Muscle proteinase activities during compensatory growth and atrophy.

Specific activities of cathepsins B and D, but not H, increased in both the tenotomized gastrocnemius and functionally overloaded soleus muscles, thus correlating with previously reported increases in protein degradation. Subsequent denervation of the overloaded soleus caused an additive increase in proteolysis, suggesting a possible greater lability of proteins in this muscle.