Glycogen Depletion of Human Skeletal Muscle Fibers in Response to High-Frequency Electrical Stimulation

2003 ◽  
Vol 28 (3) ◽  
pp. 424-433 ◽  
Author(s):  
Michel J. Johnson ◽  
Gilles Lortie ◽  
Jean-Aimé Simoneau ◽  
Marcel R. Boulay
Keyword(s):  
Electrical Stimulation ◽  
High Frequency ◽  
Human Skeletal Muscle ◽  
Glycogen Content ◽  
Isometric Force ◽  
Vastus Lateralis ◽  
Muscle Fibres ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Lateralis Muscle

The purpose of the present study was to evaluate the pattern of change in muscular glycogen content in response to high-frequency electrical stimulation (HFES). Muscle biopsies were taken from the vastus lateralis muscle of 7 healthy young men before, 15 min after, and 30 min after electrical stimulation delivered at a 50-Hz frequency (15 s on, 45 s off) at an intensity of 100 mA. The glycogen content of type I, IIA, and IIB muscle fibres was evaluated using microphotometry of periodic acid Schiff (PAS) stained fibres. After 15 min of electrical stimulation, the glycogen content in type I, IIA, and IIB muscle fibres significantly decreased from 113 ± 10 (mean ± SE) to 103 ± 10 (p ≤ 0.05), 129 ± 9 to 102 ± 12 (p ≤ 0.01), and 118 ± 8 to 90 ± 13 (p ≤ 0.01) arbitrary relative units, respectively. No further decrement in glycogen content was observed in all three fibre types following an additional 15 min of HFES. In addition, isometric force decreased by approximately 50%, from 125.9 ± 20.0 N to 64.2 ± 7.7 N (p ≤ 0.01), during the first 15 contractions. No further decrease in isometric force was observed following an additional 15 contractions of HFES. These results reveal that significant reductions in isometric force of knee extensor muscles and glycogen content of all human skeletal muscle fibre types in vastus lateralis muscle are observable after 15 min of neuromuscular high-frequency transcutaneous electrical stimulation. Key words: energy metabolism, isometric strength

scholarly journals Calcium and strontium contractile activation properties of single skinned skeletal muscle fibres from elderly women 66-90 years of age

2021 ◽  
Author(s):  
Sue M Ronaldson ◽  
George D Stephenson ◽  
Stewart I Head
Keyword(s):  
Skeletal Muscle ◽  
Elderly Women ◽  
Vastus Lateralis ◽  
Muscle Fibres ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Lateralis Muscle ◽  
Slow Twitch ◽  
Skeletal Muscle Fibres ◽  
Muscle Biopsies

The single skinned muscle fibre technique was used to investigate Ca2+- and Sr2+- activation properties of skeletal muscle fibres from elderly women (66-90 years). Muscle biopsies were obtained from the vastus lateralis muscle. Three populations of muscle fibres were identified according to their specific Sr2+- activation properties: slow-twitch (type I) fast-twitch (type II) and hybrid (type I/II) fibres. All three fibre types were sampled from the biopsies of 66 to 72 years old women, but the muscle biopsies of women older than 80 years yielded only slow-twitch (type I) fibres. The proportion of hybrid fibres in the vastus lateralis muscle of women of circa 70 years of age (24%) was several-fold greater than in the same muscle of adults (<10%), suggesting that muscle remodelling occurs around this age. There were no differences between the Ca2+- and Sr2+- activation properties of slow-twitch fibres from the two groups of elderly women, but there were differences compared with muscle fibres from adults with respect to sensitivity to Ca2+, steepness of the activation curves, and characteristics of the fibre-type dependent phenomenon of spontaneous force oscillations (SOMO) occurring at sub-maximal levels of activation. The maximal Ca2+ activated specific force from all the fibres collected from the seven old women use in the present study was significantly lower by 20% than in the same muscle of adults. Taken together these results show there are qualitative and quantitative changes in the activation properties of the contractile apparatus of muscle fibres from the vastus lateralis muscle of women with advancing age, and that these changes need to be considered when explaining observed changes in womens mobility with aging.

