A cell-based evaluation of a non-essential amino acid formulation as a non-bioactive control for activation and stimulation of muscle protein synthesis using ex vivo human serum

Abstract Objectives Healthy eating patterns consist of eating whole foods as opposed to single nutrients. The maintenance of skeletal muscle mass is of particular interest to overall health. As such, there is a need to underpin the role of eating nutrients within their natural whole-food matrix versus isolated nutrients on the regulation of postprandial muscle protein synthesis rates. This study assessed the effects of eating salmon, a potential food within a healthy Mediterranean style eating pattern, on the stimulation of post-exercise muscle protein synthesis rates versus eating these same nutrients in isolation in healthy young adults. Methods In a crossover design, 10 recreationally active adults (24 ± 4 y; 5 M, 5 F) performed an acute bout of resistance exercise followed by the ingestion of salmon (SAL) (20.5 g protein and 7.5 g fat) or its matched constituents in the form of crystalline amino acids and fish oil (ISO). Blood and muscle biopsies were collected at rest and after exercise at 2 and 5 h during primed continuous infusions of L-[ring-2H5]phenylalanine for the measurement of myofibrillar protein synthesis and plasma amino acid profiles. Data were analyzed by using a 2-factor (time × condition) repeated-measures ANOVA with Tukey's post hoc test. Results Plasma essential amino acid concentrations increased to a similar extent in both SAL and ISO during the postprandial period (P > 0.05). Likewise, postprandial plasma leucine concentrations did not differ between nutrient condition (P > 0.05). The post-exercise myofibrillar protein synthetic responses were similarly stimulated in both nutrition conditions early (0–2 h; 0.079 ± 0.039%/h (SAL) compared to 0.071 ± 0.078%/h (ISO); P = 0.64) and returned to baseline later (2–5 h; 0.046 ± 0.020%/h (SAL) compared to 0.038 ± 0.025%/h (ISO); P = 0.90). Similarly, there were no differences in the stimulation of myofibrillar protein synthesis rates between SAL and ISO during the entire 0–5 h recovery period (0.058 ± 0.024%/h compared to 0.045 ± 0.027%/h, respectively; P = 0.66). Conclusions We show that the ingestion of salmon or its isolated nutrients increases plasma amino acid concentrations and enhances the stimulation of post-exercise muscle protein synthesis rates with no differences in the temporal or cumulative responses in healthy young adults. Funding Sources USDA National Institute of Food and Agriculture Hatch project.

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Long‐term leucine induced stimulation of muscle protein synthesis is amino acid dependent

The FASEB Journal ◽

10.1096/fasebj.23.1_supplement.228.7 ◽

2009 ◽

Vol 23 (S1) ◽

Author(s):

Fiona A Wilson ◽

Agus Suryawan ◽

Maria C Gazzaneo ◽

Renán A Orellana ◽

Hanh V Nguyen ◽

...

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Stimulation Of

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A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00488.2005 ◽

2006 ◽

Vol 291 (2) ◽

pp. E381-E387 ◽

Cited By ~ 505

Author(s):

Christos S. Katsanos ◽

Hisamine Kobayashi ◽

Melinda Sheffield-Moore ◽

Asle Aarsland ◽

Robert R. Wolfe

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Vastus Lateralis ◽

The Elderly ◽

Essential Amino Acids ◽

Vastus Lateralis Muscle ◽

Young Subjects ◽

Stimulation Of

This study was designed to evaluate the effects of enriching an essential amino acid (EAA) mixture with leucine on muscle protein metabolism in elderly and young individuals. Four (2 elderly and 2 young) groups were studied before and after ingestion of 6.7 g of EAAs. EAAs were based on the composition of whey protein [26% leucine (26% Leu)] or were enriched in leucine [41% leucine (41% Leu)]. A primed, continuous infusion of l-[ ring-2H5]phenylalanine was used together with vastus lateralis muscle biopsies and leg arteriovenous blood samples for the determinations of fractional synthetic rate (FSR) and balance of muscle protein. FSR increased following amino acid ingestion in both the 26% (basal: 0.048 ± 0.005%/h; post-EAA: 0.063 ± 0.007%/h) and the 41% (basal: 0.036 ± 0.004%/h; post-EAA: 0.051 ± 0.007%/h) Leu young groups ( P < 0.05). In contrast, in the elderly, FSR did not increase following ingestion of 26% Leu EAA (basal: 0.044 ± 0.003%/h; post-EAA: 0.049 ± 0.006%/h; P > 0.05) but did increase following ingestion of 41% Leu EAA (basal: 0.038 ± 0.007%/h; post-EAA: 0.056 ± 0.008%/h; P < 0.05). Similar to the FSR responses, the mean response of muscle phenylalanine net balance, a reflection of muscle protein balance, was improved ( P < 0.05) in all groups, with the exception of the 26% Leu elderly group. We conclude that increasing the proportion of leucine in a mixture of EAA can reverse an attenuated response of muscle protein synthesis in elderly but does not result in further stimulation of muscle protein synthesis in young subjects.

