scholarly journals Effects of microgravity exposure and fructo-oligosaccharide ingestion on the proteome of soleus and extensor digitorum longus muscles in developing mice

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Takashi Ohira ◽  
Yoko Ino ◽  
Yayoi Kimura ◽  
Yusuke Nakai ◽  
Ayuko Kimura ◽  
...  
Keyword(s):  
Extensor Digitorum Longus ◽  
Space Station ◽  
Short Chain Fatty Acids ◽  
Extensor Digitorum ◽  
Metabolic Capacity ◽  
Bacterial Fermentation ◽  
Fast Twitch ◽  
And Oxidative Stress ◽  
Glutathione Redox ◽  
Developing Mice

AbstractShort-chain fatty acids produced by the gut bacterial fermentation of non-digestible carbohydrates, e.g., fructo-oligosaccharide (FOS), contribute to the maintenance of skeletal muscle mass and oxidative metabolic capacity. We evaluated the effect of FOS ingestion on protein expression of soleus (Sol) and extensor digitorum longus muscles in mice exposed to microgravity (μ-g). Twelve 9-week-old male C57BL/6J mice were raised individually on the International Space Station under μ-g or artificial 1-g and fed a diet with or without FOS (n = 3/group). Regardless of FOS ingestion, the absolute wet weights of both muscles tended to decrease, and the fiber phenotype in Sol muscles shifted toward fast-twitch type following μ-g exposure. However, FOS ingestion tended to mitigate the μ-g-exposure-related decrease in oxidative metabolism and enhance glutathione redox detoxification in Sol muscles. These results indicate that FOS ingestion mildly suppresses metabolic changes and oxidative stress in antigravity Sol muscles during spaceflight.

Myosin light chain phosphorylation-dephosphorylation in mammalian skeletal muscle

1982 ◽  
Vol 242 (3) ◽  
pp. C234-C241 ◽  
Author(s):  
D. R. Manning ◽  
J. T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Extensor Digitorum Longus ◽  
Myosin Light Chain ◽  
Extensor Digitorum Longus Muscle ◽  
Extensor Digitorum ◽  
Mammalian Skeletal Muscle ◽  
Phosphate Content ◽  
Longus Muscle ◽  
Fast Twitch

Phosphorylation of the myosin light chain 2 (LC2) subunit was examined in rat fast-twitch and slow-twitch skeletal muscles in response to repetitive stimulation at 23 and 35 degrees C and on incubation of fast-twitch skeletal muscle with isoproterenol. After a 1-s tetany at 35 degrees C, LC2 phosphate content in extensor digitorum longus muscle increased rapidly and transiently from 0.21 to 0.51 mol phosphate/mol LC2. This pattern of phosphorylation was similar to that observed at 23 degrees C. Increases in LC2 phosphate content were dependent on the frequency and duration of stimulation. In soleus muscle LC2 phosphate content was minimal following a 1-s tetany but increased markedly following more prolonged tetanies. On incubation of extensor digitorum longus muscle with isoproterenol (20 microM), LC2 phosphate content did not change, whereas phosphorylase a levels increased. A positive correlation existed between LC2 phosphate content and potentiation of peak twitch tension in both types of muscles, suggesting a physiological function for LC2 phosphorylation.

Effect of cross-reinnervation on the expression of GLUT-4 and GLUT-1 in slow and fast rat muscles

1996 ◽  
Vol 270 (6) ◽  
pp. R1355-R1360
Author(s):  
E. Johannsson ◽  
O. Waerhaug ◽  
A. Bonen
Keyword(s):  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Metabolic Phenotype ◽  
Glut 1 ◽  
Glut 4 ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Oxidative Phenotype ◽  
Slow Twitch ◽  
Fast Twitch

