EXPERIMENTAL SKELETAL-MUSCLE GRAFTS AS A MODEL OF REGENERATION

Background: It is now well established that mature skeletal muscle has the ability to regenerate, and reports on this phenomenon have existe d in the research literature for some 40 years. However, it is only re latively recently, largely due to the advances in microsurgery, that p ractising surgeons can make direct use of the regenerative ability of skeletal muscle. Methods: Most of the key data on skeletal muscle rege neration have come from experimental studies on muscle grafts in small animal models. One such model is the transplantation of the extensor digitorum muscle of the mouse or rat into the contralateral site, or t he relocation of this muscle onto the surface of the tibialis anterior muscle. These and other models, together with the important cellular mechanisms involved in the regeneration of skeletal muscle, are review ed briefly in this article. Results: Skeletal muscle cells regenerate rapidly in muscle grafts, arising from satellite cells in the survivin g peripheral fibres of the graft within 2 days after grafting. The res ultant myoblasts progress towards the necrotic graft centre and occupy the area by 5 days. Revascularization commences at 3 days after graft ing, but reinnervation takes many weeks to complete. Conclusions: With the established knowledge on skeletal muscle regeneration, largely ga ined from experimental studies of muscle grafts, an understanding of t hese mechanisms should now be fundamental knowledge for today's practi sing surgeons.