THE ACTION OF PHENOL ON NEUROMUSCULARTRANSMISSION IN THE RED MUSCLE OF FISH
1969 年 19 巻 6 号 p. 762-774
詳細
1969 年 19 巻 6 号 p. 762-774
The effect of phenol on neuromuscular transmission was investigated inthe fin red muscle fibres of the silver carp, Carassius auratus Linne. Resultsare as follows:
1. Phenol (5×10-5 to 1×10-7g/ml) had no effect on resting membrane potentials.
2. Phenol greatly increased the amplitude of excitatory junction potentials, but did not change the duration.
3. No spike generation from the muscle membrane in normal solution inresponse to nerve stimulation was observed. However, in some muscle fibres, spikes were generated by phenol from augmented excitatory junction potential.
. Phenol enormously increased the frequency but did not change the am-plitude of miniature excitatory junction potentials.
5. Phenol enhanced the size of extracellularly recorded excitatory junctioncurrents with no change in the duration. There was no effect on simultane-ously recorded action currents of the nerve ending. No effect was alsoobserved on synaptic delay.
6. Phenol had no effect on acetylcholine potential evoked by iontophoreticapplication of acetylcholine.
. Phenol had no effect on the input resistance and time constant of themuscle membrane.
From these, it was concluded that phenol facilitates the neuromusculartransmission of the silver carp fin red muscles by increasing the quantity ofAch. released from the nerve ending. Phenol had no residual transmitteraction. The increase in Ach. release by phenol is not due to changes in theresting membrane potential of the nerve ending.
The possible mechanisms involved in the action of phenol for the increasedrelease of chemical transmitter from the nerve terminal were discussed.
