scholarly journals Power Output and Force-Velocity Relationship of Live Fibres from White Myotomal Muscle of the Dogfish, Scyliorhinus Canicula

1988 ◽  
Vol 140 (1) ◽  
pp. 187-197 ◽  
Author(s):  
N. A. CURTIN ◽  
R. C. WOLEDGE
Keyword(s):  
Power Output ◽  
Maximum Velocity ◽  
Muscle Fibres ◽  
Fish Length ◽  
Skinned Fibres ◽  
Step Method ◽  
Velocity Relationship ◽  
Velocity Of Shortening ◽  
Force Velocity ◽  
Myotomal Muscle

The relationship between force and velocity of shortening and between power and velocity were examined for myotomal muscle fibre bundles from the dogfish. The maximum velocity of shortening, mean value 4.8 ± 0.2 μms−1 half sarcomere−1 (±S.E.M., N = 13), was determined by the ‘slack step’ method (Edman, 1979) and was found to be independent of fish length. The force-velocity relationship was hyperbolic, except at the high-force end where the observations were below the hyperbola fitted to the rest of the data. The maximum power output was 91 ± 14 W kg−1 wet mass (±S.E.M., N = 7) at a velocity of shortening of 1.3 ± 0.13μms−1 halfsarcomere−1 (±S.E.M., N = 7). This power output is considerably higher than that previously reported for skinned fibres (Bone et al. 1986). Correspondingly the force-velocity relationship is less curved for intact fibres than for skinned fibres. The maximum swimming speed (normalized for fish length) predicted from the observed power output of the muscle fibres decreased with increasing fish size; it ranged from 12.9 to 7.8 fish lengths s−1 for fish 0155–0.645m in length.

scholarly journals Temperature and the Force-Velocity Relationship of Live Muscle Fibres from the Teleost Myoxocephalus Scorpius

1989 ◽  
Vol 144 (1) ◽  
pp. 437-448 ◽  
Author(s):  
KAREN S. LANGFELD ◽  
JOHN D. ALTRINGHAM ◽  
IAN A. JOHNSTON
Keyword(s):  
Power Output ◽  
Muscle Power ◽  
Muscle Fibres ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Myoxocephalus Scorpius ◽  
Relationship Of ◽  
Myotomal Muscle ◽  
Best Fit ◽  
Tetanic Tension

Small bundles of fast fibres were isolated from the myotomal muscle of the teleost Myoxocephalus scorpius. The temperature-dependence of isometric contractile properties and the force-velocity (P-V) relationship were studied. Fibres were found to deteriorate above 18°C, and the force plateau during tetanic stimulation was not maintained above 15°C. Twitch and tetanic tension (P0) showed optima at around 8°C. Force-velocity curves were fitted using either Hill's hyperbolic equation or a hyperbolic-linear equation (hyp-lin). The best fit to the data was provided by the hyp-lin equation, which gave consistently higher values for unloaded contraction velocity (Vmax): 4.3, 8.1 and 9.5 muscle lengths s−1 at 1, 8 and 12°C, respectively. The P-V relationship was found to become progressively more curved at higher temperatures. Muscle power output calculated from the hyp-lin equation was 123 W kg−1 at 1°C and 256 W kg−1 at 8°C. Curves normalized for P0 and Vmax at each temperature show that the change in curvature is sufficient to increase the relative power output of the muscle by around 15% on decreasing the temperature from 8 to 1°C.

scholarly journals Power output and force-velocity relationship of red and white muscle fibres from the Pacific blue marlin (Makaira nigricans)

1984 ◽  
Vol 111 (1) ◽  
pp. 171-177 ◽  
Author(s):  
I. A. Johnston ◽  
J. Salamonski
Keyword(s):  
Power Output ◽  
White Muscle ◽  
Force Production ◽  
Muscle Fibres ◽  
Blue Marlin ◽  
Makaira Nigricans ◽  
The Pacific ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Relationship Of

