Molecular forms of the cholinesterases inside and outside muscle endplates.

Individual endplates were micro-dissected from chicken fast-twitch muscle, and the molecular forms of acetylcholinesterase and of pseudocholinesterase therein, identified by their sedimentation coefficients, were analysed directly. The forms actually present at the endplate, and those that are non-synaptic, were established. This analysis was also extended to muscle of the chicken with inherited muscular dystrophy, showing altered distributions of these forms.