[Effect of hyaluronidase on the end-plate miniature currents and potentials in the frog].

The effect of 0.1% hyaluronidase on miniature end-plate potentials and currents (MEPP and MEPC) was studied in the frog cutaneous-pectoris muscle. The action of hyaluronidase on armin-pretreated muscles caused a decrease in the amplitude, duration of half-decay time and rising phase of MEPPs and MEPCs. The positive correlation between the amplitude and half-decay time of MEPPs and MEPCs was diminished. Hyaluronidase treatment of preparations with active acetylcholinesterase caused the half-life time of MEPCs to increase without any changes in the amplitude and rising phase of MEPCs. It is suggested that enzymatic destruction of a part of the glycocalix of cells forming the neuromuscular junction and of a part of the extracellular matrix results in a weakening of the nonspecific acetylcholine binding, thus facilitating the acetylcholine diffusion into the synaptic cleft.