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Pflugers Arch
1995 Jun 01;4302:160-7. doi: 10.1007/bf00374646.
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Energetics of shortening depend on stimulation frequency in single muscle fibres from Xenopus laevis at 20 degrees C.
Buschman HP
,
Elzinga G
,
Woledge RC
.
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Single intact slow-twitch (type 3) muscle fibres from the iliofibularismuscle of Xenopus laevis were shortened at a constant velocity (0.4 L0/S, where L0 is the initial length at different levels of activation (40, 15, 12.5, and 10 Hz). A stimulation frequency of 40 Hz gave fused tetanic records. At this frequency the mean heat production rate during shortening (0.38 +/- 0.05 W/g dry weight) was slightly higher than the isometric heat production rate (0.33 +/- 0.03 W/g dry weight). The lower stimulation frequencies gave unfused tetanic contractions, the average isometric force of which was 40 +/- 3% of the isometric force at 40 Hz. In these unfused tetani during shortening the heat production rate (0.18 +/- 0.02 W/g dry weight) significantly decreased below the isometric heat production rate (0.25 +/- 0.02 W/g dry weight). At full activation the rate of total energy production (mechanical power plus heat production rate) during shortening was 1.88 +/- 0.32 times the isometric total energy production rate. This effect, i.e. an increase in energy turnover with shortening, is known as the Fenn effect. At sub-maximal stimulation the energy output during shortening was only 1.07 +/- 0.08 times the isometric value. These results show that the Fenn effect is dependent on the level of activation. The efficiency (ratio of mechanical power to total energy output) was independent of the stimulation frequency (0.37 +/- 0.06).
Allen,
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1989, Pubmed,
Xenbase
Allen,
Intracellular calcium and tension during fatigue in isolated single muscle fibres from Xenopus laevis.
1989,
Pubmed
,
Xenbase
CARLSON,
Total energy production and phosphocreatine hydrolysis in the isotonic twitch.
1963,
Pubmed
Coleman,
Myocardial oxygen consumption associated with external work: the Fenn effect.
1969,
Pubmed
Curtin,
The effect of the performance of work on total energy output and metabolism during muscular contraction.
1974,
Pubmed
Edman,
Mechanical deactivation induced by active shortening in isolated muscle fibres of the frog.
1975,
Pubmed
Elzinga,
Stable maintenance heat rate and contractile properties of different single muscle fibres from Xenopus laevis at 20 degrees C.
1987,
Pubmed
,
Xenbase
Elzinga,
The sarcomere length dependence of the rate of heat production during isometric tetanic contraction of frog muscles.
1984,
Pubmed
Fenn,
The relation between the work performed and the energy liberated in muscular contraction.
1924,
Pubmed
Fenn,
A quantitative comparison between the energy liberated and the work performed by the isolated sartorius muscle of the frog.
1923,
Pubmed
Gibbs,
Energy production in cardiac isotonic contractions.
1970,
Pubmed
HUXLEY,
Muscle structure and theories of contraction.
1957,
Pubmed
Homsher,
Energetics of shortening muscles in twitches and tetanic contractions. II. Force-determined shortening heat.
1973,
Pubmed
Homsher,
Activation heat, activation metabolism and tension-related heat in frog semitendinosus muscles.
1972,
Pubmed
Huxley,
Rapid 'give' and the tension 'shoulder' in the relaxation of frog muscle fibres.
1970,
Pubmed
Kretzschmar,
The use of the Peltier effect for simple and accurate calibration of thermoelectric devices.
1975,
Pubmed
Kushmerick,
The chemical energetics of muscle contraction. II. The chemistry, efficiency and power of maximally working sartorius muscles. Appendix. Free energy and enthalpy of atp hydrolysis in the sarcoplasm.
1969,
Pubmed
Lännergren,
Myosin isoenzymes in single muscle fibres of Xenopus laevis: analysis of five different functional types.
1984,
Pubmed
,
Xenbase
Mulieri,
Metal-film thermopiles for use with rabbit right ventricular papillary muscles.
1977,
Pubmed
Nagesser,
Metabolic changes with fatigue in different types of single muscle fibres of Xenopus laevis.
1992,
Pubmed
,
Xenbase
Pool,
Mechanochemistry of cardiac muscle. II. The isotonic contraction.
1968,
Pubmed
Potma,
Myofibrillar ATPase activity and mechanical performance of skinned fibres from rabbit psoas muscle.
1994,
Pubmed
Rall,
Sense and nonsense about the Fenn effect.
1982,
Pubmed
Rall,
A temporal dissociation of energy liberation and high energy phosphate splitting during shortening in frog skeletal muscles.
1976,
Pubmed
Smith,
Energetics of activation in frog and toad muscle.
1972,
Pubmed
Stienen,
ATPase activity of intact single muscle fibres of Xenopus laevis is related to the rate of force redevelopment after rapid shortening.
1987,
Pubmed
,
Xenbase
Stienen,
Calcium modulates the influence of length changes on the myofibrillar adenosine triphosphatase activity in rat skinned cardiac trabeculae.
1993,
Pubmed
WHALEN,
The relation of work and oxygen consumption in isolated strips of cat and rat myocardium.
1961,
Pubmed
Woledge,
The energetics of tortoise muscle.
1968,
Pubmed
Woledge,
The energetics of work and heat production by single muscle fibres from the frog.
1988,
Pubmed
