Expression of hybrid isomyosins in human skeletal muscle

1996 ◽  
Vol 271 (4) ◽  
pp. C1250-C1255 ◽  
Author(s):  
M. Wada ◽  
T. Okumoto ◽  
K. Toro ◽  
K. Masuda ◽  
T. Fukubayashi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Subunit Composition ◽  
Intact Muscle ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Myosin of human skeletal muscles was analyzed by means of several electrophoretic techniques. Myosin heavy chain (HC)-IIa-and HC-IIb-based isomyosins were identified by pyrophosphate-polyacrylamide gel electrophoresis (PP-PAGE). The electrophoretic mobilities of these fast-twitch muscle isomyosins differed in the order HC-IIa triplets < HC-IIb triplets. To determine the subunit composition of myosin molecules that function in intact muscle, two-dimensional electrophoresis in which the first and second dimensions were PP-PAGE and sodium dodecyl sulfate-PAGE, respectively, was also performed. Slow-twitch muscle isomyosin contained, in addition to slow-twitch light chain (LC) and HC-I isoforms, appreciable amounts of LC-2f, HC-IIa, and HC-IIb isoforms, and fast-twitch muscle isomyosin consisted of LC-2s and HC-I isoforms as well as fast-twitch LC and HC isoforms. Without consideration of HC- and slow-twitch alkali LC heterodimers, at least 31 possible isomyosins are derived from these findings on the subunit composition of isomyosins in human skeletal muscle.

Adaptation of rat skeletal muscle to creatine depletion: AMP deaminase and AMP deamination

1992 ◽  
Vol 73 (6) ◽  
pp. 2713-2716 ◽  
Author(s):  
J. M. Ren ◽  
J. O. Holloszy
Keyword(s):  
Skeletal Muscle ◽  
Contractile Activity ◽  
Activity Level ◽  
Amp Deaminase ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Similar Decrease

AMP deaminase catalyzes deamination of the AMP formed in contracting muscles to inosine 5′-monophosphate (IMP). Slow-twitch muscle has only approximately 30% as high a level of AMP deaminase activity as fast-twitch muscle in the rat, and rates of IMP formation during intense contractile activity are much lower in slow-twitch muscle. We found that feeding the creatine analogue beta-guanidinopropionic acid (beta-GPA) to rats, which results in creatine depletion, causes a large decrease in muscle AMP deaminase. This adaptation was used to evaluate the role of AMP deaminase activity level in accounting for differences in IMP production in slow-twitch and fast-twitch muscles. beta-GPA feeding for 3 wk lowered AMP deaminase activity in fast-twitch epitrochlearis muscle to a level similar to that found in the normal slow-twitch soleus muscle but had no effect on the magnitude of the increase in IMP in response to intense contractile activity. Despite a similar decrease in ATP in the normal soleus and the epitrochlearis from beta-GPA-fed rats, the increase in IMP was only approximately 30% as great in the soleus in response to intense contractile activity. These results demonstrate that the accumulation of less IMP in slow- compared with fast-twitch skeletal muscle during contractile activity is not due to the lower level of AMP deaminase in slow-twitch muscle.

Biochemical properties of overloaded fast-twitch skeletal muscle

1982 ◽  
Vol 52 (2) ◽  
pp. 467-472 ◽  
Author(s):  
K. M. Baldwin ◽  
V. Valdez ◽  
R. E. Herrick ◽  
A. M. MacIntosh ◽  
R. R. Roy
Keyword(s):  
Skeletal Muscle ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Biochemical Properties ◽  
Female Rats ◽  
Surgical Removal ◽  
Fiber Types ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Myofibril Atpase

Previous studies suggest that fast-twitch skeletal muscle overloaded by surgical removal of synergists contains a greater percent of slow-twitch fibers than normal muscle. Therefore we examined subcellular systems known to represent biochemical properties of slow-twitch skeletal muscle by measuring myosin ATPase, Ca2+ regulation of myofibril ATPase, Ca2+ uptake of sarcoplasmic reticulum (SR), and marker enzymes of glycogenolysis in normal soleus (NS) and in normal (NP) and surgically overloaded (OP) plantaris muscles of adult female rats. The OP muscles were 65% larger than NP muscles (P less than 0.001). Specific activity of myosin and myofibril ATPase was approximately 25% lower in OP compared with NP muscle (P less than 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myosin revealed the presence of more slow and less fast myosin light-chain components in OP muscles. Although SR of NP muscle took up more Ca2+ than OP muscle during the initial for both groups. Marker regulatory enzymes of glycogenolysis collectively were reduced by 40% in OP compared with NP muscle (P less than 0.001). Collectively the data are consistent with the concept that some muscle fiber types were converted from “fast” to “slow” in the OP muscle.

