Sex differences in intracellular Ca2+ accumulation following eccentric contractions of rat skeletal muscle in vivo

2010 ◽  
Vol 299 (4) ◽  
pp. R1006-R1012 ◽  
Author(s):  
Takashi Sonobe ◽  
Tadakatsu Inagaki ◽  
Mizuki Sudo ◽  
David C. Poole ◽  
Yutaka Kano
Keyword(s):  
Skeletal Muscle ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Length ◽  
Eccentric Contractions ◽  
Intermediate Response ◽  
The Difference ◽  
Exercise Induced ◽  
Resting Muscle

It is commonly believed that estrogen and sex influences play significant effects in skeletal muscle damage following eccentric exercise. The mechanistic bases for this sex-specific phenomenon remain to be resolved. The muscle damage has been linked to loss of Ca2+ homeostasis and resultant intramyocyte Ca2+ ([Ca2+]i) accumulation; therefore, we tested the hypothesis that the greater eccentric exercise-induced muscle damage in males would be associated with more pronounced [Ca2+]i accumulation. The intact spinotrapezius muscle of adult Wistar rats [male, female, and ovariectomized (OVX)—to investigate the effects of estrogen] was exteriorized. Tetanic eccentric contractions (100 Hz, 700-ms duration, 20 contractions/min for a total of 10 sets of 50 contractions) were elicited by electrical stimulation during synchronized muscle stretch of 10% resting muscle length. The fluorescence ratio (F340/F380 nm) was determined from images captured following each set of contractions, and fura-2 AM was used to estimate [Ca2+]i and changes thereof. Following eccentric contractions, [Ca2+]i increased significantly in male (42.8 ± 5.3%, P < 0.01) but not in female (9.4 ± 3.5%) rats. OVX evidenced an intermediate response (17.0 ± 1.2%) that remained significantly reduced compared with males. These results demonstrate that females maintain [Ca2+]i homeostasis following novel eccentric contractions, whereas males do not, which is consistent with a role for elevated [Ca2+]i in eccentric exercise-induced muscle damage. The presence of normal estrogen levels is not obligatory for the difference between the sexes.

scholarly journals Two maximal isometric contractions attenuate the magnitude of eccentric exercise-induced muscle damage

2012 ◽  
Vol 37 (4) ◽  
pp. 680-689 ◽  
Author(s):  
Hsin-Lian Chen ◽  
Kazunori Nosaka ◽  
Alan J. Pearce ◽  
Trevor C. Chen
Keyword(s):  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Soreness ◽  
Muscle Length ◽  
Peak Torque ◽  
Eccentric Contractions ◽  
Control Group ◽  
Isometric Contractions ◽  
Elbow Flexors ◽  
Exercise Induced

This study investigated whether maximal voluntary isometric contractions (MVC-ISO) would attenuate the magnitude of eccentric exercise-induced muscle damage. Young untrained men were placed into one of the two experimental groups or one control group (n = 13 per group). Subjects in the experimental groups performed either two or 10 MVC-ISO of the elbow flexors at a long muscle length (20° flexion) 2 days prior to 30 maximal isokinetic eccentric contractions of the elbow flexors. Subjects in the control group performed the eccentric contractions without MVC-ISO. No significant changes in maximal voluntary concentric contraction peak torque, peak torque angle, range of motion, upper arm circumference, plasma creatine kinase (CK) activity and myoglobin concentration, muscle soreness, and ultrasound echo intensity were evident after MVC-ISO. Changes in the variables following eccentric contractions were smaller (P < 0.05) for the 2 MVC-ISO group (e.g., peak torque loss at 5 days after exercise, 23% ± 3%; peak CK activity, 1964 ± 452 IU·L–1; peak muscle soreness, 46 ± 4 mm) or the 10 MVC-ISO group (13% ± 3%, 877 ± 198 IU·L–1, 30 ± 4 mm) compared with the control (34% ± 4%, 6192 ± 1747 IU·L–1, 66 ± 5 mm). The 10 MVC-ISO group showed smaller (P < 0.05) changes in all variables following eccentric contractions compared with the 2 MVC-ISO group. Therefore, two MVC-ISO conferred potent protective effects against muscle damage, whereas greater protective effect was induced by 10 MVC-ISO, which can be used as a strategy to minimize muscle damage.

