On the neuromuscular paralysis produced by procaine

Abstract

1 The effects of procaine on neuromuscular transmission in the rat phrenic nerve diaphragm preparation have been examined using intracellular recording techniques. 2 The paralysis produced by procaine resembled that produced by tubocurarine and it is concluded that this effect of procaine results from a change in post-junctional sensitivity to transmitter; at low rates of stimulation procaine did not depress the transmitter release. 3 During high frequency stimulation of the phrenic nerve a distinct form of prejunctional failure was observed. It is suggested that this depression results from a combination of local anaesthesia and anoxia and that it would explain reports of a reduction in the amount of transmitter released when assayed in a conventional manner.