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.

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.

Contraction of glycerinated rabbit slow-twitch muscle fibers as a function of MgATP concentration

1992 ◽  
Vol 262 (4) ◽  
pp. C1039-C1046 ◽  
Author(s):  
E. Pate ◽  
M. Lin ◽  
K. Franks-Skiba ◽  
R. Cooke
Keyword(s):  
Psoas Muscle ◽  
Isometric Tension ◽  
Maximal Velocity ◽  
Shortening Velocity ◽  
A Value ◽  
Semimembranosus Muscle ◽  
Slow Twitch Muscle ◽  
Force Velocity ◽  
Slow Twitch ◽  
Fast Twitch

We have measured the isometric tension and force-velocity relationships of glycerinated rabbit slow-twitch semimembranosus muscle as a function of MgATP concentration ([MgATP]) and have compared the results with those obtained previously from fast-twitch psoas muscle. We find that isometric tension decreases as [MgATP] increases. The magnitude of the decrease is not as great as observed in psoas. Maximum shortening velocity (Vmax) exhibits classical Michaelian saturation behavior with respect to [MgATP] with a Michaelis constant (Km) for half-maximal velocity of 18 microM and a value at saturating [MgATP] of 0.6 muscle lengths/s. Similar values were observed in fibers from soleus, another slow-twitch muscle. The corresponding values in rabbit psoas muscle are 150 microM and 1.6 lengths/s. Compared with psoas, in semimembranosus muscle Km decreases by a factor of approximately 10, whereas Vmax decreases by about a factor of 3. Thus, although in a nonphysiological regime, at low [MgATP], a "fast" muscle actually has a lower shortening velocity than a "slow" muscle.

scholarly journals Efficiency of fast- and slow-twitch muscles of the mouse performing cyclic contractions.

1994 ◽  
Vol 193 (1) ◽  
pp. 65-78 ◽  
Author(s):  
C J Barclay
Keyword(s):  
Heat Production ◽  
Power Output ◽  
Muscle Length ◽  
Mechanical Efficiency ◽  
Maximum Efficiency ◽  
Work Output ◽  
Cycle Frequency ◽  
Length Changes ◽  
Slow Twitch ◽  
Initial Heat

The mechanical efficiency of mouse fast- and slow-twitch muscle was determined during contractions involving sinusoidal length changes. Measurements were made of muscle length, force production and initial heat output from bundles of muscle fibres in vitro at 31 degrees C. Power output was calculated as the product of the net work output per sinusoidal length cycle and the cycle frequency. The initial mechanical efficiency was defined as power output/(rate of initial heat production+power output). Both power output and rate of initial heat production were averaged over a full cycle of length change. The amplitude of length changes was +/- 5% of muscle length. Stimulus phase and duration were adjusted to maximise net work output at each cycle frequency used. The maximum initial mechanical efficiency of slow-twitch soleus muscle was 0.52 +/- 0.01 (mean +/- 1 S.E.M. N = 4) and occurred at a cycle frequency of 3 Hz. Efficiency was not significantly different from this at cycle frequencies of 1.5-4 Hz, but was significantly lower at cycle frequencies of 0.5 and 1 Hz. The maximum efficiency of fast-twitch extensor digitorum longus muscle was 0.34 +/- 0.03 (N = 4) and was relatively constant (0.32-0.34) over a broad range of frequencies (4-12 Hz). A comparison of these results with those from previous studies of the mechanical efficiency of mammalian muscles indicates that efficiency depends markedly on contraction protocol.

The storage of ware potatoes in permanent buildings II. The temperature of unventilated stacks of potatoes

1955 ◽  
Vol 46 (2) ◽  
pp. 150-163 ◽  
Author(s):  
W. G. Burton ◽  
G. Mann ◽  
H. G. Wager
Keyword(s):  
Heat Production ◽  
Ambient Air ◽  
Storage Conditions ◽  
Storage Season ◽  
Average Temperature ◽  
Metabolic Heat ◽  
A Value ◽  
The Difference ◽  
Maximum Temperatures ◽  
Initial Heat

1. Under normal English storage conditions, the heat production of mature potatoes drops rapidly from a value of probably about 150 b.th.u./ton/hr. immediately after harvest to about 30–50 b.th.u./ton/hr. Sprouting is accompanied by an increase in the rate of heat production. The initial heat production of immature potatoes may be of the order of 250 b.th.u./ton/hr.2. As a result of the production of heat, the temperatures in stacks of potatoes will tend to rise to levels above that of the outside air which are just sufficient to cause the convection and conduction necessary to remove the metabolic heat as fast as it is produced.3. The difference in temperature between the potatoes and the ambient air is a function of the heat production of the potatoes and of the height of the stack, and is practically independent of its other dimensions if these exceed twice the height. Under average conditions during the middle of the storage season, and for heights of storage of from about 6 to 12 ft. it may be taken as a rough practical guide that the average and maximum temperatures of the potatoes will tend to exceed the average temperature of the store air by about 2/3 and 1° F. respectively for every foot of height.4. Overheating is possible at both the beginning and end of the storage season, when heat production is high and the outside temperatures also possibly high. In general it is safe to store unventilated potatoes to a height of about 6 ft. if they are mature, though if they are harvested with a great deal of earth late storage should not be attempted. If there is no intention of storing late, and the potatoes are fairly clean, storage to aheight of 12 ft. may be permissible. Immature potatoes should not be stored to a height of more than 3 ft.

