琥珀胆碱引起肌梭传入放电增加的时效关系

以大鼠腓肠肌内肌梭传入单位的传入放电频率为指标，观察静注不同剂量（０．５～５．０ｍｇ／ｋｇ）的ＳＣｈ后，放电频率变化的全过程，研究ＳＣｈ引起肌梭传入放电增加的时效关系及重复用药是否具有蓄积作用或快速耐受性的问题。实验结果表明：静注ＳＣｈ后，经过约１０ｓ的潜伏期，肌梭传入放电开始增加，约１ｍｉｎ放电频率达峰值，随之放电减少，约２ｍｉｎ放电频率的最大增值降低到８０％，约５ｍｉｎ降低到５０％，约１２～２６ｍｉｎ恢复到注药前的基础水平；并得出了各剂量ＳＣｈ所对应的时效关系曲线。实验证实：以２５～３５ｍｉｎ的间期，反复应用ＳＣｈ（４～６次），未出现蓄积作用或快速耐受性。

TIME-EFFECT RELATIONSHIP OF SUCCINYLCHOLINE CAUSING THE INCREASE OF AFFERENT DISCHARGE FROM MUSCLE SPINDLE IN RAT

The aim of this work is to research the time-effect relationship of SCh causing the increase of afferent discharge from muscle spindle in the rat and the reproducibility of the reponses with repeated administrations,i.e.,the degree of accumulation or tachyphylaxis. The filament was separated from tibiale nerve and with which the afferentdischarge from muscle spindle in gastrocnemius muscle was recorded. The variations of the afferent discharge frequency (ADF)were completely recorded after various doses of SCh were intravenously injected. The results showed that about 10 seconds after SCh was injected the ADF began to increase;about 1 minute the ADF came up to the peak; then the ADF began to reduce; about 2 minutes the MIF (maximum increasing frequency)decreased to 80%and 5 minutes to 50%; about 12 to 26 minutes the ADF returned to the level of pre-administration.The time-effect curves of various doses of SCh were obtained. The response to the rapid injection of a constant dose of SCh was reproducible,i.e., there was no evidence of accumulation or tachyphylaxis provided a sufficient time interval (25 to 35minutes)was given between injections and repeated administrations of SCh were made 4 to 6 times.