Anabolic reactions of skeletal muscles in mice following plant- and animal-based protein intake during resistance exercise

A growing body of evidence supports a role for tissue-to-diet 15N and 13C discrimination factors (Δ15N and Δ13C), as biomarkers of metabolic adaptations to nutritional stress, but the underlying mechanisms remain poorly understood. In obese rats fed ad libitum or subjected to gradual caloric restriction (CR), under a maintained protein intake, we measured Δ15N and Δ13C levels in tissue proteins and their constitutive amino acids (AA) and the expression of enzymes involved in the AA metabolism. CR was found to lower protein mass in the intestine, liver, heart and, to a lesser extent, some skeletal muscles. This was accompanied by Δ15N increases in urine and the protein of the liver and plasma, but Δ15N decreases in the proteins of the heart and the skeletal muscles, alongside Δ13C decreases in all tissue proteins. In Lys, Δ15N levels rose in the plasma, intestine, and some muscles, but fell in the heart, while in Ala, and to a lesser extent Glx and Asx, Δ13C levels fell in all these tissues. In the liver, CR was associated with an increase in the expression of genes involved in AA oxidation. During CR, the parallel rises of Δ15N in urine, liver, and plasma proteins reflected an increased AA catabolism occurring at the level of the liver metabolic branch point, while Δ15N decreases in cardiac and skeletal muscle proteins indicated increased protein and AA catabolism in these tissues. Thus, an increased protein and AA catabolism results in opposite Δ15N effects in splanchnic and muscular tissues. In addition, the Δ13C decrease in all tissue proteins, reflects a reduction in carbohydrate (CHO) oxidation and routing towards non-indispensable AA, to achieve fuel economy.

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Acute Dietary Protein Intake Restriction Is Associated with Changes in Myostatin Expression after a Single Bout of Resistance Exercise in Healthy Young Men

Journal of Nutrition ◽

10.3945/jn.113.183996 ◽

2013 ◽

Vol 144 (2) ◽

pp. 137-145 ◽

Cited By ~ 17

Author(s):

Tim Snijders ◽

Lex B. Verdijk ◽

Bryon R. McKay ◽

Joey S.J. Smeets ◽

Janneau van Kranenburg ◽

...

Keyword(s):

Resistance Exercise ◽

Dietary Protein ◽

Protein Intake ◽

Young Men ◽

Dietary Protein Intake ◽

Single Bout

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Pronounced energy restriction with elevated protein intake results in no change in proteolysis and reductions in skeletal muscle protein synthesis that are mitigated by resistance exercise

The FASEB Journal ◽

10.1096/fj.201700158rr ◽

2017 ◽

Vol 32 (1) ◽

pp. 265-275 ◽

Cited By ~ 38

Author(s):

Amy J. Hector ◽

Chris McGlory ◽

Felipe Damas ◽

Nicole Mazara ◽

Steven K. Baker ◽

...

Keyword(s):

Skeletal Muscle ◽

Protein Synthesis ◽

Resistance Exercise ◽

Protein Intake ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Energy Restriction ◽

Skeletal Muscle Protein ◽

Skeletal Muscle Protein Synthesis ◽

Elevated Protein

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Potato Protein Isolate Stimulates Muscle Protein Synthesis at Rest and with Resistance Exercise in Young Women

Nutrients ◽

10.3390/nu12051235 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1235 ◽

Cited By ~ 4

Author(s):

Sara Y. Oikawa ◽

Ravninder Bahniwal ◽

Tanya M. Holloway ◽

Changhyun Lim ◽

Jonathan C. McLeod ◽

...

Keyword(s):

Protein Synthesis ◽

Resistance Exercise ◽

Young Women ◽

Total Protein ◽

Protein Intake ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Control Diet ◽

Potato Protein ◽

Opposite Limb

Skeletal muscle myofibrillar protein synthesis (MPS) increases in response to protein feeding and to resistance exercise (RE), where each stimuli acts synergistically when combined. The efficacy of plant proteins such as potato protein (PP) isolate to stimulate MPS is unknown. We aimed to determine the effects of PP ingestion on daily MPS with and without RE in healthy women. In a single blind, parallel-group design, 24 young women (21 ± 3 years, n = 12/group) consumed a weight-maintaining baseline diet containing 0.8 g/kg/d of protein before being randomized to consume either 25 g of PP twice daily (1.6 g/kg/d total protein) or a control diet (CON) (0.8 g/kg/d total protein) for 2 wks. Unilateral RE (~30% of maximal strength to failure) was performed thrice weekly with the opposite limb serving as a non-exercised control (Rest). MPS was measured by deuterated water ingestion at baseline, following supplementation (Rest), and following supplementation + RE (Exercise). Ingestion of PP stimulated MPS by 0.14 ± 0.09 %/d at Rest, and by 0.32 ± 0.14 %/d in the Exercise limb. MPS was significantly elevated by 0.20 ± 0.11 %/d in the Exercise limb in CON (p = 0.008). Consuming PP to increase protein intake to levels twice the recommended dietary allowance for protein augmented rates of MPS. Performance of RE stimulated MPS regardless of protein intake. PP is a high-quality, plant-based protein supplement that augments MPS at rest and following RE in healthy young women.

