抄録
1. Effects of NH4+on the isolated muscle of frog and toad were studied. Chiefly, sartorius muscle was used. When the muscle is immersed in NH4+ Ringer, discharge frequency of miniature e.p.p. increases very much and at the same time fibrillations of muscle fibers are produced. Effects of NH4+ appears with a delay.
2. Fibrillations due to NH4+is completely suppressed by tubocurarine and can not be suppressed by tetrodotoxin. It is concluded that the augmentation of discharge frequency of miniature e.p.p. is the cause of the fibrillation.
3. Fibrillation from this origin can not be produced by K+, though discharge frequency is increased by K+. Possible causes of the difference were discussed.
