中文摘要：

目的观察神经病理性疼痛对瘙痒神经信号转导的影响,探讨瞬时受体电位M8离子通道（TRPM8）在瘙痒-疼痛共病中的作用。方法实验一：将KM雄性小鼠48只随机分为6组,神经病理性疼痛组（SNI）、假手术组（Sham）、瘙痒组（CQ）、瘙痒溶媒组（NS）、疼痛瘙痒共病组（SQ）及空白对照组（CON）;实验二：KM雄性小鼠16只,分为SQ＋AMTB（SQ-A）组和SQ＋AMTB溶媒对照组（SQ-V）。CON、SNI、Sham、SQ组在术前1 d,术后1、3、5 d测定术侧机械痛阈值（MWT）、冷痛阈值及热痛潜伏期（PWL）,CON、CQ、NS、SQ组分别注射氯喹或生理盐水后观察搔抓发作潜伏期及发作次数;实验二：SNI模型建立第5天分别鞘注AMTB（SQ-A）及溶媒（SQ-V）前后测定疼痛行为学,注射氯喹和生理盐水后观察瘙痒行为学。结果 SNI组及SQ组在术后1d冷痛阈值及MWT降低,第5天仍在较低水平,而PWL仅在术后1 d下降差异有统计学意义（P〈0.05）。SQ-A组较SQ-V组鞘注后冷痛阈值、MWT显著升高（P〈0.05）,两组PWL变化差异无统计学意义。CQ组较NS组定向搔抓次数显著增多,搔抓潜伏期缩短（P〈0.05）,SQ组搔抓次数明显低于CQ组（P〈0.05）,但搔抓潜伏期差异无统计学意义（P〉0.05）。SQ-A组搔抓次数显著高于SQ-V组（P〈0.05）,但搔抓潜伏期差异无统计学意义（P〉0.05）。结论疼痛-瘙痒共病时疼痛能够抑制瘙痒神经信号传导,可能与神经病理性疼痛引起的TRPM8受体表达上调有关。

英文摘要：

Objective To evaluate the roles for the co-morbidity of itch and pain, and to investigate the effect of TRPM8 in these processes. Methods In test 1, Forty-eight male KM mice were randomly divided into the CON group, Sham group, SNI group, CQ group, NS group and SQ group. The threshold of cold hyperalgesia, heat hy- peralgesia and mechanical hyperalgesia were measured before operation and at 1,3 and 5 d after operation in CON, SNI, Sham and SQ group. The scratching numbers were calculated within 30 minutes after chloroquine or saline in- jection in CON, CQ, NS and SQ group. In test 2, sixteen male KM mice were randomly divided into SQ-A and SQ- v group after 5 d of SNI operation,whose threshold of cold hyperalgesia, heat hyperalgesia and mechanical hyperal- gesia were measured,respectively. Mice underwent lumbar intratheeal injection of TRPM8 specific blocker AMTB 30 μg/kg in SQ-A group, while the SQ-V group received TRPM8 specific blocker AMTB vehicle. The scratching numbers were observed within 30 minutes of two groups＇ hair removal after chloroquine injection. Results Com- pared with Sham group and CON group, the total number and time of brisk lifts of operated hind paw in SNI group and SQ group were significantly increased on 1 d after SNI, and reached the peak on 3 d; MWT following SNI was significantly lower on 1 d and reached the peak on 5 d; PWL was significantly reduced only on 1 d postoperation （P 〈 0. 05 ）. Compared with SQ-V group, SQ-A group had significantly higher cold threshold and higher MWT （P 〈 0. 05 ）. However, there were no significant differences in PWL between the two groups. The directional scratching number of CQ group was significantly increased than the NS group and CON group, and the scratching latency was shorter （ P 〈 0.05 ）. The scratching number in the SQ group was significantly lower than that of CQ group （ P 〈 0. 05 ）. The directional scratching number in the SQ-A group was significantly increased than that of the SQ-V group （P 〈 0.05 ）. There wer