Influence of fiber type and muscle source on Ca2+ sensitivity of rat fibers

1989 ◽  
Vol 256 (2) ◽  
pp. C420-C427 ◽  
Author(s):  
B. Laszewski-Williams ◽  
R. L. Ruff ◽  
A. M. Gordon
Keyword(s):  
Calcium Concentration ◽  
Fiber Type ◽  
Calcium Sensitivity ◽  
One Dimensional ◽  
Protein Gel ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Adductor Longus

This study investigated the influence of muscle source and fiber type on the calcium sensitivity of skinned rat skeletal muscle fibers from predominantly slow muscles [soleus (SOL) and adductor longus (AL)], mixed muscle [posterior gracilis (PG)], and predominantly fast-twitch muscle [extensor digitorum longus (EDL)]. Fibers were characterized histochemically and by one-dimensional protein gel electrophoresis, and calcium-tension relationships were determined. Fiber type and muscle source had significant effects on the negative log of the calcium concentration associated with half-maximal tension (pCa1/2). Slow-twitch fibers had larger values of pCa1/2 than did fast-twitch fibers. Slow-twitch fibers from the predominantly slow muscles, SOL and AL, had similar values of pCa1/2 but slightly smaller values than from the mixed muscle, PG. Fast-glycolytic (FG) fibers from the predominantly fast muscle, EDL, had a higher pCa1/2 than fibers from the mixed fiber type muscle, PG. There were no differences between the pCa1/2 associated with FG and fast-oxidative-glycolytic fibers.

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.

Molecular cloning and quantification of sarcoplasmic reticulum Ca(2+)-ATPase isoforms in rat muscles

1993 ◽  
Vol 264 (2) ◽  
pp. C333-C341 ◽  
Author(s):  
K. D. Wu ◽  
J. Lytton
Keyword(s):  
Fiber Type ◽  
Smooth Muscles ◽  
Full Length ◽  
Adult Rat ◽  
Mrna Ratio ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Quantitative Immunoblotting ◽  
Fast Twitch

A cDNA encoding the full-length adult rat fast-twitch muscle Ca(2+)-adenosinetriphosphatase (ATPase) was cloned. The deduced amino acid sequence of this molecule has 97 and 90% identity with those of rabbit fast-twitch muscle and chicken skeletal muscle Ca(2+)-ATPases, respectively. Specific probes from the 3'-untranslated region of each sarcoplasmic or endoplasmic reticulum Ca(2+)-ATPase (SERCA) gene product and full-length cRNA transcript standards were used to determine the quantity of mRNA encoding each isoform in various rat muscles. Quantitative immunoblotting was also used to determine the protein content of each SERCA isoform. Fast-twitch fibers expressed both SERCA1 mRNA and protein at a level two- to fivefold higher than SERCA2 was expressed in slow-twitch fibers. We observed a protein-to-mRNA ratio that varied from approximately 500,000 molecules per molecule in the fast-twitch muscles to approximately 200,000 in cardiac and smooth muscles. There was no difference, however, between the ratio for different isoforms in the same muscle. The content of Ca2+ pump in a given muscle therefore depends on at least three factors: 1) the efficiency of gene transcription and message stability (fiber type dependent), 2) the efficiency of translation and protein stability (muscle identity dependent), and 3) fiber composition of the muscle.

Calcium sensitivity of skinned ferret EDL, soleus, and cremaster fibers

1993 ◽  
Vol 264 (5) ◽  
pp. R867-R870
Author(s):  
C. Huchet ◽  
C. Leoty
Keyword(s):  
Calcium Sensitivity ◽  
Breeding Period ◽  
Cremaster Muscle ◽  
Contractile System ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Data Points ◽  
Slow Twitch ◽  
Triton X ◽  
Fast Twitch