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Role of specific dietary amino acids in clinical conditions

British Journal Of Nutrition ◽

10.1017/s0007114512002358 ◽

2012 ◽

Vol 108 (S2) ◽

pp. S139-S148 ◽

Cited By ~ 34

Author(s):

Renate Jonker ◽

Mariëlle P. K. J. Engelen ◽

Nicolaas E. P. Deutz

Keyword(s):

Amino Acids ◽

Protein Synthesis ◽

Amino Acid ◽

Muscle Wasting ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Essential Amino Acids ◽

Dietary Proteins ◽

Disease States ◽

Stimulation Of

In a variety of chronic and acute disease states, alterations in protein synthesis, breakdown and protein turnover rates occur that are related to the loss of body protein and skeletal muscle wasting. A key observation is the stimulation of protein breakdown in muscle and the stimulation of protein synthesis in the splanchnic area; mainly liver. An altered splanchnic extraction of amino acids as well as an anabolic resistance to dietary protein, related to stress, disuse and aging play a key role in the pathogenesis of muscle wasting in these conditions. To overcome these factors, specific dietary protein and amino acid diets have been introduced. The main focus of these diets is the quantity and quality of dietary proteins and whether a balanced mixture or solely dietary essential amino acids are required with or without higher intake levels of specific amino acids. Specifically in cancer patients, stimulated muscle protein synthesis has been obtained by increasing the amount of protein in a meal and by providing additional leucine. Also in other chronic diseases such as chronic obstructive pulmonary disease and cystic fibrosis, meals with specific dietary proteins and specific combinations of dietary essential amino acids are able to stimulate anabolism. In acute diseases, a special role for the amino acid arginine and its precursor citrulline as anabolic drivers has been observed. Thus, there is growing evidence that modifying the dietary amino acid composition of a meal will positively influence the net balance between muscle protein synthesis and breakdown, leading to muscle protein anabolism in a variety of chronic and acute disease states. Specific amino acids with anabolic potential are leucine, arginine and citrulline.

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Regulation of muscle protein synthesis in an in vitro cell model using ex vivo human serum

Experimental Physiology ◽

10.1113/ep086860 ◽

2018 ◽

Vol 103 (6) ◽

pp. 783-789 ◽

Cited By ~ 5

Author(s):

Brian P. Carson ◽

Bijal Patel ◽

Miryam Amigo-Benavent ◽

Martina Pauk ◽

Sunil Kumar Gujulla ◽

...

Keyword(s):

Protein Synthesis ◽

Human Serum ◽

Cell Model ◽

Ex Vivo ◽

Muscle Protein ◽

Muscle Protein Synthesis

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Effects of high versus standard essential amino acid intakes on whole-body protein turnover and mixed muscle protein synthesis during energy deficit: A randomized, crossover study

Clinical Nutrition ◽

10.1016/j.clnu.2020.07.019 ◽

2020 ◽

Cited By ~ 3

Author(s):

Jess A. Gwin ◽

David D. Church ◽

Adrienne Hatch-McChesney ◽

Emily E. Howard ◽

Christopher T. Carrigan ◽

...

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Protein Turnover ◽

Essential Amino Acid ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Energy Deficit ◽

Whole Body ◽

Body Protein ◽

Randomized Crossover Study

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Essential amino acid and carbohydrate ingestion before resistance exercise does not enhance postexercise muscle protein synthesis

Journal of Applied Physiology ◽

10.1152/japplphysiol.90395.2008 ◽

2009 ◽

Vol 106 (5) ◽

pp. 1730-1739 ◽

Cited By ~ 75

Author(s):

Satoshi Fujita ◽

Hans C. Dreyer ◽

Micah J. Drummond ◽

Erin L. Glynn ◽

Elena Volpi ◽

...

