Development of contractile properties in avian embryonic skeletal muscle

1982 ◽  
Vol 242 (1) ◽  
pp. C52-C58 ◽  
Author(s):  
P. J. Reiser ◽  
B. T. Stokes
Keyword(s):  
Muscle Development ◽  
Force Production ◽  
Contractile Properties ◽  
In Ovo ◽  
Tetanic Force ◽  
Time To Peak ◽  
Time Differential ◽  
Fast Twitch Muscle ◽  
Fast Twitch ◽  
Kinetics Of

The development of the twitch and tetanic responses of the embryonic chick posterior latissimus dorsi muscle has been studied during the last week in ovo. Normalized twitch and tetanic forces increased 3- and 12-fold, respectively, during this period. The changes in the kinetics of the twitch and tetanic responses differed during this developmental period. The time to peak twitch force progressively decreased. The decrease in time to half-peak tetanic force and the increase in the time differential of force production of the tetanic response did not continue after day 18. A prolonged tonic contractile component was described for both the twitch and tetanic responses, particularly in muscles from the younger embryos (days 14-18). A large decrease in the time to one-half relaxation of the twitch response also takes place during the final week in ovo. This detailed description of the development of the contractile properties provides a model system of fast-twitch muscle development in which neurogenic and myogenic components of muscular differentiation can be studied from several approaches.

Isometric contractile properties and velocity of shortening during avian myogenesis

1982 ◽  
Vol 243 (3) ◽  
pp. C177-C183 ◽  
Author(s):  
P. J. Reiser ◽  
B. T. Stokes ◽  
J. A. Rall
Keyword(s):  
Atpase Activity ◽  
Myosin Atpase ◽  
Contractile Properties ◽  
In Ovo ◽  
Tetanic Force ◽  
Time To Peak ◽  
Myosin Atpase Activity ◽  
Velocity Of Shortening ◽  
Isometric Twitch ◽  
Force Time

Isometric twitch and tetanic contractile properties and velocity of unloaded shortening (V0) of whole avian posterior latissimus dorsi muscle (PLD) were examined between embryonic day 15 and the first 2 wk after hatching. The time to peak twitch force, time to half-relaxation of the twitch response, and time to half-peak tetanic force all change significantly during the final week in ovo but do not change during the first 2 wk ex ovo. Comparisons with previously published reports by others indicate that the twitch half-relaxation time at hatching is approximately the same as that of the adult PLD. The velocity of unloaded shortening increases 2.3-fold during the period studied. It has previously been shown by other that the velocity of shortening is well correlated with a muscle's myosin ATPase activity. Therefore, the observed changes in V0 suggest that the myosin ATPase activity of the avian PLD increases between embryonic day 15 and the first 2 wk posthatching, and this change could account, at least in part, for some of the changes in the isometric properties that were measured.

scholarly journals Experimentally induced differentiation of slow tonic and fast twitch muscles in the chick

1979 ◽  
Vol 36 (1) ◽  
pp. 137-154
Author(s):  
D.E. Ashhurst ◽  
G. Vrbova
Keyword(s):  
Latissimus Dorsi ◽  
Neuromuscular Junctions ◽  
Morphological Characteristics ◽  
Morphological Features ◽  
Contractile Properties ◽  
The Other ◽  
Induced Differentiation ◽  
Anterior Latissimus Dorsi ◽  
Fast Twitch Muscle ◽  
Fast Twitch

The anterior latissimus dorsi (ALD) muscle of chickens is a slow tonic muscle, while the posterior latissimus dorsi (PLD) is a fast twitch muscle. These muscles on opposite sides of a 3-week-old chick were removed, minced and replaced in the site of the other muscle and left to regenerate. The regenerating muscles were examined at various periods from 4 days onwards and their contractile properties were found to resemble those typical of the muscle they replaced and not the original muscle. The regenerating muscles from 8 days onwards displayed the morphological features of the control muscles in the contralateral site. By 14 days, differentiation was almost complete and neuromuscular junctions were seen. It is suggested that the physiological and morphological characteristics of a muscle are determined by its position and possibly also by its innervation.

