The Role of Calcium in the Mechanism of Muscle Fatigue in Intact, Single Muscle Fibres of Mice at Physiological Temperature
Abstract
The purpose of this study was to investigate the role of Ca2+ in the mechanism of fatigue during repeated submaximal contractions. Intact, mouse single muscle fibres were fatigued at 32C with intermittent submaximal stimulation until 40% of initial force. A force-[Ca2+]m relationship was determined prior to fatigue and during a 35 min recovery period. During fatigue, [Ca2+]m at 50% of maximum force (Ca50) increased significantly, demonstrating a decrease in Ca2+ sensitivity. Early in the period of intermittent contractions, Ca50 increased with an increase in [Ca2+]m followed by potentiation which was evident with a decrease in Ca50. However, Ca2+ sensitivity was never better than in the control condition. Throughout fatigue, both [Ca2+]m and sensitivity played a role in decreasing force. By 5 min of recovery, Ca50 had recovered and was not significantly different from Ca50 before fatigue. These results show that both [Ca2+]m and sensitivity play a role in fatigue.
Description
Keywords
Animal Physiology
Citation
Glass, L. (2017). The Role of Calcium in the Mechanism of Muscle Fatigue in Intact, Single Muscle Fibres of Mice at Physiological Temperature (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28320