电针与艾灸对内脏高敏感大鼠穴区辣椒素受体和热休克蛋白70表达的影响及镇痛效应

Effect of Electroacupuncture and Moxibustion on Visceral Pain and Expression of VR 1 and HSP 70 of “Tianshu”(ST 25)Region in Colorectal Distension-induced Visceral Hypersensitivity Rats

目的:探讨电针与艾灸对内脏高敏感大鼠穴区辣椒素受体1(VR 1)和热休克蛋白70(HSP 70)表达的影响及其镇痛效应是否存在差异。方法:将SD大鼠随机分为正常组、模型组、艾灸43℃组、艾灸46℃组、电针1mA组、电针3mA组,每组各10只。采取直结肠扩张(CRD)的方法制备内脏高敏感模型。艾灸和电针分别刺激"天枢"穴,每日1次,连续10d。腹部撤回反射(AWR)评分评价大鼠对直肠内不同程度扩张刺激的敏感性,免疫组化法观察穴区VR 1、HSP 70的表达。结果:在20、40、60、80mmHg CRD刺激下,模型组AWR评分均显著升高(P<0.01),艾灸43℃组、艾灸46℃组、电针1mA组、电针3mA组与模型组相比AWR评分均显著降低(P<0.01,P<0.05);艾灸46℃组在40、80mmHg时评分低于电针1mA组(均P<0.05),在40mmHg时评分低于电针3mA组(P<0.05)。模型组穴区VR 1、HSP 70的表达与正常组比较差异无统计学意义(P>0.05);艾灸43℃组、艾灸46℃组穴区VR 1的表达较模型组、电针1mA组、电针3mA组均显著升高(P<0.01),且艾灸46℃组显著高于艾灸43℃组(P<0.01);艾灸43℃组、艾灸46℃组和电针1mA组、电针3mA组穴区HSP 70的表达均较模型组显著升高(P<0.01),其中艾灸46℃组明显高于其他各组(P<0.01)。结论:43℃、46℃不同温度艾灸和1mA、3mA不同强度电针刺激均可不同程度地改善/升高内脏高敏感模型大鼠的痛阈,其中以46℃艾灸的效应最为显著;这种镇痛效应与其能在一定程度上激活穴区VR 1和HSP 70表达有关。

Objective To compare the effects of electroacupuncture（EA）and moxibustion（Moxi）on visceral pain and expression of vanilloid receptor subtype 1（VR 1）and heat shock protein（HSP）70 in＂Tianshu＂（ST 25）region in colorectal distension（CRD）-induced visceral hypersensitivity（VHS）rats.Methods Fifty male SD rats were randomly divided into normal control,VHS model,43℃-moxi,46℃-moxi,1mA-EA and 3mA-EA groups（n=10in each group）.The VSH model was established by CRD once daily for 14 days.EA or Moxi stimulation was applied to bilateral＂Tianshu＂（ST 25）for 10 min,once daily for consecutive 10 days.The abdominal withdrawal reflex（AWR）scores（0-4points）were rated according to Al-Chaer＇s and coworkers＇ standards（2000）and the expression levels of VR 1and HSP 70 in bilateral ST 25 area tissues detected by immunohistochemistry.Results The AWR scores for 20,40,60 and 80mmHg CRD pressures were significantly increased compared to the normal control group（P〈0.01）and notably decreased after 43 ℃-and 46 ℃-moxi,and 1mA-and 3mA-EA stimulation of bilateral ST 25 in comparison with the model group（P〈0.05,P〈0.01）,and the effect of 46 ℃-moxi was apparently superior to those of 1mA-EA at 40 and 80mmHg,and 3mA-EA at 40mmHg（P〈0.05）.After modeling,the expression of both VR 1and HSP 70（percentages of area of positive-cells）in ST 25 region had no significant changes（P〈0.05）.Compared to the model group,the expression levels of VR 1in the 43 ℃-moxi and 46 ℃-moxi groups,and HSP 70 in the 43 ℃-moxi and 46 ℃-moxi,1mA-EA and 3mA-EA groups were significantly up-regulated（P〈0.01）,but without obvious changes in the expression of VR 1in the 1mA-EA and 3mA-EA groups（P〈0.05）.The effects of 46 ℃-moxi were considerably better than those of 43 ℃-moxi,1mA-EA and 3mA-EA in up-regulating VR 1and HSP 70expression（P〈0.05,P〈0.01）.No significant differences were found among the 43℃-moxi,1mA-EA and 3mA-EA groups in the expression of VR 1 and HSP 70（P〈0.05）.Conclusion Moxibustion at 43℃ and 46℃ and EA at 1mA and 3mA,especially the 46℃-moxi,can relieve visceral pain in visceral hypersensitivity rats,which may be related to their effects in up-regulating expression of VR 1and HSP 70in＂Tianshu＂（ST 25）area.