Theophylline minimally alters contractile properties of canine diaphragm in vitro

1990 ◽  
Vol 69 (4) ◽  
pp. 1390-1396 ◽  
Author(s):  
E. Derom ◽  
S. Janssens ◽  
V. De Bock ◽  
M. Decramer
Keyword(s):  
High Frequency ◽  
Force Production ◽  
Contractile Properties ◽  
Diaphragm Muscle ◽  
Muscle Bundle ◽  
Time To Peak ◽  
Diaphragm In Vitro ◽  
Tetanic Tension

We examined the effects of theophylline on contractile properties and high-frequency fatigue of canine diaphragm in vitro. Eighteen diaphragm muscle bundles were obtained from 10 anesthetized dogs and equilibrated in oxygenated Krebs solution to 100, 200, or 300 mg/l theophylline. These bundles were compared with 18 matched control bundles from the contralateral hemidiaphragm. No statistically significant differences in twitch tension, tetanic tension, twitch-to-tetanus ratio, time to peak tension, or half-relaxation time were observed. Concentrations of 300 mg/l theophylline, however, significantly (P less than 0.05) increased force production at 10 Hz by 32%. A similar tendency was present at lower concentrations and exhibited a clear dose-response behavior. High-frequency fatigue was similar in control and theophylline-treated bundles. We conclude that supratherapeutic in vitro concentrations of theophylline do not increase maximal tetanic tension and do not protect against muscle fatigue but potentiate relative force production at low stimulation frequencies. This relatively small effect cannot be explained by poor diffusion of the drug in the muscle bundle, because theophylline concentrations in the muscle bath and in the muscle bundle were virtually identical. Moreover, it remains unclear whether this potentially beneficial effect can be achieved at in vivo attainable serum concentrations.

Dynamics and Consequences of Potassium Shifts in Skeletal Muscle and Heart During Exercise

2000 ◽  
Vol 80 (4) ◽  
pp. 1411-1481 ◽  
Author(s):  
Ole M. Sejersted ◽  
Gisela Sjøgaard
Keyword(s):  
Skeletal Muscle ◽  
Force Production ◽  
Membrane Conductance ◽  
Cell Swelling ◽  
Modifying Factors ◽  
Fast Twitch Muscle ◽  
T Tubules ◽  
Exercise Induced ◽  
Fast Twitch ◽  
Muscle Excitability

Since it became clear that K+shifts with exercise are extensive and can cause more than a doubling of the extracellular [K+] ([K+]s) as reviewed here, it has been suggested that these shifts may cause fatigue through the effect on muscle excitability and action potentials (AP). The cause of the K+shifts is a transient or long-lasting mismatch between outward repolarizing K+currents and K+influx carried by the Na+-K+pump. Several factors modify the effect of raised [K+]sduring exercise on membrane potential ( Em) and force production. 1) Membrane conductance to K+is variable and controlled by various K+channels. Low relative K+conductance will reduce the contribution of [K+]sto the Em. In addition, high Cl−conductance may stabilize the Emduring brief periods of large K+shifts. 2) The Na+-K+pump contributes with a hyperpolarizing current. 3) Cell swelling accompanies muscle contractions especially in fast-twitch muscle, although little in the heart. This will contribute considerably to the lowering of intracellular [K+] ([K+]c) and will attenuate the exercise-induced rise of intracellular [Na+] ([Na+]c). 4) The rise of [Na+]cis sufficient to activate the Na+-K+pump to completely compensate increased K+release in the heart, yet not in skeletal muscle. In skeletal muscle there is strong evidence for control of pump activity not only through hormones, but through a hitherto unidentified mechanism. 5) Ionic shifts within the skeletal muscle t tubules and in the heart in extracellular clefts may markedly affect excitation-contraction coupling. 6) Age and state of training together with nutritional state modify muscle K+content and the abundance of Na+-K+pumps. We conclude that despite modifying factors coming into play during muscle activity, the K+shifts with high-intensity exercise may contribute substantially to fatigue in skeletal muscle, whereas in the heart, except during ischemia, the K+balance is controlled much more effectively.

scholarly journals Variation in normalized isometric tetanic force of isolated fast-twitch muscle fibres of Rana temporaria.

