scholarly journals Effects of high-intensity intermittent exercise on the contractile properties of human type I and type II skeletal muscle fibers

2020 ◽  
Vol 128 (5) ◽  
pp. 1207-1216 ◽  
Author(s):  
Cedric. R. Lamboley ◽  
David M. Rouffet ◽  
Travis L. Dutka ◽  
Michael J. McKenna ◽  
Graham D. Lamb
Keyword(s):  
Skeletal Muscle ◽  
High Intensity ◽  
Intermittent Exercise ◽  
Muscle Fibers ◽  
Muscle Performance ◽  
Type I ◽  
Type Ii ◽  
Contractile Apparatus ◽  
Skeletal Muscle Fibers ◽  
Type Ii Fibers

This study identified important cellular changes occurring in human skeletal muscle fibers following high-intensity intermittent exercise: 1) a decrease in contractile apparatus Ca2+ sensitivity in type I but not type II fibers, 2) a decrease in specific force only in type II muscle fibers, and 3) a redox-dependent increase in Ca2+ sensitivity occurring only in type II fibers, which would help maintain muscle performance by countering the normal metabolite-induced decline in Ca2+ sensitivity.

Effects of carnosine on contractile apparatus Ca2+ sensitivity and sarcoplasmic reticulum Ca2+ release in human skeletal muscle fibers

2012 ◽  
Vol 112 (5) ◽  
pp. 728-736 ◽  
Author(s):  
T. L. Dutka ◽  
C. R. Lamboley ◽  
M. J. McKenna ◽  
R. M. Murphy ◽  
G. D. Lamb
Keyword(s):  
Skeletal Muscle ◽  
Human Muscle ◽  
Muscle Performance ◽  
Type I ◽  
Type Ii ◽  
Contractile Apparatus ◽  
Muscle Carnosine ◽  
Ec Coupling ◽  
Type I Fibers ◽  
Type Ii Fibers

There is considerable interest in potential ergogenic and therapeutic effects of increasing skeletal muscle carnosine content, although its effects on excitation-contraction (EC) coupling in human muscle have not been defined. Consequently, we sought to characterize what effects carnosine, at levels attained by supplementation, has on human muscle fiber function, using a preparation with all key EC coupling proteins in their in situ positions. Fiber segments, obtained from vastus lateralis muscle of human subjects by needle biopsy, were mechanically skinned, and their Ca2+ release and contractile apparatus properties were characterized. Ca2+ sensitivity of the contractile apparatus was significantly increased by 8 and 16 mM carnosine (increase in pCa50 of 0.073 ± 0.007 and 0.116 ± 0.006 pCa units, respectively, in six type I fibers, and 0.063 ± 0.018 and 0.103 ± 0.013 pCa units, respectively, in five type II fibers). Caffeine-induced force responses were potentiated by 8 mM carnosine in both type I and II fibers, with the potentiation in type II fibers being entirely explicable by the increase in Ca2+ sensitivity of the contractile apparatus caused by carnosine. However, the potentiation of caffeine-induced responses caused by carnosine in type I fibers was beyond that expected from the associated increase in Ca2+ sensitivity of the contractile apparatus and suggestive of increased Ca2+-induced Ca2+ release. Thus increasing muscle carnosine content likely confers benefits to muscle performance in both fiber types by increasing the Ca2+ sensitivity of the contractile apparatus and possibly also by aiding Ca2+ release in type I fibers, helping to lessen or slow the decline in muscle performance during fatiguing stimulation.

scholarly journals Myoglobin concentration in skeletal muscle fibers of chronic heart failure patients

2009 ◽  
Vol 107 (4) ◽  
pp. 1138-1143 ◽  
Author(s):  
Martijn A. Bekedam ◽  
Brechje J. van Beek-Harmsen ◽  
Willem van Mechelen ◽  
Anco Boonstra ◽  
Willem J. van der Laarse
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Chronic Heart Failure ◽  
Muscle Fibers ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Skeletal Muscle Fibers ◽  
Type I Fibers ◽  
Type Ii Fibers

