scholarly journals A 31P-n.m.r. study of the acute effects of β-blockade on the bioenergetics of skeletal muscle during contraction

1987 ◽  
Vol 246 (1) ◽  
pp. 163-172 ◽  
Author(s):  
R A Challiss ◽  
D J Hayes ◽  
G K Radda
Keyword(s):  
Skeletal Muscle ◽  
Gastrocnemius Muscle ◽  
High Energy ◽  
Muscle Stimulation ◽  
Stimulation Protocol ◽  
Unilateral Stimulation ◽  
Short Period ◽  
Supramaximal Stimulation ◽  
Contractile Performance ◽  
Stimulation Of

1. The effects of beta-adrenoceptor antagonist administration on skeletal muscle contractile performance and bioenergetics in vivo have been investigated during unilateral sciatic nerve stimulation in the rat. 2. Two muscle stimulation protocols have been used: supramaximal stimulation at 4 Hz, or incremental supramaximal stimulation at 1, 2 and 4 Hz. Changes in high-energy phosphate concentrations were followed using 31P-n.m.r., and gastrocnemius muscle twitch characteristics were monitored continuously. 3. Under all conditions investigated, DL-propranolol administration (2.5 mg/kg body wt.) caused a significant decrease in cyclic AMP concentrations in resting and stimulated gastrocnemius muscle, prevented an increase in heart rate upon muscle stimulation, but did not affect plasma glucose, fatty acid or lactate concentrations in comparison with values obtained in control experiments. 4. Administration of DL-propranolol 5 min or 35 min before unilateral stimulation of 4 Hz had no effect on changes in muscle phosphocreatine, ATP or Pi concentrations, intracellular pH or contractile performance. 5. In contrast, animals receiving DL-propranolol 5 min before unilateral stimulation of 1, 2 and 4 Hz showed a significant deterioration in gastrocnemius muscle tension development during 2 and 4 Hz stimulation compared with control animals. Concurrent with this change in contractile performance was a higher muscle concentration of phosphocreatine, a lower concentration of Pi and no significant change in intramuscular pH compared with control experiments. 6. The changes in muscle performance and bioenergetics observed during the incremental stimulation protocol were not observed when D-propranolol was administered and could be completely circumvented by a short period of muscle stimulation of 4 Hz prior to initiation of the incremental stimulation protocol. 7. Mechanisms are discussed which may account for the failure of gastrocnemius muscle to generate the expected force during the incremental stimulation protocol in the presence of beta-blockade.

Long- and Short-Term Regulation of the Na+-K+-Pump in Skeletal Muscle

Physiology ◽  
1996 ◽  
Vol 11 (1) ◽  
pp. 24-30 ◽  
Author(s):  
T Clausen
Keyword(s):  
Skeletal Muscle ◽  
Muscle Activity ◽  
Contractile Activity ◽  
Short Term ◽  
Hormonal Stimulation ◽  
Growth And Nutrition ◽  
Force Recovery ◽  
Contractile Performance ◽  
Stimulation Of

In skeletal muscle, activity and capacity of the Na+ -K+ pump are controlled by several hormones, contractile activity, growth, and nutrition. Acute or chronic reduction of the pump capacity inhibits contractile performance. Conversely, acute hormonal stimulation of the Na+ -K+ pump leads to marked, rapid force recovery in muscles where contractility is suppressed by high extracellular K+.

Skeletal muscle contractile performance and ADP accumulation in adenylate kinase-deficient mice

2005 ◽  
Vol 288 (6) ◽  
pp. C1287-C1297 ◽  
Author(s):  
Chad R. Hancock ◽  
Edwin Janssen ◽  
Ronald L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Adenylate Kinase ◽  
Energy Demand ◽  
Adenine Nucleotide ◽  
Formation Rate ◽  
High Energy ◽  
Energy Demands ◽  
Whole Muscle ◽  
Muscle Contractile ◽  
Contractile Performance