Fluorometric studies of recovery metabolism of rat fast- and slow-twitch muscles

1976 ◽  
Vol 230 (6) ◽  
pp. 1644-1649 ◽  
Author(s):  
IR Wendt ◽  
JB Chapman
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Extensor Digitorum Longus ◽  
Recovery Period ◽  
Extensor Digitorum ◽  
Nicotinamide Adenine ◽  
Base Line ◽  
Glycolytic Activity ◽  
Initial Reduction ◽  
Slow Twitch ◽  
Fast Twitch

Recovery metabolism of fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles of the rat has been investigated using fluorometric monitoring of reduction of nicotinamide adenine dinucleotide (NAD). In both EDL and SOL, groups of twitch contractions produced a decrease in fluorescence (oxidation of NADH) which returned to the resting base line after contraction ceased. These responses proceeded more quickly in EDL than SOL and were abolished by anoxia. A 1-s tetanus of SOL produced an initial reduction which could be abolished with iodoacetate followed by a prolonged oxidation which could be blocked by anoxia. The fluorescence of EDL was decreased immediately following a 1-s tetanus but then rapidly increased well beyond the resting level of reduction and persisted throughout the recovery period. This reduction was largely depressed by iodoacetate. The results indicate marked differences in the recovery metabolism of these muscles, consistent with predominantly mitochondrial oxidative activity in the slow-twitch muscles and predominantly glycolytic activity in the fast-twitch muscles.

Studies of the halothane-cooling contractures of skeletal muscle

1987 ◽  
Vol 65 (4) ◽  
pp. 697-703 ◽  
Author(s):  
Roberto T. Sudo ◽  
Gisele Zapata ◽  
Guilherme Suarez-Kurtz
Keyword(s):  
Skeletal Muscle ◽  
Synergistic Effects ◽  
Rabbit Muscle ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Dose Dependent ◽  
Muscle Biopsies ◽  
Ca Homeostasis ◽  
Potential Use

The characteristics of transient contractures elicited by rapid cooling of frog or mouse muscles perfused in vitro with solutions equilibrated with 0.5–2.0% halothane are reviewed. The data indicate that these halothane-cooling contractures are dose dependent and reproducible, and their amplitude is larger in muscles containing predominantly slow-twitch type fibers, such as the mouse soleus, than in muscles in which fast-twitch fibers predominate, such as the mouse extensor digitorum longus. The halothane-cooling contractures are potentiated in muscles exposed to succinylcholine. The effects of Ca2+-free solutions, of the local anesthetics procaine, procainamide, and lidocaine, and of the muscle relaxant dantrolene on the halothane-cooling contractures are consistent with the proposal that the halothane-cooling contractures result from synergistic effects of halothane and low temperature on Ca sequestration by the sarcoplasmic reticulum. Preliminary results from skinned rabbit muscle fibers support this proposal. The halothane concentrations required for the halothane-cooling contractures of isolated frog or mouse muscles are comparable with those observed in serum of patients during general anesthesia. Accordingly, fascicles dissected from muscle biopsies of patients under halothane anesthesia for programmed surgery develop large contractures when rapidly cooled. The amplitude of these halothane-cooling contractures declined with the time of perfusion of the muscle fascicles in vitro with halothane-free physiological solutions. It is suggested that the halothane-cooling contractures could be used as a simple experimental model for the investigation of the effects of halothane on Ca homeostasis and contractility in skeletal muscle and for study of drugs of potential use in the management of the contractures associated with the halothane-induced malignant hyperthermia syndrome. It is shown that salicylates, but not indomethacin or mefenamic acid, inhibit the halothane-cooling contractures.

scholarly journals The Functional Role of Calcineurin in Hypertrophy, Regeneration, and Disorders of Skeletal Muscle

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Kunihiro Sakuma ◽  
Akihiko Yamaguchi
Keyword(s):  
Skeletal Muscle ◽  
Functional Role ◽  
Muscular Hypertrophy ◽  
Growth And Remodeling ◽  
Muscular Disorders ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Calcineurin Activity ◽  
Muscle Remodeling

