【摘要】 目的　观察利多卡因和布比卡因对鼠脊髓背角神经元钠电流的影响 ,探讨其椎管内麻醉的作用机制。方法　以全细胞膜片钳技术记录临床浓度的利多卡因和布比卡因 (5 0～ 10 0 0 μmol/L)对急性分离新生SD鼠 (0～ 7d)脊髓背角神经元钠电流的影响。钳制电压 - 80mV ,刺激电压为 -30mV ,持续时间 2 0ms。结果　脊髓背角神经元钠峰值电流为 0 .5～ 8nA ;临床浓度的利多卡因与布比卡因对钠电流均有明显的抑制作用 ,利多卡因与布比卡因的浓度与其抑制程度呈显著性正相关 (r分别为 0 949及 0 847,P <0 0 1) ;布比卡因对钠电流的抑制效应强于相同浓度的利多卡因 (P <0 0 1) ;布比卡因对钠电流抑制的半数有效量IC5 0为 (4 5 .2 8± 8.91) μmol/L比利多卡因的半数有效量IC5 0 (99.0 85± 16 .318) μmol/L显著性降低 (P <0 .0 1)。结论　临床浓度的布比卡因与利多卡因对脊髓背角神经元钠电流具有抑制作用 ,其抑制程度随局麻药浓度的增加而增加 ;且布比卡因的抑制效应强于利多卡因。更多还原

【Abstract】 Objective The effect of lidocaine and bupivacaine on the Na+ current of dorsal horn neurons was observed to further evaluate the mechanism of local anesthetics . Methods The dorsal horn neurons of the SD neonates(0-7 d) were isolated acutely. Under the condition of holding voltage -80mV , and testing voltage -30mV with duration of 20 ms , the whole-cell patch-clamp technique was applied to recording the changes of voltage-gated Na+ currents following the administration of lidocaine or bupivacaine at 50-1000μmol/L.Results The voltage-gated Na+ currents ranged from 0.5-8nA peak amplitude , was inhibited by lidocaine and bupivacaine at clinical concentrations, the inhibitory degree was parallelly correlated with the concentration of local anesthetics(r=0.949 and 0.847 ,P<0.01) ,and the IC50 for bupivacaine (45.28±8.91)μmol/L was significantly lower than that for lidocaine (99.085±16.318)μmol/L). Conclusions The Na+ current of dorsal horn neurons can be inhibited by lidocaine and bupivacaine at clinical concentration with the more potency of bupivacaine than that of lidocaine.更多还原