Single white fibres and small bundles (two to three) of red fibres were isolated from the trunk muscle of Pacific Blue Marlin (50–121 kg body weight). Fibres were chemically skinned with 1% Brij. Maximum Ca2+-activated force production (Po) was 57 kN m-2 for red fibres and 176 kN m-2 for white fibres at 25 degrees C. The force-velocity (P-V) characteristics of these fibres were determined at 15 and 25 degrees C. Points below 0.6 Po on the P-V curve could be fitted to a linear form of Hill's equation. The degree of curvature of the P-V curve was similar at 15 and 25 degrees C (Hill's constant a/Po = 0.24 and 0.12 for red and white fibres respectively). Extrapolated maximum contraction velocities (Vmax) were 2.5 muscle lengths s-1 (Lo S-1) (red fibres) and 5.3 Lo S-1 (white fibres) at 25 degrees C. Q10(15–25 degrees C) values for Vmax were 1.4 and 1.3 for red and white fibres respectively. Maximum power output had a similar low temperature dependence and amounted to 13 W kg-1 for red and 57 W kg-1 for white muscle at 25 degrees C. The results are briefly discussed in relation to the locomotion and ecology of marlin.

scholarly journals Effects of Temperature and Thermal Acclimation on Contractile Properties and Metabolism of Skeletal Muscle in the Flounder (Platichthys Flesus L.)

1986 ◽  
Vol 120 (1) ◽  
pp. 119-130 ◽  
Author(s):  
IAN A. JOHNSTON ◽  
ALELE WOKOMA
Keyword(s):  
Power Output ◽  
Contractile Properties ◽  
Temperature Adaptation ◽  
Evolutionary Strategies ◽  
Muscle Fibres ◽  
Skinned Fibres ◽  
Thermal Dependence ◽  
Tension Development ◽  
Platichthys Flesus ◽  
Force Velocity

Flounder (Platichthys flesus L.) were acclimated in sea water for 1–2 months toeither 5°C or 23°C (12h light: 12h dark photoperiod). Single fast muscle fibres were isolated from anterior ventral myotomes and skinned with detergent (Brij 58). Fibres were maximally activated and force-velocity (P-V) characteristics determined by step tension releases using an isotonic lever. Unloaded shortening speed was independently determined using the slack-testmethod. The contractile properties of flounder skinned fibres are not altered by temperature acclimation. Maximum isometric tension development has a low thermal dependence, Q10 = 1.2, increasing from 145 kNm−2 at 0°C to 200kNm −2 at 25°C. The force-velocity relationship becomes progressively less curved with decreasing temperature (higher values of Hill's constant a/P0) such that the thermal dependence of contraction velocity is significantly less at loads for optimum power output (Q10 = 1.3) than at zero load (Q10 = 2.0). Values for a/P0 are 0.27 at 0°C, 0.12 at 10°C and 0.08 at 25°C. Reductions in the curvature of the P-V relationshipwith decreasing temperature may represent an important mechanism for stabilizing muscle power output at low temperatures. Longer term metabolic adjustments to temperature were studied by determining maximal enzyme activities in fast and slow muscles (at 15°C). Activities of marker enzymes for mitochondrial metabolism (cytochrome oxidase), aerobic glucoseutilization (hexokinase) and fatty acid oxidation (carnitine palmitoyl transferase) are1.5-2.8 times higher in muscles of cold-acclimated compared to warm-acclimatedflounders. Increases in the activities of these enzymes with cold acclimation mayserve to offset the effects of low temperature on aerobic ATP supply. Glycolyticenzyme activities (phosphofructokinase, lactate dehydrogenase), however, aresimilar at both acclimation temperatures. The results are briefly discussed in relation to the ecology of the flounder and evolutionary strategies of temperature adaptation in teleosts.

EFFICIENCY OF ENERGY CONVERSION DURING SINUSOIDAL MOVEMENT OF WHITE MUSCLE FIBRES FROM THE DOGFISH SCYLIORHINUS CANICULA

1993 ◽  
Vol 183 (1) ◽  
pp. 137-147 ◽  
Author(s):  
N. A. Curtin ◽  
R. C. Woledge
Keyword(s):  
Power Output ◽  
High Efficiency ◽  
Fibre Length ◽  
Dry Mass ◽  
Energy Output ◽  
Maximum Efficiency ◽  
Muscle Fibres ◽  
Work Output ◽  
Sinusoidal Movement ◽  
Myotomal Muscle

Net work output and heat production of white myotomal muscle fibres from the dogfish were measured during complete cycles of sinusoidal movement at 12°C. The peak-to-peak movement was about 9 % of the muscle fibre length; three stimuli at 32 ms intervals were given in each mechanical cycle. The frequency of movement and the timing of the stimulation were varied for each preparation to find the optimal conditions for power output and those optimal for efficiency (the ratio of net work output to total energy output as heat+work). To achieve either maximum power or maximum efficiency, the tetanus must start while the muscle fibres are being stretched, before the beginning of the shortening part of the mechanical cycle. The highest power output, averaged over one cycle, was 0.23+/−0.014 W g-1 dry mass (+/−s.e.m., N=9, 46.9+/−2.8 mW g-1 wet mass) and was produced during movement at 3.5 Hz. The highest efficiency, 0.41+/−0.02 (+/−s.e.m., N=13), occurred during movements at 2.0-2.5 Hz. This value is higher than the efficiency previously measured during isovelocity shortening of these fibres. The implications of the high efficiency for crossbridge models of muscle contraction are discussed.