The purpose of this study was to determine the myoglobin concentration in skeletal muscle fibers of chronic heart failure (CHF) patients and to calculate the effect of myoglobin on oxygen buffering and facilitated diffusion. Myoglobin concentration, succinate dehydrogenase (SDH) activity, and cross-sectional area of individual muscle fibers from the vastus lateralis of five control and nine CHF patients were determined using calibrated histochemistry. CHF patients compared with control subjects were similar with respect to myoglobin concentration: type I fibers 0.69 ± 0.11 mM (mean ± SD), type II fibers 0.52 ± 0.07 mM in CHF vs. type I fibers 0.70 ± 0.09 mM, type II fibers 0.49 ± 0.07 mM in control, whereas SDH activity was significantly lower in CHF in both fiber types ( P < 0.01). The myoglobin concentration in type I fibers was higher than in type II fibers ( P < 0.01). Consequently, the oxygen buffering capacity, calculated from myoglobin concentration/SDH activity was increased in CHF: type I fibers 11.4 ± 2.1 s, type II fibers 13.6 ± 3.9 s in CHF vs. type I fibers 7.8 ± 0.9 s, type II fibers 7.5 ± 1.0 s in control, all P < 0.01). The calculated extracellular oxygen tension required to prevent core anoxia (Po2crit) in muscle fibers was similar when controls were compared with patients in type I fibers 10.3 ± 0.9 Torr in CHF and 11.5 ± 3.3 Torr in control, but was lower in type II fibers of patients 6.1 ± 2.8 Torr in CHF and 14.7 ± 6.2 Torr in control, P < 0.01. The lower Po2crit of type II fibers may facilitate oxygen extraction from capillaries. Reduced exercise tolerance in CHF is not due to myoglobin deficiency.

Isoform-dependent Effects of Halothane in Human Skinned Striated Fibers

1996 ◽  
Vol 84 (5) ◽  
pp. 1138-1147 ◽  
Author(s):  
Benoit M. Tavernier ◽  
Elie Haddad ◽  
Pascal J. Adnet ◽  
Toussaint S. Etchrivi ◽  
Dominique Lacroix ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Contractile Proteins ◽  
Hill Coefficient ◽  
Type I ◽  
Type Ii ◽  
Maximal Force ◽  
Skeletal Muscle Fibers ◽  
Type Ii Fibers ◽  
Ca Sensitivity

Background Reports of the effects of halothane on isoform contractile proteins of striated muscles are conflicting. To determine whether halothane affects cardiac and skeletal contractile proteins differently, the authors examined the effects of two doses of halothane (0.44 and 1.26 mM, equivalent to 0.75 and 2.25 vol%, respectively) on the Ca++ sensitivity and maximal force in human skinned cardiac, type I (slow twitch), and type II (fast twitch) skeletal muscle fibers. Methods Left ventricular muscle strips and skeletal muscle biopsy specimens were obtained from eight and ten patients undergoing cardiac and orthopedic surgery, respectively. Sarcolemma and sarcoplasmic reticulum were destroyed with ethylene glycol bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid plus Brij 58. Ca++ sensitivity was studied by observing the isometric tension developed by skinned fibers challenged with increasing concentrations of Ca++. Muscle fiber type was determined in each skeletal fiber by the difference in strontium-induced tension measurements. Results Halothane shifted the Ca++ tension curves toward higher Ca++ concentrations and increased the Ca++ concentrations for half-maximal activation in both cardiac and type I skeletal muscle fibers (from 1.96 microM and 1.06 microM under control conditions to 2.92 microM and 1.71 microM in presence of 0.75 vol% halothane, respectively) without changing the slope of this relationship (Hill coefficient). In contrast, no significant effect was observed in type II fibers. Halothane also decreased the maximal activated tension in the three groups of fibers with a lesser effect in type II fibers. Conclusions Halothane decreases Ca++ sensitivity and maximal force in human skinned cardiac and type I fibers at 20 degrees C. It is concluded that the negative inotropic effects of halothane depend on contractile proteins isoforms.

