Muscle protein synthesis and gene expression during recovery from aerobic exercise in the fasted and fed states

2010 ◽  
Vol 299 (5) ◽  
pp. R1254-R1262 ◽  
Author(s):  
Matthew P. Harber ◽  
Adam R. Konopka ◽  
Bozena Jemiolo ◽  
Scott W. Trappe ◽  
Todd A. Trappe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Exercise ◽  
Mrna Expression ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Synthesis Rate ◽  
Myogenic Regulatory Factor ◽  
Expression Of Genes ◽  
Dependent Protein ◽  
Muscle Protein Metabolism

The purpose of this investigation was to assess mixed-muscle fractional synthesis rate (FSR) and the expression of genes involved in skeletal muscle remodeling after aerobic exercise in the fasted and fed states. Eight recreationally active males (25 ± 1 yr; V̇o2 max: 52 ± 2 ml·kg−1·min−1) performed 60-min of cycle ergometry at 72 ± 1% V̇o2 max on two occasions in a counter-balanced design. Subjects ingested a noncaloric placebo (EX-FAST) or a beverage containing (per kg body wt): 5 kcal, 0.83 g carbohydrate, 0.37 g protein, and 0.03 g fat (EX-FED) immediately and 1 h after exercise. FSR was assessed at rest and following exercise with the use of a l-[ring 2H5]-phenylalanine infusion combined with muscle biopsies at 2 and 6 h postexercise. mRNA expression was assessed at 2 and 6 h postexercise via real-time RT-PCR. FSR was higher ( P < 0.05) after exercise in both EX-FAST (0.112 ± 0.010%·h−1) and EX-FED (0.129 ± 0.014%·h−1) compared with rest (0.071 ± 0.005%·h−1). Feeding attenuated the mRNA expression ( P < 0.05) of proteolytic factors MuRF-1 (6 h) and calpain-2 (2 and 6 h) postexercise but did not alter FOXO3A, calpain-1, caspase3, or myostatin mRNA expression compared with EX-FAST. Myogenic regulatory factor (MRF4) mRNA was also attenuated ( P < 0.05) at 2 and 6 h postexercise in EX-FED compared with EX-FAST. These data demonstrate that a nonexhaustive bout of aerobic exercise stimulates skeletal muscle FSR in the fasted state and that feeding does not measurably enhance FSR between 2 and 6 h after aerobic exercise. Additionally, postexercise nutrient intake attenuates the expression of factors involved in the ubiquitin-proteosome and Ca2+-dependent protein degradation pathways. These data provide insight into the role of feeding on muscle protein metabolism during recovery from aerobic exercise.

Impact of surgical trauma on human skeletal muscle protein synthesis

2004 ◽  
Vol 107 (6) ◽  
pp. 601-607 ◽  
Author(s):  
Inga TJÄDER ◽  
Pia ESSEN ◽  
Peter J. GARLICK ◽  
Margaret A. McMNURLAN ◽  
Olav ROOYACKERS ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Pilot Study ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Major Surgery ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Surgical Trauma ◽  
Minor Surgery

Muscle protein catabolism is a considerable clinical problem following surgery. However, the impact of surgical trauma on muscle protein synthesis is not well characterized. In this pilot study, we therefore investigated whether the severity of surgical trauma is related to a decrease in muscle protein synthesis rate in humans. Metabolically healthy patients (n=28) were included in the study. Eight of the patients were day-care patients undergoing minor breast surgery (defined as minor surgery). The other 20 patients were subjected to major abdominal surgery and were therefore scheduled to stay overnight in the recovery room during the first postoperative night (defined as major surgery). Protein FSRs (fractional synthesis rates) in skeletal muscle were determined during a measurement period of 90 min before surgery and immediately after termination of surgery. FSR in skeletal muscle of the minor surgery patients was 1.72±0.25%/24 h before surgery and 1.67±0.29%/24 h after surgery (P=0.68). In the major surgery group, FSR was 1.62±0.30%/24 h before surgery and 1.57±0.40%/24 h (P=0.59) immediately following surgery. The observations made in this pilot study could not confirm a size-related decrease in muscle protein synthesis immediately following minor and major surgery. This finding is discussed in relation to confounders, postoperative course and to muscle protein degradation. The shortage of knowledge in this field is emphasized.

