Free grafting of the extensor digitorum longus muscle in the rat after Marcaine pretreatment

Normal or predenervated extensor digitorum longus muscles in the rat were given one or two preinjections of a solution of Marcaine and hyaluronidase and then freely autografted into normally innervated or denervated limbs. This procedure caused the sarcolysis of virtually all the original muscle fibers within the graft, followed by a massive regenerative response that restored the normal number of muscle fibers to the grafted muscle. Contraction times of grafts were very slow when contractile responses were first elicited by direct stimulation of the muscles. In normally innervated limbs, contraction speeded up progressively until early in the second month when the speeds approached those of the normal muscle. Grafts placed into denervated legs followed a similar pattern of development of contraotile properties during the first 3 weeks, but after that time the nerveless grafts contracted progressively more slowly than their reinnervated counterparts. Mature grafts developed a histochemically heterogeneous pattern of muscle fiber types (Types I and II) after staining for adenosine triphosphatase and succinic dehydrogenase activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21661/1/0000048.pd