[Action of acid cathepsins on the myosin and sarcoplasmic proteins of normal and denervated rat muscles].

The activity of acid cathepsins in extracts of the healthy and denervated rat muscles was determined, using the proper and homologous sarcoplasmic proteins and myosin as substrates. Splitting of the sarcoplasmic proteins produces a 50% increase and that of myosin produces a 110% increase in the activity of acid cathepsins of the denervated muscles as compared to that of healthy ones. Substrates isolated from the healthy and denervated muscles are splitted by acid cathepsins with the same intensity.