Growth hormone increases muscle mass and strength but does not rejuvenate myofibrillar protein synthesis in healthy subjects over 60 years old

1996 ◽  
Vol 81 (9) ◽  
pp. 3239-3243 ◽  
Author(s):  
S. Welle
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Muscle Mass ◽  
Healthy Subjects ◽  
Myofibrillar Protein ◽  
Myofibrillar Protein Synthesis

scholarly journals Essential Amino Acid-Enriched Diet Alleviates Dexamethasone-Induced Loss of Muscle Mass and Function through Stimulation of Myofibrillar Protein Synthesis and Improves Glucose Metabolism in Mice

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Yeongmin Kim ◽  
Sanghee Park ◽  
Jinseok Lee ◽  
Jiwoong Jang ◽  
Jiyeon Jung ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Glucose Metabolism ◽  
Muscle Mass ◽  
Muscle Atrophy ◽  
Myofibrillar Protein ◽  
Treadmill Running ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Myofibrillar Protein Synthesis ◽  
Stimulation Of

Dexamethasone (DEX) induces dysregulation of protein turnover, leading to muscle atrophy and impairment of glucose metabolism. Positive protein balance, i.e., rate of protein synthesis exceeding rate of protein degradation, can be induced by dietary essential amino acids (EAAs). In this study, we investigated the roles of an EAA-enriched diet in the regulation of muscle proteostasis and its impact on glucose metabolism in the DEX-induced muscle atrophy model. Mice were fed normal chow or EAA-enriched chow and were given daily injections of DEX over 10 days. We determined muscle mass and functions using treadmill running and ladder climbing exercises, protein kinetics using the D2O labeling method, molecular signaling using immunoblot analysis, and glucose metabolism using a U-13C6 glucose tracer during oral glucose tolerance test (OGTT). The EAA-enriched diet increased muscle mass, strength, and myofibrillar protein synthesis rate, concurrent with improved glucose metabolism (i.e., reduced plasma insulin concentrations and increased insulin sensitivity) during the OGTT. The U-13C6 glucose tracing revealed that the EAA-enriched diet increased glucose uptake and subsequent glycolytic flux. In sum, our results demonstrate a vital role for the EAA-enriched diet in alleviating the DEX-induced muscle atrophy through stimulation of myofibrillar proteins synthesis, which was associated with improved glucose metabolism.

Stimulation of myofibrillar protein synthesis in hindlimb suspended rats by resistance exercise and growth hormone

Life Sciences ◽  
1995 ◽  
Vol 57 (8) ◽  
pp. 755-762 ◽  
Author(s):  
Jon K. Linderman ◽  
Justen B. Whittall ◽  
Kristin L. Gosselink ◽  
Tommy J. Wang ◽  
Venkat R. Mukku ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Myofibrillar Protein ◽  
Myofibrillar Protein Synthesis ◽  
Stimulation Of

scholarly journals Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis

2010 ◽  
Vol 588 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Simon Doessing ◽  
Katja M. Heinemeier ◽  
Lars Holm ◽  
Abigail L. Mackey ◽  
Peter Schjerling ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Collagen Synthesis ◽  
Myofibrillar Protein ◽  
Human Tendon ◽  
Myofibrillar Protein Synthesis

scholarly journals Myofibrillar protein synthesis in myostatin-deficient mice

2006 ◽  
Vol 290 (3) ◽  
pp. E409-E415 ◽  
Author(s):  
Stephen Welle ◽  
Kirti Bhatt ◽  
Carl A. Pinkert
Keyword(s):  
Protein Synthesis ◽  
Muscle Mass ◽  
Half Life ◽  
Muscle Growth ◽  
Myofibrillar Protein ◽  
28S Rrna ◽  
Fractional Rate ◽  
Deficient Mice ◽  
Myofibrillar Protein Synthesis

