Do multiple ionic interactions contribute to skeletal muscle fatigue?
- 10 September 2008
- journal article
- review article
- Published by Wiley in The Journal of Physiology
- Vol. 586 (17), 4039-4054
- https://doi.org/10.1113/jphysiol.2008.155424
Abstract
During intense exercise or electrical stimulation of skeletal muscle the concentrations of several ions change simultaneously in interstitial, transverse tubular and intracellular compartments. Consequently the functional effects of multiple ionic changes need to be considered together. A diminished transsarcolemmal K(+) gradient per se can reduce maximal force in non-fatigued muscle suggesting that K(+) causes fatigue. However, this effect requires extremely large, although physiological, K(+) shifts. In contrast, moderate elevations of extracellular [K(+)] ([K(+)](o)) potentiate submaximal contractions, enhance local blood flow and influence afferent feedback to assist exercise performance. Changed transsarcolemmal Na(+), Ca(2+), Cl(-) and H(+) gradients are insufficient by themselves to cause much fatigue but each ion can interact with K(+) effects. Lowered Na(+), Ca(2+) and Cl(-) gradients further impair force by modulating the peak tetanic force-[K(+)](o) and peak tetanic force-resting membrane potential relationships. In contrast, raised [Ca(2+)](o), acidosis and reduced Cl(-) conductance during late fatigue provide resistance against K(+)-induced force depression. The detrimental effects of K(+) are exacerbated by metabolic changes such as lowered [ATP](i), depleted carbohydrate, and possibly reactive oxygen species. We hypothesize that during high-intensity exercise a rundown of the transsarcolemmal K(+) gradient is the dominant cellular process around which interactions with other ions and metabolites occur, thereby contributing to fatigue.This publication has 125 references indexed in Scilit:
- High-frequency fatigue of skeletal muscle: role of extracellular Ca2+European Journal of Applied Physiology, 2008
- Chloride conductance in the transverse tubular system of rat skeletal muscle fibres: importance in excitation–contraction coupling and fatigueThe Journal of Physiology, 2008
- Potassium, Na+,K+‐pumps and fatigue in rat muscleThe Journal of Physiology, 2007
- Store‐operated Ca2+ entry during intracellular Ca2+ release in mammalian skeletal muscleThe Journal of Physiology, 2007
- Additive protective effects of the addition of lactic acid and adrenaline on excitability and force in isolated rat skeletal muscle depressed by elevated extracellular K+The Journal of Physiology, 2007
- N‐acetylcysteine attenuates the decline in muscle Na+,K+‐pump activity and delays fatigue during prolonged exercise in humansThe Journal of Physiology, 2006
- Functional role of store‐operated and stretch‐activated channels in murine adult skeletal muscle fibresThe Journal of Physiology, 2006
- Lactic Acid and Exercise PerformanceSports Medicine, 2006
- Effects of alkalosis on muscle ions at rest and with intense exerciseCanadian Journal of Physiology and Pharmacology, 1990
- Distribution of potassium and chloride permeability over the surface and T-tubule membranes of mammalian skeletal muscleThe Journal of Membrane Biology, 1979