Muscle damage induced by eccentric contractions of 25% strain

1991 ◽  
Vol 70 (6) ◽  
pp. 2498-2507 ◽  
Author(s):  
R. L. Lieber ◽  
T. M. Woodburn ◽  
J. Friden
Keyword(s):  
Time Course ◽  
Fiber Type ◽  
Tibialis Anterior Muscle ◽  
Eccentric Contraction ◽  
Damage Mechanism ◽  
Treatment Method ◽  
Oxidative Capacity ◽  
Morphological Properties ◽  
Fast Twitch ◽  
Passive Stretch

Contractile and morphological properties were measured in the rabbit tibialis anterior muscle 1 h after isometric contraction (IC), passive stretch (PS), or eccentric contraction (EC). Maximal tetanic tension (Po) was reduced after 30 min of PS (P less than 0.001), IC (P less than 0.001), or EC (P less than 0.0001). However, the magnitude of the force deficit was a function of the treatment method. After 30 min of cyclic PS, Po decreased by 13%, whereas after IC or EC, Po decreased by 31 and 69%, respectively. The time course of tension decline in the various groups suggested that the EC-induced injury occurred during the first few minutes of treatment. Although the morphology of samples from the PS and IC groups appeared normal, eccentrically exercised muscles exhibited portions of abnormally large fibers (diam greater than or equal to 110 microns) when viewed in cross section. Examination of 231 such fibers from 6 muscles revealed that all enlarged fibers were exclusively of the fast-twitch glycolytic fiber type. Although no ultrastructural abnormalities were observed in any of the muscles from the IC or PS groups, a significant portion of the fibers in the EC group displayed various degrees of disorganization of the sarcomeric band pattern. Taken together, these studies highlight the importance of fiber oxidative capacity in EC-induced injury, which may be related to the damage mechanism.

Blood flow to different skeletal muscle fiber types during contraction

1983 ◽  
Vol 245 (2) ◽  
pp. H265-H275 ◽  
Author(s):  
B. G. Mackie ◽  
R. L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Skeletal Muscle Fiber ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Blood Flows ◽  
Fast Twitch

Blood flow to fast-twitch red (FTR), fast-twitch white (FTW), and slow-twitch red (STR) muscle fiber sections of the gastrocnemius-plantaris-soleus muscle group was determined using 15 +/- 3-microns microspheres during in situ stimulation in pentobarbital-anesthetized rats. Steady-state blood flows were assessed during the 10th min of contraction using twitch (0.1, 0.5, 1, 3, and 5 Hz) and tetanic (7.5, 15, 30, 60, and 120/min) stimulation conditions. In addition, an earlier blood flow determination was begun at 3 min (twitch series) or at 30 s (tetanic series) of stimulation. Blood flow was highest in the FTR (220-240 ml X min-1 X 100 g-1), intermediate in the STR (140), and lowest in the FTW (70-80) section during tetanic contraction conditions estimated to coincide with the peak aerobic function of each fiber type. These blood flows are fairly proportional to the differences in oxidative capacity among fiber types. Further, their absolute values are similar to those predicted from the relationship between blood flow and oxidative capacity found by others for dog and cat muscles. During low-frequency contraction conditions, initial blood flow to the FTR and STR sections were excessively high and not dependent on contraction frequency. However, blood flows subsequently decreased to values in keeping with the relative energy demands. In contrast, FTW muscle did not exhibit this time-dependent relative hyperemia. Thus, besides the obvious quantitative differences between skeletal muscle fiber types, there are qualitative differences in blood flow response during contractions. Our findings establish that, based on fiber type composition, a heterogeneity in blood flow distribution can occur within a whole muscle during contraction.

