scholarly journals Human vastus lateralis and soleus muscles display divergent cellular contractile properties

2008 ◽  
Vol 295 (5) ◽  
pp. R1593-R1598 ◽  
Author(s):  
Nicholas Luden ◽  
Kiril Minchev ◽  
Erik Hayes ◽  
Emily Louis ◽  
Todd Trappe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Single Fiber ◽  
Muscle Adaptation ◽  
Shortening Velocity ◽  
Mhc I ◽  
Myosin Heavy Chain Isoform ◽  
I 18 ◽  
Mhc Iia

The purpose of this study was to investigate potential differences in single-fiber contractile physiology of fibers with the same myosin heavy chain isoform (MHC I and MHC IIa) originating from different muscles. Vastus lateralis (VL) and soleus biopsies were obtained from 27 recreationally active females (31 ± 1 yr, 59 ± 1 kg). A total of 943 single fibers (MHC I = 562; MHC IIa = 301) were isolated and examined for diameter, peak tension (Po), shortening velocity (Vo), and power. The soleus had larger ( P < 0.05) fibers (MHC I +18%; MHC IIa +19%), higher MHC I Vo (+13%), and higher MHC I Po (+18%) compared with fibers from the VL. In contrast, fibers from the VL had higher ( P < 0.05) specific tension (MHC I +18%; MHC IIa +20%), and MHC I normalized power (+25%) compared with the soleus. There was a trend for MHC IIa soleus fibers to have higher Vo [MHC IIa +13% ( P = 0.058)], whereas VL MHC IIa fibers showed a trend for higher normalized power compared with soleus fibers [MHC IIa +33% ( P = 0.079)]. No differences in absolute power were detected between muscles. These data highlight muscle-specific differences in single-fiber contractile function that should serve as a scientific basis for consideration when extending observations of skeletal muscle tissue from one muscle of interest to other muscles of origin. This is important when examining skeletal muscle adaptation to physical states such as aging, unloading, and training.

scholarly journals Clustering of GLUT4, TUG, and RUVBL2 protein levels correlate with myosin heavy chain isoform pattern in skeletal muscles, but AS160 and TBC1D1 levels do not

2011 ◽  
Vol 111 (4) ◽  
pp. 1106-1117 ◽  
Author(s):  
Carlos M. Castorena ◽  
James G. MacKrell ◽  
Jonathan S. Bogan ◽  
Makoto Kanzaki ◽  
Gregory D. Cartee
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Skeletal Muscles ◽  
Vastus Lateralis ◽  
Mhc I ◽  
Myosin Heavy Chain Isoform ◽  
Protein Levels ◽  
Positive Correlations ◽  
Tensor Fasciae Latae

Skeletal muscle is a heterogeneous tissue. To further elucidate this heterogeneity, we probed relationships between myosin heavy chain (MHC) isoform composition and abundance of GLUT4 and four other proteins that are established or putative GLUT4 regulators [Akt substrate of 160 kDa (AS160), Tre-2/Bub2/Cdc 16-domain member 1 (TBC1D1), Tethering protein containing an UBX-domain for GLUT4 (TUG), and RuvB-like protein two (RUVBL2)] in 12 skeletal muscles or muscle regions from Wistar rats [adductor longus, extensor digitorum longus, epitrochlearis, gastrocnemius (mixed, red, and white), plantaris, soleus, tibialis anterior (red and white), tensor fasciae latae, and white vastus lateralis]. Key results were 1) significant differences found among the muscles (range of muscle expression values) for GLUT4 (2.5-fold), TUG (1.7-fold), RUVBL2 (2.0-fold), and TBC1D1 (2.7-fold), but not AS160; 2) significant positive correlations for pairs of proteins: GLUT4 vs. TUG ( R = 0.699), GLUT4 vs. RUVBL2 ( R = 0.613), TUG vs. RUVBL2 ( R = 0.564), AS160 vs. TBC1D1 ( R = 0.293), and AS160 vs. TUG ( R = 0.246); 3) significant positive correlations for %MHC-I: GLUT4 ( R = 0.460), TUG ( R = 0.538), and RUVBL2 ( R = 0.511); 4) significant positive correlations for %MHC-IIa: GLUT4 ( R = 0.293) and RUVBL2 ( R = 0.204); 5) significant negative correlations for %MHC-IIb vs. GLUT4 ( R = −0.642), TUG ( R = −0.626), and RUVBL2 ( R = −0.692); and 6) neither AS160 nor TBC1D1 significantly correlated with MHC isoforms. In 12 rat muscles, GLUT4 abundance tracked with TUG and RUVBL2 and correlated with MHC isoform expression, but was unrelated to AS160 or TBC1D1. Our working hypothesis is that some of the mechanisms that regulate GLUT4 abundance in rat skeletal muscle also influence TUG and RUVBL2 abundance.

