基于VBM技术的杜仲腰痛丸干预腰椎间盘突出症慢性下肢痛模型大鼠的实验研究

Experimental Study on Voxel-based Morphometry of Chronic Lower Limb Pain Rats with Lumbar Disc Herniation Intervened by Duzhong Yaotong Pills

目的基于体素的磁共振形态学(Voxel-based morphometry,VBM)技术和疼痛行为学技术,探讨杜仲腰痛丸对腰椎间盘突出症(LDH)慢性下肢痛模型大鼠脑结构及形态学改变的影响,阐明杜仲腰痛丸的作用效应,为杜仲腰痛丸更好地应用于临床提供理论和实验依据。方法将SD雄性大鼠72只,随机分为正常组、模型组、治疗组,模型组和治疗组建立自体髓核移植型腰椎间盘突出症慢性下肢痛大鼠模型。治疗组给予杜仲腰痛丸药液259.2 mg·kg^-1灌胃,每日2次,正常组和模型组给予相同剂量的生理盐水灌胃。各组分别于给药前0 d和给药后2 d、7 d、14 d、21 d、28 d进行疼痛行为学观察,主要包括机械缩足反射阈值(Mechanical withdrawal threshold,MWT)测定和热缩足反射潜伏期(Thermal withdrawal latency,TWL)测定。每组随机选取4只大鼠分别于给药前0 d和给药后14 d、28 d行T2加权结构像和VBM图像采集,采用重复测量方差分析对灰质体积进行统计分析。结果(1)正常组和模型组大鼠MWT值在给药前0 d至给药后28 d内保持相对稳定水平;与同时间点正常组比,模型组MWT值下降(P<0.05)。治疗组大鼠MWT值在给药前0 d、给药后2 d、7 d分别与同时间点模型组大鼠MWT值比较,差异无统计学意义(P>0.05);而在给药后14 d、21 d、28 d分别比同时间点模型组大鼠MWT值明显升高(P<0.05)。治疗组大鼠MWT值在给药后21 d、28 d分别与同时间点正常组大鼠MWT值比较,差异无统计学意义(P>0.05)。(2)各组TWL值比较结果与MWT值的比较结果相似。(3)3组大鼠不同时间点脑结构区域比较存在交互作用,差异具有统计学意义(P<0.05)。具体表现为左外侧内嗅皮层、左初级躯体感觉皮层、右嗅球、右视皮层、右海马、右后晶状体皮层、胼胝体及双侧皮质下灰质这些脑区的灰质体积增加。结论(1)杜仲腰痛丸能提高腰椎间盘突出症慢性下肢痛模型大鼠的MWT值和TWL值,具有缓解腰椎间盘突出症慢性疼痛作用。(2)杜仲腰痛丸可以部分改善或逆转异常的脑形态及脑结构,通过治“脑”发挥止痛作用。

Objective To investigate the effects of Duzhong Yaotong Pills on the brain structure and morphology of lubar disc herniation(LDH)chronic lower limb pain model rats by Voxel-based morphology technology and pain behavior technology,and to clarify the action effect of Duzhong Yaotong Pills and to provide theoretical and experimental basis for its better clinical application.Methods Seventy-two SD male rats aged 6-8 weeks,with body weights of(250±20)g,were selected.They were randomly divided into three groups:Normal group,LDH group and Treatment group.The model of autologous nucleus pulposus transplanted rats with chronic lower limb pain was established in the LDH group and Treatment group.Rats in the Treatment group were given Duzhong Yaotong Pills medicine at a dose of 259.2 mg·kg^-1 twice a day,and the Normal group and the LDH group were given the same dose of saline.The pain behavioral observation was performed in each group on 0 d before treatment and 2 d,7 d,14 d,21 d and 28 d after treatment,mainly including mechanical pain threshold measurement,and thermal pain threshold measurement.Four rats in each group were randomly selected to collect T2 weighted structural images and VBM images on 0 d before treatment and on 14 d and 28 d after treatment.Statistical analysis of gray matter volume was performed by repeated measurement analysis of variance.Results(1)The MWT value of rats in Normal group and LDH group remained relatively stable from 0 d before treatment to 28 d after treatment.There was no significant difference in the MWT values of rats in the Treatment group between 0 d before treatment,2 d and 7 d after treatment compared with the MWT values of LDH group at the same days(P>0.05).The MWT values of rats in the Treatment group were compared with the LDH group at the same time on 14 d,21 d,and 28 d after treatment,and the differences were statistically significant(P<0.05).The MWT values of rats in the Treatment group were compared with those of the Normal group at the same time on 21 d and 28 d after treatment,and there was no significant difference(P>0.05).(2)The TWL value results are similar to the MWT value results.(3)In the part of VBM study of LDH chronic lower limb pain model rats,there were interactions between the brain structure regions of the three groups of rats at different time points,and the differences were statistically significant(P<0.05).Gray matter volumes were reduced in these brain regions,specifically,hypothalamic region L,subiculum L,secondary motor cortex R,striatum R,septal region R,cornu ammonis R,corpus callosum andassociated subcortical gray matter L and R,molecular layer of the cerebellum L and R.Conclusion(1)Duzhong yaotong Pills can increase the MWT value and TWL value of LDH chronic lower limb pain model rats,it can relieve the chronic pain of LDH.(2)Duzhong Yaotong Pills can partially change or reverse abnormal brain morphology and structure,and exert analgesic effect by treating“brain”.