Early change in skeletal muscle protein synthesis after limb immobilization of rats

1979 ◽  
Vol 47 (5) ◽  
pp. 974-977 ◽  
Author(s):  
F. W. Booth ◽  
M. J. Seider
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Control Level ◽  
Constant Infusion ◽  
Initial Time ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Limb Immobilization

The atrophy of skeletal muscle accruing from disuse, or limb immobilization, is caused by a decreased rate of protein synthesis and an increased rate of protein degradation. Currently, little information is available regarding the initial time of the decline in the rate of protein synthesis in skeletal muscle. The purpose of the present study was to determine, as precisely as possible, the time at which the protein synthesis rate first begins to decline in skeletal muscle, utilizing immobilized limbs of rats for a model. A constant-infusion technique employing [14C]tyrosine was used to estimate protein synthesis rates. During the first 6 h of immobilization, a significant decline of 37% in the fractional rate of protein synthesis from the control level of 5.7%/day was observed. These results suggest that very early changes are occurring in molecular events that regulate protein synthesis in disused or immobilized skeletal muscle.

scholarly journals Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats

2016 ◽  
Vol 310 (6) ◽  
pp. E405-E417 ◽  
Author(s):  
Mahalakshmi Shankaran ◽  
Todd W. Shearer ◽  
Stephen A. Stimpson ◽  
Scott M. Turner ◽  
Chelsea King ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Androgen Receptor ◽  
Muscle Mass ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Synthesis Rate ◽  
Muscle Proteins ◽  
Receptor Modulator ◽  
Fractional Synthesis

Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167–201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated ( r2 = 0.90–0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM.

Smoking impairs muscle protein synthesis and increases the expression of myostatin and MAFbx in muscle

2007 ◽  
Vol 293 (3) ◽  
pp. E843-E848 ◽  
Author(s):  
Anne Marie Winther Petersen ◽  
Faidon Magkos ◽  
Philip Atherton ◽  
Anna Selby ◽  
Kenneth Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Inflammatory Markers ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Synthesis Process ◽  
Skeletal Muscle Protein ◽  
Expression Of Genes ◽  
Tnf Α

Smoking causes multiple organ dysfunction. The effect of smoking on skeletal muscle protein metabolism is unknown. We hypothesized that the rate of skeletal muscle protein synthesis is depressed in smokers compared with non-smokers. We studied eight smokers (≥20 cigarettes/day for ≥20 years) and eight non-smokers matched for sex (4 men and 4 women per group), age (65 ± 3 and 63 ± 3 yr, respectively; means ± SEM) and body mass index (25.9 ± 0.9 and 25.1 ± 1.2 kg/m2, respectively). Each subject underwent an intravenous infusion of stable isotope-labeled leucine in conjunction with blood and muscle tissue sampling to measure the mixed muscle protein fractional synthesis rate (FSR) and whole body leucine rate of appearance (Ra) in plasma (an index of whole body proteolysis), the expression of genes involved in the regulation of muscle mass (myostatin, a muscle growth inhibitor, and MAFBx and MuRF-1, which encode E3 ubiquitin ligases in the proteasome proteolytic pathway) and that for the inflammatory cytokine TNF-α in muscle, and the concentration of inflammatory markers in plasma (C-reactive protein, TNF-α, interleukin-6) which are associated with muscle wasting in other conditions. There were no differences between nonsmokers and smokers in plasma leucine concentration, leucine rate of appearance, and plasma concentrations of inflammatory markers, or TNF-α mRNA in muscle, but muscle protein FSR was much less (0.037 ± 0.005 vs. 0.059 ± 0.005%/h, respectively, P = 0.004), and myostatin and MAFBx (but not MuRF-1) expression were much greater (by ∼33 and 45%, respectivley, P < 0.05) in the muscle of smokers than of nonsmokers. We conclude that smoking impairs the muscle protein synthesis process and increases the expression of genes associated with impaired muscle maintenance; smoking therefore likely increases the risk of sarcopenia.

scholarly journals Muscle protein metabolism responds similarly to exogenous amino acids in healthy younger and older adults during NO-induced hyperemia

2011 ◽  
Vol 301 (5) ◽  
pp. R1408-R1417 ◽  
Author(s):  
E. Lichar Dillon ◽  
Shanon L. Casperson ◽  
William J. Durham ◽  
Kathleen M. Randolph ◽  
Randall J. Urban ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Older Individuals ◽  
Skeletal Muscle Protein ◽  
Age Related ◽  
Muscle Protein Metabolism

The combination of increasing blood flow and amino acid (AA) availability provides an anabolic stimulus to the skeletal muscle of healthy young adults by optimizing both AA delivery and utilization. However, aging is associated with a blunted response to anabolic stimuli and may involve impairments in endothelial function. We investigated whether age-related differences exist in the muscle protein anabolic response to AAs between younger (30 ± 2 yr) and older (67 ± 2 yr) adults when macrovascular and microvascular leg blood flow were similarly increased with the nitric oxide (NO) donor, sodium nitroprusside (SNP). Regardless of age, SNP+AA induced similar increases above baseline ( P ≤ 0.05) in macrovascular flow (4.3 vs. 4.4 ml·min−1·100 ml leg−1 measured using indocyanine green dye dilution), microvascular flow (1.4 vs. 0.8 video intensity/s measured using contrast-enhanced ultrasound), phenylalanine net balance (59 vs. 68 nmol·min−1·100 ml·leg−1), fractional synthetic rate (0.02 vs. 0.02%/h), and model-derived muscle protein synthesis (62 vs. 49 nmol·min−1·100 ml·leg−1) in both younger vs. older individuals, respectively. Provision of AAs during NO-induced local skeletal muscle hyperemia stimulates skeletal muscle protein metabolism in older adults to a similar extent as in younger adults. Our results suggest that the aging vasculature is responsive to exogenous NO and that there is no age-related difference per se in AA-induced anabolism under such hyperemic conditions.

