Effect of prostaglandins E1 and F2 alpha on neuromuscular transmission in the frog sartorius muscle.

End plate potentials (e.p.p.s.) and miniature end plate potentials (m.e.p.p.s.) were recorded intracellularly at the neuromuscular junction of the frog sartorius muscle. Addition of as little as 8.5 x10(-8)M PGE1 reduced the mean m.e.p.p. frequency. The mean amplitude of m.e.p.p.s was not changed, the mean amplitude of the e.p.p.s and the quantum content of the transmitter released by a nerve impulse was slightly reduced. A decrease in mean m.e.p.p. frequency was also seen in response to the administration of 8.5 x 10(-8)M PG2 alpha. The mean amplitude of e.p.p.s and m.e.p.p.s and the quantum content remained unchanged. The possible presynaptic mode of action of PGs in the preparation of discussed.