We determined whether the twitch-velocity phenotype or the metabolic phenotype of a muscle influences the content of GLUT-4 and GLUT-1 proteins. The soleus (Sol) and extensor digitorum longus (EDL) muscles were cross-reinnervated (X-Sol, X-EDL). After 3 mo the X-EDL had become enriched in slow-twitch oxidative (SO) fibers (70.5% SO) compared with its control (3.8% SO), whereas the X-Sol became enriched in fast-twitch oxidative-glycolytic (FOG) fibers (78.6% FOG) compared with its control (10% FOG). Thus the twitch phenotype of X-Sol shifted to fast-twitch muscle, whereas X-EDL shifted to a slow-twitch muscle. In the X-EDL, the oxidative nature of the X-EDL was increased to 97% oxidative fibers compared with 43% oxidative fibers in the normal EDL. In the Sol the oxidative nature of the X-Sol was retained at 100%. GLUT-4 content was increased 1.6-fold in the X-EDL (P < 0.05) but was not changed in the X-Sol (P > 0.05). GLUT-1 content was increased fourfold in X-EDL but was not altered in the X-Sol. We conclude that GLUT-4 and GLUT-1 content in muscle is related to the oxidative phenotype of the muscle rather than the twitch-velocity phenotype.

scholarly journals Effect of acetoacetate on glucose metabolism in the soleus and extensor digitorum longus muscles of the rat

1977 ◽  
Vol 162 (3) ◽  
pp. 557-568 ◽  
Author(s):  
E Z Maizels ◽  
N B Ruderman ◽  
M N Goodman ◽  
D Lau
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Glucose Oxidation ◽  
Extensor Digitorum Longus ◽  
Similar Rate ◽  
Extensor Digitorum ◽  
Lactate Release ◽  
Red Muscle ◽  
Slow Twitch ◽  
Fast Twitch

1. The effect of acetoacetate on glucose metabolism was compared in the soleus, a slow-twitch red muscle, and the extensor digitorum longus, a muscle composed of 50% fast-twitch red and 50% white fibres. 2. When incubated for 2h in a medium containing 5 mM-glucose and 0.1 unit of insulin/ml, rates of glucose uptake, lactate release and glucose oxidation in the soleus were 19.6, 18.6 and 1.47 micronmol/h per g respectively. Acetoacetate (1.7 mM) diminished all three rates by 25-50%; however, it increased glucose conversion into glycogen. In addition, it caused increases in tissue glucose, glucose 6-phosphate and fructose 6-phosphate, suggesting inhibition of phosphofructokinase. The concentrations of citrate, an inhibitor of phosphofructokinase, and of malate were also increased. 3. Rates of glucose uptake and lactate release in the extensor digitorum longus were 50-80% of those in the soleus. Acetoacetate caused moderate increases in tissue glucose 6-phosphate and possibly citrate, but it did not decrease glucose uptake or lactate release. 4. The rate of glycolysis in the soleus was approximately five times that previously observed in the perfused rat hindquarter, a muscle preparation in which acetoacetate inhibits glucose oxidation, but does not alter glucose uptake or glycolysis. A similar rate of glycolysis was observed when the soleus was incubated with a glucose-free medium. Under these conditions, tissue malate and the lactate/pyruvate ratio in the medium were decreased, and acetoacetate did not decrease lactate release or increase tissue citrate or glucose 6-phosphate. An intermediate rate of glycolysis, which was not decreased by acetoacetate, was observed when the soleus was incubated with glucose, but not insulin. 5. The data suggest that acetoacetate glucose inhibits uptake and glycolysis in red muscle under conditions that resemble mild to moderate exercise. They also suggest that the accumulation of citrate in these circumstances is linked to the rate of glycolysis, possibly through the generation of cytosolic NADH and malate formation.

Endothelial cell products alter mammalian skeletal muscle function in vitro

1995 ◽  
Vol 73 (6) ◽  
pp. 736-741 ◽  
Author(s):  
C. L. Murrant ◽  
J. K. Barclay
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Mammalian Skeletal Muscle ◽  
Skeletal Muscle Function ◽  
Endothelin 1 ◽  
Control Value ◽  
Endothelin 3 ◽  
Fast Twitch

