局麻药长时间阻滞外周神经对神经源性疼痛发生过程中背根神经节内GAP-43表达的影响

THE EFFECT OF CONTINUOUS PERIPHERAL NERVE BLOCKAGE BY LOCAL ANESTHETICS ON THE EXPRESSION OF GROWTH ASSOCIATED PROTEIN-43 IN THE DORSAL ROOT GANGLION DURING THE DEVELOPMENT OF NEUROPATHIC PAIN

用免疫组织化学方法观察了局麻药长时间阻滞外周神经对神经源性疼痛发生过程中生长相关蛋白(GAP-43)在背根神经节内表达的影响。实验选用SD大鼠35只,随机分成正常对照组、单纯坐骨神经横切组、坐骨神经横切前阻滞组、坐骨神经横切后阻滞组4大组,后三大组再按术后取材时间分为3、7d两个时间组。暴露大鼠右侧坐骨神经,于坐骨结节远端约1cm处横断坐骨神经。根据分组,阻滞组分别从横切前1h和横切后4h开始对神经横切的近心端进行长效局麻药阻滞,持续整个观察期。术后不同时间取与伤侧坐骨神经相连的背根神经节(DRG),应用免疫组织化学和图像分析的方法研究背根神经节中GAP-43的表达并进行定量分析。结果表明:术后3、7d,单纯坐骨神经横切组背根神经节内的GAP-43表达增高,而阻滞组内的GAP-43表达与正常组无差别。本研究结果提示坐骨神经横切前1h或之后4h开始局麻药阻滞神经均能抑制神经源性疼痛发生过程中GAP-43的高表达。

By using immunohistochemistry method, we observed the effect of continuous peripheral nerve blockage by local anesthetics on growth associated protein-43 （ GAP-43 ） expression in the dorsal root ganglion during the development of neuropathic pain. Thirty-five SD rats were randomly divided into 4 groups ： control group ; simple sciatic nerve section group ; pre-section nerve blockage group ; post-section nerve blockage group. Each experimental group was subdivided equally into 2 groups according to the different postoperative interval ： 3 and 7 days. The right sciatic nerve was exposed and transected at 1 cm distal to the ischial tuberosity. The nerve blockage groups were injected with local anesthetics 1 h before or 4 h after operation, respectively. At various intervals after surgery, the dorsal root ganglia ipsilateral to the transected sciatic nerve were harvested. Immunohistochemistry and image analysis were used to evaluate the expression of GAP-43. The results showed that at the third and seventh day after surgery, the GAP-43 expression in the simple sciatic nerve section group was higher than that in control group, nerve blockage pre- and post-operation groups, respectively. These results suggest that the continuous peripheral nerve blockage can suppress the increased expression of GAP-43 during the development of neuropathic pain.