T. Deguchi, T. Narahashi, H. G. Haas
Sep 1, 1971
Citations
0
Influential Citations
25
Citations
Journal
Pesticide Biochemistry and Physiology
Abstract
Abstract The effects of nereistoxin on the neuromuscular transmission of the frog have been studied by means of intracellular microelectrode and voltage clamp techniques. Nereistoxin blocked the neuromuscular transmission without causing depolarization of end-plate membranes. A small end-plate potential was elicited upon nerve stimulation. The frequency and amplitude of miniature end-plate potentials decreased after exposure to nereistoxin, and the quantum content of the end-plate potential tended to decrease also. Chemical sensitivity of the end-plate membrane as examined by iontophoretic application of acetylcholine was markedly reduced. Both sodium and potassium components of the end-plate current were suppressed almost equally by application of nereistoxin. It is concluded that inhibition of the mechanisms whereby the end-plate membrane conductances to sodium and potassium ions are increased is the major action of nereistoxin responsible for neuromuscular blockade.