We tested the hypothesis that endothelin and nitric oxide (NO) alter the force developed by fast-twitch and slow-twitch mammalian skeletal muscle, using a mouse skeletal muscle preparation trimmed to approximately 50% of the original diameter to decrease diffusion distances. We suspended trimmed soleus (SOL) and extensor digitorum longus (EDL) muscles in Krebs–Henseleit buffer (27 °C; pH 7.4) gassed with 95% O2 – 5% CO2. Muscles were stimulated once every 90 s for 500 ms at 50 Hz for SOL and 100 Hz for EDL. The force developed by trimmed SOL was 223.8 ± 9.1 mN/mm2 and by EDL was 247.3 ± 9.4 mN/mm2. Endothelin 1 (ET-1) had no effect on EDL but significantly accelerated the rate of decrease of developed force of SOL at concentrations of 10−10 mol/L and higher within 10 contractions. When ET-1 was removed, force returned toward control value. Endothelin 3 (ET-3) had no effect on either muscle. S-Nitroso-N-acetylpenicillamine (SNAP), a source of NO, increased developed force over time in both muscles, with a threshold of 10−6 mol/L. The effect was evident within 5 contractions in both muscles. Force remained elevated above control values after the removal of SNAP. Thus ET-1 attenuated and NO amplified mammalian skeletal muscle function.Key words: soleus, extensor digitorum longus, tetanic contractions, endothelin 1, endothelin 3, S-nitroso-N-acetylpenicillamine.

scholarly journals S1P3 receptor influences key physiological properties of fast-twitch extensor digitorum longus muscle

2016 ◽  
Vol 120 (11) ◽  
pp. 1288-1300 ◽  
Author(s):  
Elena Germinario ◽  
Michela Bondì ◽  
Francesca Cencetti ◽  
Chiara Donati ◽  
Marta Nocella ◽  
...  
Keyword(s):  
Extensor Digitorum Longus ◽  
The Body ◽  
Extensor Digitorum ◽  
Disuse Atrophy ◽  
Wild Type ◽  
Muscle Properties ◽  
Fatigue Development ◽  
Physiological Properties ◽  
Edl Muscle ◽  
Fast Twitch

To examine the role of sphingosine 1-phosphate (S1P) receptor 3 (S1P3) in modulating muscle properties, we utilized transgenic mice depleted of the receptor. Morphological analyses of extensor digitorum longus (EDL) muscle did not show evident differences between wild-type and S1P3-null mice. The body weight of 3-mo-old S1P3-null mice and the mean cross-sectional area of transgenic EDL muscle fibers were similar to those of wild-type. S1P3 deficiency enhanced the expression level of S1P1 and S1P2 receptors mRNA in S1P3-null EDL muscle. The contractile properties of S1P3-null EDL diverge from those of wild-type, largely more fatigable and less able to recover. The absence of S1P3 appears responsible for a lower availability of calcium during fatigue. S1P supplementation, expected to stimulate residual S1P receptors and signaling, reduced fatigue development of S1P3-null muscle. Moreover, in the absence of S1P3, denervated EDL atrophies less than wild-type. The analysis of atrophy-related proteins in S1P3-null EDL evidences high levels of the endogenous regulator of mitochondria biogenesis peroxisome proliferative-activated receptor-γ coactivator 1α (PGC-1α); preserving mitochondria could protect the muscle from disuse atrophy. In conclusion, the absence of S1P3 makes the muscle more sensitive to fatigue and slows down atrophy development after denervation, indicating that S1P3 is involved in the modulation of key physiological properties of the fast-twitch EDL muscle.

scholarly journals When phosphorylated at Thr148, the β2-subunit of AMP-activated kinase does not associate with glycogen in skeletal muscle

2016 ◽  
Vol 311 (1) ◽  
pp. C35-C42 ◽  
Author(s):  
Hongyang Xu ◽  
Noni T. Frankenberg ◽  
Graham D. Lamb ◽  
Paul R. Gooley ◽  
David I. Stapleton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Carbohydrate Binding ◽  
Binding Function ◽  
Physiological Relevance ◽  
Amp Activated Protein Kinase ◽  
Fast Twitch ◽  
Stimulation Of

The 5′-AMP-activated protein kinase (AMPK), a heterotrimeric complex that functions as an intracellular fuel sensor that affects metabolism, is activated in skeletal muscle in response to exercise and utilization of stored energy. The diffusibility properties of α- and β-AMPK were examined in isolated skeletal muscle fiber segments dissected from rat fast-twitch extensor digitorum longus and oxidative soleus muscles from which the surface membranes were removed by mechanical dissection. After the muscle segments were washed for 1 and 10 min, ∼60% and 75%, respectively, of the total AMPK pools were found in the diffusible fraction. After in vitro stimulation of the muscle, which resulted in an ∼80% decline in maximal force, 20% of the diffusible pool became bound in the fiber. This bound pool was not associated with glycogen, as determined by addition of a wash step containing amylase. Stimulation of extensor digitorum longus muscles resulted in 28% glycogen utilization and a 40% increase in phosphorylation of the downstream AMPK target acetyl carboxylase-CoA. This, however, had no effect on the proportion of total β2-AMPK that was phosphorylated in whole muscle homogenates measured by immunoprecipitation. These findings suggest that, in rat skeletal muscle, β2-AMPK is not associated with glycogen and that activation of AMPK by muscle contraction does not dephosphorylate β2-AMPK. These findings question the physiological relevance of the carbohydrate-binding function of β2-AMPK in skeletal muscle.