The Effect of Aerobic Exercise Training on the Distribution of Succinate Dehydrogenase Activity Throughout Muscle Fibres

1998 ◽  
Vol 23 (1) ◽  
pp. 74-86 ◽  
Author(s):  
Philip D. Chilibeck ◽  
Gordon J. Bell ◽  
Teresa Socha ◽  
Tom Martin
Keyword(s):  
Endurance Training ◽  
Succinate Dehydrogenase ◽  
Vastus Lateralis ◽  
Aerobic Exercise Training ◽  
Control Group ◽  
Muscle Fibres ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Lateralis Muscle ◽  
Subsarcolemmal Mitochondria

We evaluated the effect of endurance training (cycling 3 times per week for 12 weeks) on succinate dehydrogenase (SDH) activity in the subsarcolemmal (SS) and intermyofibrillar (IMF) regions of vastus lateralis muscle fibres in 7 individuals (4 females and 3 males). SDH activity of the SS region increased 9.4% and 12.8% in type I and II fibres, respectively (p < .05). SDH activity of the IMF region increased 4.7% and 6.7% in type I and II fibres, respectively (p < .05). This was less than the increase in the SS region (p < .O5). No significant changes were observed in a control group (4 females and 3 males). These data suggest that mitochondria in the SS and IMF regions of human vastus lateralis muscle fibres are sensitive to endurance training. The greater response in the SS region suggests that the metabolic requirements of SS mitochondria were stressed to a greater extent than IMF mitochondria with endurance training. Key words: subsarcolemmal mitochondria, intermyofibrillar mitochondria

Phosphorylase a in human skeletal muscle during exercise and electrical stimulation

1978 ◽  
Vol 45 (6) ◽  
pp. 852-857 ◽  
Author(s):  
P. D. Gollnick ◽  
J. Karlsson ◽  
K. Piehl ◽  
B. Saltin
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Muscular Activity ◽  
Voluntary Exercise ◽  
Vastus Lateralis Muscle ◽  
Minor Importance ◽  
Muscle Lactate ◽  
Needle Technique

Experiments were conducted to examine the conversions of phosphorylase b to phosphorylase a in human skeletal muscle during bicycle exercise or isometric contractions. Muscle biopsies were obtained from the vastus lateralis with the needle technique at rest and either during or immediately after activity and frozen in liquid nitrogen within 2--4 s. Total phosphorylase and phosphorylase a activities were differentiated by measurement in the presence and absence of AMP, respectively. At rest 8.5% of the total phosphorylase activity existed in the a form. Little or no change in the percent of phosphorylase in the a form occurred during voluntary dynamic or static muscular activity that produced muscle lactate concentrations in excess of 18 mmol.kg-1 wet muscle. Electrical stimulation of the vastus lateralis muscle also failed to produce an increase in the percentage of phosphorylase a. These data suggest that during exercise the conversion of phosphorylase to the a form is of minor importance. An increased activity of phosphorylase b due to changes in muscle concentrations of ATP, AMP, and inorganic phosphate may regulate glycogenolysis during voluntary exercise in man.

Diurnal Variation of Glycogen Content in Human Vastus Lateralis Muscle

2014 ◽  
Vol 46 ◽  
pp. 755
Author(s):  
Hideyuki Takahashi ◽  
Akiko Kamei ◽  
Takuya Osawa ◽  
Keisuke Shiose ◽  
Takashi Kawahara ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
Lateralis Muscle

scholarly journals History-dependence of muscle slack length in humans: effects of contraction intensity, stretch amplitude, and time

2020 ◽  
Vol 129 (4) ◽  
pp. 957-966
Author(s):  
Martin Eric Héroux ◽  
Ida Anderman ◽  
Sofia Nykvist Vouis ◽  
Joanna Diong ◽  
Peter William Stubbs ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Large Amplitude ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
History Dependence ◽  
Lateralis Muscle ◽  
Slack Length ◽  
Passive Stretch

The slack length of a relaxed human skeletal muscle is not fixed; it can be modified by contraction and stretch. Contraction of the human vastus lateralis muscle at short lengths reduces the muscle’s slack length. Even very weak contractions are sufficient to induce this effect. The effect persists for at least 5 min but can be reduced or abolished with a large-amplitude passive stretch.

