Non-quantal acetylcholine release is increased after nitric oxide synthaseinhibition

After anticholinesterase treatment, depolarization of the postsynaptic musc le membrane by about 5 mV develops due to non-quantally released acetylchol ine from the motor nerve terminal and can be revealed as hyperpolarization by the addition of curare (H-effect). The H-effect increases significantly to 8.7 mV after inhibition of NO-synthase by L-nitroarginine methylester (L -NAME) whilst no changes in the amplitude and frequency of quantal miniatur e endplate potentials are observed.