Simultaneous Assessment of Isometric Forces in Fast- and Slow-Twitch Muscles of Single Rat Hindlimbs in Situ

1996 ◽  
Vol 21 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Andrew J. Carvalho ◽  
Nancy H. McKee
Keyword(s):  
Extensor Digitorum Longus ◽  
Mechanical Performance ◽  
Contractile Function ◽  
Small Strain ◽  
Extensor Digitorum ◽  
Published Data ◽  
Slow Twitch ◽  
Isometric Twitch ◽  
Simultaneous Assessment

An apparatus, consisting of a pair of small strain gauge transducers, was designed for the simultaneous assessment of isometric contractile function in two muscles, composed of a predominance of either fast- or slow-twitch fibers, and within a single rat hindlimb in situ. This facilitates assessment of mechanical performance of two separate muscles under identical conditions. In anesthetized rats (N = 10), the voltages and frequencies required to produce isometric twitch and tetanic forces from the soleus (SOL) and extensor digitorum longus (EDL) muscles were determined. The apparatus was then used to demonstrate the simultaneous assessment of forces produced by the SOL and EDL from the same hindlimbs (n = 5) during 30 min of fatigue and 30 min of recovery. With this apparatus, data collected were comparable to published data. The apparatus can be used for the simultaneous assessment of isometric contractile function and fatigue in both a fast- and a slow-twitch muscle of a single rat hindlimb in situ. Key words: model, fatigue, ischemia, soleus, extensor digitorum longus

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.

Recovery in skeletal muscle contractile function after prolonged hindlimb immobilization

1985 ◽  
Vol 59 (3) ◽  
pp. 916-923 ◽  
Author(s):  
R. H. Fitts ◽  
C. J. Brimmer
Keyword(s):  
Contractile Function ◽  
Vastus Lateralis ◽  
Weight Ratio ◽  
Contractile Properties ◽  
Shortening Velocity ◽  
Slow Twitch ◽  
Isometric Twitch ◽  
Fast Twitch ◽  
Muscle Contractile

Contractile properties of slow-twitch soleus (SOL), fast-twitch extensor digitorum longus (EDL), and fast-twitch superficial region of the vastus lateralis were determined in vitro (22 degrees C) in rats remobilized after prolonged (3 mo) hindlimb immobilization (IM). For all muscles the muscle-to-body weight ratio was significantly depressed by IM, and the ratios failed to completely recover even after 90 days. The contractile properties of the fast-twitch muscles were less affected by IM than the slow-twitch SOL. The IM shortened the SOL isometric twitch duration due to a reduced contraction and half-relaxation time. These parameters returned to control levels by the 14th day of recovery. Peak tetanic tension (Po, g/cm2) declined with IM by 46% in the SOL but showed no significant change in the fast-twitch muscles. After IM the SOL Po (g/cm2) recovered to control values by 28 days. The recovery of Po in absolute units (g) was considerably slower and did not return to control levels until 60 (SOL) to 90 (EDL) days. The maximum shortening velocity was not altered by IM in any of the muscles studied. These results demonstrate that both fast- and slow-twitch skeletal muscles possess the ability to completely recover normal contractile function following prolonged periods of hindlimb IM.

Insulin binding and 2-deoxy-D-glucose uptake in fast- and slow-twitch mouse skeletal muscle at 18 and 37 °C

1984 ◽  
Vol 62 (12) ◽  
pp. 1460-1465 ◽  
Author(s):  
Wendy M. Watson-Wright ◽  
Meng H. Tan ◽  
Arend Bonen
Keyword(s):  
Extensor Digitorum Longus ◽  
Insulin Binding ◽  
Extensor Digitorum ◽  
Insulin Degradation ◽  
Response Curves ◽  
Slow Twitch Muscle ◽  
Two Temperatures ◽  
Higher Temperature ◽  
Slow Twitch ◽  
Insulin Responsiveness

Insulin binding, insulin degradation, and 2-deoxyglucose uptake were examined at 18 and 37 °C in soleus and extensor digitorum longus muscles of mice. Insulin binding and degradation were greater in the soleus than in the extensor digitorum longus at both temperatures (p < 0.05). At 37 °C, binding was decreased in both muscles while percentage degradation was increased in comparison with 18 °C (p < 0.05). Dose–response curves (percentage of binding at 4 nM of insulin) remained the same for both muscles at the two temperatures. Basal (no insulin) 2-deoxyglucose uptake was increased at 37 °C in the extensor digitorum longus but not the soleus. Insulin responsiveness in terms of the amount of 2-deoxyglucose taken up per femtomole of insulin bound was almost identical for the two muscles at 18 °C, whereas at 37 °C it was increased more in the soleus than in the extensor digitorum longus. The results indicate that in the presence of physiological concentrations of insulin (0.2–4 nM), insulin binding trends are minimally affected by increased temperature. In contrast, the ability of insulin to stimulate 2-deoxyglucose uptake varies between the two temperatures, and at the higher temperature between fast- and slow-twitch muscle.

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.