Parallel Increases in Phosphocreatine and Total Creatine in Human Vastus Lateralis Muscle during Creatine Supplementation

2007 ◽  
Vol 17 (6) ◽  
pp. 624-634 ◽  
Author(s):  
Jeffrey J. Brault ◽  
Theodore F. Towse ◽  
Jill M. Slade ◽  
Ronald A. Meyer
Keyword(s):  
Skeletal Muscle ◽  
Free Energy ◽  
Gibbs Free Energy ◽  
Human Skeletal Muscle ◽  
Atp Hydrolysis ◽  
Vastus Lateralis ◽  
Creatine Supplementation ◽  
Vastus Lateralis Muscle ◽  
Lateralis Muscle ◽  
Total Creatine

Short-term creatine supplementation is reported to result in a decreased ratio of phosphocreatine (PCr) to total creatine (TCr) in human skeletal muscle at rest. Assuming equilibrium of the creatine kinase reaction, this decrease in PCr:TCr implies increased cytoplasmic ADP and decreased Gibbs free energy of ATP hydrolysis in muscle, which seems contrary to the reported ergogenic benefits of creatine supplementation. This study measured changes in PCr and TCr in vastus lateralis muscle of adult men (N = 6, 21–35 y old) during and 1 day after 5 d of creatine monohydrate supplementation (0.43 g·kg body weight−1·d−1) using noninvasive 31P and 1H magnetic-resonance spectroscopy (MRS). Plasma and red-blood-cell creatine increased by 10-fold and 2-fold, respectively, by the third day of supplementation. MRS-measured skeletal muscle PCr and TCr increased linearly and in parallel throughout the 5 d, and there was no significant difference in the percentage increase in muscle PCr (11.7% ± 2.3% after 5 d) vs. TCr (14.9% ± 4.1%) at any time point. The results indicate that creatine supplementation does not alter the PCr:TCr ratio, and hence the cytoplasmic Gibbs free energy of ATP hydrolysis, in human skeletal muscle at rest.

scholarly journals Myofibril and Mitochondrial Area Changes in Type I and II Fibers Following 10 Weeks of Resistance Training in Previously Untrained Men

2021 ◽  
Vol 12 ◽  
Author(s):  
Bradley A. Ruple ◽  
Joshua S. Godwin ◽  
Paulo H. C. Mesquita ◽  
Shelby C. Osburn ◽  
Casey L. Sexton ◽  
...  
Keyword(s):  
Resistance Training ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Vastus Lateralis ◽  
Thigh Muscle ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Cross Sectional ◽  
Lateralis Muscle ◽  
Actin Protein

Resistance training increases muscle fiber hypertrophy, but the morphological adaptations that occur within muscle fibers remain largely unresolved. Fifteen males with minimal training experience (24±4years, 23.9±3.1kg/m2 body mass index) performed 10weeks of conventional, full-body resistance training (2× weekly). Body composition, the radiological density of the vastus lateralis muscle using peripheral quantitative computed tomography (pQCT), and vastus lateralis muscle biopsies were obtained 1week prior to and 72h following the last training bout. Quantification of myofibril and mitochondrial areas in type I (positive for MyHC I) and II (positive for MyHC IIa/IIx) fibers was performed using immunohistochemistry (IHC) techniques. Relative myosin heavy chain and actin protein abundances per wet muscle weight as well as citrate synthase (CS) activity assays were also obtained on tissue lysates. Training increased whole-body lean mass, mid-thigh muscle cross-sectional area, mean and type II fiber cross-sectional areas (fCSA), and maximal strength values for leg press, bench press, and deadlift (p&lt;0.05). The intracellular area occupied by myofibrils in type I or II fibers was not altered with training, suggesting a proportional expansion of myofibrils with fCSA increases. However, our histological analysis was unable to differentiate whether increases in myofibril number or girth occurred. Relative myosin heavy chain and actin protein abundances also did not change with training. IHC indicated training increased mitochondrial areas in both fiber types (p=0.018), albeit CS activity levels remained unaltered with training suggesting a discordance between these assays. Interestingly, although pQCT-derived muscle density increased with training (p=0.036), suggestive of myofibril packing, a positive association existed between training-induced changes in this metric and changes in mean fiber myofibril area (r=0.600, p=0.018). To summarize, our data imply that shorter-term resistance training promotes a proportional expansion of the area occupied by myofibrils and a disproportional expansion of the area occupied by mitochondria in type I and II fibers. Additionally, IHC and biochemical techniques should be viewed independently from one another given the lack of agreement between the variables assessed herein. Finally, the pQCT may be a viable tool to non-invasively track morphological changes (specifically myofibril density) in muscle tissue.

