The energetic cost of activation of white muscle fibres from the dogfish Scyliorhinus canicula

1997 ◽  
Vol 200 (3) ◽  
pp. 495-501 ◽  
Author(s):  
F Lou ◽  
N Curtin ◽  
R Woledge
Keyword(s):  
Heat Production ◽  
White Muscle ◽  
Isometric Force ◽  
Force Production ◽  
Total Heat ◽  
Energetic Cost ◽  
Maximum Efficiency ◽  
Muscle Fibres ◽  
Scyliorhinus Canicula ◽  
A Value

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.

Elastic energy storage and release in white muscle from dogfish scyliorhinus canicula

1999 ◽  
Vol 202 (2) ◽  
pp. 135-142 ◽  
Author(s):  
F. Lou ◽  
N.A. Curtin ◽  
R.C. Woledge
Keyword(s):  
Energy Cost ◽  
White Muscle ◽  
Isometric Force ◽  
Muscle Length ◽  
Maximum Velocity ◽  
Muscle Fibres ◽  
External Work ◽  
Scyliorhinus Canicula ◽  
Velocity Of Shortening ◽  
In Series

The production of work by the contractile component (CC) and the storage and release of work in the elastic structures that act in series (the series elastic component, SEC) with the contractile component were measured using white muscle fibres from the dogfish Scyliorhinus canicula. Heat production was also measured because the sum of work and heat is equivalent to the energy cost of the contraction (ATP used). These energy fluxes were evaluated in contractions with constant-velocity shortening either during stimulation or during relaxation. The muscle preparation was tetanized for 0.6 s and shortened by 1 mm (approximately 15 % of L0) at 3.5 or 7.0 mm s-1 (approximately 15 or 30 % of V0), where L0 is the muscle length at which isometric force is greatest and V0 is the maximum velocity of shortening. In separate experiments, the stiffness of the SEC was characterized from measurements of force responses to step changes in the length of contracting muscle. Using the values of SEC stiffness, we evaluated separately the work and heat associated with the CC and with the SEC. The major findings were (1) that work stored in the SEC could be completely recovered as external work when shortening occurred during relaxation (none of the stored work being degraded into heat) and (2) that, when shortening occurred progressively later during the contraction, the total energy cost of the contraction declined towards that of an isometric contraction.

Heat production and oxygen consumption during metabolic recovery of white muscle fibres from the dogfish Scyliorhinus canicula

2000 ◽  
Vol 203 (7) ◽  
pp. 1201-1210 ◽  
Author(s):  
F. Lou ◽  
W. J. van Der Laarse ◽  
N.A. Curtin ◽  
R.C. Woledge
Keyword(s):  
Oxygen Consumption ◽  
Heat Production ◽  
White Muscle ◽  
Recovery Period ◽  
Atp Synthesis ◽  
Muscle Fibres ◽  
Scyliorhinus Canicula ◽  
Maximum Value ◽  
The Difference ◽  
Time Courses

Oxygen consumption and heat production were measured during contraction and recovery of isolated, white muscle fibres from dogfish (Scyliorhinus canicula) at 19 degrees C. The contraction period consisted of 20 isometric twitches at 3 Hz; this was followed by a recovery period of 2 h without stimulation. We tested the hypothesis that recovery is wholly oxidative (not glycolytic) in these fibres. The following features support this hypothesis. (i) The ratio of total heat produced to oxygen consumed, 451+/−34 kJ mol(−)(1) (mean +/− s.e.m., N=29), was close to that expected for either the oxidation of carbohydrate, 473 kJ mol(−)(1), or the oxidation of fat, 439 kJ mol(−)(1). Even assuming the maximum value (95 % confidence limit) of the observed heat production, glycolysis could account for resynthesis of at most 18 % of the ATP used during the contractions. (ii) When the difference in rates of diffusion of oxygen and heat within the muscle are taken into account, the time courses of oxygen consumption and heat production match each other well during the entire recovery period. The efficiency of recovery (=energy used for ATP synthesis/energy available for ATP synthesis) was estimated from the results. This value, 84.0+/−20.1 % (mean +/− s.e.m., N=29), is relatively high and represents the first such measurement in functioning muscle.

scholarly journals Mechanics of myosin function in white muscle fibres of the dogfish, Scyliorhinus canicula

2012 ◽  
Vol 590 (8) ◽  
pp. 1973-1988 ◽  
Author(s):  
S. Park‐Holohan ◽  
M. Linari ◽  
M. Reconditi ◽  
L. Fusi ◽  
E. Brunello ◽  
...  
Keyword(s):  
White Muscle ◽  
Muscle Fibres ◽  
Scyliorhinus Canicula