The properties of the contractile system at different times of the year in the ferret extensor digitorum longus (EDL), soleus and cremaster muscles were examined by using chemically skinned (Triton X-100) preparations. The results show clear differences in calcium sensitivity between these skeletal muscles. The apparent calcium threshold for activation was lower in soleus than in EDL, while calcium concentrations ([Ca2+]) required to obtain the half-maximal tension, expressed as pCa50 (-log[Ca2+]), was lower in EDL than in soleus muscle. In fact, pCa50 obtained in fast and slow fibers by fitting the experimental data points by a modified Hill equation was 5.92 +/- 0.02 (n = 9) and 6.09 +/- 0.03 (n = 11) respectively. So EDL appears to be a typical fast-twitch muscle and soleus a typical slow-twitch muscle. Adult ferret cremaster muscle was composed of two types of fibers during the quiescent period similar to EDL and soleus, and only one type that was intermediate between EDL and soleus in the breeding period, as assessed by pCa50 values. These annual modifications in calcium activation of adult ferret cremaster muscle could be related to changes in the function of these muscles and may be correlated with seasonal variations of sexual activity.

Cloning and characterization of fiber type-specific ryanodine receptor isoforms in skeletal muscles of fish

1998 ◽  
Vol 275 (2) ◽  
pp. C401-C415 ◽  
Author(s):  
Jens P. C. Franck ◽  
Jeffery Morrissette ◽  
John E. Keen ◽  
Richard L. Londraville ◽  
Mark Beamsley ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Ryanodine Receptor ◽  
Extraocular Muscle ◽  
Fiber Type ◽  
Sequence Identity ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Rna Probe ◽  
Fast Twitch

We have cloned a group of cDNAs that encodes the skeletal ryanodine receptor isoform (RyR1) of fish from a blue marlin extraocular muscle library. The cDNAs encode a protein of 5,081 amino acids with a calculated molecular mass of 576,302 Da. The deduced amino acid sequence shows strong sequence identity to previously characterized RyR1 isoforms. An RNA probe derived from a clone of the full-length marlin RyR1 isoform hybridizes to RNA preparations from extraocular muscle and slow-twitch skeletal muscle but not to RNA preparations from fast-twitch skeletal or cardiac muscle. We have also isolated a partial RyR clone from marlin and toadfish fast-twitch muscles that shares 80% sequence identity with the corresponding region of the full-length RyR1 isoform, and a RNA probe derived from this clone hybridizes to RNA preparations from fast-twitch muscle but not to slow-twitch muscle preparations. Western blot analysis of slow-twitch muscles in fish indicates the presence of only a single high-molecular-mass RyR protein corresponding to RyR1. [3H]ryanodine binding assays revealed the fish slow-twitch muscle RyR1 had a greater sensitivity for Ca2+ than the fast-twitch muscle RyR1. The results indicate that, in fish muscle, fiber type-specific RyR1 isoforms are expressed and the two proteins are physiologically distinct.

scholarly journals Unaffected contractility of diaphragm muscle fibers in humans on mechanical ventilation

2014 ◽  
Vol 307 (6) ◽  
pp. L460-L470 ◽  
Author(s):  
Pleuni E. Hooijman ◽  
Marinus A. Paul ◽  
Ger J. M. Stienen ◽  
Albertus Beishuizen ◽  
Hieronymus W. H. Van Hees ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Muscle Fibers ◽  
Calcium Sensitivity ◽  
Diaphragm Muscle ◽  
Cross Sectional ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Kinetics Of ◽  
Contractile Performance

Several studies have indicated that diaphragm dysfunction develops in patients on mechanical ventilation (MV). Here, we tested the hypothesis that the contractility of sarcomeres, i.e., the smallest contractile unit in muscle, is affected in humans on MV. To this end, we compared diaphragm muscle fibers of nine brain-dead organ donors (cases) that had been on MV for 26 ± 5 h with diaphragm muscle fibers from nine patients (controls) undergoing surgery for lung cancer that had been on MV for less than 2 h. In each diaphragm specimen we determined 1) muscle fiber cross-sectional area in cryosections by immunohistochemical methods and 2) the contractile performance of permeabilized single muscle fibers by means of maximum specific force, kinetics of cross-bridge cycling by rate of tension redevelopment, myosin heavy chain content and concentration, and calcium sensitivity of force of slow-twitch and fast-twitch muscle fibers. In case subjects, we noted no statistically significant decrease in outcomes compared with controls in slow-twitch or fast-twitch muscle fibers. These observations indicate that 26 h of MV of humans is not invariably associated with changes in the contractile performance of sarcomeres in the diaphragm.