α7β1-Integrin regulates mechanotransduction and prevents skeletal muscle injury

2006 ◽  
Vol 290 (6) ◽  
pp. C1660-C1665 ◽  
Author(s):  
Marni D. Boppart ◽  
Dean J. Burkin ◽  
Stephen J. Kaufman
Keyword(s):  
Skeletal Muscle ◽  
Muscle Damage ◽  
Intracellular Signaling ◽  
Ex Vivo ◽  
Negative Regulator ◽  
Blue Dye ◽  
The Matrix ◽  
Mitogen Activated Protein ◽  
Exercise Induced

α7β1-Integrin links laminin in the extracellular matrix with the cell cytoskeleton and therein mediates transduction of mechanical forces into chemical signals. Muscle contraction and stretching ex vivo result in activation of intracellular signaling molecules that are integral to postexercise injury responses. Because α7β1-integrin stabilizes muscle and provides communication between the matrix and cytoskeleton, the role of this integrin in exercise-induced cell signaling and skeletal muscle damage was assessed in wild-type and transgenic mice overexpressing the α7BX2 chain. We report here that increasing α7β1-integrin inhibits phosphorylation of molecules associated with muscle damage, including the mitogen-activated protein kinases (JNK, p38, and ERK), following downhill running. Likewise, activation of molecules associated with hypertrophy (AKT, mTOR, and p70S6k) was diminished in mice overexpressing integrin. While exercise resulted in Evans blue dye-positive fibers, an index of muscle damage, increased integrin protected mice from injury. Moreover, exercise leads to an increase in α7β1 protein. These experiments provide the first evidence that α7β1-integrin is a negative regulator of mechanotransduction in vivo and provides resistance to exercise-induced muscle damage.

scholarly journals Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nosratollah Hedayatpour ◽  
Deborah Falla
Keyword(s):  
Muscle Damage ◽  
Motor Unit ◽  
Muscle Weakness ◽  
Eccentric Exercise ◽  
Muscle Function ◽  
Muscle Hypertrophy ◽  
Eccentric Contractions ◽  
Neural Adaptations ◽  
Neuromuscular Adaptations ◽  
Exercise Induced

Eccentric exercise is characterized by initial unfavorable effects such as subcellular muscle damage, pain, reduced fiber excitability, and initial muscle weakness. However, stretch combined with overload, as in eccentric contractions, is an effective stimulus for inducing physiological and neural adaptations to training. Eccentric exercise-induced adaptations include muscle hypertrophy, increased cortical activity, and changes in motor unit behavior, all of which contribute to improved muscle function. In this brief review, neuromuscular adaptations to different forms of exercise are reviewed, the positive training effects of eccentric exercise are presented, and the implications for training are considered.

Honokiol protects rats against eccentric exercise-induced skeletal muscle damage by inhibiting NF-κB induced oxidative stress and inflammation

2009 ◽  
Vol 610 (1-3) ◽  
pp. 119-127 ◽  
Author(s):  
Jasson Chiang ◽  
Yuh-Chiang Shen ◽  
Yea-Hwey Wang ◽  
Yu-Chang Hou ◽  
Chien-Chih Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Skeletal Muscle Damage ◽  
Exercise Induced

Cellular adaptation to repeated eccentric exercise-induced muscle damage

2001 ◽  
Vol 91 (4) ◽  
pp. 1669-1678 ◽  
Author(s):  
N. Stupka ◽  
M. A. Tarnopolsky ◽  
N. J. Yardley ◽  
S. M. Phillips
Keyword(s):  
Skeletal Muscle ◽  
Protein Content ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Protein ◽  
Vastus Lateralis ◽  
Relative Magnitude ◽  
Knee Extension ◽  
Proteolytic Pathway ◽  
Exercise Induced

Eccentrically biased exercise results in skeletal muscle damage and stimulates adaptations in muscle, whereby indexes of damage are attenuated when the exercise is repeated. We hypothesized that changes in ultrastructural damage, inflammatory cell infiltration, and markers of proteolysis in skeletal muscle would come about as a result of repeated eccentric exercise and that gender may affect this adaptive response. Untrained male ( n = 8) and female ( n = 8) subjects performed two bouts ( bout 1and bout 2), separated by 5.5 wk, of 36 repetitions of unilateral, eccentric leg press and 100 repetitions of unilateral, eccentric knee extension exercises (at 120% of their concentric single repetition maximum), the subjects' contralateral nonexercised leg served as a control (rest). Biopsies were taken from the vastus lateralis from each leg 24 h postexercise. After bout 2, the postexercise force deficit and the rise in serum creatine kinase (CK) activity were attenuated. Women had lower serum CK activity compared with men at all times ( P < 0.05), but there were no gender differences in the relative magnitude of the force deficit. Muscle Z-disk streaming, quantified by using light microscopy, was elevated vs. rest only after bout 1 ( P< 0.05), with no gender difference. Muscle neutrophil counts were significantly greater in women 24 h after bout 2 vs. rest and bout 1 ( P < 0.05) but were unchanged in men. Muscle macrophages were elevated in men and women after bout 1 and bout 2 ( P < 0.05). Muscle protein content of the regulatory calpain subunit remained unchanged whereas ubiquitin-conjugated protein content was increased after both bouts ( P < 0.05), with a greater increase after bout 2. We conclude that adaptations to eccentric exercise are associated with attenuated serum CK activity and, potentially, an increase in the activity of the ubiquitin proteosome proteolytic pathway.