Recovery heat production of mammalian fast- and slow-twitch muscles

1976 ◽  
Vol 230 (6) ◽  
pp. 1637-1643 ◽  
Author(s):  
IR Wendt ◽  
CL Gibbs
Keyword(s):  
Heat Production ◽  
Total Heat ◽  
Anaerobic Conditions ◽  
A Value ◽  
Glycolytic Activity ◽  
Slow Twitch ◽  
Initial Recovery ◽  
Fast Twitch ◽  
Mitochondrial Oxidative Metabolism ◽  
Initial Heat

Relationships between initial heat and recovery heat in fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles of the rat have been investigated by estimating the ratio of total heat (initial + recovery) to estimated initial heat. Results obtained from SOL agreed well with earlier data from amphibian skeletal muscle and indicated that in tetanic contractions of SOL the ratio,total heat/initial heat, was slightly greater than 2. Experiments on EDL revealed complexities not previously reported for amphibian muscle. Anaerobic total heat production by EDL was as much as 75% of aerobic heat production. When the initial heat was estimated under anaerobic conditions and with iodacetate present, the apparent ratio of total heat/initial heat in tetanic contractions of EDL approached a value of 2. The results are discussed in relation to the enzymatic characteristics of these muscles, and it is suggested that the recovery heat of SOL arises mainly from mitochondrial oxidative metabolism while that of EDL arises, to a large extent, from glycolytic activity.

Power at the expense of efficiency in contraction of white muscle fibres from dogfish Scyliorhinus canicula

1996 ◽  
Vol 199 (3) ◽  
pp. 593-601 ◽  
Author(s):  
N Curtin ◽  
R Woledge
Keyword(s):  
Duty Cycle ◽  
White Muscle ◽  
Fibre Length ◽  
Energy Output ◽  
Muscle Fibres ◽  
Cycle Duration ◽  
Scyliorhinus Canicula ◽  
Stimulus Timing ◽  
High Level ◽  
Myotomal Muscle

Work and heat production of white myotomal muscle fibres from dogfish were measured during sinusoidal movement (0.71-5.0 Hz) at 12 C. Stimulus phase (stimulus timing relative to movement) and duty cycle (stimulus duration as a fraction of movement cycle duration) were varied to determine the parameters optimal for power output and for efficiency (work/total energy output). Movements of 0.067 and 0.120L0 were used, where L0 is the muscle fibre length giving maximum force in an isometric tetanus. At each frequency of movement and duty cycle, the stimulus phase giving the highest power was the same as that giving the highest efficiency. In contrast, at each frequency and optimal stimulus phase, the dependence of power on duty cycle was very different from the dependence of efficiency on duty cycle. Power generally increased with increasing duty cycle, whereas efficiency decreased. Thus, high power can be achieved at the expense of efficiency by adjusting stimulus duty cycle. When stimulus phase and duty cycle were optimized, efficiency was always higher for the larger distance of movement. The efficiency of energy conversion can be maintained at a high level as the frequency of movement increases from 1.25 to 5.0 Hz.

The Variation of Isometric Energy Rates With Muscle Length: A Distribution-Moment Model Analysis

1992 ◽  
Vol 114 (4) ◽  
pp. 542-546 ◽  
Author(s):  
E. Rouhaud ◽  
G. I. Zahalak
Keyword(s):  
Heat Production ◽  
Isometric Force ◽  
Muscle Length ◽  
Simple Relation ◽  
Isometric Tension ◽  
Model Parameters ◽  
A Value ◽  
Muscle Dynamics ◽  
Dimensionless Constant ◽  
Distribution Moment

The Distribution-Moment Model of skeletal muscle, which has been enhanced recently to make possible the calculation of chemical energy release (E˙) and heat production (H˙) rates [1], is applied to isometric muscle. Under steady-state isometric conditions the model predicts a simple relation between the energy rates and the muscle length, namely (E/˙E˙max)=(H/˙H˙max)=[1+Bα(Λ)]/[1+B], where Λ is the ratio of muscle length to the “optimal” length at which maximal isometric tension is produced, and α(Λ) is a function numerically equal to the ratio of the tetanic isometric force to its maximum value. The single dimensionless constant in this relation, B, can be calculated from model parameters characterizing muscle dynamics at the optimum length, and has a value near unity for frog sartorius at 0°C. The predicted behavior is shown to agree reasonably well with experimental measurements of heat production and phosphocreatine (PCr) hydrolysis. The model relates the isometric energy rates to PCr hydrolysis in (1) cross-bridge interactions, and (2) calcium pumping into the sarcoplasmic reticulum.

scholarly journals Sustained performance by red and white muscle fibres from the dogfish Scyliorhinus canicula

2010 ◽  
Vol 213 (11) ◽  
pp. 1921-1929 ◽  
Author(s):  
N. A. Curtin ◽  
F. Lou ◽  
R. C. Woledge
Keyword(s):  
White Muscle ◽  
Muscle Fibres ◽  
Scyliorhinus Canicula ◽  
Sustained Performance

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.

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