AUTOGRAFTED MINCED MUSCLE FRAGMENTS DO NOT AFFECT MUSCLE REGENERATIONIN PARTIALLY EXCISED RAT GASTROCNEMIUS-MUSCLE

The kinetics of the regeneration process following partial excision or mincing in the rat gastrocnemius muscle was compared using histologic al and physiological methods. Immediately following injury there was a marked decrease in the distance of shortening (DS) values during isot onic contraction, followed by a progressive increase until 2 weeks aft er injury. By 85 days the DS values attained those of control muscle d uring contraction against low loads (up to 50 g), and 80 and 62% of co ntrol values at 150 and 250 g, respectively. However, there was no dif ference in the DS values at 28 and 85 days after injury between muscle s that were partially excised or when the removed part of the muscle w as minced and placed in the injured site. It is concluded that the enr ichment of an injured area of the gastrocnemius muscle with minced aut ografted muscle does not result in long-term improvement of the functi onal capacity of the regenerated muscle due to the addition of satelli te cells and/or other factors in the minced tissue.