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Resistance Exercise ◽

Essential Amino Acid ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Exercise Bout ◽

Control Group ◽

Carbohydrate Ingestion ◽

Postexercise Recovery

Ingestion of an essential amino acid-carbohydrate (EAA + CHO) solution following resistance exercise enhances muscle protein synthesis during postexercise recovery. It is unclear whether EAA + CHO ingestion before resistance exercise can improve direct measures of postexercise muscle protein synthesis (fractional synthetic rate; FSR). We hypothesized that EAA + CHO ingestion before a bout of resistance exercise would prevent the exercise-induced decrease in muscle FSR and would result in an enhanced rate of muscle FSR during postexercise recovery. We studied 22 young healthy subjects before, during, and for 2 h following a bout of high-intensity leg resistance exercise. The fasting control group ( n = 11) did not ingest nutrients, and the EAA + CHO group ( n = 11) ingested a solution of EAA + CHO 1 h before beginning the exercise bout. Stable isotopic methods were used in combination with muscle biopsies to determine FSR. Immunoblotting procedures were utilized to assess cell signaling proteins associated with the regulation of FSR. We found that muscle FSR increased in the EAA + CHO group immediately following EAA + CHO ingestion ( P < 0.05), returned to basal values during exercise, and remained unchanged at 1 h postexercise. Muscle FSR decreased in the fasting group during exercise and increased at 1 h postexercise ( P < 0.05). However, the 2 h postexercise FSR increased by ∼50% in both groups with no differences between groups ( P > 0.05). Eukaryotic elongation factor 2 phosphorylation was reduced in both groups at 2 h postexercise (EAA + CHO: 39 ± 7%; fasting: 47 ± 9%; P < 0.05). We conclude that EAA + CHO ingestion before resistance exercise does not enhance postexercise FSR compared with exercise without nutrients.

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The Muscle Protein Synthetic Response to the Ingestion of a Plant-Based Protein Blend Is Not Different From Milk Protein in Healthy, Young Males

Current Developments in Nutrition ◽

10.1093/cdn/nzab041_032 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 517-517

Author(s):

Philippe J.M. Pinckaers ◽

Imre W.K. Kouw ◽

Stefan H.M. Gorissen ◽

Joan M. Senden ◽

Lisette C.P.G.M. de Groot ◽

...

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Essential Amino Acid ◽

Milk Protein ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Myofibrillar Protein ◽

Pea Protein ◽

Young Males ◽

Myofibrillar Protein Synthesis

Abstract Objectives It has been reported that plant-based proteins are not as effective as animal-based proteins in their capacity to stimulate muscle protein synthesis rates. This has been attributed to the lower essential amino acid content and the selective deficiency in specific amino acids. It has been hypothesized that a blend of different plant-based proteins may complement each other and, as such, compensate for such deficits. This study compares post-prandial muscle protein synthesis rates following the ingestion of 30 g milk protein with the ingestion of a 30 g blend of wheat, corn, and pea protein in vivo, in healthy young males. Methods In a randomized, double blind, parallel-group design, 24 healthy young males (24 ± 4 y) received a primed continuous infusion of L-[ring-13C6]-phenylalanine and ingested 30 g milk protein (MILK), or a 30 g protein blend with 15 g wheat, 7.5 g corn, and 7.5 g pea protein (PLANT) in beverage form (n = 12 per group). Both interventional drinks were matched for leucine content. Blood and muscle biopsies were collected for 5 h following protein ingestion to assess post-prandial plasma amino acid profiles and myofibrillar protein synthesis rates. Data are expressed as mean ± SD. Results MILK increased plasma essential amino acid concentrations ∼2 fold more than PLANT over the 5 h post-prandial period (incremental area under curve (iAUC): 151 ± 31 vs 79 ± 12 mmol∙5 h∙L−1 respectively; P < 0.001). Similarly, the leucine iAUC was ∼16% greater for MILK vs PLANT (36 ± 7 vs 31 ± 4 mmol∙5 h∙L−1 respectively; P < 0.05). Ingestion of both MILK and PLANT increased myofibrillar protein synthesis rates when compared to basal post-absorptive values (P < 0.001), with no significant differences between treatments (0.053 ± 0.013 vs 0.064 ± 0.016%∙h−1, respectively; P > 0.05). Conclusions Ingestion of 30 g of a wheat, corn, and pea protein blend increases muscle protein synthesis rates in healthy, young males. The post-prandial muscle protein synthetic response to the ingestion of 30 g of a wheat, corn and pea protein blend does not differ from the ingestion of an equivalent amount of milk protein in healthy, young males. Funding Sources TiFN

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