scholarly journals BFR Exercise Increases S6K1 Phosphorylation in Type‐I and Type‐II Skeletal Muscle Fibers

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
David M Gundermann ◽  
Dillon K Walker ◽  
Christopher S Fry ◽  
Jared M Dickinson ◽  
Micah J Drummond ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Type I ◽  
Type Ii ◽  
Skeletal Muscle Fibers

Acute effects of taurine on sarcoplasmic reticulum Ca2+ accumulation and contractility in human type I and type II skeletal muscle fibers

2014 ◽  
Vol 117 (7) ◽  
pp. 797-805 ◽  
Author(s):  
T. L. Dutka ◽  
C. R. Lamboley ◽  
R. M. Murphy ◽  
G. D. Lamb
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Contractile Apparatus ◽  
Type Ii Fibers

Taurine occurs in high concentrations in muscle and is implicated in numerous physiological processes, yet its effects on many aspects of contractility remain unclear. Using mechanically skinned segments of human vastus lateralis muscle fibers, we characterized the effects of taurine on sarcoplasmic reticulum (SR) Ca2+ accumulation and contractile apparatus properties in type I and type II fibers. Prolonged myoplasmic exposure (>10 min) to taurine substantially increased the rate of accumulation of Ca2+ by the SR in both fiber types, with no change in the maximum amount accumulated; no such effect was found with carnosine. SR Ca2+ accumulation was similar with 10 or 20 mM taurine, but was significantly slower at 5 mM taurine. Cytoplasmic taurine (20 mM) had no detectable effects on the responsiveness of the Ca2+ release channels in either fiber type. Taurine caused a small increase in Ca2+ sensitivity of the contractile apparatus in type I fibers, but type II fibers were unaffected; maximum Ca2+-activated force was unchanged in both cases. The effects of taurine on SR Ca2+ accumulation 1) only became apparent after prolonged cytoplasmic exposure, and 2) persisted for some minutes after complete removal of taurine from the cytoplasm, consistent with the hypothesis that the effects were due to an action of taurine from inside the SR. In summary, taurine potentiates the rate of SR Ca2+ uptake in both type I and type II human fibers, possibly via an action from within the SR lumen, with the degree of potentiation being significantly reduced at low physiological taurine levels.

scholarly journals Effect of 23-day muscle disuse on sarcoplasmic reticulum Ca2+ properties and contractility in human type I and type II skeletal muscle fibers

2016 ◽  
Vol 121 (2) ◽  
pp. 483-492 ◽  
Author(s):  
C. R. Lamboley ◽  
V. L. Wyckelsma ◽  
B. D. Perry ◽  
M. J. McKenna ◽  
G. D. Lamb
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Muscle Fibers ◽  
Type I ◽  
Fiber Types ◽  
Specific Force ◽  
Type Ii ◽  
Muscle Disuse ◽  
Type I Fibers ◽  
Type Ii Fibers

Inactivity negatively impacts on skeletal muscle function mainly through muscle atrophy. However, recent evidence suggests that the quality of individual muscle fibers is also altered. This study examined the effects of 23 days of unilateral lower limb suspension (ULLS) on specific force and sarcoplasmic reticulum (SR) Ca2+ content in individual skinned muscle fibers. Muscle biopsies of the vastus lateralis were taken from six young healthy adults prior to and following ULLS. After disuse, the endogenous SR Ca2+ content was ∼8% lower in type I fibers and maximal SR Ca2+ capacity was lower in both type I and type II fibers (−11 and −5%, respectively). The specific force, measured in single skinned fibers from three subjects, decreased significantly after ULLS in type II fibers (−23%) but not in type I fibers (−9%). Western blot analyses showed no significant change in the amounts of myosin heavy chain (MHC) I and MHC IIa following the disuse, whereas the amounts of sarco(endo)plasmic reticulum Ca2+-ATPase 1 (SERCA1) and calsequestrin increased by ∼120 and ∼20%, respectively, and the amount of troponin I decreased by ∼21%. These findings suggest that the decline in force and power occurring with muscle disuse is likely to be exacerbated in part by reductions in maximum specific force in type II fibers, and in the amount of releasable SR Ca2+ in both fiber types, the latter not being attributable to a reduced calsequestrin level. Furthermore, the ∼3-wk disuse in human elicits change in SR properties, in particular a more than twofold upregulation in SERCA1 density, before any fiber-type shift.

