Nonspecific collagenolytic activity of the femoral bone in immobilized rat extremities.

Nonspecific collagenolytic activity was studied in rat bones after immobilization. The left hind limb was immobilized by sectioning the sciatic nerve. Enzyme activity was determined by using synthetic pentapeptide substrate (Pz-Pro-Leu-Gly-Pro-D-Arg). After immobilization the activity of nonspecific collagenase increased and reached its maximum on the third day after the operation. The activity was decreased after one week and attained levels of control bones three weeks after sciatic nerve section.