Shortage of chemical fuel as a cause of fatigue. Studies by nuclear magnetic resonance and bicycle ergometry
Deutscher übersetzter Titel: | Mangel an Energiesubstraten als Ursache fuer Ermuedung. Untersuchungen durch nuklear-magnetische Resonanz und Fahrradergometrie |
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Autor: | Wilkie, Douglas |
Herausgeber: | Porter, Ruth; Whelan, Julie |
Erschienen in: | Human muscle fatigue. Physiological mechanisms |
Veröffentlicht: | London: Pitman Medical (Verlag), 1981, S. 102-119 |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Sammelwerksbeitrag |
Medienart: | Gedruckte Ressource |
Sprache: | Englisch |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU198205016684 |
Quelle: | BISp |
Abstract
The technique of nuclear magnetic resonance (n.m.r.) is briefly described to illustrate its use for estimating metabolite levels in vivo. Our studies of fatigue in anaerobic frog muscle at 4 degrees C are described in relation to (a) force development, (b) speed of relaxation and (c) the switching on and off of glycolysis. Both (a) and (b) are closely related, though in different ways, to the concentrations of key metabolites. In contrast, (c) is not related to metabolite levels as such but to the events of contraction and relaxation. A special n.m.r. technique (saturation transfer) has been used to study the creatine kinase system in vivo. The results show that this system ishighly active and is in equilibrium in resting muscle. The free (ADP) is consequently only a small fraction of that found by analysis of muscle extracts. Studies of human power production as a function of duration of exercise also indicate that it is shortage of chemical fuel that brings short-and medium- term exercise (0.1-10 min) to a halt. It is proposed to extend n.m.r. methods to human subjects in the near future. A working hypothesis to account for fatigue is suggested in which both the contractilesystems and theactivating system play a part. Verf.-Referat