Muscle Biopsy Samples for Histochemical Processing: Alterations Induced by Storage

1988 ◽  
Vol 25 (1) ◽  
pp. 77-82 ◽  
Author(s):  
K. G. Braund ◽  
K. A. Amling
Keyword(s):  
Skeletal Muscle ◽  
Cell Morphology ◽  
Type I ◽  
Type Ii ◽  
Tissue Samples ◽  
Frozen Tissue ◽  
Fresh Frozen ◽  
Healthy Dogs ◽  
Morphology And Morphometry ◽  
Type Ii Fibers

Skeletal muscle samples from two healthy dogs were stored in ice at 0 C for up to 30 hours to examine the influence of time on cell morphology and morphometry. Cytochemical and histochemical properties of muscle to 18 hours were not markedly different from fresh frozen tissue. Samples stored to 30 hours were still satisfactory, despite a decline and unevenness in depth of staining. Morphometry from samples stored at 0 C for 6 hours or longer is not recommended, due to the statistically significant increase in diameter (from 21 to 25%) of type I and type II fibers.

Effect of varied extracellular P O 2 on muscle performance inXenopus single skeletal muscle fibers

1999 ◽  
Vol 86 (6) ◽  
pp. 1812-1816 ◽  
Author(s):  
Creed M. Stary ◽  
Michael C. Hogan
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Respiration ◽  
Muscle Fibers ◽  
Muscle Performance ◽  
Tetanic Force ◽  
Skeletal Muscle Fibers ◽  
Rate Limiting ◽  
Single Living ◽  
Initial Peak ◽  
Text Condition

The purpose of this study was to examine the development of fatigue in isolated, single skeletal muscle fibers when O2 availability was reduced but not to levels considered rate limiting to mitochondrial respiration. Tetanic force was measured in single living muscle fibers ( n = 6) from Xenopus laevis while being stimulated at increasing contraction rates (0.25, 0.33, 0.5, and 1 Hz) in a sequential manner, with each stimulation frequency lasting 2 min. Muscle fatigue (determined as 75% of initial maximum force) was measured during three separate work bouts (with 45 min of rest between) as the perfusate [Formula: see text] was switched between values of 30 ± 1.9, 76 ± 3.0, or 159 Torr in a blocked-order design. No significant differences were found in the initial peak tensions between the high-, intermediate-, and low-[Formula: see text] treatments (323 ± 22, 298 ± 27, and 331 ± 24 kPa, respectively). The time to fatigue was reached significantly sooner ( P < 0.05) during the 30-Torr treatment (233 ± 39 s) compared with the 76- (385 ± 62 s) or 159-Torr (416 ± 65 s) treatments. The calculated critical extracellular [Formula: see text]necessary to develop an anoxic core within these fibers was 13 ± 1 Torr, indicating that the extracellular[Formula: see text] of 30 Torr should not have been rate limiting to mitochondrial respiration. The magnitude of an unstirred layer (243 ± 64 μm) or an intracellular O2 diffusion coefficient (0.45 ± 0.04 × 10−5cm2/s) necessary to develop an anoxic core under the conditions of the study was unlikely. The earlier initiation of fatigue during the lowest extracellular[Formula: see text] condition, at physiologically high intracellular [Formula: see text] levels, suggests that muscle performance may be O2 dependent even when mitochondrial respiration is not necessarily compromised.

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