中文摘要：

目的：观察人参皂甙-Rd（Ginsenoside-Rd,G-Rd）对坐骨神经分支选择损伤（spared nerve injury,SNI）大鼠痛敏异常及脊髓背角内P物质（substance P,SP）和NK-1受体表达的影响,进而探讨G-Rd镇痛的脊髓机制。方法：成年雄性SD大鼠（30只）随机分成五组：空白对照组（blank control）、假手术组（sham operation）、坐骨神经分支选择损伤组（spared nerve injury,SNI）、SNI＋saline（腹腔注射,i.p.）组、SNI＋G-Rd（i.p.）组。行为学采用von Frey法测定上述各组手术侧机械缩足反射阈值（paw withdrawal mechanical thresholds,PWMT）;用免疫荧光组织化学染色法检测对比上述各组大鼠脊髓L4-6节段背角内SP免疫荧光产物的荧光强度和NK-1阳性细胞的数量。结果：SNI术后10 d,大鼠手术侧PWMT值明显低于正常对照组和假手术组,术后20 d到达最低值;而在SNI＋G-Rd组PWMT值则明显高于SNI组和SNI＋sline组（P〈0.05）。免疫荧光染色结果显示：术后20 d时,SNI组和SNI＋saline组的脊髓手术侧L4-6背角内SP样免疫荧光的强度和NK-1样阳性细胞的数量明显有所增高,与对照组和假手术组相比较具有显著性意义（P〈0.05）;但SNI＋G-Rd组与SNI组和SNI＋saline组相比,其SP样免疫荧光的强度和NK-1样阳性细胞的数量则明显有所下降（P〈0.05）。结论：人参皂甙-Rd抑制神经病理性疼痛的机制之一可能与有效减少脊髓背角内SP和NK-1受体的表达有关。

英文摘要：

Objective：To investigate the effect of Ginsenoside-Rd（G-Rd）on allodynia and expression of substance P（SP） and NK-1 receptor in the spinal dorsal horn of rats induced with spared nerve injury（SNI）,and to probe the mechanisms of G-Rd analgesia.Methods：Thirty male SD rats were randomly divided into five groups：（1）blank control,（2）sham operation,（3） SNI,（4）SNI＋saline（i.p.）,（5）and SNI＋G-Rd（i.p.） groups.We measured paw withdrawal mechanical thresholds（PWMT） using calibrated von Frey filaments to stimulate the glabrous surface of the lateral plantar of the hindpaw.Immunofluorescent histochemical staining was used to measure the mean fluorescent intensity（MFI） of SP fluorescent immunoreactivity and the number of NK-1 positive cells in the spinal dorsal horn（L4-6） of rat in five groups.Results：On 10 d after SNI,the mean PWMT value in SNI side revealed clearly lower than that of control and sham operation groups;on 20 d PWMT value dropped to the lowest.In SNI＋G-Rd group,the PWMT value was significantly higher than that in SNI group and SNI＋saline group（P0.05）,respectively.The immunofluorescent staining results showed that the MFI of SP like immunoreactivity and the number of NK-1-like positive cells in the spinal dorsal horn（L4-6） of SNI and SNI＋saline groups were significantly higher compared with that of control and sham operation groups on 20 d after SNI（P0.05）.In SNI＋G-Rd group,the MFI of SP-like immunoreactivity and the number of NK-1-like positive cells were detected clearly lower than that of SNI and SNI＋saline groups（P0.05）.Conclusion：The expressional decrease of SP and NK-1 receptor in the spinal dorsal horn may be involved in one of mechanism of G-Rd inhibited the neuropathic pain of rat.