[Stimulating action of viadryl on the frog neuromuscular synapse].

The effect of the steroid anaesthetic "Viadril G" (hydroxydione) on the frog neuromuscular synapse and the potential of action of the muscular fibre was studied. The effect of the anaesthetic was compared with the action of the well-known stimulator of myoneural synapse--4-aminopyridine. It was revealed, that viadril increases the frequency of miniature potentials of the end plate, the amplitude and latent period of the end plate potential, reduces the amplitude of end plate miniature potentials, the time of growth and half-abate of the end plate potential. In the muscle fibre viadril does not influence significantly the resting potential, decreases the amplitude and rate of growth of the action potential and increases the time of its half-abatement. Viadril effects differ from those of 4-aminopyridine and tetraethylammonium. A supposition is made on the possible significance of the obtained results for clinical practice.