Abstract: The confocal laser scanning microscopy was adopted to observe the changes of resting Ca2+ in soleus intrafusal muscle cells of rats after hindlimb immobilization for a week, and the effect of Na2ATP on Ca2+ cells of intrafusal hindlimb immobilization in rats was observed. The results showed that the resting Ca2+ in soleus intrafusal muscle cells of rats increased significantly after hindlimb immobilization for a week, and after Na2ATP injection, the resting Ca2+ in soleus intrafusal muscle cells of rats had no obvious increase. The experiment suggests that Na2ATP can resist calcium overload of intrafusal muscle cell induced by hindlimb immobilization. This study provides valuable information for the study of rat muscle spindle physiology and the experimental study of calcium ion and weightlessness.

Key words: Na2ATP, Ca2+, muscle spindle, soleus muscle