Neuromuscular junctions and alpha‐bungarotoxin‐binding sites in denervated and contralateral cat skeletal muscles.

Publisher Website
Google Scholar
Abstract
The distributions of cholinesterase (ChE) activity and acetylcholine (ACh) receptors were studied in normal and denervated cat hind-limb fast-twitch skeletal muscles and in muscles contralateral to denervated muscles. On normal muscle fibers almost all receptors were confined to the immediately post-junctional membrane, although a perijunctional gradient of increased ACh receptor density was found on both fast- and slow-twitch fibers. After denervation, the extrajunctional ACh receptor density increased greatly and remained high for at least 10 mo. Ectopic regions staining for ChE activity and having a high density of ACh receptors appeared in denervated muscle. The number of junctional ACh receptors decreased slowly after denervation, with a half-time of about 140 days. Fast-twitch muscles contralateral to denervated muscles also showed changes, including an increase in junctional size and a small but significant increase in extrajunctional ACh receptor density.