Calcium uptake in mitochondria from different skeletal muscle types

1985 ◽  
Vol 59 (1) ◽  
pp. 137-141 ◽  
Author(s):  
W. L. Sembrowich ◽  
J. J. Quintinskie ◽  
G. Li
Keyword(s):  
Skeletal Muscle ◽  
Muscle Relaxation ◽  
Muscular Contraction ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Uptake Process ◽  
Muscle Types ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Skeletal Muscle Types

The kinetics of calcium (Ca2+) uptake have been studied in mitochondria isolated from the different types of skeletal muscle. These studies demonstrate that the Ca2+ uptake properties of skeletal mitochondria are similar to those from liver and cardiac mitochondria. The Ca2+ carriers apparently have a high affinity for Ca2+ (Michaelis constants in the microM range). The relationship between Ca2+ uptake and initial Ca2+ concentration (10(-5) to 10(-7) M) is sigmoid in all mitochondria from the different skeletal muscle types suggesting that the uptake process is cooperative. Hill plots reveal coefficients of approximately 2 for mitochondria from fast-twitch muscle and 3.5 for slow-twitch muscle, adding further evidence to the concept that the uptake process is cooperative. An analysis of the potential role of mitochondria in the sequestration of Ca2+ during muscular contraction demonstrated that mitochondria from slow-twitch muscle of both rats and rabbits can potentially account for 100% of the relaxation rate at a low frequency of stimulation (5 Hz). In fast-twitch muscle, the mitochondria appear unable to play a significant role in muscle relaxation, particularly at stimulation frequencies that are considered in the normal physiological range. In summary, it appears that Ca2+ uptake by mitochondria from slow-twitch skeletal muscle has kinetic characteristics which make it important as a potential regulator of Ca2+ within the muscle cell under normal physiological conditions.

Differential regulation of glycogen synthase by insulin and glucose in vivo in skeletal muscles of the rat.

1997 ◽  
Vol 273 (3) ◽  
pp. E479 ◽  
Author(s):  
M C Sugden ◽  
M J Holness ◽  
L G Fryer
Keyword(s):  
Skeletal Muscle ◽  
Glycogen Synthase ◽  
Intravenous Glucose ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Glucose Tolerance Tests ◽  
Slow Twitch ◽  
Intravenous Glucose Tolerance Tests ◽  
Fast Twitch

Glucose 6-phosphate (G-6-P)-independent glycogen synthase (GSa) and glycogen synthase (GS) total activities were measured in muscles from 24-h-starved rats. Intravenous glucose tolerance tests (0.5 g/kg body wt) were used to produce physiological, transient increases in insulin and glucose concentrations. GS activation occurred at approximately 10 min after glucose administration with peak activation at approximately 15 min. GS activation was reversed approximately 15 min after insulin and glucose concentrations had returned to basal. No differences existed between fast- and slow-twitch muscles. Hyperinsulinemia (approximately 160 mU/ml) in the absence of hyperglycemia elicited 1.5-fold activation of GS (P < 0.001) in two of three fast-twitch muscles but did not activate GS in slow-twitch muscles. Glucose infusion (glycemia approximately 8 mM; insulin approximately 40 mU/ml) significantly (P < 0.01) increased the percentage of total GS in the GSa form in four of the five muscles. Hyperglycemia with modest hyperinsulinemia evoked greater enhancement of GSa activity in fast-twitch muscle than insulin alone at a higher concentration (P < 0.01). In summary, hyperinsulinemia without hyperglycemia does not result in maximal activation of GS in fast-twitch muscle, and a rise in glycemia is obligatory for GS activation by insulin in slow-twitch muscle. The data support an important role for glycemia in modulating the response of skeletal muscle GS to insulin and provide further evidence of heterogeneity among skeletal muscle types.

Purine nucleoside formation in rat skeletal muscle fiber types

1993 ◽  
Vol 264 (5) ◽  
pp. C1246-C1251 ◽  
Author(s):  
P. G. Arabadjis ◽  
P. C. Tullson ◽  
R. L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Skeletal Muscle Fiber ◽  
Purine Nucleoside ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

To determine the capacity for purine nucleotide degradation among skeletal muscle fiber types, we established energy-depleted conditions in muscles of the rat hindlimb by inducing muscle contraction during ischemia. After 5, 10, 15, or 20 min of ischemic contractions, representative muscle sections were freeze-clamped and analyzed for purine nucleotides, nucleosides, and bases. Fast-twitch muscle sections accumulated about fourfold more IMP than the slow-twitch red soleus muscle. Inosine begins to accumulate at < 0.5 mumol/g IMP in slow-twitch muscle and at approximately 2 mumol/g IMP in fast-twitch muscle. This suggests that inosine is formed intracellularly by 5'-nucleotidase acting on IMP and that the activity and/or substrate affinity of the 5'-nucleotidase present in slow-twitch muscle may be higher than in fast-twitch muscle. At similar concentrations of precursor IMP, slow-twitch muscle has a greater capacity for purine nucleoside formation and should be more dependent on salvage and de novo synthesis of purine for the maintenance of muscle adenine nucleotides. Fast-twitch muscles are better able to retain IMP for subsequent reamination due to their lower capacity to degrade IMP to inosine.

