net protein balance and dietary protein–derived amino acid incorporation into mitochondrial protein respond to increasing protein intake in a dose-dependent manner. Ingestion of 30 g protein is sufficient to maximize MyoPS rates during recovery from a single bout of endurance exercise. This trial was registered at trialregister.nl as NTR5111.


1988 ◽  
Vol 254 (2) ◽  
pp. 579-584 ◽  
Author(s):  
P J Garlick ◽  
I Grant

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.


Author(s):  
Kevin J. M. Paulussen ◽  
Rafael A. Alamilla ◽  
Amadeo F. Salvador ◽  
Colleen F. McKenna ◽  
Andrew T. Askow ◽  
...  

Leucine is regarded as an anabolic trigger for the mTORC1 pathway and the stimulation muscle protein synthesis rates. More recently, there has been an interest in underpinning the relevance of BCAA-containing dipeptides and their intact absorption into circulation to regulate muscle anabolic responses. We investigated the effects of dileucine and leucine ingestion on postprandial muscle protein turnover. Ten healthy young men (age: 23±3 y) consumed either 2 g of leucine (LEU) or 2 g of dileucine (DILEU) in a randomized crossover design. The participants underwent repeated blood and muscle biopsy sampling during primed continuous infusions of L-[ring-13C6]phenylalanine and L-[15N]phenylalanine to determine myofibrillar protein synthesis (MPS) and mixed muscle protein breakdown rates (MPB), respectively. LEU and DILEU similarly increased plasma leucine net area under the curve (AUC; P = 0.396). DILEU increased plasma dileucine AUC to a greater extent than LEU (P = 0.013). Phosphorylation of Akt (P = 0.002), rpS6 (P <0.001) and p70S6K (P < 0.001) increased over time in both LEU and DILEU conditions. Phosphorylation of 4E-BP1 (P = 0.229) and eEF2 (P = 0.999) did not change over time irrespective of condition. Cumulative (0-180 min) MPS increased in DILEU (0.075±0.032 %⋅hour-1), but not in LEU (0.047±0.029 %⋅hour-1; P=0.023). MPB did not differ between LEU (0.043±0.030 %⋅h-1) and DILEU conditions (0.051±0.027 %⋅hour-1; P = 0.659). Our results showed that dileucine ingestion elevated plasma dileucine concentrations and muscle protein turnover by stimulating MPS in young men.


2020 ◽  
Vol 112 (2) ◽  
pp. 318-333 ◽  
Author(s):  
Alistair J Monteyne ◽  
Mariana O C Coelho ◽  
Craig Porter ◽  
Doaa R Abdelrahman ◽  
Thomas S O Jameson ◽  
...  

ABSTRACT Background Mycoprotein is a fungal-derived sustainable protein-rich food source, and its ingestion results in systemic amino acid and leucine concentrations similar to that following milk protein ingestion. Objective We assessed the mixed skeletal muscle protein synthetic response to the ingestion of a single bolus of mycoprotein compared with a leucine-matched bolus of milk protein, in rested and exercised muscle of resistance-trained young men. Methods Twenty resistance-trained healthy young males (age: 22 ± 1 y, body mass: 82 ± 2 kg, BMI: 25 ± 1 kg·m−2) took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of L-[ring-2H5]phenylalanine and ingested either 31 g (26.2 g protein: 2.5 g leucine) milk protein (MILK) or 70 g (31.5 g protein: 2.5 g leucine) mycoprotein (MYCO) following a bout of unilateral resistance-type exercise (contralateral leg acting as resting control). Blood and m. vastus lateralis muscle samples were collected before exercise and protein ingestion, and following a 4-h postprandial period to assess mixed muscle fractional protein synthetic rates (FSRs) and myocellular signaling in response to the protein beverages in resting and exercised muscle. Results Mixed muscle FSRs increased following MILK ingestion (from 0.036 ± 0.008 to 0.052 ± 0.006%·h−1 in rested, and 0.035 ± 0.008 to 0.056 ± 0.005%·h−1 in exercised muscle; P &lt;0.01) but to a greater extent following MYCO ingestion (from 0.025 ± 0.006 to 0.057 ± 0.004%·h−1 in rested, and 0.024 ± 0.007 to 0.072 ± 0.005%·h−1 in exercised muscle; P &lt;0.0001) (treatment × time interaction effect; P &lt;0.05). Postprandial FSRs trended to be greater in MYCO compared with MILK (0.065 ± 0.004 compared with 0.054 ± 0.004%·h−1, respectively; P = 0.093) and the postprandial rise in FSRs was greater in MYCO compared with MILK (Delta 0.040 ± 0.006 compared with Delta 0.018 ± 0.005%·h−1, respectively; P &lt;0.01). Conclusions The ingestion of a single bolus of mycoprotein stimulates resting and postexercise muscle protein synthesis rates, and to a greater extent than a leucine-matched bolus of milk protein, in resistance-trained young men. This trial was registered at clinicaltrials.gov as 660065600.