Either increased protein synthesis or prolonged protein half-life is necessary to support the excessive muscle growth and maintenance of enlarged muscles in myostatin-deficient mice. This issue was addressed by determining in vivo rates of myofibrillar protein synthesis in mice with constitutive myostatin deficiency (MstnΔE3/ΔE3) or normal myostatin expression (Mstn+/+) by measuring tracer incorporation after a systemic flooding dose of l-[ ring-2H5]phenylalanine. At 5–6 wk of age, MstnΔE3/ΔE3 mice had increased muscle mass (40%), fractional rates of myofibrillar synthesis (14%), and protein synthesis per whole muscle (60%) relative to Mstn+/+ mice. With maturation, fractional rates of synthesis declined >50% in parallel with decreased DNA and RNA [total, 28S rRNA, and poly(A) RNA] concentrations in muscle. At 6 mo of age, MstnΔE3/ΔE3 mice had even greater increases in muscle mass (90%) and myofibrillar synthesis per muscle (85%) relative to Mstn+/+ mice, but the fractional rate of synthesis was normal. Estimated myofibrillar protein half-life was not affected by myostatin deficiency. Muscle DNA concentrations were reduced in both young and mature MstnΔE3/ΔE3 mice, whereas RNA concentrations were normal, so the ratio of RNA to DNA was ∼30% greater than normal in MstnΔE3/ΔE3 mice. Thus the increased protein synthesis and RNA content per muscle in myostatin-deficient mice cannot be explained entirely by an increased number of myonuclei.

scholarly journals The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

2021 ◽  
pp. 1-8
Author(s):  
Heitor O. Santos ◽  
Gederson K. Gomes ◽  
Brad J. Schoenfeld ◽  
Erick P. de Oliveira
Keyword(s):  
Protein Synthesis ◽  
Muscle Mass ◽  
Young Men ◽  
Egg Yolk ◽  
Egg White ◽  
Myofibrillar Protein ◽  
Current Evidence ◽  
Limited Evidence ◽  
Whole Egg ◽  
Myofibrillar Protein Synthesis

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.

scholarly journals Presleep dietary protein-derived amino acids are incorporated in myofibrillar protein during postexercise overnight recovery

2018 ◽  
Vol 314 (5) ◽  
pp. E457-E467 ◽  
Author(s):  
Jorn Trommelen ◽  
Imre W. K. Kouw ◽  
Andrew M. Holwerda ◽  
Tim Snijders ◽  
Shona L. Halson ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Dietary Protein ◽  
Myofibrillar Protein ◽  
Whole Body ◽  
Body Protein ◽  
Protein Ingestion ◽  
Casein Protein ◽  
The Impact ◽  
Myofibrillar Protein Synthesis

The purpose of this study was to determine the impact of ingesting 30 g casein protein with and without 2 g free leucine before sleep on myofibrillar protein synthesis rates during postexercise overnight recovery. Thirty-six healthy young men performed a single bout of resistance-type exercise in the evening (1945) after a full day of dietary standardization. Thirty minutes before sleep (2330), subjects ingested 30 g intrinsically l-[1-13C]phenylalanine-labeled protein with (PRO+leu, n = 12) or without (PRO, n = 12) 2 g free leucine, or a noncaloric placebo (PLA, n = 12). Continuous intravenous l-[ ring-2H5]phenylalanine, l-[1-13C]leucine, and l-[ ring-2H2]tyrosine infusions were applied. Blood and muscle tissue samples were collected to assess whole body protein net balance, myofibrillar protein synthesis rates, and overnight incorporation of dietary protein-derived amino acids into myofibrillar protein. Protein ingestion before sleep improved overnight whole body protein net balance ( P < 0.001). Myofibrillar protein synthesis rates did not differ significantly between treatments as assessed by l-[ ring-2H5]phenylalanine (0.057 ± 0.002, 0.055 ± 0.002, and 0.055 ± 0.004%/h for PLA, PRO, and PRO+leu, respectively; means ± SE; P = 0.850) or l-[1-13C]leucine (0.080 ± 0.004, 0.073 ± 0.004, and 0.083 ± 0.006%/h, respectively; P = 0.328). Myofibrillar l-[1-13C]phenylalanine enrichments increased following protein ingestion but did not differ between the PRO and PRO+leu treatments. In conclusion, protein ingestion before sleep improves whole body protein net balance and provides amino acids that are incorporated into myofibrillar protein during sleep. However, the ingestion of 30 g casein protein with or without additional free leucine before sleep does not increase muscle protein synthesis rates during postexercise overnight recovery.

scholarly journals Hypoenergetic diet-induced reductions in myofibrillar protein synthesis are restored with resistance training and balanced daily protein ingestion in older men

2015 ◽  
Vol 308 (9) ◽  
pp. E734-E743 ◽  
Author(s):  
Caoileann H. Murphy ◽  
Tyler A. Churchward-Venne ◽  
Cameron J. Mitchell ◽  
Nathan M. Kolar ◽  
Amira Kassis ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Training ◽  
Older Men ◽  
Myofibrillar Protein ◽  
Energy Restriction ◽  
Protein Distribution ◽  
Protein Meal ◽  
Fed State ◽  
Sarcoplasmic Protein ◽  
Myofibrillar Protein Synthesis

