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

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.

1989 ◽  
Vol 144 (1) ◽  
pp. 437-448 ◽  
Author(s):  
KAREN S. LANGFELD ◽  
JOHN D. ALTRINGHAM ◽  
IAN A. JOHNSTON

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.


1988 ◽  
Vol 140 (1) ◽  
pp. 187-197 ◽  
Author(s):  
N. A. CURTIN ◽  
R. C. WOLEDGE

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.


1998 ◽  
Vol 201 (1) ◽  
pp. 103-114 ◽  
Author(s):  
N A Curtin ◽  
A R Gardner-Medwin ◽  
R C Woledge

The aim of this study was to identify the principal factors that determine the time course of force and power output by muscle during patterns of stimulation and movement similar to those during fish swimming. Fully activated, white muscle fibres isolated from dogfish Scyliorhinus canicula were used to characterize the force-velocity relationship of the contractile component (CC) and the stress-strain relationship of the passive, elastic component (SEC) in series with the CC. A simple model of the time course of crossbridge activation during brief contractions was devised. Using the mechanical properties of the CC and SEC and the activation time course, force and power were predicted for brief contractions with constant-velocity movement and also for brief contractions starting at various times during sinusoidal movement. The predicted force and power were compared with observations for these patterns of stimulation and movement. The predictions matched the observations well for the period during stimulation. Matching of force was much less good for some specific conditions during relaxation, the period during which force persists after the end of stimulation. If either the slow rise of activation or the SEC was omitted from the calculation, the predictions were poor, even during stimulation. Additional factors which may influence force are discussed. These include the after-effects of shortening and stretch, the variation of force during constant-velocity stretch and non-uniform behaviour within the muscle.


1959 ◽  
Vol 100 (2) ◽  
pp. 282-285 ◽  
Author(s):  
B. A. Schottelius ◽  
D. D. Schottelius

1981 ◽  
Vol 51 (3) ◽  
pp. 750-754 ◽  
Author(s):  
V. J. Caiozzo ◽  
J. J. Perrine ◽  
V. R. Edgerton

Seventeen male and female subjects (ages 20–38 yr) were tested pre- and posttraining for maximal knee extension torque at seven specific velocities (0, 0.84, 1.68, 2.51, 3.35, 4.19, and 5.03 rad . s-1) with an isokinetic dynamometer. Maximal knee extension torques were recorded at a specific joint angle (0.52 rad below the horizontal plane) for all test speeds. Subjects were randomly assigned to one of three experimental groups: group A, control, n = 7; group B, training at 1.68 rad . s-1, n = 5; or group C, training at 4.19 rad . s-1, n = 5. Subjects trained the knee extensors by performing two sets of 10 single maximal voluntary efforts three times a week for 4 wk. Before training, each training group exhibited a leveling-off of muscular tension in the slow velocity-high force region of the in vivo force-velocity relationship. Training at 1.68 rad . s-1 resulted in significant (P less than 0.05) improvements at all velocities except for 5.03 rad . s-1 and markedly affected the leveling-off in the slow velocity-high force region. Training at 4.19 rad . s-1 did not affect the leveling-off phenomenon but brought about significant improvements (P less than 0.05) at velocities of 2.51, 3.35, and 4.19 rad . s-1. The changes seen in the leveling-off phenomenon suggest that training at 1.68 rad . s-1 might have brought about an enhancement of motoneuron activation.


PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0190335 ◽  
Author(s):  
Axel J. Fenwick ◽  
Alexander M. Wood ◽  
Bertrand C. W. Tanner

1997 ◽  
Vol 200 (3) ◽  
pp. 495-501 ◽  
Author(s):  
F Lou ◽  
N Curtin ◽  
R Woledge

The energetic cost of activation was measured during an isometric tetanus of white muscle fibres from the dogfish Scyliorhinus canicula. The total heat production by the fibres was taken as a measure of the total energetic cost. This energy consists of two parts. One is due to crossbridge interaction which produces isometric force, and this part varies linearly with the degree of filament overlap in the fibres. The other part of the energy is that associated with activation of the crossbridges by Ca2+, mainly with uptake of Ca2+ into the sarcoplasmic reticulum by the ATP-driven Ca2+ pump. Total heat production was measured at various degrees of filament overlap beyond the optimum for force development. Extrapolation of heat versus force production data to evaluate the heat remaining at zero force gave a value of 34±5 % (mean ± s.e.m., N=24) for activation heat as a percentage of total heat production in a 2.0 s isometric tetanus. Values for 0.4 and 1.0 s of stimulation were similar. Comparison with values in the literature shows that the energetic cost of activation in dogfish muscle is very similar to that of frog skeletal muscle and it cannot explain the lower maximum efficiency of dogfish muscle compared with frog muscle. The proportion of energy for activation (Ca2+ turnover) is similar to that expected from a simple model in which Ca2+ turnover was varied to minimize the total energy cost for a contraction plus relaxation cycle.


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