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Faculty Opinions recommendation of Pronounced energy restriction with elevated protein intake results in no change in proteolysis and reductions in skeletal muscle protein synthesis that are mitigated by resistance exercise.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.731119894.793549735 ◽

2018 ◽

Author(s):

Aaron Russell

Keyword(s):

Skeletal Muscle ◽

Protein Synthesis ◽

Resistance Exercise ◽

Protein Intake ◽

Muscle Protein ◽

Muscle Protein Synthesis ◽

Energy Restriction ◽

Skeletal Muscle Protein ◽

Skeletal Muscle Protein Synthesis ◽

Elevated Protein

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Response to comment on: Thomson et al. Muscle strength gains during resistance exercise training are attenuated with soy compared with dairy or usual protein intake in older adults: A randomized controlled trial. Clinical Nutrition 35:27–33, 2016

Clinical Nutrition ◽

10.1016/j.clnu.2016.07.006 ◽

2016 ◽

Vol 35 (6) ◽

pp. 1573-1574

Author(s):

Rebecca L. Thomson ◽

Grant D. Brinkworth ◽

Manny Noakes ◽

Jonathan D. Buckley

Keyword(s):

Older Adults ◽

Randomized Controlled Trial ◽

Muscle Strength ◽

Exercise Training ◽

Resistance Exercise ◽

Protein Intake ◽

Controlled Trial ◽

Clinical Nutrition ◽

Resistance Exercise Training ◽

Randomized Controlled

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Protein Intake to Maximize Whole-Body Anabolism during Postexercise Recovery in Resistance-Trained Men with High Habitual Intakes is Severalfold Greater than the Current Recommended Dietary Allowance

Journal of Nutrition ◽

10.1093/jn/nxz249 ◽

2019 ◽

Cited By ~ 4

Author(s):

Michael Mazzulla ◽

Sidney Abou Sawan ◽

Eric Williamson ◽

Sarkis J Hannaian ◽

Kimberly A Volterman ◽

...

Keyword(s):

Protein Synthesis ◽

Steady State ◽

Amino Acid ◽

Resistance Exercise ◽

Protein Intake ◽

Whole Body ◽

Total Amino Acid ◽

Acid Oxidation ◽

Amino Acid Oxidation ◽

Habitual Protein Intake

ABSTRACT Background Dietary protein supports resistance exercise–induced anabolism primarily via the stimulation of protein synthesis rates. The indicator amino acid oxidation (IAAO) technique provides a noninvasive estimate of the protein intake that maximizes whole-body protein synthesis rates and net protein balance. Objective We utilized IAAO to determine the maximal anabolic response to postexercise protein ingestion in resistance-trained men. Methods Seven resistance-trained men (mean ± SD age 24 ± 3 y; weight 80 ± 9 kg; 11 ± 5% body fat; habitual protein intake 2.3 ± 0.6 g·kg−1·d−1) performed a bout of whole-body resistance exercise prior to ingesting hourly mixed meals, which provided a variable amount of protein (0.20–3.00 g·kg−1·d−1) as crystalline amino acids modeled after egg protein. Steady-state protein kinetics were modeled with oral l-[1-13C]-phenylalanine. Breath and urine samples were taken at isotopic steady state to determine phenylalanine flux (PheRa), phenylalanine excretion (F13CO2; reciprocal of protein synthesis), and net balance (protein synthesis − PheRa). Total amino acid oxidation was estimated from the ratio of urinary urea and creatinine. Results Mixed model biphasic linear regression revealed a plateau in F13CO2 (mean: 2.00; 95% CI: 1.62, 2.38 g protein·kg−1·d−1) (r2 = 0.64; P ˂ 0.01) and in net balance (mean: 2.01; 95% CI: 1.44, 2.57 g protein·kg−1·d−1) (r2 = 0.63; P ˂ 0.01). Ratios of urinary urea and creatinine concentrations increased linearly (r = 0.84; P ˂ 0.01) across the range of protein intakes. Conclusions A breakpoint protein intake of ∼2.0 g·kg−1·d−1, which maximized whole-body anabolism in resistance-trained men after exercise, is greater than previous IAAO-derived estimates for nonexercising men and is at the upper range of current general protein recommendations for athletes. The capacity to enhance whole-body net balance may be greater than previously suggested to maximize muscle protein synthesis in resistance-trained athletes accustomed to a high habitual protein intake. This trial was registered at clinicaltrials.gov as NCT03696264.

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