scholarly journals Contractile benefits of doublet-initiated low-frequency stimulation in rat extensor digitorum longus muscle exposed to high extracellular [K+] or fatiguing contractions

2019 ◽  
Vol 317 (1) ◽  
pp. C39-C47 ◽  
Author(s):  
Katja Krustrup Pedersen ◽  
Ole Bækgaard Nielsen ◽  
Kristian Overgaard
Keyword(s):  
High Frequency ◽  
Extensor Digitorum Longus ◽  
Muscle Activation ◽  
Extensor Digitorum ◽  
Maximal Velocity ◽  
Constant Frequency ◽  
Dynamic Contraction ◽  
Dynamic Contractions ◽  
Fast Twitch

During dynamic contractions, high-frequency muscle activation is needed to achieve optimal power. This must be balanced against an increased excitation-induced accumulation of extracellular K+, which can reduce excitability and ultimately may prevent adequate responses to high-frequency activation. Mean activation frequencies in vivo are often low (subtetanic), but activation patterns contain bursts of high (supratetanic) frequencies known as doublets, which enhance dynamic contraction in rested muscles at normal extracellular K+ concentration ([K+]o). Here, we examine how dynamic contractions in fast-twitch fibers stimulated by high frequency/doublets are affected during exposure to 11 mM [K+]o and during fatigue. Dynamic contractions were elicited by electrical stimulation in isolated rat extensor digitorum longus muscles incubated at 4 or 11 mM K+. When stimulation frequency was maintained constant, an increase from 150 to 300 Hz enhanced maximal power (Pmax), maximal velocity ( Vmax), and rate of force development (RFD) at 4 mM K+ but only Vmax at 11 mM K+. With the use of subtetanic frequency trains (50 Hz) with or without an initiating doublet (300 Hz), the addition of a doublet increased maximal force, Pmax, Vmax, and RFD at both 4 and 11 mM K+. Furthermore, a work-matched fatiguing protocol was performed comparing a doublet-initiated subtetanic train (DT) of 60 Hz with a constant-frequency train (CFT) of 71 Hz during 100 dynamic contractions. We found that DT produced higher power, velocity, and RFD than CFT throughout the fatiguing protocol. The results indicate that doublets enhance dynamic contraction in fast-twitch muscles stimulated at subtetanic frequency during both normal and fatiguing conditions.

scholarly journals Exercise training reduces skeletal muscle membrane arachidonate in the obese (fa/fa) Zucker rat

1998 ◽  
Vol 85 (5) ◽  
pp. 1898-1902 ◽  
Author(s):  
Kerry J. Ayre ◽  
Stephen D. Phinney ◽  
Anna B. Tang ◽  
Judith S. Stern
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Zucker Rats ◽  
Muscle Membrane ◽  
Positive Effects ◽  
Fast Twitch ◽  
White Gastrocnemius

Compared with the lean ( Fa/−) genotype, obese ( fa/fa) Zucker rats have a relative deficiency of muscle phospholipid arachidonate, and skeletal muscle arachidonate in humans is positively correlated with insulin sensitivity. To assess the hypothesis that the positive effects of exercise training on insulin sensitivity are mediated by increased muscle arachidonate, we randomized 20 lean and 20 obese weanling male Zucker rats to sedentary or treadmill exercise groups. After 9 wk, fasting serum, three skeletal muscles (white gastrocnemius, soleus, and extensor digitorum longus), and heart were obtained. Fasting insulin was halved by exercise training in the obese rat. In white gastrocnemius and extensor digitorum longus (fast-twitch muscles), but not in soleus (a slow-twitch muscle) or heart, phospholipid arachidonate was lower in obese than in lean rats ( P < 0.001). In all muscles, exercise in the obese rats reduced arachidonate ( P < 0.03, by ANOVA contrast). We conclude that improved insulin sensitivity with exercise in the obese genotype is not mediated by increased muscle arachidonate and that reduced muscle arachidonate in obese Zucker rats is unique to fast-twitch muscles.