In vitro O2 uptake and histochemical fiber type of resting hamster muscles

1984 ◽  
Vol 57 (1) ◽  
pp. 246-253 ◽  
Author(s):  
S. M. Sullivan ◽  
R. N. Pittman
Keyword(s):  
Surface Area ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Histochemical Staining ◽  
Striated Muscles ◽  
Type Composition ◽  
Slow Twitch ◽  
Pattern Number ◽  
Fast Twitch

In vitro oxygen consumption (VO2), histochemical fiber type, capillary arrangement, and muscle fiber geometry were measured in three hamster striated muscles. These muscles varied markedly in their histochemical fiber type composition (% by number): retractor (70% FG, fast-twitch, glycolytic; 16% FOG, fast-twitch, oxidative-glycolytic; 14% SO, slow-twitch, oxidative); soleus (57% FOG, 43% SO), and sartorius (98% FG, 2% FOG). Sartorius VO2 [0.80 +/- 0.034 (SE) ml O2 X min-1 X 100 g-1] was significantly different (P less than 0.01) from VO2 of retractor (0.89 +/- 0.038) and soleus (1.00 +/- 0.048).The number of capillaries around a fiber and the surface area/volume were greater for FOG and SO fibers than for FG fibers. Fibers of all types appeared to be roughly elliptical in shape. Capillaries were uniformly distributed around fibers in the soleus, but they were located more toward the ends of the major diameter in the retractor and sartorius. The results suggest a relationship among a fiber's oxidative capacity (based on its histochemical staining pattern), number of surrounding capillaries and surface area/volume. Furthermore, results suggest that VO2 and capillary spacing around a fiber may depend on fiber type.

scholarly journals Calcineurin Is Necessary for the Maintenance but Not Embryonic Development of Slow Muscle Fibers

2005 ◽  
Vol 25 (15) ◽  
pp. 6629-6638 ◽  
Author(s):  
Misook Oh ◽  
Igor I. Rybkin ◽  
Victoria Copeland ◽  
Michael P. Czubryt ◽  
John M. Shelton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Specific Expression ◽  
Interacting Protein ◽  
Type Composition ◽  
Slow Fiber ◽  
Fast Twitch

ABSTRACT Skeletal muscles are a mosaic of slow and fast twitch myofibers. During embryogenesis, patterns of fiber type composition are initiated that change postnatally to meet physiological demand. To examine the role of the protein phosphatase calcineurin in the initiation and maintenance of muscle fiber types, we used a “Flox-ON” approach to obtain muscle-specific overexpression of the modulatory calcineurin-interacting protein 1 (MCIP1/DSCR1), an inhibitor of calcineurin. Myo-Cre transgenic mice with early skeletal muscle-specific expression of Cre recombinase were used to activate the Flox-MCIP1 transgene. Contractile components unique to type 1 slow fibers were absent from skeletal muscle of adult Myo-Cre/Flox-MCIP1 mice, whereas oxidative capacity, myoglobin content, and mitochondrial abundance were unaltered. The soleus muscles of Myo-Cre/Flox-MCIP1 mice fatigued more rapidly than the wild type as a consequence of the replacement of the slow myosin heavy chain MyHC-1 with a fast isoform, MyHC-2A. MyHC-1 expression in Myo-Cre/Flox-MCIP1 embryos and early neonates was normal. These results demonstrate that developmental patterning of slow fibers is independent of calcineurin, while the maintenance of the slow-fiber phenotype in the adult requires calcineurin activity.

Increased oxidative capacity does not protect skeletal muscle fibers from eccentric contraction-induced injury

1998 ◽  
Vol 274 (5) ◽  
pp. R1300-R1308 ◽  
Author(s):  
T. J. Patel ◽  
D. Cuizon ◽  
O. Mathieu-Costello ◽  
J. Fridén ◽  
R. L. Lieber
Keyword(s):  
Electrical Stimulation ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Exercise Bout ◽  
Eccentric Contraction ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Training Effect ◽  
Muscle Oxidative Capacity ◽  
Tetanic Tension

