scholarly journals Erratum: Polge, C., et al. UBE2E1 Is Preferentially Expressed in the Cytoplasm of Slow-Twitch Fibers and Protects Skeletal Muscles from Exacerbated Atrophy upon Dexamethasone Treatment. Cells 2018, 7, 214

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 242 ◽  
Author(s):  
Cécile Polge ◽  
Julien Aniort ◽  
Andrea Armani ◽  
Agnès Claustre ◽  
Cécile Coudy-Gandilhon ◽  
...  
Keyword(s):  
Skeletal Muscles ◽  
Dexamethasone Treatment ◽  
Slow Twitch ◽  
Slow Twitch Fibers

Change in author names (order). [...]

Imaging caffeine-induced Ca2+transients in individual fast-twitch and slow-twitch rat skeletal muscle fibers

1998 ◽  
Vol 274 (3) ◽  
pp. C623-C632 ◽  
Author(s):  
Murali K. D. Pagala ◽  
Stuart R. Taylor
Keyword(s):  
Skeletal Muscles ◽  
Prolonged Exposure ◽  
Muscle Fibers ◽  
Lower Sensitivity ◽  
Rat Skeletal Muscle ◽  
Acetoxymethyl Ester ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Higher Doses

Fast-twitch and slow-twitch rat skeletal muscles produce dissimilar contractures with caffeine. We used digital imaging microscopy to monitor Ca2+ (with fluo 3-acetoxymethyl ester) and sarcomere motion in intact, unrestrained rat muscle fibers to study this difference. Changes in Ca2+ in individual fibers were markedly different from average responses of a population. All fibers showed discrete, nonpropagated, local Ca2+ transients occurring randomly in spots about one sarcomere apart. Caffeine increased local Ca2+ transients and sarcomere motion initially at 4 mM in soleus and 8 mM in extensor digitorum longus (EDL; ∼23°C). Ca2+release subsequently adapted or inactivated; this was surmounted by higher doses. Motion also adapted but was not surmounted. Prolonged exposure to caffeine evidently suppressed myofilament interaction in both types of fiber. In EDL fibers, 16 mM caffeine moderately increased local Ca2+ transients. In soleus fibers, 16 mM caffeine greatly increased Ca2+ release and produced propagated waves of Ca2+(∼1.5–2.5 μm/s). Ca2+waves in slow-twitch fibers reflect the caffeine-sensitive mechanism of Ca2+-induced Ca2+ release. Fast-twitch fibers possibly lack this mechanism, which could account for their lower sensitivity to caffeine.

Increased lipoprotein lipase activity of skeletal muscle in cold-acclimated rats

1977 ◽  
Vol 55 (12) ◽  
pp. 1241-1243 ◽  
Author(s):  
N. Bégin-Heick ◽  
H. M. C. Heick
Keyword(s):  
Skeletal Muscle ◽  
Cold Acclimation ◽  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Skeletal Muscles ◽  
Lipoprotein Lipase Activity ◽  
Slow Twitch ◽  
Respiratory Movements ◽  
Parallel Fashion

The activity of lipoprotein lipase (LPL) in the heart, diaphragm, and soleus muscles was markedly increased in cold-acclimated rats and it was even greater in rats treated with oxytetracycline (OTC) while exposed to cold. Other skeletal muscles studied had low and variable activities which were not significantly increased by cold acclimation or by cold plus OTC treatment. It appears therefore that, apart from the heart and the muscles involved in respiratory movements, LPL activity is primarily associated with those muscles which contain a predominance of slow-twitch oxidative fibers, and that the enzyme in muscle, heart, and diaphragm responds to cold acclimation and cold plus OTC treatment in a parallel fashion in these tissues.

Glutamine synthetase induction by glucocorticoids is preserved in skeletal muscle of aged rats

1996 ◽  
Vol 271 (6) ◽  
pp. E1061-E1066 ◽  
Author(s):  
D. Meynial-Denis ◽  
M. Mignon ◽  
A. Miri ◽  
J. Imbert ◽  
E. Aurousseau ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glutamine Synthetase ◽  
Skeletal Muscles ◽  
Female Rats ◽  
Mrna Levels ◽  
Aged Rats ◽  
Adult Rats ◽  
Adult Age ◽  
Slow Twitch ◽  
Fast Twitch

Glutamine synthetase (GS) is a glucocorticoid-inducible enzyme that has a key role for glutamine synthesis in muscle. We hypothesized that the glucocorticoid induction of GS could be altered in aged rats, because alterations in the responsiveness of some genes to glucocorticoids were reported in aging. We compared the glucocorticoid-induced GS in fast-twitch and slow-twitch skeletal muscles (tibialis anterior and soleus, respectively) and heart from adult (age 6-8 mo) and aged (age 22 mo) female rats. All animals received dexamethasone (Dex) in their drinking water (0.77 +/- 0.10 and 0.80 +/- 0.08 mg/day per adult and aged rat, respectively) for 5 days. Dex caused an increase in both GS activity and GS mRNA in fast-twitch and slow-twitch skeletal muscles from adult and aged rats. In contrast, Dex increased GS activity in heart of adult rats, without any concomitant change in GS mRNA levels. Furthermore, Dex did not affect GS activity in aged heart. Thus the responsiveness of GS to an excess of glucocorticoids is preserved in skeletal muscle but not in heart from aged animals.

