Department of Anaesthesiology, Gunma University, Showa-machi, Maebashi, Japan.
Br J Anaesth. 2010 Apr;104(4):482-6. doi: 10.1093/bja/aeq030. Epub 2010 Mar 1.
Local anaesthetics exhibit direct neurotoxic effects on neurones. Numerous studies have investigated the factors that may reverse this neuropathology, but the effects of glucose conditions on neuronal regeneration after lidocaine-induced injury have not been examined by observing living neurones. The present study investigated the effects of different glucose conditions on neurite length, growth cone regeneration, and cell death in dorsal root ganglia (DRG) neurones after lidocaine-induced injury in vitro.
DRG explants were isolated from chick embryos at embryonic day 8 and cultured in media containing low, normal, or high glucose concentrations (10, 25, or 40 mM) for 24 h. Tissues were exposed to lidocaine 8 mM for 1 h, then rinsed and incubated for a further 24 h. Neurite length and growth cone collapse assays were performed to assess neuronal growth and regeneration. Lactate dehydrogenase (LDH) and caspase assays were also performed to detect neuronal cell death.
Addition of lidocaine for 1 h resulted in >97% growth cone collapse and neurite destruction under all three glucose conditions. Two hours after rinsing out the lidocaine, significant reversal of growth cone collapse and neurite elongation was observed under all glucose conditions. Growth cone collapse was higher under low-glucose condition (P<0.05). High glucose negatively affected neurite length more than growth cone collapse. At 24 h, LDH release with both low- and high-glucose conditions was higher than with normal glucose (P<0.05). Low- and high-glucose conditions increased caspase 3/7 activation.
Normal glucose is optimal for neuronal recovery after lidocaine-induced injury in vitro.
局部麻醉剂对神经元表现出直接的神经毒性作用。许多研究已经调查了可能逆转这种神经病理学的因素，但尚未通过观察活神经元来检查葡萄糖条件对利多卡因诱导损伤后神经元再生的影响。本研究在体外研究了不同葡萄糖条件对利多卡因诱导损伤后背根神经节（DRG）神经元轴突长度、生长锥再生和细胞死亡的影响。
从胚胎 8 天的鸡胚中分离 DRG 外植体，并在含有低、正常或高葡萄糖浓度（10、25 或 40mM）的培养基中培养 24 小时。组织暴露于 8mM 利多卡因 1 小时，然后冲洗并进一步孵育 24 小时。进行轴突长度和生长锥塌陷测定以评估神经元的生长和再生。还进行乳酸脱氢酶（LDH）和半胱氨酸天冬氨酸蛋白酶（caspase）测定以检测神经元细胞死亡。
在三种葡萄糖条件下，加入利多卡因 1 小时可导致>97%的生长锥塌陷和轴突破坏。冲洗掉利多卡因 2 小时后，在所有葡萄糖条件下均观察到生长锥塌陷和轴突伸长的显著逆转。在低糖条件下生长锥塌陷更高（P<0.05）。高葡萄糖比生长锥塌陷更不利于轴突长度。在 24 小时时，低葡萄糖和高葡萄糖条件下的 LDH 释放均高于正常葡萄糖（P<0.05）。低葡萄糖和高葡萄糖条件增加了 caspase 3/7 的激活。
正常葡萄糖是利多卡因诱导的体外损伤后神经元恢复的最佳选择。