Changes in muscle proteins and spermidine content in response to unloading and clenbuterol treatment

2003 ◽  
Vol 81 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Daniel A. von Deutsch ◽  
Imad K Abukhalaf ◽  
Lawrence E Wineski ◽  
Natalia A Silvestrov ◽  
Mohamed A Bayorh ◽  
...  
Keyword(s):  
Nonlinear Regression ◽  
Fiber Type ◽  
Male Rats ◽  
Skeletal Muscle Atrophy ◽  
Control Treatment ◽  
Protein Levels ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Anabolic agents such clenbuterol (Cb) are useful tools for probing the mechanisms by which muscles respond to disuse. Cb was examined under different loading conditions with respect to its effects on muscle mass, protein (myofibrillar and cytosolic), and spermidine content in mature male rats. Compared with control treatment, Cb significantly increased loaded and unloaded soleus, plantaris, and extensor digitorum longus (EDL) mass. Likewise, Cb significantly increased loaded and unloaded soleus (24.8 and 21.6%, respectively), plantaris (12.1 and 22.9%, respectively), and EDL (22.4 and 13.3%, respectively) myofibrillar protein content. After unloading, cytosolic proteins significantly increased in the EDL but decreased in the soleus and plantaris. Cb significantly increased cytosolic protein levels in all loaded muscles, while only causing increases in unloaded soleus. When compared with controls, unloading caused significant reductions in spermidine levels in the soleus (40.4%) and plantaris (35.9%) but caused increases in the EDL (54.8%). In contrast, Cb increased spermidine levels in unloaded soleus (42.9%), plantaris (102.8%), and EDL (287%). In loaded muscles, Cb increased spermidine levels in all three muscles, but to a lesser degree than under unloading conditions. Nonlinear regression analyses indicated that the plantaris behaves like a slow-twitch muscle under unloading conditions and like a fast-twitch muscle when loaded. This suggests that the responses of these muscles to unloading and (or) Cb treatment might be influenced by factors beyond fiber type alone.Key words: microgravity, skeletal muscle atrophy, nonlinear regression, clenbuterol, polyamines.

scholarly journals Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

2012 ◽  
Vol 139 (4) ◽  
pp. 261-272 ◽  
Author(s):  
Stephen M. Baylor ◽  
Stephen Hollingworth
Keyword(s):  
Action Potentials ◽  
Muscle Fibers ◽  
Mouse Muscle ◽  
Contraction Coupling ◽  
Individual Mouse ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Indicator Dye

In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller.

Slow to fast alterations in skeletal muscle fibers caused by clenbuterol, a beta 2-receptor agonist

1988 ◽  
Vol 254 (6) ◽  
pp. E726-E732 ◽  
Author(s):  
R. J. Zeman ◽  
R. Ludemann ◽  
T. G. Easton ◽  
J. D. Etlinger
Keyword(s):  
Muscle Fiber ◽  
Receptor Agonist ◽  
Fiber Type ◽  
Fiber Types ◽  
Cross Sectional ◽  
Type Composition ◽  
Slow Twitch ◽  
Beta 2 ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Chronic treatment of rats with clenbuterol, a beta 2-receptor agonist (8–12 wk), caused hypertrophy of histochemically identified fast- but not slow-twitch fibers within the soleus, while the mean areas of both fiber types were increased in the extensor digitorum longus (EDL). In contrast, treatment with the beta 2-receptor antagonist, butoxamine, reduced fast-twitch fiber size in both muscles. In the solei and to a lesser extent in the EDLs, the ratio of the number of fast- to slow-twitch fibers was increased by clenbuterol, while the opposite was observed with butoxamine. The muscle fiber hypertrophy observed in the EDL was accompanied by parallel increases in maximal tetanic tension and muscle cross-sectional area, while in the solei, progressive increases in rates of force development and relaxation toward values typical of fast-twitch muscles were also observed. Our results suggest a role of beta 2-receptors in regulating muscle fiber type composition as well as growth.