scholarly journals Effect of a cyclooxygenase-2 inhibitor on postexercise muscle protein synthesis in humans

2010 ◽  
Vol 298 (2) ◽  
pp. E354-E361 ◽  
Author(s):  
Nicholas A. Burd ◽  
Jared M. Dickinson ◽  
Jennifer K. LeMoine ◽  
Chad C. Carroll ◽  
Bridget E. Sullivan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Vastus Lateralis ◽  
Constant Infusion ◽  
Synthesis Rate ◽  
Cox 2 ◽  
Cox 1

Nonselective blockade of the cyclooxygenase (COX) enzymes in skeletal muscle eliminates the normal increase in muscle protein synthesis following resistance exercise. The current study tested the hypothesis that this COX-mediated increase in postexercise muscle protein synthesis is regulated specifically by the COX-2 isoform. Sixteen males (23 ± 1 yr) were randomly assigned to one of two groups that received three doses of either a selective COX-2 inhibitor (celecoxib; 200 mg/dose, 600 mg total) or a placebo in double-blind fashion during the 24 h following a single bout of knee extensor resistance exercise. At rest and 24 h postexercise, skeletal muscle protein fractional synthesis rate (FSR) was measured using a primed constant infusion of [2H5]phenylalanine coupled with muscle biopsies of the vastus lateralis, and measurements were made of mRNA and protein expression of COX-1 and COX-2. Mixed muscle protein FSR in response to exercise ( P < 0.05) was not suppressed by the COX-2 inhibitor (0.056 ± 0.004 to 0.108 ± 0.014%/h) compared with placebo (0.074 ± 0.004 to 0.091 ± 0.005%/h), nor was there any difference ( P > 0.05) between the placebo and COX-2 inhibitor postexercise when controlling for resting FSR. The COX-2 inhibitor did not influence COX-1 mRNA, COX-1 protein, or COX-2 protein levels, whereas it did increase ( P < 0.05) COX-2 mRNA (3.0 ± 0.9-fold) compared with placebo (1.3 ± 0.3-fold). It appears that the elimination of the postexercise muscle protein synthesis response by nonselective COX inhibitors is not solely due to COX-2 isoform blockade. Furthermore, the current data suggest that the COX-1 enzyme is likely the main isoform responsible for the COX-mediated increase in muscle protein synthesis following resistance exercise in humans.

scholarly journals Feeding a DHA-enriched diet increases skeletal muscle protein synthesis in growing pigs: association with increased skeletal muscle insulin action and local mRNA expression of insulin-like growth factor 1

2013 ◽  
Vol 110 (4) ◽  
pp. 671-680 ◽  
Author(s):  
Hong-Kui Wei ◽  
Yuanfei Zhou ◽  
Shuzhong Jiang ◽  
Ya-Xiong Tao ◽  
Haiqing Sun ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Mrna Expression ◽  
Protein Tyrosine Phosphatase ◽  
Insulin Action ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Tyrosine Phosphatase ◽  
Growing Pigs ◽  
Fed State

Dietary n-3 PUFA have been demonstrated to promote muscle growth in growing animals. In the present study, fractional protein synthesis rates (FSR) in the skeletal muscle of growing pigs fed a DHA-enriched (DE) diet (DE treatment) or a soyabean oil (SO) diet (SO treatment) were evaluated in the fed and feed-deprived states. Feeding-induced increases in muscle FSR, as well as the activation of the mammalian target of rapamycin and protein kinase B, were higher in the DE treatment as indicated by the positive interaction between diet and feeding. In the fed state, the activation of eIF4E-binding protein 1 in the skeletal muscle of pigs on the DE diet was higher than that in pigs on the SO diet (P <0·05). Feeding the DE diet increased muscle insulin-like growth factor 1 (IGF-1) expression (P <0·05) and insulin action (as demonstrated by increased insulin receptor (IR) phosphorylation, P <0·05), resulting in increased IR substrate 1 activation in the fed state. However, no difference in plasma IGF-1 concentration or hepatic IGF-1 expression between the two treatments was associated. The increased IGF-1 expression in the DE treatment was associated with increased mRNA expression of the signal transducer and activator of transcription 5A and decreased mRNA expression of protein tyrosine phosphatase, non-receptor type 3 in skeletal muscle. Moreover, mRNA expression of protein tyrosine phosphatase, non-receptor type 1 (PTPN1), the activation of PTPN1 and the activation of NF-κB in muscle were significantly lower in the DE treatment (P <0·05). The results of the present study suggest that feeding a DE diet increased feeding-induced muscle protein synthesis in growing pigs, and muscle IGF-1 expression and insulin action were involved in this action.

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