2007 ◽  
Vol 32 (6) ◽  
pp. 1132-1138 ◽  
Author(s):  
Jason E. Tang ◽  
Joshua J. Manolakos ◽  
Greg W. Kujbida ◽  
Paul J. Lysecki ◽  
Daniel R. Moore ◽  
...  

Whey protein is a supplemental protein source often used by athletes, particularly those aiming to gain muscle mass; however, direct evidence for its efficacy in stimulating muscle protein synthesis (MPS) is lacking. We aimed to determine the impact of consuming whey protein on skeletal muscle protein turnover in the post-exercise period. Eight healthy resistance-trained young men (age = 21 ± 1 .0 years; BMI = 26.8 ± 0.9 kg/m2 (means ± SE)) participated in a double-blind randomized crossover trial in which they performed a unilateral leg resistance exercise workout (EX: 4 sets of knee extensions and 4 sets of leg press; 8–10 repetitions/set; 80% of maximal), such that one leg was not exercised and acted as a rested (RE) comparator. After exercise, subjects consumed either an isoenergetic whey protein plus carbohydrate beverage (WHEY: 10 g protein and 21 g fructose) or a carbohydrate-only beverage (CHO: 21 g fructose and 10 g maltodextran). Subjects received pulse-tracer injections of l-[ring-2H5]phenylalanine and l-[15N]phenylalanine to measure MPS. Exercise stimulated a rise in MPS in the WHEY-EX and CHO-EX legs, which were greater than MPS in the WHEY-RE leg and the CHO-RE leg (all p < 0.05), respectively. The rate of MPS in the WHEY-EX leg was greater than in the CHO-EX leg (p < 0.001). We conclude that a small dose (10 g) of whey protein with carbohydrate (21 g) can stimulate a rise in MPS after resistance exercise in trained young men that would be supportive of a positive net protein balance, which, over time, would lead to hypertrophy.


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 ◽  
...  

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.


2019 ◽  
Vol 127 (6) ◽  
pp. 1792-1801 ◽  
Author(s):  
Stephan van Vliet ◽  
Joseph W. Beals ◽  
Andrew M. Holwerda ◽  
Russell S. Emmons ◽  
Joy P. Goessens ◽  
...  

The anabolic action of “fast” whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. We assessed the time course of anabolic signaling activation and stimulation of myofibrillar protein synthesis rates (MPS) after ingestion of a food source that represents a more typical meal-induced pattern of aminoacidemia. Seven young men (age: 22 ± 1 y) underwent repeated blood and biopsy sampling during primed, continuous l-[ ring-2H5]phenylalanine and l-[1-13C]leucine tracer infusions and ingested 38 g of l-[1-13C]phenylalanine- and l-[1-13C]leucine-labeled milk protein concentrate. A total of ∼27 ± 4 (∼10 g) and ∼31 ± 1% (∼12 g) of dietary protein-derived amino acids were released in circulation between 0 and 120 min and 120–300 min, respectively, of the postprandial period. l-[ ring-2H5]phenylalanine-based MPS increased above basal (0.025 ± 0.008%/h) by ∼75% (0.043 ± 0.009%/h; P = 0.05) between 0 and 120 min and by ∼86% (0.046 ± 0.004%/h; P = 0.02) between 120 and 300 min, respectively. l-[1-13C]leucine-based MPS increased above basal (0.027 ± 0.002%/h) by ∼72% (0.051 ± 0.016%/h; P = 0.10) between 0 and 120 min and by ∼62% (0.047 ± 0.004%/h; P = 0.001) between 120 and 300 min, respectively. Myofibrillar protein-bound l-[1-13C]phenylalanine increased over time ( P < 0.001) and equaled 0.004 ± 0.001, 0.008 ± 0.002, 0.017 ± 0.004, and 0.020 ± 0.003 mole percent excess at 60, 120, 180, and 300 min, respectively, of the postprandial period. Milk protein ingestion increased mTORC1 phosphorylation at 120, 180, and 300 min of the postprandial period (all P < 0.05). Our results show that ingestion of 38 g of milk protein results in sustained increases in MPS throughout a 5-h postprandial period in healthy young men. NEW & NOTEWORTHY The stimulation of muscle protein synthesis after whey protein ingestion is short-lived due to its transient systemic appearance of amino acids. Our study characterized the muscle anabolic response to a protein source that results in a more gradual release of amino acids into circulation. Our work demonstrates that a sustained increase in postprandial plasma amino acid availability after milk protein ingestion results in a prolonged stimulation of muscle protein synthesis rates in healthy young men.


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