Isomyosin changes after functional electrical stimulation of denervated sheep muscle

Isomyosin analyses by biochemical, immunochemical, and histochemical investigations have been carried out in five sheep following unilateral recurrent laryngeal nerve paralysis and direct functional electrostimulation of the denervated cricoarytenoid posterior muscle. Myosin light chains were identified by two‐dimensional gel electrophoresis. Myosin heavy chains were analyzed by one‐dimensional SDS‐polyacrylamide gel electrophoresis. Slow myosin heavy chain was identified by orthogonal peptide mapping and immunochemistry. The stimulation effect at cellular level was determined using adenosine triphosphatase (ATPase) histochemistry. A dramatic increase of the type 1 fiber area (slow, fatigue‐resistant fibers) could be seen after many weeks of an increasing regime of low‐frequency direct electrical stimulation. Biochemically, the amout of slow myosin was always higher than in normal muscles. Some muscles were transformed almost completely to the slow type. At the time they were studied a...