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W F Mommaerts

Publications and source records attributed to W F Mommaerts.

At least 55 records · Page 3Linked to original sources
PubMed1967

Energetics of cardiac contractions.

1. The average resting heat production of a muscle under zero tension is 24.8 mcal/g muscle .min at 20 degrees C. In the majority of muscles examined the resting heat production increases when the resting tension and muscle length are increased.2. The relation between actively developed tension and heat produced is similar to that existing in skeletal muscle. The plot of heat against developed tension can be obtained either by altering muscle length or by varying the stimulus frequency.3. The mean maximum total efficiency work/(work + heat) in the work experiments was 11.6%. The total energy produced (work + heat) correlates with the load rather than with the work done.4. In isotonic contractions more heat is liberated than the heat versus tension plot predicts. This extra heat is load-dependent.

Animals↗
PubMed1967

The break-down of adenosine triphosphate in the contraction cycle of the frog sartorius muscle.

1. It is confirmed that a fluorodinitrobenzene (FDNB)-treated frog sartorius muscle does not split phosphorylcreatine in the course of its contraction cycle, but does use adenosine triphosphate (ATP).2. Good stoicheiometric relations between the diminution of ATP and the formation of adenosine diphosphate (ADP), adenosine monophosphate (AMP) and phosphate are obtained, and in a 0.2 sec tetanus at 0 degrees C the net break-down of ATP amounts to 0.27, the total equivalent break-down to 0.34 mumoles/g.3. There is no difference in this quantity between muscles interrupted at the height of contraction and those that have also relaxed, and, in experiments specifically designed to determine relaxation metabolism separately, no such metabolism is found. Thus, all the ATP-break-down occurs in the contraction phase.

Adenine Nucleotides↗
PubMed1966

Activation heat in frog sartorius muscle.

Upon excitation of a muscle with two stimuli and variation of the interval between them up to the end of the period of full mechanical fusion, an increment of the isometric heat over that found in a single twitch is obtained. This is a good approximation to the activation heat, directly at 0 degrees C, or after certain corrections which become important at higher temperature. The activation heat so found is independent of the muscle length and nearly independent of temperature. It is increased by nitrate and caffeine.

Animals↗