抄録
The mechanism through which narcotics of various kind act on the nerve ov nerve fibers is yet not elucidated. Some authors assumed that the narcotics caused the fixation of nerve membrane but others inversely. The authoress atempted to measure the potential difference between the normal and narcotized part of the nerve to inquire into the mechanism of narcotic action. Because the potential change of narcotized part, if occurs, would enable to assume the mechanism of narcotic action, as Manaka's report of model experiment on narcotic action indicated.
The experimental material was the N. ischiadicus of the bull-frog with muscles of lower leg. The narcotics were applied on the nerve at the part apart 1 cm from the leg and the effect of narcotics was tested by the movement of leg when the nerve was stimulated at the part near the central end. Potential difference between the narcotized and normal part was measured when the conduction was brocken and after the recovery from the narcotic action.
(1) By narcotizing by urethan, aqua ammoniac and MgCl solution the narcotized part became positive than the normal part (15 mV).
(2) By narcotizing by alcohol the applied part became somewhat negarive but in some occasion a little positive.
(3) By application of hydrochloric procain and ether the narcotized part became negative (13mV).
By discussion of the results above obtained the authoress assumed the mechanism of narcotic action that urethan, aqua ammoniac and MgCl cause the fixation of the excitable membrane of the nerve fiber, alcohol increase the resistance against action current or decrease of the amplitude of action potential evoked at the applied part and hydrochloric procain, ether cause continuous excitation or increase the permeability of the part bringing the inconductivity of the part.
