scholarly journals Prior acetaminophen consumption impacts the early adaptive cellular response of human skeletal muscle to resistance exercise

2018 ◽  
Vol 124 (4) ◽  
pp. 1012-1024 ◽  
Author(s):  
Andrew C. D’Lugos ◽  
Shivam H. Patel ◽  
Jordan C. Ormsby ◽  
Donald P. Curtis ◽  
Christopher S. Fry ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Adaptive Response ◽  
Cellular Response ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Adaptation ◽  
Cox Inhibitor

Resistance exercise (RE) is a powerful stimulus for skeletal muscle adaptation. Previous data demonstrate that cyclooxygenase (COX)-inhibiting drugs alter the cellular mechanisms regulating the adaptive response of skeletal muscle. The purpose of this study was to determine whether prior consumption of the COX inhibitor acetaminophen (APAP) alters the immediate adaptive cellular response in human skeletal muscle after RE. In a double-blinded, randomized, crossover design, healthy young men ( n = 8, 25 ± 1 yr) performed two trials of unilateral knee extension RE (8 sets, 10 reps, 65% max strength). Subjects ingested either APAP (1,000 mg/6 h) or placebo (PLA) for 24 h before RE (final dose consumed immediately after RE). Muscle biopsies (vastus lateralis) were collected at rest and 1 h and 3 h after exercise. Mammalian target of rapamycin (mTOR) complex 1 signaling was assessed through immunoblot and immunohistochemistry, and mRNA expression of myogenic genes was examined via RT-qPCR. At 1 h p-rpS6Ser240/244 was increased in both groups but to a greater extent in PLA. At 3 h p-S6K1Thr389 was elevated only in PLA. Furthermore, localization of mTOR to the lysosome (LAMP2) in myosin heavy chain (MHC) II fibers increased 3 h after exercise only in PLA. mTOR-LAMP2 colocalization in MHC I fibers was greater in PLA vs. APAP 1 h after exercise. Myostatin mRNA expression was reduced 1 h after exercise only in PLA. MYF6 mRNA expression was increased 1 h and 3 h after exercise only in APAP. APAP consumption appears to alter the early adaptive cellular response of skeletal muscle to RE. These findings further highlight the mechanisms through which COX-inhibiting drugs impact the adaptive response of skeletal muscle to exercise. NEW & NOTEWORTHY The extent to which the cellular reaction to acetaminophen impacts the mechanisms regulating the adaptive response of human skeletal muscle to resistance exercise is not well understood. Consumption of acetaminophen before resistance exercise appears to suppress the early response of mTORC1 activity to acute resistance exercise. These data also demonstrate, for the first time, that resistance exercise elicits fiber type-specific changes in the intracellular colocalization of mTOR with the lysosome in human skeletal muscle.

scholarly journals Impact of acetaminophen consumption and resistance exercise on extracellular matrix gene expression in human skeletal muscle

2017 ◽  
Vol 313 (1) ◽  
pp. R44-R50 ◽  
Author(s):  
Shivam H. Patel ◽  
Andrew C. D’Lugos ◽  
Erica R. Eldon ◽  
Donald Curtis ◽  
Jared M. Dickinson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Human Skeletal Muscle ◽  
Type I Collagen ◽  
Type Iii Collagen ◽  
Type I ◽  
Matrix Gene ◽  
The Impact

Acetaminophen (APAP) given during chronic exercise reduces skeletal muscle collagen and cross-linking in rats. We propose that the effect of APAP on muscle extracellular matrix (ECM) may, in part, be mediated by dysregulation of the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs). The purpose of this study was to evaluate the impact of APAP consumption during acute resistance exercise (RE) on several regulators of the ECM in human skeletal muscle. In a double-blinded, placebo-controlled, randomized crossover design, recreationally active men ( n = 8, 25 ± 2 yr) performed two trials of knee extension. Placebo (PLA) or APAP (1,000 mg/6 h) was given for 24 h before and immediately following RE. Vastus lateralis biopsies were taken at baseline and 1 and 3 h post-RE. Quantitative RT-PCR was used to determine differences in mRNA expression. MMP-2, type I collagen, and type III collagen mRNA expression was not altered by exercise or APAP ( P > 0.05). When compared with PLA, TIMP-1 expression was lower at 1 h post-RE during APAP conditions but greater than PLA at 3 h post-RE ( P < 0.05). MMP-9 expression and protein levels were elevated at 3 h post-RE independent of treatment ( P < 0.05). Lysyl oxidase expression was greater at 3 h post-RE during APAP consumption ( P < 0.05) compared with PLA. MMP-2 and TIMP-1 protein was not altered by RE or APAP ( P > 0.05). Phosphorylation of ERK1/2 and p38-MAPK increased ( P < 0.05) with RE but was not influenced by APAP. Our findings do not support our hypothesis and suggest that short-term APAP consumption before RE has a small impact on the measured ECM molecules in human skeletal muscle following acute RE.