1997 ◽  
Vol 200 (3) ◽  
pp. 523-529
Author(s):  
H P Buschman ◽  
W J van der Laarse ◽  
G J Stienen ◽  
G Elzinga
Keyword(s):  
Total Variation ◽  
Rana Temporaria ◽  
Unit Length ◽  
Force Production ◽  
Rest Period ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Cross Sectional ◽  
Tetanic Force ◽  
Fast Twitch

The origin of the threefold variation found previously in isometric force normalized to cross-sectional area of single fast-twitch tibialis anterior muscle fibres of the frog Rana temporaria was studied by using (1) a strictly defined stimulus protocol, and (2) influencing the condition of the frog using artificial hibernation. Variation in normalized force was found to be influenced by the length of the rest period between tetani. After a long rest (> 6h), tetanic force production was less than for a tetanus produced after 1 h. The length of the rest period accounted for a factor of 1.24 of the total variation in normalized force. The condition of the frog also influenced normalized force production. Little variation in normalized force was observed between different fibres from the same animal, whereas a significant difference was found between animals. After artificial hibernation, force normalized to cross-sectional area remained unchanged, but force normalized to dry mass per unit length increased; the total variation increased from a factor of 1.37 to a factor of 1.64. Force normalized to muscle protein mass per unit length, however, was not affected by artificial hibernation. We conclude that variation in normalized tetanic force can be partly reduced by standardization of the stimulation protocol and normalization to protein content per unit length.

Mechanical properties of muscle units in the cat diaphragm

1988 ◽  
Vol 59 (3) ◽  
pp. 1055-1066 ◽  
Author(s):  
M. Fournier ◽  
G. C. Sieck
Keyword(s):  
Contractile Properties ◽  
Fatigue Properties ◽  
Tetanic Force ◽  
Wide Range ◽  
The Mean ◽  
Slow Twitch ◽  
The Right ◽  
Fast Twitch ◽  
Tetanic Tension

1. Muscle units in the right sternocostal region of the cat diaphragm (DIA) were isolated in situ by dissecting filaments of the C5 ventral root. Isometric contractile and fatigue properties of DIA units were then measured. Contractile properties included: twitch contraction time (CT), peak twitch tension (Pt), maximum tetanic tension (P0), and the frequency dependence of tension production. Muscle-unit fatigue resistance was estimated using a 2-min fatigue test. 2. DIA muscle units were classified as fast (F) or slow (S) based on the presence or absence of sag in their unfused tetanic force responses. Muscle-unit fatigue indices (FI) were used to further classify DIA units as slow-twitch fatigue-resistant (S), fast-twitch fatigue-resistant (FR) fast-twitch fatigue-intermediate (FInt), or fast-twitch fatigable (FF) types. 3. Based on a total of 47 completely characterized DIA muscle units, 21% were classified as S, 4% as FR, 28% as FInt, and 47% as FF. In contrast to the distribution of unit types in other mixed appendicular muscles, the DIA was composed of a very low proportion of FR units and a relatively high proportion of FInt units. An interval of FIs between 0.50 and 0.75 separated units into fatigue-resistant and fatigable groups. The distribution of FIs for FF and most FInt units was continuous, indicating that they formed a single fatigable group. Relatively few FF units in the DIA had FIs less than 0.10. 4. A wide range of contractile properties was observed for DIA muscle units. Type S units had longer CTs and lower Pt and P0 values than type F units. The mean Pt and P0 of FF and FInt units were comparable, whereas the mean Pt and P0 of the two FR units were lower. Type S units produced a greater proportion of their P0 at lower frequencies of activation than type F units. The lower P0S produced by type F units in the DIA indicated that they were smaller than similar units in appendicular muscles. It was concluded that in meeting most normal ventilatory requirements, adequate force could be generated by the recruitment of only type S and FR units. The recruitment of the more fatigable FF and FInt units may occur only during more forceful respiratory and nonrespiratory behaviors of the DIA.