Voluntary Running Exercise Ameliorates Muscle Loss in Mice

2007 ◽  
Author(s):  
Andrea M. Hanson ◽  
Louis S. Stodieck ◽  
Virginia L. Ferguson
Keyword(s):  
Soleus Muscle ◽  
Fiber Type ◽  
Bed Rest ◽  
Muscle Loss ◽  
Running Exercise ◽  
Voluntary Running ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Both spaceflight and bed rest studies are known to cause substantial muscle loss in humans. Of particular interest in atrophy studies is the postural, slow-twitch fiber soleus muscle. It has been demonstrated that during periods of disuse, slow-twitch fibers undergo fiber type switching and morph into fast-twitch fibers [1]. Alternatively, when exercise is prescribed, there is switching of fast-to slow-twitch fibers [2], indicating a profound adaptability of the muscle to exercise.

Contractile function of single muscle fibers after hindlimb suspension

1989 ◽  
Vol 66 (6) ◽  
pp. 2739-2749 ◽  
Author(s):  
P. R. Gardetto ◽  
J. M. Schluter ◽  
R. H. Fitts
Keyword(s):  
Contractile Function ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Hindlimb Suspension ◽  
Type I ◽  
Single Muscle ◽  
Peak Tension ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

The purpose of this investigation was to determine how muscle atrophy produced by the hindlimb suspension (HS) model alters the contractile function of slow- and fast-twitch single muscle fibers. After 2 wk of HS, small bundles of fibers were isolated from the soleus and the deep and superficial regions of the lateral and medial heads of the gastrocnemius, respectively. The bundles were placed in skinning solution and stored at -20 degrees C until studied. Single fibers were isolated and suspended between a motor arm and force transducer, the functional properties were studied, and subsequently the fiber type was established by myosin heavy chain (MHC) analysis on 1-D sodium dodecyl sulfate polyacrylamide gel electrophoresis. After HS, slow-twitch fibers of the soleus showed a significant reduction in fiber diameter (68 +/- 2 vs. 41 +/- 1 micron) and peak tension (1.37 +/- 0.01 vs. 0.99 +/- 0.06 kg/cm2), whereas the maximal shortening speed (Vmax) increased [1.49 +/- 0.11 vs. 1.92 +/- 0.14 fiber lengths (FL)/s]. A histogram showed two populations of fibers: one with Vmax values identical to control slow-twitch fibers and a second with significantly elevated Vmax values. This latter group frequently contained both slow and fast MHC protein isoforms. The pCa-force relation of the soleus slow-twitch fibers was shifted to the right; consequently, the free Ca2+ required for the onset of tension and for 50% of peak tension was significantly higher after HS. Slow-twitch fibers isolated from the gastrocnemius after HS showed a significant reduction in diameter (67 +/- 4 vs. 44 +/- 3 microns) and peak tension (1.2 +/- 0.06 vs. 0.96 +/- 0.07 kg/cm2), but Vmax was unaltered (1.70 +/- 0.13 vs. 1.65 +/- 0.18 FL/s). Fast-twitch fibers from the red gastrocnemius showed a significant reduction in diameter (59 +/- 2 vs. 49 +/- 3 microns) but no change in peak tension or Vmax. Fast-twitch fibers from the white superficial region of the medial head of the gastrocnemius were unaffected by HS. Collectively, these data suggest that the effects of HS on fiber function depend on the fiber type and location. Both slow-twitch type I and fast-twitch type IIa fibers atrophied; however, only slow-twitch fibers showed a decline in peak tension, and the increase in Vmax was restricted to a subpopulation of slow-twitch soleus fibers.

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