Plasmin generation is increased during skeletal muscle regeneration.

Histograms show plasmin-specific activity (SA) (expressed as mOD/min per milligram protein) in muscle of wild-type mice 0, 2, 5, 7, and 9 days after injury. The assays were performed in 0.1 M Tris-HCl and 2 mM EDTA, pH 7.6, containing the chromogenic substrate S-2251. No plasmin activity is detected in extracts from noninjured muscle tissue, but it is induced on muscle injury.