Effect of extracellular potassium accumulation on muscle fiber conduction velocity: a simulation study

摘要: A progressive reduction in muscle fiber conduction velocity is typically observed during fatiguing contraction. Although the exact causes of decrease have not yet been fully established, increasing evidence suggests that changes extracellular potassium concentration may be largely responsible. In this study, a mathematical model was developed to examine effect on action potential and velocity. The used simulate at range temperatures accumulation repetitive stimulation 37 °C. broadened, its amplitude decreased as increased. potassium-induced shape were eliminated when inward rectifier channels removed from model. results support hypothesis ions major contributor loss membrane excitability contractions. They additionally suggest currents play critical role depolarization, leading increased sodium inactivation resulting excitability.