锂剂促进周围神经损伤修复的初步研究

目的 探讨锂剂对周围神经损伤后神经再生的影响.方法 取48只雌性SD大鼠,制作大鼠右侧坐骨神经损伤动物模型,通过腹腔注射氯化锂,在不同时间点观察动物下肢活动情况,检测小腿三头肌神经电生理及肌湿重,并对损伤远端神经纤维的神经丝蛋白(NF200)、单核巨噬细胞抗原(ED1)、P-75和运动终板进行免疫组织化学染色观察.结果 损伤后4周,实验组动物下肢已接近正常行走步态,对照组右侧肢体仍明显跛行;损伤后2周和4周,实验组的复合肌肉动作电位(CMAP)波幅较对照组明显增大,两组间的差异有统计学意义(P＜0.05);损伤后4周、8周,实验组的小腿三头肌重量较对照组明显增大,两组间差异有统计学意义(P＜0.05);损伤后3 d,在距离损伤远端5 mm处,实验组坐骨神经纤维内NF200呈连续丝状染色,而对照组仍然是颗粒状染色;损伤后4周,在神经肌肉接头处,可观察到实验组肌肉运动终板有新生神经纤维支配,而对照组运动终板上无神经纤维支配,两组ED1及P75染色未见明显差别.结论 锂剂可有效促进周围神经损伤后的再生,但其机制仍需进一步研究.

Promotion of nerve regeneration after crash injury using lithium: a preliminary study

Objective To evaluate the effect of lithium on nerve regeneration after peripheral nerve injury.Methods Sciatic nerve crash injury model was created on the right side of 48 female SD rats.Lithium was administered after the injury by intraperitoneal injection.Locomotion of the lower limbs, electromyography and wet muscle weight of the triceps muscles were measured at different time points after the injury.Changes of NF200, ED1, P-75 and motor end plate at the distal part of the injured nerve were detected by immunohistostaining.Results Four weeks after sciatic nerve crash injury, animals that received lithium injection restored near normal gait, whereas the control animals were limping.Two and four weeks after the injury, the lithium injection group had significantly higher CMAP amplitude than the control group.Four and eight weeks after the injury, the wet muscle weight in lithium injection group was significantly heavier than the control group.Three days after crush injury, continuous NF200 positive fibers were found 5 mm distal to the injury site in the lithium injection group, whereas in the control group, only granular NF200 positive staining was observed Four weeks after crush injury, new innervations to the motor end plate were detected in the neuromuscular junction in the lithium injection group, but not in the control group.No differences in ED1 and P75 staining were detected.Conclusion Lithium could significantly promote axon regeneration after peripheral nerve crush injury.Its mechanism is subject to further investigation.