Isometric electrical stimulation was delivered to rabbit dorsiflexor muscles at 10 Hz for 1 s on and 1 s off over 30 min, 5 days/wk for 3 wk to induce an increase in muscle oxidative capacity. Stimulation-trained muscles as well as untrained muscles were then subjected to a 30-min eccentric exercise bout to test whether increased oxidative capacity provided a protective effect against muscle injury. Electrical stimulation resulted in significant training of both the extensor digitorum longus (EDL) and tibialis anterior (TA) muscles, with EDL citrate synthase (CS) activity increasing an average of 67% ( P < 0.0001) and TA CS activity increasing by 27% ( P < 0.05). For all parameters measured, the magnitude of change was much greater for EDL than for TA muscle. Dorsiflexor fatigability decreased significantly during the 3-wk training period ( P < 0.0001), whereas the EDL and TA individually showed strong decreasing trends in fatigability after training. TA and EDL capillary density measured histomorphometrically increased from 839 ± 56 to 1,026 ± 71 mm−2( P = 0.07) and from 589 ± 37 to 792 ± 66 mm−2( P < 0.05), respectively. TA and EDL capillary-to-fiber ratio increased from 1.32 ± 0.10 to 1.55 ± 0.16 ( P > 0.2) and 1.08 ± 0.07 to 1.36 ± 0.14 ( P > 0.1), respectively. Type 2A fiber type percentage increased after stimulation training by 68% ( P < 0.0001) for the EDL and by 32% ( P > 0.1) for the TA at the expense of type 2D fibers. Despite the large training effect for the EDL and the modest training effect for the TA, no differences were observed between stimulation-trained and untrained groups for maximum dorsiflexion torque ( P > 0.3) or maximum tetanic tension ( P > 0.3) after eccentric contraction-induced injury. Additionally, no significant correlation was observed between CS activity and maximum tetanic tension after eccentric contraction-induced injury for either muscle ( P > 0.2). Thus we conclude that increasing muscle oxidative capacity by isometric electrical stimulation training did not protect muscle against eccentric contraction-induced injury.

Glucocorticoid receptor activation during exercise in muscle

1990 ◽  
Vol 68 (4) ◽  
pp. 1615-1620 ◽  
Author(s):  
S. M. Czerwinski ◽  
R. C. Hickson
Keyword(s):  
Glucocorticoid Receptor ◽  
Time Course ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Receptor Activation ◽  
Endurance Running ◽  
Similar Time ◽  
Receptor Complexes ◽  
Diethylaminoethyl Cellulose ◽  
Fast Twitch

This investigation was undertaken to evaluate whether endurance running of the type known to retard the muscle atrophy associated with glucocorticoid excess inhibits activation of glucocorticoid-receptor complexes to a DNA binding state. Female adrenalectomized rats received an injection (50 microCi/100 g body wt ip) of [3H]triamcinolone acetonide and remained sedentary or were immediately exercised by endurance running at 23 m/min for up to 90 min. Receptor activation, as quantified by binding to DNA-cellulose, steadily increased from 10-20% of the receptors capable of binding DNA in uninjected controls to 25-45% by 5 min and to 53-80% by 90 min after receiving the hormone in all muscles studied (fast-twitch red vastus lateralis, fast-twitch white vastus lateralis, slow-twitch soleus, mixed gastrocnemius, and heart). Exercise did not influence the time-course changes in percent activation. When activation was determined from changes in the conformational state of the receptor as measured by diethylaminoethyl-cellulose anion exchange chromatography, there was a similar time-dependent formation of activated receptor forms in all muscle types. However, exercise did not inhibit or delay the appearance of the activated receptor from the unactivated state. These results indicate that glucocorticoid receptor activation occurs at a rate that is independent of both fiber type and delivery of steroid to working muscles during exercise. If exercise alters receptor activation, a longer time period, beyond 90 min of running, or even additional training may be needed for inhibition to be expressed.

Influence of acidosis on AMP deaminase activity in contracting fast-twitch muscle

1985 ◽  
Vol 248 (1) ◽  
pp. C43-C50 ◽  
Author(s):  
G. A. Dudley ◽  
R. L. Terjung
Keyword(s):  
Time Course ◽  
Fiber Type ◽  
Muscle Blood Flow ◽  
Iodoacetic Acid ◽  
Substrate Effect ◽  
Fiber Types ◽  
Amp Deaminase ◽  
Fast Twitch Muscle ◽  
Fast Twitch

