Acetylcholinesterase in singly and multiply innervated muscles of normal and dystrophic chickens.

Abstract

AbstractAChE isozymes, localization and activities of multiply innervated anterior latissimus dorsi (ALD), singly innervated posterior latissimus dorsi (PLD) and mixed semispinalis capitis muscles from 2, 6 and 12 week normal and dystrophic chicks were studied. AChE forms characteristic of chick embryo muscles were maintained in normal ALD and semispinalis muscles and lost in normal PLD muscles after two weeks of age. Dystrophic ALD and semispinalis muscles were similar in their AChE forms, localization and levels to their normal counterparts. Dystrophic PLD muscles exhibited embryo AChE forms, high AChE activity and AChE outside of the neuromuscular junctions within the sarcoplasm of the muscle fibers. The data suggest that tonic fibers of the chicken lack and that dystrophic fast twitch fibers are defective in a system that suppresses embryo AChE forms after hatching.