Ultrasound Treatment and Recovery from Eccentric-Exercise-Induced Muscle Damage

2002 ◽  
Vol 11 (4) ◽  
pp. 305-314 ◽  
Author(s):  
Peter M. Tiidus ◽  
Joel Cort ◽  
Sarah J. Woodruff ◽  
Pamela Bryden
Keyword(s):  
Muscle Damage ◽  
Outcome Measures ◽  
Eccentric Exercise ◽  
Muscle Soreness ◽  
Peak Torque ◽  
Ultrasound Treatment ◽  
Eccentric Contractions ◽  
Random Assignment ◽  
Elbow Angle ◽  
Exercise Induced

Objectives:To evaluate ultrasound’s effectiveness after eccentric-exercise-induced muscle damage.Participants:22 subjects.Intervention:Random assignment to ultrasound (UT) or placebo (PT). Ultrasound was applied immediately and 24, 48, and 72 h after 50 maximum eccentric contractions of the biceps.Outcome Measures:Concentric and eccentric peak torques, resting elbow angle, and subjective muscle soreness were measured before and 24, 48, 72, and 96 h afterward.Results:No significant differences between UT and PT for biceps concentric or eccentric peak torque were noted. Both groups exhibited significant (P< .01) depression in eccentric and concentric peak torques with a slow return toward preexercise values over 96 h. Resting elbow angles for both groups were significantly lower than preexercise values up to 96 h (P< .01). Muscle soreness increased significantly (P< .05) at 24 and 48 h and returned to preexercise levels by 96 h.Conclusions:Daily ultrasound did not influence recovery after eccentric-exercise-induced muscle damage.

scholarly journals Phytoecdysteroids Accelerate Recovery of Skeletal Muscle Function Following in vivo Eccentric Contraction-Induced Injury in Adult and Old Mice

2021 ◽  
Vol 2 ◽  
Author(s):  
Kevin A. Zwetsloot ◽  
R. Andrew Shanely ◽  
Joshua S. Godwin ◽  
Charles F. Hodgman
Keyword(s):  
Skeletal Muscle ◽  
Muscle Damage ◽  
Muscle Function ◽  
Recovery Period ◽  
Eccentric Contraction ◽  
Eccentric Contractions ◽  
Post Injury ◽  
Skeletal Muscle Function ◽  
Old Mice

Background: Eccentric muscle contractions are commonly used in exercise regimens, as well as in rehabilitation as a treatment against muscle atrophy and weakness. If repeated multiple times, eccentric contractions may result in skeletal muscle injury and loss of function. Skeletal muscle possesses the remarkable ability to repair and regenerate after an injury or damage; however, this ability is impaired with aging. Phytoecdysteroids are natural plant steroids that possess medicinal, pharmacological, and biological properties, with no adverse side effects in mammals. Previous research has demonstrated that administration of phytoecdysteroids, such as 20-hydroxyecdysone (20E), leads to an increase in protein synthesis signaling and skeletal muscle strength.Methods: To investigate whether 20E enhances skeletal muscle recovery from eccentric contraction-induced damage, adult (7–8 mo) and old (26–27 mo) mice were subjected to injurious eccentric contractions (EC), followed by 20E or placebo (PLA) supplementation for 7 days. Contractile function via torque-frequency relationships (TF) was measured three times in each mouse: pre- and post-EC, as well as after the 7-day recovery period. Mice were anesthetized with isoflurane and then electrically-stimulated isometric contractions were performed to obtain in vivo muscle function of the anterior crural muscle group before injury (pre), followed by 150 EC, and then again post-injury (post). Following recovery from anesthesia, mice received either 20E (50 mg•kg−1 BW) or PLA by oral gavage. Mice were gavaged daily for 6 days and on day 7, the TF relationship was reassessed (7-day).Results: EC resulted in significant reductions of muscle function post-injury, regardless of age or treatment condition (p &lt; 0.001). 20E supplementation completely recovered muscle function after 7 days in both adult and old mice (pre vs. 7-day; p &gt; 0.05), while PLA muscle function remained reduced (pre vs. 7-day; p &lt; 0.01). In addition, histological markers of muscle damage appear lower in damaged muscle from 20E-treated mice after the 7-day recovery period, compared to PLA.Conclusions: Taken together, these findings demonstrate that 20E fully recovers skeletal muscle function in both adult and old mice just 7 days after eccentric contraction-induced damage. However, the underlying mechanics by which 20E contributes to the accelerated recovery from muscle damage warrant further investigation.

scholarly journals A semiquantitative scoring tool to evaluate eccentric exercise-induced muscle damage in trained rats