Na current density at and away from end plates on rat fast- and slow-twitch skeletal muscle fibers

1992 ◽  
Vol 262 (1) ◽  
pp. C229-C234 ◽  
Author(s):  
R. L. Ruff
Keyword(s):  
Skeletal Muscle ◽  
Current Density ◽  
Muscle Fibers ◽  
Postsynaptic Membrane ◽  
Na Current ◽  
End Plate ◽  
Skeletal Muscle Fibers ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Na current density and membrane capacitance were studied with the loose patch voltage clamp technique on rat fast- and slow-twitch skeletal muscle fibers at three different regions on the fibers: 1) the end plate border, 2) greater than 200 microns from the end plate (extrajunctional), and 3) on the end plate postsynaptic membrane. Fibers were treated with collagenase to improve visualization of the end plate and to enzymatically remove the nerve terminal. The capacitance of membrane patches was similar on fast- and slow-twitch fibers and patches of membrane on the end plate had twice the capacitance of patches elsewhere. For fast- and slow-twitch fibers, the sizes of the Na current normalized to the area of the patch were as follows: end plate greater than end plate border greater than extrajunctional. For both types of fibers, the amplitudes of the Na current normalized to the capacitance of the membrane patch were as follows: end plate approximately end plate border greater than extrajunctional. At each of the three regions, the Na current densities were larger on fast-twitch fibers and fast-twitch fibers had a larger increase in Na current density at the end plate border compared with extrajunctional membrane.

scholarly journals lncRNA-Six1 Is a Target of miR-1611 that Functions as a ceRNA to Regulate Six1 Protein Expression and Fiber Type Switching in Chicken Myogenesis

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 243 ◽  
Author(s):  
Manting Ma ◽  
Bolin Cai ◽  
Liang Jiang ◽  
Bahareldin Ali Abdalla ◽  
Zhenhui Li ◽  
...  
Keyword(s):  
Fiber Type ◽  
Muscle Fibers ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Proliferation And Differentiation ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Emerging studies indicate important roles for non-coding RNAs (ncRNAs) as essential regulators in myogenesis, but relatively less is known about their function. In our previous study, we found that lncRNA-Six1 can regulate Six1 in cis to participate in myogenesis. Here, we studied a microRNA (miRNA) that is specifically expressed in chickens (miR-1611). Interestingly, miR-1611 was found to contain potential binding sites for both lncRNA-Six1 and Six1, and it can interact with lncRNA-Six1 to regulate Six1 expression. Overexpression of miR-1611 represses the proliferation and differentiation of myoblasts. Moreover, miR-1611 is highly expressed in slow-twitch fibers, and it drives the transformation of fast-twitch muscle fibers to slow-twitch muscle fibers. Together, these data demonstrate that miR-1611 can mediate the regulation of Six1 by lncRNA-Six1, thereby affecting proliferation and differentiation of myoblasts and transformation of muscle fiber types.

scholarly journals Calsequestrin Distribution, Structure and Function, Its Role in Normal and Pathological Situations and the Effect of Thyroid Hormones

2011 ◽  
pp. 439-452 ◽  
Author(s):  
P. NOVÁK ◽  
T. SOUKUP
Keyword(s):  
Thyroid Hormones ◽  
Calcium Binding ◽  
Skeletal Muscles ◽  
Scientific Community ◽  
Cardiac Tissue ◽  
Structure And Function ◽  
Multiple Roles ◽  
Important Regulator ◽  
Slow Twitch ◽  
And Function

Calsequestrin is the main calcium binding protein of the sarcoplasmic reticulum, serving as an important regulator of Ca2+. In mammalian muscles, it exists as a skeletal isoform found in fast- and slow-twitch skeletal muscles and a cardiac isoform expressed in the heart and slow-twitch muscles. Recently, many excellent reviews that summarised in great detail various aspects of the calsequestrin structure, localisation or function both in skeletal and cardiac muscle have appeared. The present review focuses on skeletal muscle: information on cardiac tissue is given, where differences between both tissues are functionally important. The article reviews the known multiple roles of calsequestrin including pathology in order to introduce this topic to the broader scientific community and to stimulate an interest in this protein. Newly we describe our results on the effect of thyroid hormones on skeletal and cardiac calsequestrin expression and discuss them in the context of available literary data on this topic.

scholarly journals Activity of mu- and m-calpain in regenerating fast and slow twitch skeletal muscles.