Subcellular fractionation reveals HSP72 does not associate with SERCA in human skeletal muscle following damaging eccentric and concentric exercise

2014 ◽  
Vol 116 (11) ◽  
pp. 1503-1511 ◽  
Author(s):  
Noni T. Frankenberg ◽  
Graham D. Lamb ◽  
Kristian Vissing ◽  
Robyn M. Murphy
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Human Skeletal Muscle ◽  
Physiological Stress ◽  
Vastus Lateralis ◽  
Tight Binding ◽  
Fold Increase ◽  
Subcellular Fractionation ◽  
Vastus Lateralis Muscle ◽  
Type I

Through its upregulation and/or translocation, heat shock protein 72 (HSP72) is involved in protection and repair of key proteins after physiological stress. In human skeletal muscle we investigated HSP72 protein after eccentric (ECC1) and concentric (CONC) exercise and repeated eccentric exercise (ECC2; 8 wk later) and whether it translocated from its normal cytosolic location to membranes/myofibrils. HSP72 protein increased ∼2-fold 24 h after ECC1, with no apparent change after CONC or ECC2. In resting (nonstressed) human skeletal muscle the total pool of HSP72 protein was present almost exclusively in the cytosolic fraction, and after each exercise protocol the distribution of HSP72 protein remained unaltered. Overall, the amount of HSP72 protein in the cytosol increased 24 h after ECC1, matching the fold increase that was measured in total HSP72 protein. To better ascertain the capabilities and limitations of HSP72, using quantitative Western blotting we determined the HSP72 protein content to be 11.4 μmol/kg wet weight in resting human vastus lateralis muscle, which is comprised of Type I (slow-twitch) and Type II (fast-twitch) fibers. HSP72 protein content was similar in individual Type I or II fiber segments. After physiological stress, HSP72 content can increase and, although the functional consequences of increased amounts of HSP72 protein are poorly understood, it has been shown to bind to and protect protein pumps like SERCA and Na+-K+-ATPase. Given no translocation of cytosolic HSP72, these findings suggest eccentric contractions, unlike other forms of stress such as heat, do not trigger tight binding of HSP72 to its primary membrane-bound target proteins, in particular SERCA.

scholarly journals Cocaine and exercise: α-1 receptor blockade does not alter muscle glycogenolysis or blood lactacidosis

2000 ◽  
Vol 88 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Robert K. Conlee ◽  
K. Patrick Kelly ◽  
Edward O. Ojuka ◽  
Roger L. Hammer
Keyword(s):  
Glycogen Content ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Vastus Lateralis Muscle ◽  
Rapid Rise ◽  
Glycogen Depletion ◽  
Time Intervals ◽  
Exercise Challenge ◽  
Lateralis Muscle

In our previous work, we routinely observed that a combined cocaine-exercise challenge results in an abnormally rapid muscle glycogen depletion and excessive blood lactacidosis. These phenomena occur simultaneously with a rapid rise in norepinephrine and in the absence of any rise in epinephrine. We postulated that norepinephrine may cause vasoconstriction of the muscle vasculature through activation of α-1 receptors during cocaine-exercise, thus inducing hypoxia and a concomitant rise in glycogenolysis and lactate accumulation. To test this hypothesis, rats were pretreated with the selective α-1-receptor antagonist prazosin (P) (0.1 mg/kg iv) or saline (S). Ten minutes later, the animals were treated with cocaine (-C) (5 mg/kg iv) or saline (-S) and run for 4 or 15 min at 22 m/min at 10% grade. In the S-S group, glycogen content of the white vastus lateralis muscle was unaffected by exercise at both time intervals, whereas in S-C rats glycogen was reduced by 47%. This effect of cocaine-exercise challenge was not attenuated by P. Similarly, blood lactate concentration in S-C rats was threefold higher than that of S-S after exercise, a response also not altered by pretreatment with P. On the basis of these observations, we conclude that the excessive glycogenolysis and lactacidosis observed during cocaine-exercise challenge is not the result of vasoconstriction secondary to norepinephrine activation of α-1 receptors.

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