Effect of resistance training on single muscle fiber contractile function in older men

2000 ◽  
Vol 89 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Scott Trappe ◽  
David Williamson ◽  
Michael Godard ◽  
David Porter ◽  
Greg Rowden ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Older Men ◽  
Single Muscle ◽  
Mhc I ◽  
Before And After ◽  
Mhc Iia

The purpose of this study was to examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older men ( n = 7; age = 74 ± 2 yr and weight = 75 ± 5 kg). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsy samples were obtained from the vastus lateralis before and after PRT (pre- and post-PRT, respectively). For analysis, chemically skinned single muscle fibers were studied at 15°C for peak tension [the maximal isometric force (Po)], unloaded shortening velocity ( V o), and force-velocity parameters. In this study, a total of 199 (89 pre- and 110 post-PRT) myosin heavy chain (MHC) I and 99 (55 pre- and 44 post-PRT) MHC IIa fibers were reported. Because of the minimal number of hybrid fibers identified post-PRT, direct comparisons were limited to MHC I and IIa fibers. Muscle fiber diameter increased 20% (83 ± 1 to 100 ± 1 μm) and 13% (86 ± 1 to 97 ± 2 μm) in MHC I and IIa fibers, respectively ( P < 0.05). Po was higher ( P < 0.05) in MHC I (0.58 ± 0.02 to 0.90 ± 0.02 mN) and IIa (0.68 ± 0.02 to 0.85 ± 0.03 mN) fibers. Muscle fiber V o was elevated 75% (MHC I) and 45% (MHC IIa) after PRT ( P < 0.05). MHC I and IIa fiber power increased ( P < 0.05) from 7.7 ± 0.5 to 17.6 ± 0.9 μN · fiber lengths · s−1 and from 25.5 to 41.1 μN · fiber lengths · s−1, respectively. These data indicate that PRT in elderly men increases muscle cell size, strength, contractile velocity, and power in both slow- and fast-twitch muscle fibers. However, it appears that these changes are more pronounced in the MHC I muscle fibers.

Single muscle fiber function with concurrent exercise or nutrition countermeasures during 60 days of bed rest in women

2007 ◽  
Vol 103 (4) ◽  
pp. 1242-1250 ◽  
Author(s):  
Scott Trappe ◽  
Andrew Creer ◽  
Dustin Slivka ◽  
Kiril Minchev ◽  
Todd Trappe
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Bed Rest ◽  
Vastus Lateralis Muscle ◽  
Single Muscle ◽  
Mhc I ◽  
Lateralis Muscle ◽  
Concurrent Exercise ◽  
And Function

