罗非昔布对急性痛大鼠的超前镇痛效应  

Effect of preemptive analgesia with rofecoxib in a rat model of acute pain

作　　者：马柯[1] 卢中平[1] 江伟[1] 

机构地区：[1]上海市第六人民医院麻醉科,200233

出　　处：《中华麻醉学杂志》2005年第1期49-51,共3页Chinese Journal of Anesthesiology

摘　　要：目的 探讨罗非昔布对急性痛大鼠的超前镇痛效应及其机制。方法 75只SD大鼠随机分为5组,每组15只。A组为空白对照组,接受伪手术和管饲安慰剂;B组为手术对照组,术前管饲安慰剂;C组为术前镇痛组,术前1h管饲罗非昔布10mg·kg-1;D组为术后镇痛组Ⅰ,术后即刻管饲罗非昔布10mg·kg-1;E组为术后镇痛组Ⅱ,术后1h管饲罗非昔布10mg·kg-1。B、C、D、E组建立大鼠急性痛模型,右足底行1 cm长手术切门。测定各组术前、术后2、6、12、48、96 h手术侧机械痛阈变化。全细胞膜片钳术观察术后24、48、96 h手术侧L3-5背根神经节上河豚毒素不敏感型钠通道电流密度和电流特性的改变。结果 机械痛阈:与术前及A组比较,B、C、D、E组术后各时点降低(P<0.05或0.01);与B组比较,C、D、E组术后各时点升高(P<0.05或0.01);与C组比较,D、E组术后各时点降低(P<0.05);D、E组比较差异无统计学意义(P>0.05)。电流密度:与术前及A组比较,B、C、D、E组术后24、48 h升高(P<0.01);与B组比较,C、D、E组术后24、48 h降低(P<0 05或0.01);与C组比较,D、E组术后24、48 h升高(P<0.05或0.01);D、E组比较差异无统计学意义(P>0 05)。结论 罗非昔布预先给药对急性痛大鼠有较好的超前镇痛效应,其机制可能与更强地抑制河豚毒素不敏感型钠通道电流有关。Objective There are still different news on the preemptive analgesia. We aimed to investigate the preemptive analgesic effect of rofecoxib on the tetrodotoxin-resistant (TTX-R) sodium current in dorsal root ganglion (DRG) neurons m a rat model of acute pain. Methods Seventy-five male SD rats weighing 100-140 g were randomly divided into five groups with 15 animals in each group: (A) sham operation + placebo group; (B) operation control group received placebo orally before operation; (C) preoperatine rofecoxib group received oral rofecoxib 10mg·kg-1 h before operation; (D) and (E) postoperatire, rofecoxib group Ⅰ and Ⅱ received oral rofecoxib 10mg·kg immediately (D) and 1 h (E) after operation. Acute pain was produced by an 1 cm long incision in the plantar surface of the right hindpaw through skin, fascia and muscle. Pain threshold to mechanical stimulation with von Frey filament was measured before (baseline) and 2, 6,12, 48, 96 h after operation. The animals were killed by cervical dislocation before and 24, 48, 96 h after incision. DRGs at L3.5 on the operated side were isolated and minced. DRG neurons were isolated by digestion with collagenase Ⅰ A and trypsin TTX-R Na-current density in DRG neurons were measured by using whole-cell patch clamp technique. Results There was no significant change in pain threshold to mechanical stimulation and Na-current density in DRG neurons during the experiment in group A, The withdrawal threshold to mechanical stimuli was significantly decreased after operation compared to the baseline in the four groups ( B, C, D, E). The decrease in pain threshold was significantly less in group C,D,E than that m group B at 2, 6, 12, 24, 48 h after operation and was the least in group C Current density (pA/pF) was significantly increased at 24 h and 48 h after operation compared to baseline in group B, C, D, E. The increase in current density was significantly less in group C, D, E than in group B and was the least in group C.Conclusion Rofecoxib given before operation has preemp

关 键 词：罗非昔布 急性痛 大鼠 超前镇痛效应 钠通道 脊髓 

分 类 号：R965[医药卫生—药理学]