Preventive Effect of Isometric Contraction Exercise on Disuse Muscle Atrophy Using Tail Suspension Mice

Abstract

In the present study, we demonstrated the preventive effect of isometric contraction exercise on disuse muscle atrophy with tail suspension immobilization model mice. Mice were divided into three groups: tail suspension alone (group TS), addition of exercise to tail suspension (group EX), and control (group C). Muscle mass (muscle weight divided by body weight) of soleus (SOL) and gastrocnemius (GAS) muscles were lower in group TS than in group C. In group EX, muscle mass of SOL increased compared to group TS at 2 weeks. Histological examination indicated that group TS mice developed muscle atrophy in both SOL and GAS, while group EX mice did not develop atrophy in SOL. Moreover, this study first demonstrated that muscle mass recovered from atrophy in group EX at 2 weeks. Myosin heavy chain expression was significantly higher in group EX than in group TS at 2 weeks. Our results suggest that isometric contraction exercise prevented disuse muscle atrophy in the soleus muscle.