There is limited information on skeletal muscle properties in women with unloading and countermeasure programs to protect the unloading-induced atrophy. The current investigation tested the hypothesis that a concurrent aerobic and resistance exercise training program would preserve size and contractile function of slow- and fast-twitch muscle fibers. A secondary objective was to test the hypothesis that a leucine-enriched high-protein diet would partially attenuate single fiber characteristics. Vastus lateralis muscle biopsies were obtained before and on day 59 of bed rest from a control (BR; n = 8), nutrition (BRN; n = 8), or exercise (BRE; n = 8) group. Single muscle fibers were studied for diameter, peak force (Po), contractile velocity, and power. Those in the BR group had a decrease ( P < 0.05) in myosin heavy chain (MHC) I diameter (−14%), Po (−35%), and power (−42%) and MHC IIa diameter (−16%) and Po (−31%; P = 0.06) and an increase ( P < 0.05) in MHC hybrid fibers. Changes in size and function of MHC I (−19 to −44%) and IIa (−21% to −30%) fibers and MHC distribution in BRN individuals were similar to results in the BR group. In BRE conditions, MHC I and IIa size and contractile function were preserved during bed rest. These data show that the concurrent exercise program preserved the myocellular profile of the vastus lateralis muscle during 60-day bed rest. To combat muscle atrophy and function with long-term unloading, the exercise prescription program used in this study should be considered as a viable training program for the upper leg muscles, whereas the nutritional intervention used cannot be recommended as a countermeasure for skeletal muscle.

scholarly journals Skeletal muscle signature of a champion sprint runner

2015 ◽  
Vol 118 (12) ◽  
pp. 1460-1466 ◽  
Author(s):  
Scott Trappe ◽  
Nicholas Luden ◽  
Kiril Minchev ◽  
Ulrika Raue ◽  
Bozena Jemiolo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Power Output ◽  
Contractile Function ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Transcriptional Level ◽  
World Record ◽  
World Champion ◽  
Mhc Iia

We had the unique opportunity to study the skeletal muscle characteristics, at the single fiber level, of a world champion sprint runner who is the current indoor world record holder in the 60-m hurdles (7.30 s) and former world record holder in 110-m hurdles (12.91 s). Muscle biopsies were obtained from the vastus lateralis at rest and 4 h after a high-intensity exercise challenge (4 × 7 repetitions of resistance exercise). Single muscle fiber analyses were conducted for fiber type distribution (myosin heavy chain, MHC), fiber size, contractile function (strength, speed, and power) and mRNA expression (before and after the exercise bout). The world-class sprinter's leg muscle had a high abundance (24%) of the pure MHC IIx muscle fibers with a total fast-twitch fiber population of 71%. Power output of the MHC IIx fibers (35.1 ± 1.4 W/l) was 2-fold higher than MHC IIa fibers (17.1 ± 0.5 W/l) and 14-fold greater than MHC I fibers (2.5 ± 0.1 W/l). Additionally, the MHC IIx fibers were highly responsive to intense exercise at the transcriptional level for genes involved with muscle growth and remodeling ( Fn14 and myostatin). To our knowledge, the abundance of pure MHC IIx muscle fibers is the highest observed in an elite sprinter. Further, the power output of the MHC IIa and MHC IIx muscle fibers was greater than any human values reported to date. These data provide a myocellular basis for the high level of sprinting success achieved by this individual.

Recovery in skeletal muscle contractile function after prolonged hindlimb immobilization

1985 ◽  
Vol 59 (3) ◽  
pp. 916-923 ◽  
Author(s):  
R. H. Fitts ◽  
C. J. Brimmer
Keyword(s):  
Contractile Function ◽  
Vastus Lateralis ◽  
Weight Ratio ◽  
Contractile Properties ◽  
Shortening Velocity ◽  
Slow Twitch ◽  
Isometric Twitch ◽  
Fast Twitch ◽  
Muscle Contractile

Contractile properties of slow-twitch soleus (SOL), fast-twitch extensor digitorum longus (EDL), and fast-twitch superficial region of the vastus lateralis were determined in vitro (22 degrees C) in rats remobilized after prolonged (3 mo) hindlimb immobilization (IM). For all muscles the muscle-to-body weight ratio was significantly depressed by IM, and the ratios failed to completely recover even after 90 days. The contractile properties of the fast-twitch muscles were less affected by IM than the slow-twitch SOL. The IM shortened the SOL isometric twitch duration due to a reduced contraction and half-relaxation time. These parameters returned to control levels by the 14th day of recovery. Peak tetanic tension (Po, g/cm2) declined with IM by 46% in the SOL but showed no significant change in the fast-twitch muscles. After IM the SOL Po (g/cm2) recovered to control values by 28 days. The recovery of Po in absolute units (g) was considerably slower and did not return to control levels until 60 (SOL) to 90 (EDL) days. The maximum shortening velocity was not altered by IM in any of the muscles studied. These results demonstrate that both fast- and slow-twitch skeletal muscles possess the ability to completely recover normal contractile function following prolonged periods of hindlimb IM.

