维库溴铵对大鼠膈肌神经肌肉接头微终板电位及终板电位的影响

The effects of vecuronium on MEPP and EPP in isolated nonuniform stretched muscle preparation of rats

目的 :利用成年大鼠膈肌膈神经不均匀牵拉标本 ,研究维库溴铵对神经肌肉接头部位的电生理学影响。方法 :成年健康Wistar大鼠 ,体重 16 0～ 2 2 0g,雌雄皆用。快速处死制备离体大鼠不均匀牵张膈肌膈神经标本 ;记录到正常微终板电位 (MEPP)和终板电位 (EPP)后 ,观察相当大鼠 4×ED95、2×ED95、1×ED95和 0 5×ED95剂量时的血药浓度药物维库溴铵对MEPP频率和幅度的影响。结果 :维库溴铵在 0 5 μg/ml浓度时对正常INSMP上的MEPP的频率、幅度及EPP的幅度无明显影响 ;在 1μg/ml剂量时 ,在 5min时点始对MEPP频率、幅度及EPP幅度产生明显抑制作用 ;在 2～ 4μg/ml剂量时维库溴铵在 3min时点始产生对MEPP频率、幅度及EPP幅度的抑制作用 ,在 10min时点 ,维库溴铵 4μg/ml抑制MEPP的产生及EPP幅度的作用达最大。结论 :维库溴铵能减少突触前递质的释放 ,推测维库溴铵可能具有一定强度的突触前作用。

Objective:To investigate the effects of vecuronium on neuromuscular junction of rat diaphragm. Methods:In isolated non-uniform stretched muscle preparation (INSMP) of rat diaphragm, miniature endplate potentials (MEPP) and endplate potentials(EPP) could be recorded simultaneously with one microelectrode from one endplate. The effects of four doses of vecuronium at 0.5,1,2,4 μg/ml on the amplitude and frequency of MEPP and the amplitude of EPP were observed. These doses were corresponded to the blood concentration of 0.5,1,2,4*ED 95of thedrug respectively. Results:Vecuronium could decrease both amplitude and frequency of MEPP obviously and the onset time was at 3 and, 5 min after drug administration. The amplitude of EPP was depressed by vecuronium at different time like MEPP.The dosage of vecuronium which had no effects on amplitude of EPP were 0.5μg/ml. Conclusion:The results indicated that vecuronium might have presynaptic effect on neuromuscular junction in INSMP of rats.