Experimental investigations on hypokinesis of skeletal muscles with different functions, II. Quantitative changes in...

The effect of hypokinesis on the quantitative changes in the nucleic acids was studied in functionally different muscles of rabbits on the 5th, 10th, 14th and 28th days following plaster cast immobilization of the limbs. As a consequence of the immobilization, the total amount of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) decreased in both the tonic and the tetanic nuscles. The decrease was more marked in the tonic muscles. As a result of the hypokinesis, the RNA/DNA ratio increased in the m. gastrocnemius, and decreased in the m. soleus. The plaster cast immobilization has a greater effect on the homoeostasis of the nucleic acids of the tonic muscles than in the case of the tetanic muscles.