Muscular regeneration by autograft of in vitro multiplied satellite cells

We used a free-grafting technique modified from that described by Carlson and Gutmann, to induce an ischemic injury of Extensor Digitorum Longus (EDL) muscle in adult rats. In these muscles, a peripheral rim, three to five muscle fibers thick, survive ischemia whereas the muscle fibers occupying the central part follow a sequential pattern of necrosis, degradation and regeneration. Association of X-irradiation to the experimental injury inhibits mitosis of myogenic cells, thus preventing, the regeneration of the injured fibers. At the 14th postoperative day, the muscle is reduced to a cystic structure. The center of this structure is occupied by a loose fibrinous and collagenic network with a few cellular elements. In vitro multiplied autologous satellite cells, labelled with fluorescent latex beads, were injected back into this preparation. Our results indicate that these cells have retained their myogenic characteristics and are able to reform fully differentiated muscle fibers.