逆灸神阙、关元对痛经大鼠脊髓背角和下丘脑BDNF-TrkB通路的影响

Effects of preventative moxibustion at Shenque(CV8)and Guanyuan(CV4)on BDNF-TrkB pathway in the spinal dorsal horn and hypothalamus in rats with dysmenorrhea

目的:观察逆灸神阙、关元对寒湿凝滞型痛经大鼠的镇痛效果,以及对P物质(SP)、前列腺素(PG)F_(2α)及PGE_(2)的影响,探讨其镇痛机制。方法:将64只雌性Wistar未孕大鼠随机分为空白组、模型组、西药物及逆灸组,每组16只。大鼠动情间期每组筛选出合格大鼠8只。除空白组外,其他三组使用冰水浴结合苯甲酸雌二醇复合缩宫素的方法建立寒湿凝滞型痛经模型。第8 d造模后,逆灸组温和灸神阙、关元穴治疗,西药组布洛芬溶液灌胃,连续4 d。至第11 d,干预组(即西药组和逆灸组)注射缩宫素后再治疗1次。计算大鼠扭体评分,测定痛阈;检测血清脑源性神经生长因子(BDNF)、SP、PGF_(2α)及PGE_(2)含量,检测脊髓背角及下丘脑中BDNF及其受体原肌球蛋白受体激酶B(TrkB)mRNA及蛋白表达。结果:与空白组比较,模型组扭体评分升高(P<0.01),痛阈降低(P<0.01);血清BDNF、SP及PGF_(2α)含量升高(P<0.01),PGE_(2)降低(P<0.01);脊髓背角及下丘脑中BDNF、TrkB蛋白及mRNA表达升高(P<0.01)。与模型组比较,逆灸组和西药组的扭体评分明显降低,痛阈升高,血清BDNF、SP、PGF_(2α)含量降低,PGE_(2)含量升高,脊髓背角及下丘脑中BDNF、TrkB蛋白及mRNA表达降低,组间差异均有统计学意义(P<0.01)。与西药组比较,逆灸组扭体评分降低,痛阈升高,血清BDNF、SP及PGF_(2α)含量降低,PGE_(2)含量升高,脊髓背角、下丘脑中BDNF、TrkB蛋白及mRNA表达显著降低,组间差异均有统计学意义(P<0.05或P<0.01)。结论:逆灸神阙、关元可改善寒湿凝滞型痛经大鼠痛觉敏化状态,下调脊髓背角和下丘脑BDNF、TrkB mRNA和蛋白表达;调节血清SP、PGF_(2α)和PGE_(2)含量可能是其部分作用机制。

Objective:To observe the effects of preventative moxibustion on analgesia,substance P(SP),prostaglandin(PG)F_(2α)and PGE_(2) in rats with dysmenorrhea due to cold-dampness stagnation,and to explore the analgesic mechanism.Methods:Sixty-four female Wistar non-pregnant rats were randomly divided into a blank group,a model group,a Western medicine group,and a preventative moxibustion group,with 16 rats in each group.Eight qualified diestrus rats were selected from each group.Except for the blank group,the other three groups established models of dysmenorrhea due to cold-dampness stagnation using an ice water bath combined with estradiol benzoate and oxytocin.On the 8th day after modeling,the preventative moxibustion group was treated with gentle moxibustion at Shenque(CV8)and Guanyuan(CV4),and the Western medicine group was given ibuprofen solution for 4 consecutive days.On the 11th day,the intervention groups(i.e.the Western medicine group and the preventative moxibustion group)were treated once again after being injected with oxytocin.The writhing score and the pain threshold of rats were determined;the serum levels of brain-derived neurotrophic factor(BDNF),SP,PGF_(2α),and PGE_(2) were measured;the mRNA and protein expression levels of BDNF and its receptor tropomyosin receptor kinase B(TrkB)in the spinal dorsal horn and hypothalamus were detected.Results:Compared with the blank group,the writhing score increased(P<0.01),the pain threshold decreased(P<0.01),the serum levels of BDNF,SP,and PGF_(2α)increased(P<0.01),while the PGE_(2) decreased(P<0.01);the protein and mRNA expression levels of BDNF and TrkB in the spinal dorsal horn and hypothalamus increased(P<0.01)in the model group.Compared with the model group,the writhing score decreased,the pain threshold increased,the serum BDNF,SP,and PGF_(2α)levels decreased significantly,the serum PGE_(2) level increased,and the protein and mRNA expression levels of BDNF and TrkB in the spinal dorsal horn and hypothalamus decreased significantly in the preventative moxibustion group and the Western medicine group,while the inter-group differences were significant(P<0.01).Compared with the Western medicine group,the writhing score decreased,the pain threshold increased,the serum BDNF,SP,and PGF_(2α),levels decreased,the serum PGE_(2) level increased,and the protein and mRNA expression levels of BDNF and TrkB in the spinal dorsal horn and hypothalamus in the preventative moxibustion group decreased significantly,while the inter-group differences were significant(P<0.05 or P<0.01).Conclusion:Preventative moxibustion at Shenque(CV8)and Guanyuan(CV4)can improve the pain sensitization state of rats with dysmenorrhea due to cold-dampness stagnation,down-regulate the mRNA and protein expression levels of BDNF and TrkB in the spinal dorsal horn and hypothalamus;regulation of the serum SP,PGF_(2α),and PGE_(2) levels may be part of the mechanism.