Molecular and Functional Heterogeneity of Na,K-ATPase in the Skeletal Muscle

A century of exercise physiology: effects of muscle contraction and exercise on skeletal muscle Na+,K+-ATPase, Na+ and K+ ions, and on plasma K+ concentration—historical developments

“…This suggests that α 1 is sensitive to chronic reductions in activity levels in rats and also that a component of the training responses in earlier studies in rats was simply due to restoration of their normal daily activity. Several studies recently demonstrated early, localised changes in α 2 (but not α 1 ) and E m in m. soleus after inactivity induced via short-term hindlimb suspension in rats (Kravtsova et al 2015 , 2016 ; Kravtsova and Krivoi 2021 ; Petrov et al 2017 ). The α 2 was unchanged after 6 h, increased by 150% after 12 h, by 125% after 24 h, primarily at extrajunctional membranes (caveolae and t-tubules), but did not differ from control by 72 h. Resting E m was slightly depolarised at each time, primarily due to small reductions in the electrogenic contribution of α 2 to the E m , at both junctional and extrajunctional regions.…”