The rate of AMP deamination to IMP and NH4, by the action of AMP deaminase, is increased in vitro by acidosis and elevations in [AMP] and [ADP]. We evaluated the influence of acidosis on the activity of AMP deaminase in contracting muscle (5 Hz) by relating the time course of IMP and NH4 production to lactate-induced acidosis in low-oxidative, fast-twitch white (FTW) and high-oxidative, fast-twitch red (FTR) muscle of the rat. Cellular acidosis was modified by controlling lactic acid accumulation by regulating muscle blood flow and using trained animals. A significant activation of AMP deaminase occurred in both muscle types, but only at times when the estimated pH was 6.6 and below (lactate content 20 mu mol/g and above). Cellular acidosis, however, is not absolutely essential, since iodoacetic acid-blocked muscle lost 85-90% of its ATP to IMP during contractions. Thus cellular acidosis seems to be an important, but not the sole, factor activating AMP deaminase during contractions. Further, the influence of acidosis is probably different between fiber types, since the estimated free AMP and ADP contents, calculated from the creatine kinase and myokinase reactions, were different in the two fiber types. Most of the activation of AMP deaminase in FTR muscle could be attributed to a substrate effect of the increased free AMP content. In contrast, most of the activation of AMP deaminase in the FTW muscle was due to factors other than a substrate effect. These results suggest that cellular acidosis during intense contraction conditions is a major factor activating AMP deaminase, especially in the low-oxidative FTW muscle fiber type.

Relationship between somatotype components and muscle fiber type

2021 ◽  
Vol 25 (2) ◽  
pp. 110-116
Author(s):  
Fahri S. Çınarlı
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Linear Correlation ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
The Body ◽  
Morphological Properties ◽  
Vastus Lateralis Muscle ◽  
Test Protocol ◽  
Fast Twitch

Background and Study Aim. It is stated that genetic factors, lifestyle and demographic components affect the morphological properties of the muscle; moreover, there is a relationship between adiposity indicators and skeletal muscle. The aim of this study is to examine the relationship between the somatotype components and obesity markers and the percentage of the fast twitch fibril type of skeletal muscle. Material and Methods. Nine male students of sports sciences voluntarily participated in the study (age = 22 ± 3.24 years). By applying the isokinetic fatigue test protocol, which is a non-invasive method, the percentage of fast twitch fibril of the vastus lateralis muscle was estimated. Body fat ratio and somatotype body types of the participants were determined as indicators of obesity. Results. There was a high positive linear correlation between the obesity indicators (endomorphy and body fat ratio) and the percentage of fast twitch fibril (r=0.738; r=0.809, p<0.01 respectively). The variance between the endomorphy and body fat ratio expressing fatness and the fast twitch fibril percentage were found to be acceptable  (54-65% explained variance). A moderate negative linear correlation was found between the ectomorphy and percentage of fast-twitch fibril (r= -0.674, p<0.05). Finally, a moderate positive but statistically insignificant linear correlation was found between the mesomorphy and the percentage of fast twitch fibril (r=0.623, p>0.05). Conclusion. The findings show that the total fatness level of the body and the percentage of fast twitch fibril are not independent parameters and have a positive effect on each other.

Muscle fiber involvement during training of different intensities and durations

1976 ◽  
Vol 230 (4) ◽  
pp. 946-950 ◽  
Author(s):  
RL Terjung
Keyword(s):  
Muscle Fiber ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Group Iv ◽  
Intense Exercise ◽  
Group Iii ◽  
Oxidative Markers ◽  
Group I ◽  
Fast Twitch

The extent of skeletal muscle fiber type involvement during exercise training was evaluated by assessing the increase in oxidative markers in the muscles of rats trained by various exercise programs. Rats were trained by running 6 days/wk at 1 mph for 12 wk by one of four protocols: group I-10% grade, 2 h/day; group II-10% grade, 4 h/day; group III-30% grade, 40 min/day; and group IV-30% grade, 2 h/day. No distinction was found between the different programs for the increase in cytochrome c content or citrate synthase (CS) activity of mixed muscle. The more intense programs utilizing a 30% grade induced an increase in CS activity in the fast-twitch white (FTW) fiber that was twice that found in the 10% grade groups. The fast-twitch red (FTR) fibers of the 2 h/day or more groups showed a similar increase (90-95%) in CS activity except for the group that ran for only 40 min/day. These data suggest that: 1) running durations of moderately intense exercise longer than 2 h/day do not further increase the oxidative capacity of the working muscles; and 2) more intense exercise builds on the performance of previously used FTR fibers and additionally involves the low oxidative FTW fibers.