scholarly journals Influenza Infection has Fiber Type-Specific Effects on Cellular and Molecular Skeletal Muscle Function in Aged Mice

2020 ◽  
Vol 75 (12) ◽  
pp. 2333-2341
Author(s):  
Chad R Straight ◽  
Olivia R Ringham ◽  
Jenna M Bartley ◽  
Spencer R Keilich ◽  
George A Kuchel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Isometric Force ◽  
Fiber Type ◽  
Influenza Infection ◽  
Fiber Types ◽  
Specific Force ◽  
Mhc Iia ◽  
Mhc Iib ◽  
Maximal Isometric Force

Abstract Skeletal muscle myopathies represent a common non-pulmonary manifestation of influenza infection, leading to reduced physical function and hospitalization in older adults. However, underlying mechanisms remain poorly understood. Our study examined the effects of influenza virus A pulmonary infection on contractile function at the cellular (single fiber) and molecular (myosin-actin interactions and myofilament properties) levels in soleus and extensor digitorum longus muscles of aged (20 months) C57BL/6 male mice that were healthy or flu-infected for 7 (7-days post-infection; 7-DPI) or 12 days (12-DPI). Cross-sectional area (CSA) of myosin heavy chain (MHC) IIA and IIB fibers was reduced at 12-DPI relative to 7-DPI and healthy. Maximal isometric force in MHC IIA fibers was also reduced at 12-DPI relative to 7-DPI and healthy, resulting in no change in specific force (maximal isometric force divided by CSA). In contrast, MHC IIB fibers produced greater isometric force and specific force at 7-DPI compared to 12-DPI or healthy. The increased specific force in MHC IIB fibers was likely due to greater myofilament lattice stiffness and/or an increased number or stiffness of strongly bound myosin-actin cross-bridges. At the molecular level, cross-bridge kinetics were slower in MHC IIA fibers with infection, while changes in MHC IIB fibers were largely absent. In both fiber types, greater myofilament lattice stiffness was positively related to specific force. This study provides novel evidence that cellular and molecular contractile function is impacted by influenza infection in a fiber type-specific manner, suggesting potential molecular mechanisms to help explain the impact of flu-induced myopathies.

Phenotypic adaptations in human muscle fibers 6 and 24 wk after spinal cord injury

2002 ◽  
Vol 92 (1) ◽  
pp. 147-154 ◽  
Author(s):  
R. J. Talmadge ◽  
M. J. Castro ◽  
D. F. Apple ◽  
G. A. Dudley
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Early Time ◽  
Mhc I ◽  
Time Period ◽  
Plasmic Reticulum ◽  
Cord Injury ◽  
Mhc Iia

