To determine whether there are defects in glucose metabolism of the immobilized skeletal muscle, alterations of glycogen concentration, glycogen synthesis and insulin binding were studied in the hindlimbs of adult Sprague-Dawley rats.
The experiments were performed in vivo on the 3rd, 7th, and 21st days of the immobilization. The ratio of soleus and plantaris muscle weight to body weight decreased in proportion to the duration of the immobilization. The protein concentration
of
the
immobilized muscles fell slightly during first 3 days, and then the concentration remained nearly constant throughout the immobilization period.
The glycogen concentration and glycogen synthetic activity of the immobilized muscles significantly decreased at the 3rd day of immobilization, but these values began to increase at the 7th day of the immobilization. And by the 21st day of the
immobilization both of these values were around the control value.
The insulin bindings of the immobilized muscle had tendency to increase on the 3rd day of immobilization. Thereafter the values decreased to that of control muscle.
In conclusion, in spite of the initial decreases of the carbohydrate metabolism of immobilized muscles, the metabolism increased after 7-21 days of immobilization to control ones. The increased metabolism in not directly related with the
activities
of
insulin receptors muscle.
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