Comparative force-velocity relation and analyses of myosin of dog atria and ventricles

1982 ◽  
Vol 243 (3) ◽  
pp. H391-H397 ◽  
Author(s):  
J. Wikman-Coffelt ◽  
H. Refsum ◽  
G. Hollosi ◽  
L. Rouleau ◽  
L. Chuck ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Calcium Concentration ◽  
Maximum Velocity ◽  
Calcium Sensitivity ◽  
Myofibrillar Proteins ◽  
Maximal Velocity ◽  
Velocity Of Shortening ◽  
Force Velocity ◽  
Normal Calcium ◽  
Actin Concentration

The isolated muscle and purified myofibrillar proteins of canine atria and ventricles were compared relative to force-velocity relations and rate of adenosine 5'-triphosphatase (ATPase) activity as a function of calcium concentrations. The maximal stress development of isolated trabeculae of canine atria was similar to that of canine right ventricular papillary muscles when analyzed at saturating calcium concentrations (7.5 mM); however, stress was less in the atria when studied at normal calcium concentrations (2.5 mM). The maximal velocity of shortening of atrial trabeculae was about 2.3 times higher than that of ventricular muscle. Regulated actomyosin characterized from the myofibrillar proteins of the two tissues gave directionally similar calcium sensitivity. The maximum velocity of shortening for actin-activated atrial myosin of the dog was approximately 1.8 times higher when the latter was analyzed as a function of actin concentration. Both maximal tension of isolated muscle and regulated actomyosin ATPase activity were dependent on calcium concentration.

scholarly journals Effects of cross-bridge compliance on the force-velocity relationship and muscle power output

PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0190335 ◽  
Author(s):  
Axel J. Fenwick ◽  
Alexander M. Wood ◽  
Bertrand C. W. Tanner
Keyword(s):  
Power Output ◽  
Muscle Power ◽  
Cross Bridge ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Muscle Power Output

scholarly journals Differences in maximum velocity of shortening along single muscle fibres of the frog.

1985 ◽  
Vol 365 (1) ◽  
pp. 147-163 ◽  
Author(s):  
K A Edman ◽  
C Reggiani ◽  
G te Kronnie
Keyword(s):  
Maximum Velocity ◽  
Muscle Fibres ◽  
Single Muscle ◽  
Velocity Of Shortening

Force–Velocity Relationship of Upper Body Muscles: Traditional Versus Ballistic Bench Press

2016 ◽  
Vol 32 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Amador García-Ramos ◽  
Slobodan Jaric ◽  
Paulino Padial ◽  
Belén Feriche
Keyword(s):  
Bench Press ◽  
Maximum Velocity ◽  
Maximum Force ◽  
Upper Body ◽  
Strongly Correlated ◽  
Mean Values ◽  
Repetition Maximum ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Relationship Of

This study aimed to (1) evaluate the linearity of the force–velocity relationship, as well as the reliability of maximum force (F0), maximum velocity (V0), slope (a), and maximum power (P0); (2) compare these parameters between the traditional and ballistic bench press (BP); and (3) determine the correlation of F0 with the directly measured BP 1-repetition maximum (1RM). Thirty-two men randomly performed 2 sessions of traditional BP and 2 sessions of ballistic BP during 2 consecutive weeks. Both the maximum and mean values of force and velocity were recorded when loaded by 20–70% of 1RM. All force–velocity relationships were strongly linear (r > .99). While F0 and P0 were highly reliable (ICC: 0.91–0.96, CV: 3.8–5.1%), lower reliability was observed for V0 and a (ICC: 0.49–0.81, CV: 6.6–11.8%). Trivial differences between exercises were found for F0 (ES: < 0.2), however the a was higher for the traditional BP (ES: 0.68–0.94), and V0 (ES: 1.04–1.48) and P0 (ES: 0.65–0.72) for the ballistic BP. The F0 strongly correlated with BP 1RM (r: 0.915–0.938). The force–velocity relationship is useful to assess the upper body maximal capabilities to generate force, velocity, and power.

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