Slow- and fast-twitch hindlimb skeletal muscle phenotypes 12 wk after ⅚ nephrectomy in Wistar rats of both sexes

2015 ◽  
Vol 309 (7) ◽  
pp. F638-F647 ◽  
Author(s):  
Luz M. Acevedo ◽  
Alan Peralta-Ramírez ◽  
Ignacio López ◽  
Verónica E. Chamizo ◽  
Carmen Pineda ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Soleus Muscle ◽  
Fiber Type ◽  
Serum Testosterone ◽  
Oxidative Capacity ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Nuclear Density ◽  
Type Transformation ◽  
Fast Twitch

This study describes fiber-type adaptations in hindlimb muscles, the interaction of sex, and the role of hypoxia on this response in 12-wk ⅚ nephrectomized rats (Nx). Contractile, metabolic, and morphological features of muscle fiber types were assessed in the slow-twitch soleus and the fast-twitch tibialis cranialis muscles of Nx rats, and compared with sham-operated controls. Rats of both sexes were considered in both groups. A slow-to-fast fiber-type transformation occurred in the tibialis cranialis of Nx rats, particularly in males. This adaptation was accomplished by impaired oxidative capacity and capillarity, increased glycolytic capacity, and no changes in size and nuclear density of muscle fiber types. An oxidative-to-glycolytic metabolic transformation was also found in the soleus muscle of Nx rats. However, a modest fast-to-slow fiber-type transformation, fiber hypertrophy, and nuclear proliferation were observed in soleus muscle fibers of male, but not of female, Nx rats. Serum testosterone levels decreased by 50% in male but not in female Nx rats. Hypoxia-inducible factor-1α protein level decreased by 42% in the tibialis cranialis muscle of male Nx rats. These data demonstrate that 12 wk of Nx induces a muscle-specific adaptive response in which myofibers do not change (or enlarge minimally) in size and nuclear density, but acquire markedly different contractile and metabolic characteristics, which are accompanied by capillary rarefaction. Muscle function and sex play relevant roles in these adaptations.

The effects of PGC-1α on control of microvascular Po2 kinetics following onset of muscle contractions

2014 ◽  
Vol 117 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Yutaka Kano ◽  
Shinji Miura ◽  
Hiroaki Eshima ◽  
Osamu Ezaki ◽  
David C. Poole
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Endurance Performance ◽  
Oxidative Capacity ◽  
Muscle Contractions ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Phosphorescence Quenching ◽  
Slow Twitch ◽  
Fast Twitch

During contractions, regulation of microvascular oxygen partial pressure (Pmvo2), which drives blood-myocyte O2 flux, is a function of skeletal muscle fiber type and oxidative capacity and can be altered by exercise training. The kinetics of Pmvo2 during contractions in predominantly fast-twitch muscles evinces a more rapid fall to far lower levels compared with slow-twitch counterparts. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) improves endurance performance, in part, due to mitochondrial biogenesis, a fiber-type switch to oxidative fibers, and angiogenesis in skeletal muscle. We tested the hypothesis that improvement of exercise capacity by genetic overexpression of PGC-1α would be associated with an altered Pmvo2 kinetics profile of the fast-twitch (white) gastrocnemius during contractions toward that seen in slow-twitch muscles (i.e., slowed response kinetics and elevated steady-state Pmvo2). Phosphorescence quenching techniques were used to measure Pmvo2 at rest and during separate bouts of twitch (1 Hz) and tetanic (100 Hz) contractions in gastrocnemius muscles of mice with overexpression of PGC-1α and wild-type littermates (WT) mice under isoflurane anesthesia. Muscles of PGC-1α mice exhibited less fatigue than WT ( P < 0.01). However, except for the Pmvo2 response immediately following onset of contractions, WT and PGC-1α mice demonstrated similar Pmvo2 kinetics. Specifically, the time delay of the Pmvo2 response was shortened in PGC-1α mice compared with WT (1 Hz: WT, 6.6 ± 2.4 s; PGC-1α, 2.9 ± 0.8 s; 100 Hz: WT, 3.3 ± 1.1 s, PGC-1α, 0.9 ± 0.3 s, both P < 0.05). The ratio of muscle force to Pmvo2 was higher for the duration of tetanic contractions in PGC-1α mice. Slower dynamics and maintenance of higher Pmvo2 following muscle contractions is not obligatory for improved fatigue resistance in fast-twitch muscle of PGC-1α mice. Moreover, overexpression of PGC-1α may accelerate O2 utilization kinetics to a greater extent than O2 delivery kinetics.

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