电针对佐剂性关节炎大鼠病灶局部皮肤组织GDNF阳性细胞免疫反应性的影响

目的：探讨电针对佐剂性关节炎大鼠的镇痛作用机制。方法：将SD大鼠48只随机分为空白对照组（n=8）、炎症组（n=10）、穴位电针组（n=10）、非穴位电针组（n=10）及对侧穴位电针组（n=10）。采用完全弗氏佐剂制备关节炎模型。对穴位、非穴位及对侧穴位电针组大鼠隔天针刺,穴位为“环跳”“阳陵泉”;非穴位为两穴旁开5mm处。观察背屈踝关节疼痛试验评分、足部肿胀程度,以及关节炎大鼠踝关节周围皮肤及皮下组织胶质细胞源性神经营养因子（GDNF）阳性细胞免疫反应性。结果：炎症组大鼠注射足出现了明显的痛觉过敏和局部肿胀,同时外周局部组织GDNF表达增加。电针患侧、对侧穴位可以显著缓解疼痛,加速炎症足肿胀的恢复,并显著降低炎症侧踩关节真皮层及皮下浅层组织GDNF阳性细胞的平均光密度和阳性面积百分比;而非穴位电针对照组没有显著疗效。结论：电针可以调控佐剂性关节炎大鼠炎性痛病灶局部皮肤组织GDNF的表达,从而发挥消炎镇痛的作用。穴位与非穴位之间存在作用的差异。

Effects of electroacupuncture on GDNF positive cell immunoreactivity in local dermal tissue of the inflammatory pain focus in the rat of adjuvant arthritis

OBJECTIVE: To study on the analgesic mechanism of electroacupuncture (EA) in the rat of adjuvant arthritis (AA). METHODS: Forty-eight SD rats were randomly divided into a blank control group (n = 8), an inflammatory group (n = 10), an acupoint EA group (n = 10), a non-acupoint EA group (n = 10) and a contralateral acupoint EA group (n = 10). Complete Freund's adjuvant (CFA) 50 microL were injected into the left malleolus' articular cavity in the rats except the blank control group for preparing single local adjuvant arthritis (AA) model. EA was given every other day to the acupoint EA group, the non-acupoint EA group and the contralateral acupoint EA group. The improving effects of EA at "Huantiao" (GB 30) and "Yanglingquan" (GB 34) on the dorsal flexion pain score and the swell of dorsum of hind paw were investigated, and effects of EA on Glial cell line-derived neurotrophic factor (GDNF) positive cells immunoreactivity in the inflammatory tissue of the AA rats on the 14th day after injection of adjuvant were observed with immunohistochemical technique. RESULTS: Hyperalgesia and local swell, and GDNF in the dermal and subcutaneous tissue around the inflammatory ankle joint in the inflammatory groups were significantly higher than those in the blank control group. EA on the ipsilateral and contralateral acupoints reduced the pain, promoted the recovery of swell, and decreased the positive area percentage and mean optical density of GDNF positive cells in the dermal and the subcutaneous tissues. However, the non-acupoint EA group did not have this action. CONCLUSION: EA can regulate expression of GDNF in local dermal tissue of the inflammatory focus in the AA rat, so as to exert the anti-inflammatory and analgesic effects.