1996 ◽  
Vol 43 (4) ◽  
pp. 693-700 ◽  
Author(s):  
J Moraczewski ◽  
E Piekarska ◽  
M Zimowska ◽  
M Sobolewska
Keyword(s):  
Intracellular Calcium ◽  
Soleus Muscle ◽  
Muscle Regeneration ◽  
Skeletal Muscles ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Slow Twitch ◽  
Edl Muscle ◽  
Calpain Ii ◽  
Complete Regeneration

Calpains--non-lysosomal intracellular calcium-activated neutral proteinases, form a family consisting of several distinct members. Two of the isoenzymes: mu (calpain I) and m (calpain II) responded differently to the injury during complete regeneration of Extensor digitorum longus (EDL) muscle and partial regeneration of Soleus muscle. In the crushed EDL the level of m-calpain on the 3rd and 7th day of regeneration was higher than in non-operated muscles, whereas the activity of this calpain in injured Soleus decreased. The level of mu-calpain in EDL oscillated irregularly during regeneration whereas in Soleus of both injured and contralateral muscles its level rapidly rose. Our results support the hypothesis that m-calpain is involved in the process of fusion of myogenic cells whereas mu-calpain plays a significant but indirect role in muscle regeneration.

Electrolytes in slow and fast muscle fibers of humans at rest and with dynamic exercise

1983 ◽  
Vol 245 (1) ◽  
pp. R25-R31 ◽  
Author(s):  
G. Sjogaard
Keyword(s):  
Skeletal Muscles ◽  
Vastus Lateralis ◽  
Fiber Types ◽  
Triceps Brachii ◽  
Sodium Potassium ◽  
Mean Values ◽  
Fiber Composition ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Muscle Fiber Membrane

Sodium, potassium, and magnesium were analyzed in human slow-twitch (ST) and fast-twitch (FT) skeletal muscles. In contrast to other species, no relation was found between fiber composition and electrolyte distribution. In soleus (S), vastus lateralis (VL), and triceps brachii (TB) the overall mean values for 6 men and 6 women were 44 mmol K/100 g dry wt and 11 mmol Na/100 g dry wt; the intracellular concentrations were 161 mmol K/l and 26 mmol Na/l with no differences between the muscles. Analysis of fragments of single ST and FT fibers from each of the muscles also showed no difference between the fiber types in Na and K content. Small differences were seen between the muscles with regard to Mg, but these were not related to fiber composition compared with other species. During exercise to exhaustion (3 bouts of bicycling for 3 min at 325-395 W, 6 men) the extracellular electrolyte concentrations for Na, K, and Mg increased from 134 to 140, 4.5 to 5.8, and 0.75 to 0.87 mmol/l, respectively (P less than 0.05). In VL Na content increased from 9.8 to 16.5 mmol/100 g dry wt, while intracellular [Na] remained constant. In contrast, intracellular [K] decreased from 161 to 141 mmol/l (P less than 0.05). No such changes occurred in TB. In concert with other studies the present changes in electrolytes in the working muscles indicate that muscle fatigue may be related to changes at the muscle fiber membrane.

scholarly journals Comparative analysis of the transcriptomes of EDL, psoas, and soleus muscles from mice

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Pabodha Hettige ◽  
Uzma Tahir ◽  
Kiisa C. Nishikawa ◽  
Matthew J. Gage
Keyword(s):  
Skeletal Muscles ◽  
Striated Muscle ◽  
Fiber Type ◽  
Expression Patterns ◽  
Fiber Types ◽  
Muscle Adaptation ◽  
Myosin Heavy Chain Isoform ◽  
Genes Encoding ◽  
Slow Twitch ◽  
Fast Twitch

Abstract Background Individual skeletal muscles have evolved to perform specific tasks based on their molecular composition. In general, muscle fibers are characterized as either fast-twitch or slow-twitch based on their myosin heavy chain isoform profiles. This approach made sense in the early days of muscle studies when SDS-PAGE was the primary tool for mapping fiber type. However, Next Generation Sequencing tools permit analysis of the entire muscle transcriptome in a single sample, which allows for more precise characterization of differences among fiber types, including distinguishing between different isoforms of specific proteins. We demonstrate the power of this approach by comparing the differential gene expression patterns of extensor digitorum longus (EDL), psoas, and soleus from mice using high throughput RNA sequencing. Results EDL and psoas are typically classified as fast-twitch muscles based on their myosin expression pattern, while soleus is considered a slow-twitch muscle. The majority of the transcriptomic variability aligns with the fast-twitch and slow-twitch characterization. However, psoas and EDL exhibit unique expression patterns associated with the genes coding for extracellular matrix, myofibril, transcription, translation, striated muscle adaptation, mitochondrion distribution, and metabolism. Furthermore, significant expression differences between psoas and EDL were observed in genes coding for myosin light chain, troponin, tropomyosin isoforms, and several genes encoding the constituents of the Z-disk. Conclusions The observations highlight the intricate molecular nature of skeletal muscles and demonstrate the importance of utilizing transcriptomic information as a tool for skeletal muscle characterization.

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