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Updated: Jul 10, 2026
14:02
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Published on: November 1, 2012
Impaired calcium release during fatigue
D G Allen1, G D Lamb, H Westerblad
1School of Medical Sciences and Bosch Institute, Univ. of Sydney F13, NSW 2006, Australia. davida@physiol.usyd.edu.au
Journal of Applied Physiology (Bethesda, Md. : 1985)
|October 27, 2007
Summary
Muscle fatigue involves impaired calcium release from the sarcoplasmic reticulum (SR). Caffeine can help assess this, but new methods are needed to study it in whole muscles and pinpoint causes.
Area of Science:
- Exercise Physiology
- Skeletal Muscle Biology
- Cellular Physiology
Background:
- Impaired calcium release from the sarcoplasmic reticulum (SR) contributes to skeletal muscle fatigue.
- Caffeine can augment SR Ca(2+) release, serving as a tool to study fatigue mechanisms.
Purpose of the Study:
- To explore proposed mechanisms of impaired SR Ca(2+) release during muscle fatigue.
- To highlight the need for methods to assess SR Ca(2+) release in intact muscles.
Main Methods:
- Review of proposed mechanisms for impaired SR Ca(2+) release.
- Discussion of the role of action potential amplitude, intracellular ATP, Mg(2+), and inorganic phosphate.
Main Results:
- Several factors contribute to impaired SR Ca(2+) release, including reduced action potential amplitude, decreased SR Ca(2+) channel effectiveness due to low ATP and high Mg(2+), and Ca(2+) precipitation within the SR.
Conclusions:
- Understanding muscle fatigue requires distinguishing between various causes of impaired SR Ca(2+) release.
- Development of techniques to study SR Ca(2+) release in intact, perfused muscles is crucial for future research.
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