GLUT-3 expression in human skeletal muscle

2000 ◽  
Vol 279 (4) ◽  
pp. E855-E861 ◽  
Author(s):  
Charles A. Stuart ◽  
Gary Wen ◽  
Bi-Hung Peng ◽  
Vsevolod L. Popov ◽  
S. David Hudnall ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Electron Microscopic ◽  
Microscopic Evaluation ◽  
Slow Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Muscle biopsy homogenates contain GLUT-3 mRNA and protein. Before these studies, it was unclear where GLUT-3 was located in muscle tissue. In situ hybridization using a midmolecule probe demonstrated GLUT-3 within all muscle fibers. Fluorescent-tagged antibody reacting with affinity-purified antibody directed at the carboxy-terminus demonstrated GLUT-3 protein in all fibers. Slow-twitch muscle fibers, identified by NADH-tetrazolium reductase staining, possessed more GLUT-3 protein than fast-twitch fibers. Electron microscopy using affinity-purified primary antibody and gold particle-tagged second antibody showed that the majority of GLUT-3 was in association with triads and transverse tubules inside the fiber. Strong GLUT-3 signals were seen in association with the few nerves that traversed muscle sections. Electron microscopic evaluation of human peripheral nerve demonstrated GLUT-3 within the axon, with many of the particles related to mitochondria. GLUT-3 protein was found in myelin but not in Schwann cells. GLUT-1 protein was not present in nerve cells, axons, myelin, or Schwann cells but was seen at the surface of the peripheral nerve in the perineurium. These studies demonstrated that GLUT-3 mRNA and protein are expressed throughout normal human skeletal muscle, but the protein is predominantly found in the triads of slow-twitch muscle 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.

ATP depletion in slow-twitch red muscle of rat

1987 ◽  
Vol 253 (3) ◽  
pp. C426-C432 ◽  
Author(s):  
D. M. Whitlock ◽  
R. L. Terjung
Keyword(s):  
Adenine Nucleotide ◽  
Atp Depletion ◽  
Cellular Events ◽  
Contraction Condition ◽  
Red Muscle ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Rat slow-twitch muscle, in contrast to fast-twitch muscle, maintains its ATP content near normal during intense stimulation conditions that produce rapid fatigue. An extensive depletion of adenine nucleotide content by the deamination of AMP to IMP + NH3, typical of fast-twitch muscle, does not occur. We evaluated whether this response of slow-twitch muscle could be simply due to failure of synaptic transmission or related to cellular conditions influencing enzyme activity. Stimulation of soleus muscles in situ via the nerve or directly in the presence of curare at 120 tetani/min for 3 min resulted in extensive fatigue but normal ATP contents. Thus the lack of ATP depletion must be related to cellular events distal to neuromuscular transmission. Even nerve and direct muscle stimulation (with curare) during ischemia did not cause a large depletion of ATP or a large elevation of lactate content (12.0 +/- 0.7 mumol/g), even though the decline in tension was essentially complete. However, if the same tension decline during ischemia was prolonged by stimulating for 10 min at 12 tetani/min a large decrease in ATP (2.24 +/- 0.09 mumol/g) and increase in IMP (2.47 +/- 0.16 mumol/g) and lactate (30.4 +/- 2.0 mumol/g) content occurred. Thus adenine nucleotide deamination to IMP can occur in slow-twitch muscle during specific contraction conditions. The cellular events leading to the activation of AMP deaminase require an intense contraction condition and may be related to acidosis caused by a high lactate content.

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.

scholarly journals Dual Effects of Beta-Hydroxy-Beta-Methylbutyrate (HMB) on Amino Acid, Energy, and Protein Metabolism in the Liver and Muscles of Rats with Streptozotocin-Induced Type 1 Diabetes

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1475
Author(s):  
Milan Holeček ◽  
Melita Vodeničarovová ◽  
Radana Fingrová
Keyword(s):  
Protein Content ◽  
Positive Effects ◽  
Severe Diabetes ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Methyl Butyrate ◽  
Slow Twitch ◽  
Branched Chain ◽  
Fast Twitch

Beta-hydroxy-beta-methyl butyrate (HMB) is a unique product of leucine catabolism with positive effects on protein balance. We have examined the effects of HMB (200 mg/kg/day via osmotic pump for 7 days) on rats with diabetes induced by streptozotocin (STZ, 100 mg/kg intraperitoneally). STZ induced severe diabetes associated with muscle wasting, decreased ATP in the liver, and increased α-ketoglutarate in muscles. In plasma, liver, and muscles increased branched-chain amino acids (BCAAs; valine, isoleucine, and leucine) and decreased serine. The decreases in mass and protein content of muscles and increases in BCAA concentration were more pronounced in extensor digitorum longus (fast-twitch muscle) than in soleus muscle (slow-twitch muscle). HMB infusion to STZ-treated animals increased glycemia and serine in the liver, decreased BCAAs in plasma and muscles, and decreased ATP in the liver and muscles. The effects of HMB on the weight and protein content of tissues were nonsignificant. We concluded that fast-twitch muscles are more sensitive to STZ than slow-twitch muscles and that HMB administration to STZ-treated rats has dual effects. Adjustments of BCAA concentrations in plasma and muscles and serine in the liver can be considered beneficial, whereas the increased glycemia and decreased ATP concentrations in the liver and muscles are detrimental.

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