10.1152/japplphysiol.000247.2001.—The effects of spinal cord injury (SCI) on the profile of sarco(endo) plasmic reticulum calcium-ATPase (SERCA) and myosin heavy chain (MHC) isoforms in individual vastus lateralis (VL) muscle fibers were determined. Biopsies from the VL were obtained from SCI subjects 6 and 24 wk postinjury ( n = 6). Biopsies from nondisabled (ND) subjects were obtained at two time points 18 wk apart ( n = 4). In ND subjects, the proportions of VL fibers containing MHC I, MHC IIa, and MHC IIx were 46 ± 3, 53 ± 3, and 1 ± 1%, respectively. Most MHC I fibers contained SERCA2. Most MHC IIa fibers contained SERCA1. All MHC IIx fibers contained SERCA1 exclusively. SCI resulted in significant increases in fibers with MHC IIx (14 ± 4% at 6 wk and 16 ± 2% at 24 wk). In addition, SCI resulted in high proportions of MHC I and MHC IIa fibers with both SERCA isoforms (29% at 6 wk and 54% at 24 wk for MHC I fibers and 16% at 6 wk and 38% at 24 wk for MHC IIa fibers). Thus high proportions of VL fibers were mismatched for SERCA and MHC isoforms after SCI (19 ± 3% at 6 wk and 36 ± 9% at 24 wk) compared with only ∼5% in ND subjects. These data suggest that, in the early time period following SCI, fast fiber isoforms of both SERCA and MHC are elevated disproportionately, resulting in fibers that are mismatched for SERCA and MHC isoforms. Thus the adaptations in SERCA and MHC isoforms appear to occur independently.

scholarly journals Skeletal muscle phosphatidylcholine and phosphatidylethanolamine are related to insulin sensitivity and respond to acute exercise in humans

2016 ◽  
Vol 120 (11) ◽  
pp. 1355-1363 ◽  
Author(s):  
Sean A. Newsom ◽  
Joseph T. Brozinick ◽  
Katja Kiseljak-Vassiliades ◽  
Allison N. Strauss ◽  
Samantha D. Bacon ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Acute Exercise ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Mass Spectrometry Analysis ◽  
Vastus Lateralis Muscle ◽  
Intravenous Glucose ◽  
Exercise In Humans

Several recent reports indicate that the balance of skeletal muscle phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is a key determinant of muscle contractile function and metabolism. The purpose of this study was to determine relationships between skeletal muscle PC, PE and insulin sensitivity, and whether PC and PE are dynamically regulated in response to acute exercise in humans. Insulin sensitivity was measured via intravenous glucose tolerance in sedentary obese adults (OB; n = 14), individuals with type 2 diabetes (T2D; n = 15), and endurance-trained athletes (ATH; n = 15). Vastus lateralis muscle biopsies were obtained at rest, immediately after 90 min of cycle ergometry at 50% maximal oxygen consumption (V̇o2 max), and 2-h postexercise (recovery). Skeletal muscle PC and PE were measured via infusion-based mass spectrometry/mass spectrometry analysis. ATH had greater levels of muscle PC and PE compared with OB and T2D ( P < 0.05), with total PC and PE positively relating to insulin sensitivity (both P < 0.05). Skeletal muscle PC:PE ratio was elevated in T2D compared with OB and ATH ( P < 0.05), tended to be elevated in OB vs. ATH ( P = 0.07), and was inversely related to insulin sensitivity among the entire cohort ( r = −0.43, P = 0.01). Muscle PC and PE were altered by exercise, particularly after 2 h of recovery, in a highly group-specific manner. However, muscle PC:PE ratio remained unchanged in all groups. In summary, total muscle PC and PE are positively related to insulin sensitivity while PC:PE ratio is inversely related to insulin sensitivity in humans. A single session of exercise significantly alters skeletal muscle PC and PE levels, but not PC:PE ratio.

Single muscle fiber contractile properties during a competitive season in male runners

2004 ◽  
Vol 287 (5) ◽  
pp. R1124-R1131 ◽  
Author(s):  
M. P. Harber ◽  
P. M. Gallagher ◽  
A. R. Creer ◽  
K. M. Minchev ◽  
S. W. Trappe
Keyword(s):  
Cell Size ◽  
Peak Power ◽  
Fiber Strength ◽  
Muscle Fibers ◽  
Contractile Properties ◽  
Shortening Velocity ◽  
Cross Sectional ◽  
Mhc I ◽  
Intense Training ◽  
Mhc Iia