Muscle inflammatory cells after passive stretches, isometric contractions, and lengthening contractions

2002 ◽  
Vol 92 (5) ◽  
pp. 1873-1878 ◽  
Author(s):  
Francis X. Pizza ◽  
Timothy J. Koh ◽  
Stephen J. McGregor ◽  
Susan V. Brooks
Keyword(s):  
Cross Sections ◽  
Muscle Injury ◽  
Extensor Digitorum Longus ◽  
Inflammatory Cells ◽  
Extensor Digitorum ◽  
Protective Mechanism ◽  
Isometric Contractions ◽  
Lengthening Contractions

We tested the hypotheses that lengthening contractions, isometric contractions, and passive stretches increase muscle inflammatory cells (neutrophils and macrophages) and that prior conditioning with lengthening contractions, isometric contractions, or passive stretches reduces neutrophils and macrophages after subsequent lengthening contractions. Extensor digitorum longus muscles in anesthetized mice were subjected in situ to lengthening contractions, isometric contractions, or passive stretches. Six hours or 3 days after a protocol of contractions or passive stretches, neutrophils and macrophages were quantified in muscle cross sections. Three days after isometric contractions or passive stretches, neutrophils were elevated ( P < 0.05) 3.7- and 5.5-fold, respectively, relative to controls. Both macrophages and neutrophils were increased 51.2- and 7.9-fold, respectively, after lengthening contractions. Prior lengthening contractions, isometric contractions, or passive stretches reduced inflammatory cells after lengthening contractions performed 2 wk later. The major finding of this study was that passive stretches and isometric contractions elevated neutrophils without causing overt signs of injury. Because both passive stretches and isometric contractions elevated neutrophils and afforded some protection from contraction-induced muscle injury, neutrophils and/or the related inflammatory events may contribute to the induction of a protective mechanism.

scholarly journals Computational assessment of transport distances in living skeletal muscle fibers studied in situ

2020 ◽  
Author(s):  
Kenth-Arne Hansson ◽  
Andreas Våvang Solbrå ◽  
Kristian Gundersen ◽  
Jo Christiansen Bruusgaard
Keyword(s):  
Skeletal Muscle ◽  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Transportation Network ◽  
Muscle Fibers ◽  
Extensor Digitorum ◽  
Nuclear Density ◽  
Skeletal Muscle Fibers ◽  
Longus Muscle

AbstractTransport distances in skeletal muscle fibers are mitigated by these cells having multiple nuclei. We have studied mouse living slow (soleus) and fast (extensor digitorum longus) muscle fibers in situ and determined cellular dimensions and the positions of all the nuclei within fiber segments. We modelled the effect of placing nuclei optimally and randomly using the nuclei as the origin of a transportation network. It appeared that an equidistant positioning of nuclei minimizes transport distances along the surface for both muscles. In the soleus muscle however, which were richer in nuclei, positioning of nuclei to reduce transport distances to the cytoplasm were of less importance, and these fibers exhibit a pattern not statistically different from a random positioning of nuclei. Together, these results highlight the importance of spatially distribute nuclei to minimize transport distances to the surface when nuclear density is low, while it appears that the distribution are of less importance at higher nuclear densities.

Plasticity of the Muscles in the Protein Sensitization. Involvement of Cholinergic asnd Purinergic Mechanisms

10.12737/3300 ◽  
2014 ◽  
Vol 21 (1) ◽  
pp. 6-12
Author(s):  
Теплов ◽  
O. Teplov ◽  
Миннебаев ◽  
M. Minnebaev ◽  
Фархутдинов ◽  
...  
Keyword(s):  
Adenosine Triphosphate ◽  
Extensor Digitorum Longus ◽  
Striated Muscle ◽  
Contractile Function ◽  
Experimental Models ◽  
Extensor Digitorum ◽  
Chronic Obstructive ◽  
Respiratory Muscle Fatigue ◽  
Development Of Resistance ◽  
Protein Sensitization

The authors investigated the involvement of the adenosine triphosphate (ATF) in the mechanisms of plasticity in the striated muscle in condition of protein sensitization. Contractile function and non-quantum secretion of the acetylcholine in the endplate zone were studied in isolated skeletal muscles of mouse legs (musculus soleus and musculus extensor digitorum longus) and strips musculus diaphragm. The authors studied the soleus and diaphragm dynamics of the force vector of muscle contraction after effects of exogenous adenosine triphosphate correlated with changes non-quantum secretion of acetylcholine in all the experimental models. However, the extent of these changes in sensitized animals is less pronounced than in the controls. It is suggested that adenosine is a party change mechanisms and functional properties soleus and diaphragm at the protein sensitization. The basis of the development of resistance, stability to long as the external stress, and at the initial stages of the experimental allergic these muscles are dependent adenosine mechanisms regulating their sensitivity to acetylcholine. These processes provide a reduction in respiratory muscle fatigue in hypoxia that occurs in asthma, chronic obstructive pulmonary disease and broncho-spastic syndrome, as well in increase their performance during prolonged physical activity. The reasons for changes in the force reduction extensor digitorum longus at a protein sensitization doesn’t associated with the mechanisms of muscle excitation mediated by adenosine triphosphate.

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