The production of AMP by adenylate kinase (AK) and subsequent deamination by AMP deaminase limits ADP accumulation during conditions of high-energy demand in skeletal muscle. The goal of this study was to investigate the consequences of AK deficiency (−/−) on adenine nucleotide management and whole muscle function at high-energy demands. To do this, we examined isometric tetanic contractile performance of the gastrocnemius-plantaris-soleus (GPS) muscle group in situ in AK1−/− mice and wild-type (WT) controls over a range of contraction frequencies (30–120 tetani/min). We found that AK1−/− muscle exhibited a diminished inosine 5′-monophosphate formation rate (14% of WT) and an inordinate accumulation of ADP (∼1.5 mM) at the highest energy demands, compared with WT controls. AK-deficient muscle exhibited similar initial contractile performance (521 ± 9 and 521 ± 10 g tension in WT and AK1−/− muscle, respectively), followed by a significant slowing of relaxation kinetics at the highest energy demands relative to WT controls. This is consistent with a depressed capacity to sequester calcium in the presence of high ADP. However, the overall pattern of fatigue in AK1−/− mice was similar to WT control muscle. Our findings directly demonstrate the importance of AMP formation and subsequent deamination in limiting ADP accumulation. Whole muscle contractile performance was, however, remarkably tolerant of ADP accumulation markedly in excess of what normally occurs in skeletal muscle.

Long-term electrical stimulation of rabbit skeletal muscle increases growth of paired arteries and veins

1995 ◽  
Vol 269 (2) ◽  
pp. H717-H724 ◽  
Author(s):  
T. H. Adair ◽  
J. Hang ◽  
M. L. Wells ◽  
F. D. Magee ◽  
J. P. Montani
Keyword(s):  
Skeletal Muscle ◽  
Vascular System ◽  
Common Peroneal Nerve ◽  
Numerical Density ◽  
Muscle Stimulation ◽  
Longus Muscle ◽  
The Right ◽  
Arteries And Veins ◽  
Stimulation Of

We tested whether chronic stimulation of skeletal muscle can increase the growth of paired arteries and veins in rabbit extensor digitorum longus muscle (EDL). The right EDL of female New Zealand White rabbits was stimulated via the common peroneal nerve at 10 Hz using 300 microseconds square waves at 3-4 V. Two-hour periods of stimulation was alternated with 4-h periods of rest, 7 days/wk for approximately 60 days. The left EDL served as control. The hindlimb vascular system was maximally dilated and perfuse-fixed with 3% glutaraldehyde and 2% paraformaldehyde at arterial and venous pressures of 80-100 and 15-20 mmHg, respectively. Muscles were postfixed in OsO4 and embedded in EPOX 812 resin. One millimeter-thick transverse sections were cut at uniform locations through the entire breadth of the muscle and analyzed using videomicroscopy along with computerized morphometric and stereological techniques. All paired arteries and veins on each full muscle section were analyzed. Chronic muscle stimulation caused the wall volume of paired arteries and veins to increase by an average of approximately twofold and the lumen volume to increase by an average of approximately threefold compared with the contralateral muscles. The wall-to-lumen area ratio of the arteries and veins was not affected. Muscle stimulation also caused the numerical density of arteries having a diameter > 100 microns to increase by approximately fourfold and the density of veins having a perimeter > 500 microns to increase by approximately 10-fold.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin stimulates protein synthesis in skeletal muscle by enhancing the association of eIF-4E and eIF-4G

1997 ◽  
Vol 272 (2) ◽  
pp. C754-C759 ◽  
Author(s):  
S. R. Kimball ◽  
C. V. Jurasinski ◽  
J. C. Lawrence ◽  
L. S. Jefferson
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Gastrocnemius Muscle ◽  
Binding Protein ◽  
Fold Increase ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Phosphorylated Form ◽  
Stimulation Of

Insulin stimulated protein synthesis in gastrocnemius muscle of perfused rat hindlimb preparations by approximately twofold. The stimulation of protein synthesis was associated with a 12-fold increase in the amount of eukaryotic initiation factor eIF-4G bound to the mRNA cap-binding protein eIF-4E. In part, the increased binding of eIF-4G to eIF-4E was a result of release of eIF-4E bound to the translational regulator, PHAS-I, through a mechanism involving enhanced phosphorylation of PHAS-I. However, the insulin-induced association of eIF-4E and eIF-4G was not due to increased net phosphorylation of eIF-4E because insulin decreased the amount present in the phosphorylated form from 86 to 59% of total eIF-4E. Overall, the results suggest that insulin stimulates protein synthesis in gastrocnemius muscle through a mechanism involving increased binding of eIF-4G to eIF-4E, which is in part due to phosphorylation of PHAS-I, resulting in a release of eIF-4E from the inactive PHAS-I x eIF-4E complex.