Contractile properties of single-skinned skeletal muscle fibres of the extensor digitorum longus muscle of the Australian short-nosed echidna

2005 ◽  
Vol 53 (4) ◽  
pp. 237
Author(s):  
Anthony J. Bakker ◽  
Ann L. Parkinson ◽  
Stewart I. Head
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Contractile Properties ◽  
Extensor Digitorum ◽  
Muscle Fibres ◽  
Force Response ◽  
Response Data ◽  
The Mean ◽  
Fast Twitch ◽  
Skeletal Muscle Fibres

Eutherian mammal fast-twitch muscle fibres share similar contractile activation properties, suggesting that these properties are highly conserved in mammals. To investigate this hypothesis, we examined the contractile properties of skeletal muscle from the order Monotremata, a mammalian order that separated from eutherians 150 million years ago. The Ca2+- and Sr2+-activation properties of single mechanically skinned skeletal muscle fibres from the extensor digitorum longus (EDL) muscle of the short-nosed echidna were determined. Sigmoidal curves fitted to force response data plotted as a function of pCa (–log[Ca2+]), had a mean slope of 4.32 ± 0.28 and a mean pCa50 and pCa10 value of 6.18 ± 0.01 and 6.41 ± 0.02 respectively (n = 20). The mean pSr50, pSr10 and slope values of curves fitted to the force-response data after activation with Sr2+ were 4.80 ± 0.03, 5.29 ± 0.07 and 2.75 ± 0.18 respectively (n = 20). The mean pCa50–pSr50 value for the echidna EDL fibres was 1.37 ± 0.04. In five of the echidna fibres, exposure to submaximal Ca2+ concentrations produced myofibrillar force oscillations (mean frequency, 0.13 ± 0.01 Hz), a phenomenon found only in eutherian slow and intermediate muscle fibres. These results show that echidna EDL fibres generally have similar contractile properties to eutherian fast-twitch skeletal muscle fibres, such as those found in the EDL of the rat.

scholarly journals Carbonic anhydrase activity in skeletal muscle fiber types, axons, spindles, and capillaries of rat soleus and extensor digitorum longus muscles.

1982 ◽  
Vol 30 (12) ◽  
pp. 1275-1288 ◽  
Author(s):  
D A Riley ◽  
S Ellis ◽  
J Bain
Keyword(s):  
Carbonic Anhydrase ◽  
Extensor Digitorum Longus ◽  
Muscle Fibers ◽  
Extensor Digitorum ◽  
Female Rats ◽  
Male Rats ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Slow Twitch ◽  
Fast Twitch

Carbonic anhydrase (CA) activities were studied in soluble extracts and cryostat sections of skeletal muscles from prepubertal and postpubertal rats. Acetazolamide inhibition was utilized to distinguish between activities of the acetazolamide-sensitive (CA I and II) and acetazolamide-resistant (CA III) forms of the enzyme. The inhibition studies indicated that fast-twitch oxidative-glycolytic muscle fibers contained both the sensitive and resistant forms of CA. Acetazolamide-sensitive activity was localized within muscle fibers, axons, myelin, and capillaries. Axoplasmic staining was restricted to subpopulations of myelinated axons in both the dorsal and ventral roots. Soleus muscles exhibited significantly greater activity of CA III than extensor digitorum longus muscles at all ages examined. CA III was richest in slow-twitch oxidative and intrafusal fibers. During puberty, soleus muscle fibers matured and converted from fast-twitch oxidative-glycolytic to slow-twitch oxidative fibers. There was a shift from the sensitive to the resistant form of CA; CA III activity increased about sevenfold. This activity peaked earlier in the muscles of female rats than male rats. These results demonstrated a complex distribution of CA isozymes in the neuromuscular system and pointed out that isozyme content depends on both the type of muscle and the age and sex of the animal.

Sign in / Sign up

Export Citation Format

Share Document