三碘季铵酚对琥珀酰胆碱引起肌梭传入放电增加的抑制作用

目的研究三碘季铵酚(GT)对琥珀酰胆碱(SCh)引起肌梭传入放电增加的影响。方法以大鼠为对象,在支配腓肠肌的胫神经上分离神经细束,引导肌梭的传入放电。先注射一定剂量的GT,4min后再注射SCh,以放电频率峰值(DPF)、放电频率最大增值(MIF)和峰频率(PF)出现时间为指标,定量计算出GT对SCh引起肌梭传入放电增加的抑制效应。结果①当GT的剂量分别为0.005、0.010mmol/kg和0.020mmol/kg,SCh的剂量为0.005mmol/kg时,DPF分别降低到对照值的67.2%、52.5%和37.1%,MIF分别降低到对照值的61.4%、40.2%和25.4%,PF出现时间分别较对照值后移43.9s、64.3s和80.4s;②当GT的剂量为0.005mmol/kg,而SCh的剂量为0.010mmol/kg时,DPF和MIF分别降低到对照值的83.3%和77.8%,PF出现时间较对照值后移22.5s。结论GT对SCh引起的肌梭传入放电增加有明显的抑制作用,且呈一定的剂量依从性。

Suppression by gallamine triethiodide on the increased afferent discharge from the muscle spindle caused by succinylcholine

Objective To study the effect of gallamine triethiodide (GT) on the increased afferent discharge from the muscle spindle caused by succinylcholine (SCh). Methods The nervous filaments of rats were separated from tibial nerve innervating the gastrocnemius muscle, and afferent discharge from the muscle spindle was recorded. SCh of a certain dose was injected after 4 minutes of injection of a certain dose of GT. The effect of suppression by GT on the increased afferent discharge from the muscle spindle caused by SCh was measured by counting the decrease in discharge peak frequency (DPF) and maximum increase frequency (MIF) and by counting the time of peak frequency (PF) appearing delayed than the controls. Results When the dose of SCh was 0.005mmol/kg, the dose of GT was 0.005mmol/kg, 0.010mmol/kg and 0.020mmol/kg, DPF reduced to 67.2%, 52.5% and 37.1% of the controls, respectively; MIF reduced to 61.4%, 40.2.% and 25.4%; PF appearing time delayed 43.9s, 64.3s and 80.4s than the controls. When the dose of GT was 0.005mmol/kg but the dose of SCh was 0.010mmol/kg, DPF and MIF reduced to 83.3% and 77.8% of the controls, respectively; PF appearing time delayed 22.5s than the controls. Conclusion GT has a remarkably suppressive effect on the increase in afferent discharge from the muscle spindle induced by SCh. The suppression of GT is dose-dependent, and the action of SCh and GT on muscle spindle is in competition.