针刺外关穴对甲醛致炎性疼痛模型大鼠痛阈及海马Bcl-2表达的影响

Effect of Needling at Waiguan(SJ5)on Pain Threshold and the Expression of Bcl-2 in Hippocampus of Rats with Inflammatory Pain Induced by Formaldehyde

目的探讨针刺对甲醛致炎性疼痛大鼠痛阈及海马Bcl-2表达的影响。方法将炎性疼痛模型大鼠随机分为模型组、外关30min组、非经穴30min组、外关60min组及非经穴60min组,每组6只。模型组:造模成功后予模拟抓取动作,余不做任何处理,置鼠笼60min后取材。外关30min组、非经穴30min组予相应的针刺干预后,置鼠笼中30min后取材;外关60min组、非经穴60min组在干预后置鼠笼中60min后取材。采用鼠尾测痛仪检测鼠甩尾潜伏期,采用免疫组化检测海马Bcl-2蛋白表达水平。结果外关30min组、外关60min组的鼠甩尾潜伏期比干预前提高,经配对t检验,干预后两组鼠甩尾潜伏期时间评分与干预前比较有显著性差异(P<0.05)。各组干预后,经单因素方差分析,外关30min组、外关60min组与模型组比较有显著性差异(P<0.05)。海马Bcl-2蛋白经免疫组化检测结果经LSD(L)分析,结果显示外关30min组与模型组比较有显著性差异(P<0.05)。结论针刺炎性疼痛大鼠外关穴后30min或60min均可明显提高大鼠痛阈。外关30min组与外关60min组、非经穴30min组、非经穴60min组相比无显著性差异(P>0.05)。同时,针刺外关30min后可上调海马区Bcl-2表达,初步表明针刺干预可能通过Bcl-2介导的凋亡传导通路发挥抗细胞凋亡作用。

Objective To investigate the effect of acupuncture on Pain threshold and the expression of Bcl-2 in hippocampus of rats with inflammatory pain Induced by formaldehyde. Methods The rats with inflammatory pain were randomly divided into model group （group A）, 30 min group needled at Waiguan （SJ5）（group B）, 30 min group needled at non-acupoint （group C）, 60 min group needled at Waiguan（group D） and 60 min group needled at non-acupoint（group E）, 6 rats in each group. The rats with inflammatory pain for 30 min groups were retained 30 mins after intervention, and then sacrificed for sampling. And the rats with inflammatory pain for 60 min groups were retained 60 mins after intervention, and then sacrificed for sampling. The model group had no acupuncture treatment. Tail-flick latency was determined with Tail Flick Analgesia Meter. And the expression of Bcl-2 in hippocampus was detected by immunohistochemical techniques. Results After paired t-test, differences were significant before and after intervention in group B and group D.（P〈0.05）. After intervention, comparisons between the five groups were tested by One-Way ANOVA analysis, both group B and group D were obviously better than model group （P〈0.05）. then we used LSD test for the comparisons of the expression of Bcl-2 in hippocampus in these groups. It showed that group B was obviously better than group A （P〈0.05）. Conclusion Afer needling at Waiguan （SJ5）, Pain threshold of the inflammatory pain rats retained 30 min or 60 min was significantly improved. And there was no significant difference among group B、 group C、 group D and group E （P〉0.05）. Meanwhile, afer needling Waiguan （SJ5）, the expression of Bcl-2 in the inflammatory pain rats＆#39; hippocampus retained 30 min was increased. It is primary proved that effect of acupuncture on antiapoptosis may through the role of Bcl-2 anti-apoptotic signal pathway.