ACETYLCHOLINE AND NEURO-MUSCULAR TRANSMISSION

Abstract

A pure endplate potential (e.p.p.) was recorded after neuro-muscular block by soaking frog''s sartorii in 1:-100,000 prostigmine and 1:500,000 acetylcholine. These e.p.p. show much the same time course and size as those set up in muscles soaked in curarine and prostigmine and are much slower than with curarine only. The two former are also comparable in that following repetitive stimulation an initial quick phase of decay passes over to a very prolonged slow phase. Addition of acetylcholine to the curarized pro-stigminized muscle reduces all phases of the e.p.p. to the same extent. The mechanism of acetylcholine block is discussed.