Decay of Ca2+ and force transients in fast- and slow-twitch skeletal muscles from the rat, mouse and Etruscan shrew.

1998 ◽  
Vol 201 (3) ◽  
pp. 375-384 ◽  
Author(s):  
P Wetzel ◽  
G Gros
Keyword(s):  
Skeletal Muscles ◽  
Muscle Relaxation ◽  
Muscle Fibres ◽  
Fura 2 ◽  
Single Twitch ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
The Right ◽  
Fast Twitch

Isometric single-twitch force and intracellular Ca2+ transients were recorded simultaneously, using fura-2, from slow- and fast-twitch muscle fibres of the rat, mouse and Etruscan shrew Suncus etruscus. In the slow-twitch rat soleus, force half-relaxation time was three times longer than the 50 % decay time of the fura-2 signal. In contrast, in the fast-twitch extensor digitorum longus muscles of all three animals, muscle relaxation preceded Ca2+ decay. It is proposed that this surprising property of fast-twitch muscles is due to their pCa­tension curve, which is shifted to the right compared with that of slow-twitch 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.

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.

IP3-induced tension and IP3-receptor expression in rat soleus muscle during postnatal development

2002 ◽  
Vol 282 (4) ◽  
pp. R1164-R1173 ◽  
Author(s):  
Sophie Talon ◽  
Olivier Vallot ◽  
Corinne Huchet-Cadiou ◽  
Anne-Marie Lompré ◽  
Claude Léoty
Keyword(s):  
Postnatal Development ◽  
Receptor Expression ◽  
Ip3 Receptor ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Rat Soleus Muscle ◽  
Slow Twitch ◽  
Sequence Encoding ◽  
Fast Twitch

The present study was designed to examine whether changes in Ca2+ release by inositol-1,4,5-trisphosphate (IP3) in 8-, 15-, and 30-day-old rat skeletal muscles could be associated with the expression of IP3 receptors. Experiments were conducted in slow-twitch muscle in which both IP3-induced Ca2+ release and IP3-receptor (IP3R) expression have been shown to be larger than in fast-twitch muscle. In saponin-skinned fibers, IP3 induced transient contractile responses in which the amplitude was dependent on the Ca2+-loading period with the maximal IP3 contracture being at 20 min of loading. The IP3 tension decreased during postnatal development, was partially inhibited by ryanodine (100 μM), and was blocked by heparin (20–400 μg/ml). Amplification of the DNA sequence encoding for IP3R isoforms (using the RT-PCR technique) showed that in slow-twitch muscle, the type 2 isoform is mainly expressed, and its level decreases during postnatal development in parallel with changes in IP3 responses in immature fibers. IP3-induced Ca2+ release would then have greater participation in excitation-contraction coupling in developing fibers than in mature muscle.

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.

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