Time‐dependoent increases in Na+,K+‐ATPase content of low‐frequency‐stimulated rabbit muscle

Abstract

Chronic low‐frequency stimulation of rabbit fast‐twitch muscle induced time‐dependent increases in the concentration of the sarcoleminal Na⁺,K⁺‐ATPase and in mitochondrial citrate synthase activity. The almost twofold increase in Na⁺,K⁺‐ATPase preceded the rise in citrate synthase and was complete after 10 days of stimulation, We suggest that the increase in Na⁺,K⁺‐ATPase enhances resistance to fatigue of low‐frequency‐stimulated muscle prior to elevations in aerobic‐oxidative capacity.