scholarly journals Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle

2016 ◽  
Vol 41 (8) ◽  
pp. 856-863 ◽  
Author(s):  
Neil A. Schwarz ◽  
Sarah K. McKinley-Barnard ◽  
Mike B. Spillane ◽  
Thomas L. Andre ◽  
Joshua J. Gann ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Exercise Intensity ◽  
Human Skeletal Muscle ◽  
Peroxisome Proliferator ◽  
Transcriptional Expression ◽  
Lower Intensity ◽  
Peroxisome Proliferator Activated Receptor ◽  
Body Resistance

The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

Influence of muscle glycogen availability on ERK1/2 and Akt signaling after resistance exercise in human skeletal muscle

2005 ◽  
Vol 99 (3) ◽  
pp. 950-956 ◽  
Author(s):  
Andrew Creer ◽  
Philip Gallagher ◽  
Dustin Slivka ◽  
Bozena Jemiolo ◽  
William Fink ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Muscle Glycogen ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Akt Signaling ◽  
Cellular Growth ◽  
Muscle Glycogen Content ◽  
Ribosomal S6 Kinase

Two pathways that have been implicated for cellular growth and development in response to muscle contraction are the extracellular signal-regulated kinase (ERK1/2) and Akt signaling pathways. Although these pathways are readily stimulated after exercise, little is known about how nutritional status may affect stimulation of these pathways in response to resistance exercise in human skeletal muscle. To investigate this, experienced cyclists performed 30 repetitions of knee extension exercise at 70% of one repetition maximum after a low (2%) or high (77%) carbohydrate (LCHO or HCHO) diet, which resulted in low or high (∼174 or ∼591 mmol/kg dry wt) preexercise muscle glycogen content. Muscle biopsies were taken from the vastus lateralis before, ∼20 s after, and 10 min after exercise. ERK1/2 and p90 ribosomal S6 kinase phosphorylation increased ( P ≤ 0.05) 10 min after exercise, regardless of muscle glycogen availability. Akt phosphorylation was elevated ( P < 0.05) 10 min after exercise in the HCHO trial but was unaffected after exercise in the LCHO trial. Mammalian target of rapamycin phosphorylation was similar to that of Akt during each trial; however, change or lack of change was not significant. In conclusion, the ERK1/2 pathway appears to be unaffected by muscle glycogen content. However, muscle glycogen availability appears to contribute to regulation of the Akt pathway, which may influence cellular growth and adaptation in response to resistance exercise in a low-glycogen state.

scholarly journals Fiber type dependent upregulation of human skeletal muscle UCP2 and UCP3 mRNA expression by high-fat diet

2001 ◽  
Vol 25 (4) ◽  
pp. 449-456 ◽  
Author(s):  
P Schrauwen ◽  
H Hoppeler ◽  
R Billeter ◽  
AHF Bakker ◽  
DR Pendergast
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
High Fat Diet ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
High Fat

Concurrent aerobic exercise interferes with the satellite cell response to acute resistance exercise

2012 ◽  
Vol 302 (12) ◽  
pp. R1458-R1465 ◽  
Author(s):  
Lyle Babcock ◽  
Matthew Escano ◽  
Andrew D'Lugos ◽  
Kent Todd ◽  
Kevin Murach ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Aerobic Exercise ◽  
Satellite Cell ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Adaptation ◽  
Mhc I ◽  
Fiber Growth ◽  
Concurrent Exercise