Strategies to enhance weight loss with a high fat-to-lean ratio in overweight/obese older adults are important since lean loss could exacerbate sarcopenia. We examined how dietary protein distribution affected muscle protein synthesis during energy balance (EB), energy restriction (ER), and energy restriction plus resistance training (ER + RT). A 4-wk ER diet was provided to overweight/obese older men (66 ± 4 yr, 31 ± 5 kg/m2) who were randomized to either a balanced (BAL: 25% daily protein/meal × 4) or skewed (SKEW: 7:17:72:4% daily protein/meal; n = 10/group) pattern. Myofibrillar and sarcoplasmic protein fractional synthetic rates (FSR) were measured during a 13-h primed continuous infusion of l-[ ring-13C6]phenylalanine with BAL and SKEW pattern of protein intake in EB, after 2 wk ER, and after 2 wk ER + RT. Fed-state myofibrillar FSR was lower in ER than EB in both groups ( P < 0.001), but was greater in BAL than SKEW ( P = 0.014). In ER + RT, fed-state myofibrillar FSR increased above ER in both groups and in BAL was not different from EB ( P = 0.903). In SKEW myofibrillar FSR remained lower than EB ( P = 0.002) and lower than BAL ( P = 0.006). Fed-state sarcoplasmic protein FSR was reduced similarly in ER and ER + RT compared with EB ( P < 0.01) in both groups. During ER in overweight/obese older men a BAL consumption of protein stimulated the synthesis of muscle contractile proteins more effectively than traditional, SKEW distribution. Combining RT with a BAL protein distribution “rescued” the lower rates of myofibrillar protein synthesis during moderate ER.

scholarly journals Dietary protein intake does not modulate daily myofibrillar protein synthesis rates or loss of muscle mass and function during short-term immobilization in young men: a randomized controlled trial

2020 ◽  
Author(s):  
Sean Paul Kilroe ◽  
Jonathan Fulford ◽  
Sarah Jackman ◽  
Andrew Holwerda ◽  
Annemie Gijsen ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Dietary Protein ◽  
Protein Intake ◽  
Quadriceps Muscle ◽  
Myofibrillar Protein ◽  
Muscle Volume ◽  
Dietary Protein Intake ◽  
Short Term ◽  
Muscle Disuse ◽  
Myofibrillar Protein Synthesis

ABSTRACT Background Short-term (&lt;1 wk) muscle disuse lowers daily myofibrillar protein synthesis (MyoPS) rates resulting in muscle mass loss. The understanding of how daily dietary protein intake influences such muscle deconditioning requires further investigation. Objectives To assess the influence of graded dietary protein intakes on daily MyoPS rates and the loss of muscle mass during 3 d of disuse. Methods Thirty-three healthy young men (aged 22 ± 1 y; BMI = 23 ± 1 kg/m2) initially consumed the same standardized diet for 5 d, providing 1.6 g protein/kg body mass/d. Thereafter, participants underwent a 3-d period of unilateral leg immobilization during which they were randomly assigned to 1 of 3 eucaloric diets containing relatively high, low, or no protein (HIGH: 1.6, LOW: 0.5, NO: 0.15 g protein/kg/d; n = 11 per group). One day prior to immobilization participants ingested 400 mL deuterated water (D2O) with 50-mL doses consumed daily thereafter. Prior to and immediately after immobilization upper leg bilateral MRI scans and vastus lateralis muscle biopsies were performed to measure quadriceps muscle volume and daily MyoPS rates, respectively. Results Quadriceps muscle volume of the control legs remained unchanged throughout the experiment (P &gt; 0.05). Immobilization led to 2.3 ± 0.4%, 2.7 ± 0.2%, and 2.0 ± 0.4% decreases in quadriceps muscle volume (P &lt; 0.05) of the immobilized leg in the HIGH, LOW, and NO groups (P &lt; 0.05), respectively, with no significant differences between groups (P &gt; 0.05). D2O ingestion resulted in comparable plasma free [2H]-alanine enrichments during immobilization (∼2.5 mole percentage excess) across groups (P &gt; 0.05). Daily MyoPS rates during immobilization were 30 ± 2% (HIGH), 26 ± 3% (LOW), and 27 ± 2% (NO) lower in the immobilized compared with the control leg, with no significant differences between groups (P &gt; 0.05). Conclusions Three days of muscle disuse induces considerable declines in muscle mass and daily MyoPS rates. However, daily protein intake does not modulate any of these muscle deconditioning responses. Clinical trial registry number: NCT03797781

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