Developmental changes in diaphragm contractile properties

1993 ◽  
Vol 75 (2) ◽  
pp. 522-526 ◽  
Author(s):  
B. J. Moore ◽  
H. A. Feldman ◽  
M. B. Reid
Keyword(s):  
Force Production ◽  
Respiratory Muscles ◽  
Contractile Properties ◽  
Stimulus Parameter ◽  
Direct Stimulation ◽  
Cross Sectional ◽  
Tetanic Force ◽  
Effective Excitation ◽  
Maximal Tetanic Force

The contractile properties of pre- and early postnatal respiratory muscles are incompletely understood. We examined the effects of development on isometric contractile properties, with an emphasis on properties at 37 degrees C. One-day-old (n = 10), 3-wk-old (n = 10), and adult (n = 10) rabbits were studied. Isometric contractile properties of costal diaphragm strips were measured in vitro by using direct stimulation. Twitch and maximal, i.e., fused, tetanic force production increased with strip dimension and with age. Maximal tetanic force developed per unit cross-sectional area (stress) was significantly decreased in muscle from 1-day olds, whereas it was greatest in muscle from 3-wk olds. Twitch stress was similar in all three groups. Only when the stimulus duration was prolonged did twitch and fused tetanic force achieve maximal values values for the 1-day-old and 3-wk-old strips, suggesting less effective excitation-contraction coupling in those muscles. We conclude that immature rabbit diaphragm has unique isometric contractile properties and stimulus parameter requirements that cannot be deduced from studies using mature diaphragm.

Kinetics of force generation and phosphate release in skinned rabbit soleus muscle fibers

1992 ◽  
Vol 262 (5) ◽  
pp. C1239-C1245 ◽  
Author(s):  
N. C. Millar ◽  
E. Homsher
Keyword(s):  
Steady State ◽  
Phase Ii ◽  
Flash Photolysis ◽  
Sudden Increase ◽  
State Reduction ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Kinetics Of

The kinetics of the force generating and Pi release steps of the actomyosin-adenosinetriphosphatase (ATPase) cycle have been compared in Ca(2+)-activated skinned fibers of rabbit soleus (slow twitch) and psoas (fast twitch) muscle. Pi was rapidly photogenerated within the fiber lattice by laser flash photolysis of caged Pi [1-(2-nitro)phenylethyl phosphate]. Pi reduces isometric tension in the steady state but is less effective in slow-twitch muscle than in fast-twitch muscle (e.g., 14 mM Pi reduces tension by 29 +/- 4.6% in slow and by 47 +/- 5.3% in fast). The tension response to a sudden increase in Pi concentration in slow-twitch muscle has four phases, but as in fast-twitch muscle, only phase II (an exponential decline in force) appears to be caused by Pi binding to cross bridges, whereas the other three phases are probably indirect effects caused by caged Pi photolysis. The amplitude of phase II is consistent with the steady-state reduction in force by Pi. The rate of phase II (kappa Pi) is 3.9 +/- 0.33 s-1 at 20 degrees C and 0.28 +/- 0.02 s-1 at 10 degrees C (1 mM Pi). kappa Pi is thus 33 times slower in slow-twitch muscle than in fast at 20 degrees C and 84 times slower at 10 degrees C. In contrast to fast-twitch muscle, in slow muscle kappa Pi is sufficiently slow to partially limit the ATPase turnover rate.

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.

Sign in / Sign up

Export Citation Format

Share Document