The addition of aerobic exercise (AE) to a resistance exercise (RE) program (concurrent exercise, CE) can interfere with maximum muscle fiber growth achieved with RE. Further, CE appears to markedly affect the growth of myosin heavy chain (MHC) I, but not MHC IIa fibers. The mechanism responsible for this “interference” is unclear. Satellite cell (SC) responsiveness to exercise appears to influence muscle adaptation but has not yet been examined following acute concurrent exercise. Thus, we assessed the fiber-type-specific SC response to RE, AE, and CE exercise. Eight college-aged males completed the following two exercise trials: the RE trial, which consisted of unilateral leg extensions and presses (4 sets ≥ 10 repetitions: 75% 1 repetition maximum, RM); and the AE/CE trial, which included an identical RE protocol with the opposite leg, immediately followed by subjects cycling for 90 min (60% Wmax). Muscle biopsies were obtained from the vastus lateralis before and 4 days after each session. Samples were cross-sectioned, stained with antibodies against NCAM, Ki-67, and MHC I, counterstained with DAPI, and analyzed for SC density (SC per fiber), SC activation, and fiber type. SC density increased to a greater extent following RE (38 ± 10%), compared with CE (−6 ± 8%). Similarly, MHC I muscle fiber SC density displayed a greater increase following RE (46 ± 14%), compared with AE (−7 ± 17%) and CE (−8 ± 8%). Our data indicate that the SC response to RE is blunted when immediately followed by AE, at least in MHC I muscle fibers, and possibly MHC II fibers. This suggests that the physiological environment evoked by AE might attenuate the eventual addition of myonuclei important for maximum muscle fiber growth and consequent force-producing capacity.

scholarly journals Super-relaxed state of myosin in human skeletal muscle is fiber-type dependent

2020 ◽  
Author(s):  
Lien A. Phung ◽  
Aurora D. Foster ◽  
Mark S. Miller ◽  
Dawn A. Lowe ◽  
David D. Thomas
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Epifluorescence Microscopy ◽  
Model Organisms ◽  
Muscle Physiology ◽  
Fiber Types ◽  
Mhc I

AbstractThe myosin super-relaxed state (SRX) in skeletal muscle is hypothesized to play an important role in regulating muscle contractility and thermogenesis in humans, but has only been examined in model organisms. Here we report the first human skeletal muscle SRX measurements, using quantitative epifluorescence microscopy of fluorescent 2’/3’-O-(N-methylanthraniloyl) ATP (mantATP) single-nucleotide turnover. Myosin heavy chain (MHC) isoform expression was determined using gel electrophoresis for each permeabilized vastus lateralis fiber, to allow for novel comparisons of SRX between fiber-types. We find that the fraction of myosin in SRX is less in MHC IIA fibers than in MHC I and IIAX fibers (p = 0.008). ATP turnover of SRX is faster in MHC IIAX fibers compared to MHC I and IIA fibers (p = 0.001). We conclude that SRX biochemistry is measurable in human skeletal muscle, and our data indicate that SRX depends on fiber type as classified by MHC isoform. Extension from this preliminary work would provide further understanding regarding the role of SRX in human muscle physiology.

scholarly journals Effect of Resistance Exercise Intensity on the mRNA Expression of PGC-1α Isoforms in Human Skeletal Muscle

2015 ◽  
Vol 47 ◽  
pp. 188
Author(s):  
Neil A. Schwarz ◽  
Sarah K. McKinley ◽  
Mike Spillane ◽  
Joshua J. Gann ◽  
Thomas L. Andre ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Mrna Expression ◽  
Exercise Intensity ◽  
Human Skeletal Muscle

Variablity in vastus lateralis fiber type distribution, fiber size and myonuclear content along and the between legs

2021 ◽  
Author(s):  
Oscar Horwath ◽  
Helena Envall ◽  
Julia Röja ◽  
Eric Bengt Emanuelsson ◽  
Gema Sanz ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Domain Size ◽  
Type I ◽  
Longitudinal Orientation ◽  
Type Composition ◽  
Fiber Size ◽  
Myonuclear Domain

Human skeletal muscle characteristics such as fiber type composition, fiber size and myonuclear content are widely studied in clinical and sports related contexts. Being aware of the methodological and biological variability of the characteristics is a critical aspect in study design and outcome interpretation, but comprehensive data on the variability of morphological features in human skeletal muscle is currently limited. Accordingly, in the present study, m. vastus lateralis biopsies (10 per subject) from young and healthy individuals, collected in a systematic manner, were analyzed for various characteristics using immunohistochemistry (n=7) and SDS-PAGE (n=25). None of the analyzed parameters; fiber type % (FT%), type I and II CSA (fCSA), percentage fiber type area (fCSA%), myosin heavy chain composition (MyHC%), type IIX content, myonuclear content or myonuclear domain varied in a systematic manner longitudinally along the muscle or between the two legs. The average within subject coefficient of variation for FT%, fCSA, fCSA%, and MyHC% ranged between 13-18%, but was only 5% for fiber specific myonuclear content, which reduced the variability for myonuclear domain size to 11-12%. Pure type IIX fibers and type IIX MyHC were randomly distributed and present in <24% of the analyzed samples, with the average content being 0.1 and 1.1%, respectively. In conclusion, leg or longitudinal orientation does not seem to be an important aspect to consider when investigating human vastus lateralis characteristics. However, single muscle biopsies should preferably not be used when studying fiber type and fiber size related aspects given the notable sample to sample variability.