2015 ◽  
Vol 59 (4) ◽  
Author(s):  
D. Rizo-Roca ◽  
J.G. Ríos-Kristjánsson ◽  
C. Núñez-Espinosa ◽  
A. Ascensão ◽  
J. Magalhães ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Damage ◽  
Muscle Fibre ◽  
Eccentric Exercise ◽  
Muscle Injury ◽  
Time Course ◽  
Intraclass Correlation ◽  
Post Injury ◽  
Exercise Induced ◽  
Scoring Tool

Unaccustomed eccentric exercise is a well-documented cause of exercise-induced muscle damage. However, in trained subjects muscle injury involves only light or moderate tissue damage. Since trained rats are widely used as a model for skeletal muscle injury, here we propose a semiquantitative scoring tool to evaluate muscle damage in trained rats. Twenty male Sprague-Dawley rats were trained fortwo weeks following a two-week preconditioning period, and randomly divided into two groups: control rats (CTL; n=5) and rats with eccentric exercise-induced muscle damage (INJ; n=15). Injured rats were sacrificed at three time points: 1, 3 and 7 days post injury (n=5 each). Transverse sections from the right soleus were cut (10 µm) and stained with haematoxylin-eosin. Samples were evaluated by two groups of observers (four researchers experienced in skeletal muscle histopathology and four inexperienced) using the proposed tool, which consisted of six items organised in three domains: abnormal fibre morphology, necrotic/(re)degenerating fibres (<em>muscle fibre domain</em>), endomysial and perimysial infiltration (<em>inflammatory state domain</em>) and endomysium and perimysium distension (<em>interstitial compartment domain)</em>. We observed the expected time course in the six evaluated items. Furthermore, agreement among observers was evaluated by measuring the Intraclass Correlation Coefficient (ICC). Within the experienced group, items from the <em>muscle fibre</em> and <em>interstitial compartment</em> domains showed <em>good</em> agreement and the two items from the <em>infiltration compartment domain</em> showed <em>excellent</em> agreement. in conclusion, the proposed tool allowed quick and correct evaluation of light to moderate muscle damage in trained rats with good agreement between observers.

Low-intensity elbow flexion eccentric contractions attenuate maximal eccentric exercise-induced muscle damage of the contralateral arm

2018 ◽  
Vol 21 (10) ◽  
pp. 1068-1072 ◽  
Author(s):  
Trevor C. Chen ◽  
Ming-Ju Lin ◽  
Jian-Han Lai ◽  
Hsin-Lian Chen ◽  
Hui-I Yu ◽  
...  
Keyword(s):  
Muscle Damage ◽  
Eccentric Exercise ◽  
Elbow Flexion ◽  
Eccentric Contractions ◽  
Low Intensity ◽  
Exercise Induced

Eccentric exercise-induced injury to rat skeletal muscle

1983 ◽  
Vol 54 (1) ◽  
pp. 80-93 ◽  
Author(s):  
R. B. Armstrong ◽  
R. W. Ogilvie ◽  
J. A. Schwane
Keyword(s):  
Skeletal Muscle ◽  
Eccentric Exercise ◽  
Mononuclear Cells ◽  
Late Phase ◽  
Eccentric Contractions ◽  
Muscle Pathology ◽  
Plasma Enzymes ◽  
Exercise Induced ◽  
Lower Magnitude ◽  
Glucose 6 Phosphate Dehydrogenase

These experiments were designed to study skeletal muscle pathology resulting from eccentric-biased exercise in rats. The effects on the muscles of running on a treadmill on a 0 degrees incline (similar amounts of concentric and eccentric contractions), down a 16 degrees incline (primarily eccentric contractions), and up a 16 degrees incline (primarily concentric contractions) at 16 m . min-1 for 90 min were assessed by following postexercise changes in 1) plasma creatine kinase and lactate dehydrogenase activities, 2) glucose-6-phosphate dehydrogenase (G-6-PDase) activity (bio- and histochemically) in the physiological extensor muscles, and 3) histological appearance of the muscles. The data indicate the following. 1) Whereas all exercise protocols resulted in elevations of plasma enzymes immediately after running, only eccentric exercise caused late phase elevations 1.5–2 days postexercise. 2) Significant increases in muscle G-6-PDase activity, which were always associated with accumulations of mononuclear cells, always occurred within some muscles of each extensor group 1–3 days following downhill and uphill running and did not occur following level running; the increases in activity were usually of lower magnitude in the muscles of uphill runners than in those of downhill runners; the deeply located, predominantly slow-twitch muscles were most affected by both down- and uphill running. 3) Muscle histology demonstrated localized disruption of normal banding patterns of some fibers immediately after exercise and accumulations of macrophages in the interstitium and in some (less than 5%) muscle fibers by 24 h postexercise in the deep slow muscles of the antigravity groups. Although the data generally indicated that eccentric exercise causes greater injury to the muscles, questions remain.

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