背根神经节S1PR1在瑞芬太尼诱发切口痛大鼠痛觉过敏中的作用

Role of S1PR1 in dorsal root ganglion in remifentanil-induced hyperalgesia in rats with incisional pain

目的评价背根神经节鞘氨醇-1-磷酸-1受体(S1PR1)在瑞芬太尼诱发切口痛大鼠痛觉过敏中的作用。方法取鞘内置管和尾静脉置管成功的雄性SD大鼠48只,体质量260~280 g,2~3月龄,采用随机数字表法分为6组(n=8):对照组(C组)、S1PR1拮抗剂组(F组)、瑞芬太尼组(R组)、瑞芬太尼+S1PR1拮抗剂组组(R+F组)、瑞芬太尼+切口痛组(R+I组)和瑞芬太尼+切口痛+S1PR1拮抗剂组(R+I+F组)。C组尾静脉输注生理盐水0.1 ml·kg^(-1)·min^(-1)60 min;R组尾静脉输注瑞芬太尼1.0μg·kg^(-1)·min^(-1)60 min;F组鞘内注射FTY7203 noml,10 min后尾静脉输注生理盐水1.0μg·kg^(-1)·min^(-1)60 min;R+F组鞘内注射FTY7203 nmol,10 min后尾静脉输注瑞芬太尼1.0μg·kg^(-1)·min^(-1)60 min;R+I组建立切口痛模型的同时尾静脉输注瑞芬太尼1.0μg·kg^(-1)·min^(-1)60 min;R+I+F组鞘内注射FTY7203 nmol,10 min后建立切口痛模型,同时尾静脉注射瑞芬太尼1.0μg·kg^(-1)·min^(-1)60 min。于输注瑞芬太尼或生理盐水前24 h和停止输注后2、6、24、48 h(T_(1~4))时测定机械缩足反应阈(MWT)和热缩足潜伏期(TWL)。最后1次测定痛阈后处死大鼠,取L4~6节段背根神经节,分别采用Western blot和q-PCR法测定S1PR1、NOD样受体热蛋白结构域相关蛋白3(NLRP3)、白细胞介素1β(IL-1β)和谷氨酸转运体-1(GLT-1)及其mRNA的表达水平。结果与C组比较,R组和RI组T1~4时MWT降低,TWL缩短,背根神经节S1PR1、NLRP3、IL-1β及其mRNA表达上调,GLT-1表达及其mRNA下调(P<0.05),F组上述指标差异无统计学意义(P>0.05)。与R组比较,R+I组T1~4时MWT降低,TWL缩短,背根神经节S1PR1、NLRP3、IL-1β及其mRNA表达上调,GLT-1表达及其mRNA下调,R+F组T1~4时MWT升高,TWL延长,背根神经节S1PR1、NLRP3、IL-1β及其mRNA表达下调,GLT-1及其mRNA表达上调(P<0.05)。与R+I组比较,R+I+F组T1~4时MWT升高,TWL延长,背根神经节S1PR1、NLRP3、IL-1β及其mRNA表达下调,GLT-1及其mRNA表达上调(P<0.05)。结论瑞芬太尼诱发切口痛大鼠痛觉过敏的机制与上调S1PR1的表达,激活炎症因子,下调GLT-1的表达有关。

Objective To evaluate the role of sphingosine-1-phospho-1receptor(S1PR1)in the dorsal root ganglion in remifentanil-induced hyperalgesia in rats with incisional pain.Methods Forty-eight male Sprague-Dawley rats with successful intrathecal and caudal vein catheterization,weighing 260-280 g,aged 2-3 months,were divided into 6 groups(n=8 each)using a random number table method:control group(group C),S1PR1 antagonist(FTY720)group(group F),remifentanil group(group R),remifentanil+S1PR1 antagonist(FTY720)group(group R+F),remifentanil+incisional pain group(group R+I),and remifentanil+incisional pain+S1PR1 antagonist(FTY720)group(group R+I+F).In C group,normal saline 0.1μg·kg^(-1)·min^(-1)was intravenously infused for 60 min.In R group,remifentanil 1.0μg·kg^(-1)·min^(-1)was infused for 60 min through the caudal vein.In F group,FTY7203 nmol was intrathecally injected,and 10 min later normal saline 1.0μg·kg^(-1)·min^(-1)was infused for 60 min via the caudal vein.In R+F group,FTY7203 nmol was intrathecally injected,and 10 min later remifentanil 1.0μg·kg^(-1)·min^(-1)was infused for 60 min through the caudal vein.In R+I group,remifentanil 1.0μg·kg^(-1)·min^(-1)was infused for 60 min through the caudal vein while the model of incisional pain was developed.In R+I+F group,FTY7203 nmol was intrathecally injected,10 min later the incisional pain model was prepared,and remifentanil 1.0μg·kg^(-1)·min^(-1)was injected for 60 min through the caudal vein at the same time.The mechanical paw withdrawal threshold(MWT)and thermal paw withdrawal latency(TWL)were measured at 24 h before remifentanil or normal saline infusion(T0)and 2,6,24 and 48 h after stopping remifentanil or normal saline infusion(T1-4).Rats were sacrificed after the last measurement of pain threshold,and the L4-6 segments of dorsal root ganglion were taken for determination of the expression of S1PR1,NOD-like receptor thermal protein domain-associated protein 3(NLRP3),interleukin-1β(IL-1β)and glutamate transporter-1(GLT-1)protein and mRNA(by Western blot and quantitative polymerase chain reaction).Results Compared with C group,the MWT was significantly decreased and TWL was shortened at T1-4,the expression of S1PR1,NLRP3 and IL-1βprotein and mRNA in dorsal root ganglion was up-regulated,and the expression of GLT-1 protein and mRNA in dorsal root ganglion was down-regulated in R group(P<0.05),and no significant change was found in the parameters mentioned above in group F(P>0.05).Compared with R group,MWT was significantly decreased and TWL was shortened at T1-4,the expression of S1PR1,NLRP3 and IL-1βprotein and mRNA in dorsal root ganglion was up-regulated,and GLT-1 protein and mRNA expression in dorsal root ganglion was down-regulated in R+I group,and MWT was significantly increased and TWL was prolonged at T1-4,the expression of S1PR1,NLRP3 and IL-1β protein and mRNA in the dorsal root ganglion was down-regulated,and GLT-1 protein and mRNA expression in the dorsal root ganglion was up-regulated in R+F group(P<0.05).Compared with R+I group,MWT was significantly increased and TWL was prolonged at T1-4,the expression of S1PR1,NLRP3 and IL-1βprotein and mRNA in the dorsal root ganglion was down-regulated,and the expression of GLT-1 protein and mRNA in the dorsal root ganglion was up-regulated in R+I+F group(P<0.05).Conclusions The mechanism by which remifentanil induces hyperalgesia is associated with up-regulation of S1PR1 expression,activation of inflammatory factors,and down-regulation of GLT-1expression in the rats with incisional pain.