[Effect of proserine and eserine on synaptic potentials of the frog sartorius muscle].

Anticholinesterases proserine (2-10(-7)-2-10(-6) M) and eserine (2-10(-6)-2-10(-5) M) prolonged end-plate poteutials (e. p. p. s.) and miniature end-plate potentials (m. e. p. p. s.) and increased their amplitude; higher concentrations of these drugs first increased and then decreased the amplitude and duration. Thus, higher concentrations, in addition to anticholinesterase effect, exert also the inhibiting influence on postjunction membrane. These two effects are reversible when washing out the drugs. Neither proserine nor eserine affect the frequency of m. e. p. p. and the quantum content of e. p. p. No cholinssensitive effect of these drugs was observed.