Bupivacaine Inhibits Glutamatergic Transmission in Spinal Dorsal Horn Neurons
Bupivacaine Inhibits Glutamatergic Transmission in Spinal Dorsal Horn Neurons
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DOI：
10.1097/01.anes.0000365964.97138.9a
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发表时间：
2010-01-01
期刊：
影响因子：
8.8
通讯作者：
Kohno, Tatsuro
中科院分区：
文献类型：
--
作者：
Furutani, Kenta;Koma, Miho;Kohno, Tatsuro
背景：局部麻醉药布比卡因被认为不仅能阻滞钠通道，而且能与多种受体相互作用。在这里，作者专注于脊髓背角浅层的兴奋性多巴胺能传递，就其对伤害性加工的重要性而言。方法：采用全细胞膜片钳技术，在成年大鼠脊髓切片的第II层神经元上检测布比卡因对外源性N-甲基-D-天冬氨酸（NMDA）受体激动剂的反应的影响。布比卡因（0.5，2 mM）剂量依赖性地降低外源性NMDA诱导的电流的峰值振幅。然而，布比卡因（2 mM）的这种抑制作用不被河豚毒素（钠通道阻滞剂）或La 3+（电压门控Ca 2+通道阻滞剂）的存在所阻断，并且不受pH条件变化的影响。而且。移液管内鸟苷-5 ′-O-（2-硫代二磷酸）（1 mM），一种G蛋白抑制剂，不能阻断布比卡因引起的NMIDA电流幅度的降低。同样，利多卡因，罗哌卡因，甲哌卡因也减少了NMDA诱导的currents.Conclusions的振幅：这些研究结果提高的可能性，布比卡因的镇痛作用可能是由于直接调制的NMDA受体在浅背角。除了电压门控钠通道外，谷氨酸NMDA受体对局麻药诱导的镇痛作用也很重要。
Background: The local anesthetic bupivacaine is thought not only to block sodium channels but also to interact with various receptors. Here, the authors focus on excitatory glutamatergic transmission in the superficial dorsal horn of the spinal cord with respect to its importance for nociceptive processing.Methods: The effects of bupivacaine on the response to exogenous administration of N-methyl-D-aspartate (NMDA) receptor agonists were examined in lamina II neurons of adult rat spinal cord slices using the whole-cell patch-clamp technique.Results: Bupivacaine (0.5, 2 mM) dose-dependently reduced the peak amplitudes of exogenous NMDA-induced currents. However, this inhibitory effect of bupivacaine (2 mM) was not blocked by the presence of tetrodotoxin, a sodium channel blocker, or La3+ , a voltage-gated Ca2+ channel blocker, and was unaffected by changes in pH conditions. Moreover. intrapipette guanosine-5'-O-(2-thiodiphosphate) (1 mM), a G-protein inhibitor, did not block the reduction of NMIDA current amplitudes by bupivacaine. Similarly, lidocaine, ropivacaine, and mepivacaine also reduced the amplitudes of NMDA-induced currents.Conclusions: These findings raise the possibility that the antinociceptive effect of bupivacaine may be due to direct modulation of NMDA receptors in the Superficial dorsal horn. In addition to voltage-gated sodium channels, glutamate NMDA receptors are also important for analgesia induced by local anesthetics.