抄録
1. The effects of divalent cations (Ca++, Mg++, Sr++ and Ba++) on the frequency of miniature end-plate potentials (m. e. p. p. s) in the amphibian neuromuscularjunction were investigated intracellularly in the presence of 2 to 8% ethanol
2. The frequency of m. e. p. p. s was increased when the concentration of calcium ion was raised in ethanol-Ringer's solution and magnesium ion acted as an antagonist to calcium ion.
3. The frequency of m. e. p. p. s was also increased by strontium and barium ions in the presence of ethanol and magnesium ions acted as an antagonist to these ions. The effect of barium ion was exerted in concentrated ethanol (4% or more).
4. In the spontaneous transmitter release, calcium and strontium ions competed with magnesium ion on a one-to-one basis and barium ion competed with magnesium ion on a one-to-several (4 to 8) basis.
