Neuromuscular actions of edrophonium in the lateral segmental tail muscle of the rat in vivo

The actions of edrophonium on neuromuscular transmission in vivo have been studied using the lateral segmental tail muscles of the rat. The drug produced an increase in amplitude of the miniature endplate potentials (m.e.p.p.s) without an effect on their frequency and increased the amplitude of the end-plate potentials (e.p.p.s) without increasing quantal release of transmitter. It is concluded that the anticholinesterase action of this drug in vivo facilitates neuromuscular transmission, which confirms many of the findings from in vitro studies.