Skeletal muscle uses calcium as a second messenger to respond and adapt to environmental stimuli. Elevations in intracellular calcium levels activate calcineurin, a serine/threonine phosphatase, resulting in the expression of a set of genes involved in the maintenance, growth, and remodeling of skeletal muscle. In this review, we discuss the effects of calcineurin activity on hypertrophy, regeneration, and disorders of skeletal muscle. Calcineurin is a potent regulator of muscle remodeling, enhancing the differentiation through upregulation of myogenin or MEF2A and downregulation of the Id1 family and myostatin. Foxo may also be a downstream candidate for a calcineurin signaling molecule during muscle regeneration. The strategy of controlling the amount of calcineurin may be effective for the treatment of muscular disorders such as DMD, UCMD, and LGMD. Activation of calcineurin produces muscular hypertrophy of the slow-twitch soleus muscle but not fast-twitch muscles.

Guinea pig soleus and gastrocnemius electromyograms at varying speeds, grades, and loads

1982 ◽  
Vol 52 (2) ◽  
pp. 451-457 ◽  
Author(s):  
K. R. Gardiner ◽  
P. F. Gardiner ◽  
V. R. Edgerton
Keyword(s):  
Guinea Pig ◽  
Work Load ◽  
Burst Duration ◽  
Lateral Gastrocnemius ◽  
Biochemical Alterations ◽  
Hindlimb Muscles ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Grade Increase ◽  
Emg Electrodes

The purpose of the study was to describe changes that occur in the usage of fast-twitch and slow-twitch guinea pig hindlimb muscles, as estimated using chronically implanted electromyogram (EMG) electrodes, during voluntary locomotion under various conditions. Guinea pigs, in which fine wire electrodes were implanted in soleus (SOL) and lateral gastrocnemius (LG) muscles, were exercised at various speeds (13.4, 26.8, 40.2 m/min), grades (0–30%) and in some conditions loads (50–150 g) on a motor-driven treadmill. Bipolar EMG signals were rectified-averaged (RA-EMG) and analyzed for burst duration, amplitude, and the integral of each burst (IEMG). For each condition and muscle, total IEMG/min (IEMG/step x steps/min) was calculated and expressed as a percent of the maximum IEMG recorded. With increasing speed at 0% grade, the ratio of LG to SOL IEMG, each expressed as percent of maximum, remained constant at about 0.82. An increased stepping rate of 150 (at 13.4 m/min) to 225 (at 40.2 m/min) steps/min was accompanied by a 37% decrease in burst duration in LG and SOL. When the treadmill belt speed was increased from 13.4 to 4.02 m/min at 30% grade, the LG/SOL ratio increased from 0.83 to 1.03, whereas burst duration decreased by 49% (SOL) and 51% (LG). Soleus IEMG did not change significantly with increases in speed or grade; LG IEMG increased significantly with speed at 10% grade and with grade increase at the highest speed (40.2 m/min). These data provide some insight into how modifications of work load on a treadmill affect overall muscle activity and may assist in the interpretation of training-induced muscle biochemical alterations previously noted by other investigators.

Glutamine synthetase induction by glucocorticoids is preserved in skeletal muscle of aged rats

1996 ◽  
Vol 271 (6) ◽  
pp. E1061-E1066 ◽  
Author(s):  
D. Meynial-Denis ◽  
M. Mignon ◽  
A. Miri ◽  
J. Imbert ◽  
E. Aurousseau ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glutamine Synthetase ◽  
Skeletal Muscles ◽  
Female Rats ◽  
Mrna Levels ◽  
Aged Rats ◽  
Adult Rats ◽  
Adult Age ◽  
Slow Twitch ◽  
Fast Twitch

Glutamine synthetase (GS) is a glucocorticoid-inducible enzyme that has a key role for glutamine synthesis in muscle. We hypothesized that the glucocorticoid induction of GS could be altered in aged rats, because alterations in the responsiveness of some genes to glucocorticoids were reported in aging. We compared the glucocorticoid-induced GS in fast-twitch and slow-twitch skeletal muscles (tibialis anterior and soleus, respectively) and heart from adult (age 6-8 mo) and aged (age 22 mo) female rats. All animals received dexamethasone (Dex) in their drinking water (0.77 +/- 0.10 and 0.80 +/- 0.08 mg/day per adult and aged rat, respectively) for 5 days. Dex caused an increase in both GS activity and GS mRNA in fast-twitch and slow-twitch skeletal muscles from adult and aged rats. In contrast, Dex increased GS activity in heart of adult rats, without any concomitant change in GS mRNA levels. Furthermore, Dex did not affect GS activity in aged heart. Thus the responsiveness of GS to an excess of glucocorticoids is preserved in skeletal muscle but not in heart from aged animals.

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