The purpose of this investigation was to examine the contractile properties of individual myofibers in response to periodized training periods throughout a collegiate cross-country season in male runners. Muscle biopsies of the gastrocnemius were taken after a summer base training phase (T1), an 8-wk intense training period (T2), and a 4-wk taper phase (T3). Five runners ( n = 5; age = 20 ± 1 yr; wt = 65 ± 4 kg; ht = 178 ± 3 cm) completed all three time points. A total of 328 individual muscle fibers [myosin heavy chain (MHC) I = 66%; MHC IIa = 33%; hybrids = 1%] were isolated and studied at 15°C for their contractile properties. Diameter of MHC I fibers was 3% smaller ( P < 0.05) at T2 compared with T1 and an additional 4% smaller ( P < 0.05) after the taper. Cell size was unaltered in the MHC IIa fibers. MHC I and IIa fiber strength increased 18 and 11% ( P < 0.05), respectively, from T1 to T2. MHC I fibers produced 9% less force ( P < 0.05) after the taper, whereas MHC IIa fibers were 9% stronger ( P < 0.05). Specific tension increased 38 and 26% ( P < 0.05) for MHC I and IIa fibers, respectively, from T1 to T2 and was unchanged with the taper. Maximal shortening velocity ( Vo) of the MHC I fibers decreased 23% ( P < 0.05) from T1 to T2 and 17% ( P < 0.05) from T2 to T3, whereas MHC IIa Vo was unchanged. MHC I peak power decreased 20% ( P < 0.05) from T1 to T2 and 25% ( P < 0.05) from T2 to T3, whereas MHC IIa peak power was unchanged. Power corrected for cell size decreased 15% ( P < 0.05) from T2 to T3 and was 24% ( P < 0.05) lower at T3 compared with T1 for the MHC I fibers only. These data suggest that changes in run training alter myocellular physiology via decreases in fiber size, Vo, and power of MHC I fibers and through increases in force per cross-sectional area of slow- and fast-twitch muscle fibers.

scholarly journals Contractility of permeabilized rat vastus intermedius muscle fibres following high-fat, high-sucrose diet consumption

2021 ◽  
Author(s):  
Ian C Smith ◽  
Curtis Ostertag ◽  
Jennifer J O'Reilly ◽  
Jaqueline Lourdes Rios ◽  
Teja Klancic ◽  
...  
Keyword(s):  
Contractile Function ◽  
Force Production ◽  
Muscle Fibres ◽  
Chow Diet ◽  
High Fat ◽  
Force Output ◽  
Mhc I ◽  
Diet Induced Obesity ◽  
High Sucrose ◽  
Mhc Iia

Obesity is a worldwide health concern associated with impaired physical function. It is not clear if contractile protein dysfunction contributes to the impairment of muscle function observed with obesity. The purpose of this study was to examine if diet-induced obesity affects contractile function of chemically permeabilized vastus intermedius fibres of male Sprague Dawley rats expressing fast myosin heavy chain (MHC) IIa or slow MHC I. Rats consumed either a high-fat, high-sucrose (HFHS) diet or a standard (CHOW) diet beginning as either weanlings (7-week duration: WEAN7 cohort, or 14-week duration: WEAN14 cohort) or young adults (12-week duration: ADULT12 cohort, 24-week duration: ADULT24 cohort). HFHS-fed rats had higher (P<0.05) whole-body adiposity (derived from dual-energy X-ray absorptiometry) than CHOW-fed rats in all cohorts. Relative to CHOW diet groups, the HFHS diet was associated with impaired force production in a) MHC I fibres in the ADULT24 cohort, and b) MHC IIa fibres in the ADULT12 and ADULT24 cohorts combined. However, the HFHS diet did not significantly affect the Ca2+-sensitivity of force production, unloaded shortening velocity, or ratio of active force to active stiffness in any cohort. We conclude that diet-induced obesity can impair force output of permeabilized muscle fibres of adult rats. Novelty Bullets: • We assessed contractile function of permeabilized skeletal muscle fibres in a rat model of diet-induced obesity. • The high-fat, high-sucrose diet was associated with impaired force output of fibres expressing MHC I or MHC IIa in some cohorts of rats. • Other measures of contractile function were not significantly affected by diet.

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