Myothermic experiments in salt‐solutions in relation to the various stages of a muscular contraction1

Weizsäcker, Viktor von

doi:10.1113/jphysiol.1914.sp001672

Cited by 33 publications

(11 citation statements)

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“…Onset of oxidative and of glycolytic recovery Heart studies It has been known since the work of Hill (1913) and of WeizsAcker (1914) that the initial heat production resulting from muscular contraction is almost unaffected when oxygen is excluded, whereas the later recovery heat production is dramatically reduced. The extra heat that appears only in oxygen must arise from the oxidative recovery process, so its time of onset should [indicate when oxidation begins (see Hill, 1965, Chapter 5).…”

Section: To Poison or Not To Poisonmentioning

confidence: 99%

Chemical change and energy output during muscular contraction

Gilbert¹,

Kretzschmar²,

Wilkie³

et al. 1971

The Journal of Physiology

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SUMMARY1. The production of heat and (internal) work and the changes in the amount of phosphocreatine (PCr), ATP, inorganic phosphate (Pi) and sometimes lactate have been measured from moment to moment during and after tetanic isometric contractions of isolated frog muscles at 0°C.2. Heat production was measured by thermopiles and a novel apparatus was employed for freezing the muscles rapidly at a chosen instant so as to halt the chemical processes before analysis.3. Using unpoisoned muscles in oxygen, it was shown that neither oxidative recovery processes nor glycolytic ones led to appreciable restitution of PCr or ATP during 15 see of contraction. However, clear signs of recovery processes could be seen within a minute. In our preparations artificial 'ageing' by storage at low temperature did not interfere with the capacity for glycolysis.4. Our clearest result was that the break-down of PCr was not nearly large enough to account for the rapid heat production during the first few sec of contraction. By the end of a 15 see tetanus as much as 10 mcal/g remained unaccounted for.5. The source of this heat is not clear. At no time is there any sign of net

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Section: To Poison or Not To Poisonmentioning

confidence: 99%

Chemical change and energy output during muscular contraction

Gilbert¹,

Kretzschmar²,

Wilkie³

et al. 1971

The Journal of Physiology

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show abstract

“…We have avoided going into the subject more in detail here as the investigations now proceeding may throw considerably more light on this interesting side of muscular activity. 4. DisCUSSION.…”

mentioning

confidence: 97%

The four phases of heat‐production of muscle

Hill¹,

Hartree²

1920

The Journal of Physiology

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“…Weizsacker, at Heidelberg, had been occupied (55) with a comparison of mechanical work and oxygen consump tion in frogs' hearts and also with the inhibiting effects of cyanide. At Cam bridge he made the fundamental observation (56,57) that the "initial" heat is independent of the presence of oxygen and is unaltered by a heavy dose of cyanide. The chemical reactions, therefore, which liberate energy for the primary process of contraction are altogether nonoxidative in character.…”

Section: Department Of Physiology University College London Englandmentioning

confidence: 99%