Efficiency of rat medial gastrocnemius muscle in contractions with and without an active prestretch

1989 ◽  
Vol 141 (1) ◽  
pp. 327-341 ◽  
Author(s):  
A. De Haan ◽  
G. J. Van Ingen Schenau ◽  
G. J. Ettema ◽  
P. A. Huijing ◽  
M. A. Lodder
Keyword(s):  
Gastrocnemius Muscle ◽  
High Energy ◽  
Medial Gastrocnemius ◽  
Stimulation Protocol ◽  
High Energy Phosphate ◽  
Concentric Contractions ◽  
Work Done ◽  
Positive Work ◽  
Medial Gastrocnemius Muscle

The efficiency of positive work was measured for rat medial gastrocnemius muscle at 25 degrees C during repeated contractions. Six muscles were stimulated to perform concentric contractions preceded by an active prestretch (PS contractions) and six muscles made to give concentric contractions from an isometric state (PI contractions). Both lengthening and shortening of the muscles (distance: 6 mm) occurred at a constant velocity of 20 mm s-1 (1.5 fibre lengths s-1). Stimulation was started 150 ms prior to the onset of concentric contraction for both types of contraction. For the PS contractions this meant that the active state was developed during the last 2.4 mm of the lengthening. Energy consumption (calculated from high-energy phosphate consumption) appeared to be equal for both types of contraction, although positive work output was 39.4% higher in the PS contractions than in the PI contractions. The efficiency of positive work was 36.8 +/− 3.5% in the PS contractions and 26 +/− 2.0% in the PI contractions. In contrast to results of previous studies, the positive work done by the muscle in the PS contractions was much larger than the negative work done on the muscle during stretch owing to the applied stimulation protocol which was intended to simulate in vivo conditions during running. The efficiency of positive work in the PS contractions is too low to explain the efficiencies of 40–70% reported for human and animal running.

Slow skeletal muscle myosin-binding protein-C (MyBPC1) mediates recruitment of muscle-type creatine kinase (CK) to myosin

2011 ◽  
Vol 436 (2) ◽  
pp. 437-445 ◽  
Author(s):  
Zhe Chen ◽  
Tong-Jin Zhao ◽  
Jie Li ◽  
Yan-Song Gao ◽  
Fan-Guo Meng ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Creatine Kinase ◽  
Muscle Contraction ◽  
Binding Protein ◽  
High Energy ◽  
Functional Coupling ◽  
Muscle Type ◽  
Myosin Binding Protein ◽  
Slow Skeletal Muscle ◽  
Myosin Binding

Muscle contraction requires high energy fluxes, which are supplied by MM-CK (muscle-type creatine kinase) which couples to the myofibril. However, little is known about the detailed molecular mechanisms of how MM-CK participates in and is regulated during muscle contraction. In the present study, MM-CK is found to physically interact with the slow skeletal muscle-type MyBPC1 (myosin-binding protein C1). The interaction between MyBPC1 and MM-CK depended on the creatine concentration in a dose-dependent manner, but not on ATP, ADP or phosphocreatine. The MyBPC1–CK interaction favoured acidic conditions, and the two molecules dissociated at above pH 7.5. Domain-mapping experiments indicated that MM-CK binds to the C-terminal domains of MyBPC1, which is also the binding site of myosin. The functional coupling of myosin, MyBPC1 and MM-CK is further corroborated using an ATPase activity assay in which ATP expenditure accelerates upon the association of the three proteins, and the apparent Km value of myosin is therefore reduced. The results of the present study suggest that MyBPC1 acts as an adaptor to connect the ATP consumer (myosin) and the regenerator (MM-CK) for efficient energy metabolism and homoeostasis.

scholarly journals Ca-ATPase isozyme expression in sarcoplasmic reticulum is altered by chronic stimulation of skeletal muscle

FEBS Letters ◽  
1990 ◽  
Vol 259 (2) ◽  
pp. 269-272 ◽  
Author(s):  
F.Norman Briggs ◽  
K.Francis Lee ◽  
Joseph J. Feher ◽  
Andrew S. Wechsler ◽  
Kay Ohiendieck ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Chronic Stimulation ◽  
Stimulation Of
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