[An experimental study on repair and recovery of lacerated muscles--histological and histochemical observations].

A histological and histochemical study of the repairing process of skeletal muscle after transection and immediate suture was conducted using the gastrocnemius muscle of hamsters. The muscles were examined from one hour to twelve weeks after operation and were prepared as specimens for either transverse or longitudinal sections. During the first two days, necrotic fibers were scavenged by macrophages. Early regenerating fibers appeared at the extent of about 1-2 mm on both sides of the cut ends by the fourth day. After one week, myotubes identified as type 2C were abundant. By the fourth week regenerating fibers had grown longitudinally and bridged the injury site between the proximal and distal muscle fiber segments. After six weeks, they had almost matured histochemically. After eight weeks, there was substantial repair of the injury site with scarce fibrous tissue. This study has clearly demonstrated the histological and histochemical findings of repairing process of the skeletal muscle after transection.