Increase in S6K1 phosphorylation in human skeletal muscle following resistance exercise occurs mainly in type II muscle fibers

2006 ◽  
Vol 290 (6) ◽  
pp. E1245-E1252 ◽  
Author(s):  
René Koopman ◽  
Antoine H. G. Zorenc ◽  
Rudy J. J. Gransier ◽  
David Cameron-Smith ◽  
Luc J. C. van Loon
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Initiation Factor ◽  
Exercise Session ◽  
Type I ◽  
Type Ii ◽  
Postexercise Recovery

To investigate the in vivo effects of resistance exercise on translational control in human skeletal muscle, we determined the phosphorylation of AMP-activated kinase (AMPK), eukaryotic initiation factor 4E-binding protein (4E-BP1), p70/p85-S6 protein kinase (S6K1), and ribosomal S6 protein (S6). Furthermore, we investigated whether changes in the phosphorylation of S6K1 are muscle fiber type specific. Eight male subjects performed a single high-intensity resistance exercise session. Muscle biopsies were collected before and immediately after exercise and after 30 and 120 min of postexercise recovery. The phosphorylation statuses of AMPK, 4E-BP1, S6K1, and S6 were determined by Western blotting with phospho-specific and pan antibodies. To determine fiber type-specific changes in the phosphorylation status of S6K1, immunofluorescence microscopy was applied. AMPK phosphorylation was increased approximately threefold immediately after resistance exercise, whereas 4E-BP1 phosphorylation was reduced to 27 ± 6% of preexercise values. Phosphorylation of S6K1 at Thr421/Ser424 was increased 2- to 2.5-fold during recovery but did not induce a significant change in S6 phosphorylation. Phosphorylation of S6K1 was more pronounced in the type II vs. type I muscle fibers. Before exercise, phosphorylated S6K1 was predominantly located in the nuclei. After 2 h of postexercise recovery, phospho-S6K1 was primarily located in the cytosol of type II muscle fibers. We conclude that resistance exercise effectively increases the phosphorylation of S6K1 on Thr421/Ser424, which is not associated with a substantial increase in S6 phosphorylation in a fasted state.

Single-fiber expression and fiber-specific adaptability to short-term intense exercise training of Na+-K+-ATPase α- and β-isoforms in human skeletal muscle

2015 ◽  
Vol 118 (6) ◽  
pp. 699-706 ◽  
Author(s):  
V. L. Wyckelsma ◽  
M. J. McKenna ◽  
F. R. Serpiello ◽  
C. R. Lamboley ◽  
R. J. Aughey ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Western Blotting ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Single Fiber ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Functional Roles

The Na+-K+-ATPase (NKA) plays a key role in muscle excitability, but little is known in human skeletal muscle about fiber-type-specific differences in NKA isoform expression or adaptability. A vastus lateralis muscle biopsy was taken in 17 healthy young adults to contrast NKA isoform protein relative abundance between type I and IIa fibers. We further investigated muscle fiber-type-specific NKA adaptability in eight of these adults following 4-wk repeated-sprint exercise (RSE) training, comprising three sets of 5 × 4-s sprints, 3 days/wk. Single fibers were separated, and myosin heavy chain (I and IIa) and NKA (α1–3 and β1–3) isoform abundance were determined via Western blotting. All six NKA isoforms were expressed in both type I and IIa fibers. No differences between fiber types were found for α1-, α2-, α3-, β1-, or β3-isoform abundances. The NKA β2-isoform was 27% more abundant in type IIa than type I fibers ( P < 0.05), with no other fiber-type-specific trends evident. RSE training increased β1 in type IIa fibers (pretraining 0.70 ± 0.25, posttraining 0.84 ± 0.24 arbitrary units, 42%, P < 0.05). No training effects were found for other NKA isoforms. Thus human skeletal muscle expresses all six NKA isoforms and not in a fiber-type-specific manner; this points to their different functional roles in skeletal muscle cells. Detection of elevated NKA β1 after RSE training demonstrates the sensitivity of the single-fiber Western blotting technique for fiber-type-specific intervention effects.

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