环氧合酶1抑制剂对大鼠术后机械痛敏及ASIC3表达的影响

Effect of cyclooxygenase 1 inhibitor on mechanical hyperalgesia and ASIC3 expression in a rat model of postoperative pain

目的观察环氧合酶(COX)1抑制剂对术后痛大鼠机械痛敏及背根神经节(DRG)酸敏感离子通道3(ASIC3)表达的影响,探讨ASIC3在术后急性疼痛中的作用。方法 SPF级雄性SD大鼠48只,其中18只按Brennan法建立术后痛模型,随机均分为二甲基亚砜(DMSO)+SC560组(S组)、DMSO组(D组)和对照组(C组)。其中S组和D组造模前分别鞘内给予用10μl DMSO溶解后的SC560 100μg和单纯DMSO 10μl,C组不作处理。于术后2、4、12、24、48h测定三组大鼠机械痛阈(MWT),观察最痛时点。另30只大鼠随机均分为相同三组,采用Western blotting法测定最痛时间点三组大鼠L3～L5 DRG ASIC3表达水平。结果 D组和C组大鼠术后各时点MWT差异无统计学意义。C组大鼠术后24h MWT明显低于其他时间点(P<0.05)。术后24hS组大鼠MWT明显高于C组和D组(P<0.05),DRG ASIC3蛋白表达灰度值明显低于C组和D组(P<0.01)。C组和D组大鼠MWT和ASIC3蛋白表达灰度值差异无统计学意义。结论术后24h大鼠机械痛敏最强,DRG ASIC3表达增高。给予SC560可抑制ASIC3表达,减轻痛敏。

Objective To observe the effect of cyclooxygenase（COX） 1 inhibitor on mechanical hyperalgesia and acid-sensing ion channel 3 （ASIC3） expression in DRG in a rat model of postoperative pain. To find the role of ASIC3 in acute postoperative pain. Methods A total of 48 SD rats using classic Brennan postoperative pain model, 18 rats were randomly divided into 3 groups, making postoperative pain model as Brennan, which were DMSO＋SC560（group S） ,DMSO（group D） and control（group C） group. Group S and group D separately intrathecally given 100 μg SC560 dissolved in 10μl DMSO and 10μ1 DMSO before surgery, group C given nothing. MWT was tested at 2,4,12,24 and 48 h of three groups after surgery to find the most painful time point. Then 30 rats were randomly divided into the same 3 groups. The expression of L3-L5 DRG ASIC3 of the three groups at the most painful time point were tested by western blot. Results MWT in groups D and C had no difference at all the time points after surgery. MWT in group C was the lowest compared with the other time points and was higher than that in group C at 24 h（P〈0.05）. DRG ASIC3 protein density in group S was lower than that in groups C and D at 24 h（P〈0.01）. There was no differene between groups C and D. Conclusion Mechanical hyperalgesia was strongest at 24 h after surgery, the expression of DRG ASIC3 increased. Given SC560 can inhibit the expression of ASIC3 and release mechanical hyperalgesia.