孤啡肽及其前体mRNA在神经痛大鼠脊髓背角神经元中表达的变化

孤啡肽是新近发现的一种 1 7肽 ,为阿片受体家族中一个新成员“孤儿受体”的内源性配基。孤啡肽在痛觉调制中的作用与内阿片肽明显不同 ,其在脊髓水平痛觉调制过程中起着重要作用。神经痛是临床上常见的一种慢性痛。本实验目的是探讨慢性限制性损伤大鼠模型上 (ＣＣＩ)孤啡肽及其前体ｍＲＮＡ在神经痛大鼠脊髓背角表达的变化。大鼠左侧后肢坐骨神经结扎 ,右侧假手术 ,通过光热刺激大鼠后肢脚掌测量抬脚潜伏期 (ＰＷＬ) ,ＣＣＩ模型 3天后手术侧ＰＷＬ明显低于对侧 ,提示痛敏的出现 ,痛敏持续不超过 30天。结果表明ＣＣＩ模型后第 4天或 7天 …

Effects of Chronic Constriction Injury on Nociceptin and Prepronociceptin mRNA Expression in Rat Spinal Dorsal Horn

Nociceptin (also named Orphanin FQ), plays a very important role in spinal pain modulation. The present study was designed to explore the effect of nociceptin o n neuropathic pain in rats with chronic constrictive injury (CCI). Paw withdrawl latency (PWL) was measured by the stimulation of radiant heat on the foot pad o f rats. It was observed that 3 days after CCI, the PWL of the operated lateral w as significantly shorter than that of the contralateral, indicating the existenc e of hyperalgesia. The hyperalgesia remained for no less than 30 days. It was sh owed that significant decrease of the number of OFQ LI neurons in the dorsal ho rn of spinal cord (L 4～6 ) 4 or 7 days after CCI. The changes of expression of prepronociceptin mRNA in the spinal dorsal horn after t he thermal hyperalgesia were also investigated. The integral optical density (I OD) and mean optical den sity (OD) of the stained spinal cord sections were measured using the image proc essing following in situ hybridizationon (DIG oligonucleotide tailing test). It was showed that the values of IOD and OD in the spinal dorsal horn in constri ction injury treatment groups were increased significantly (from day 7 after CCI to day 14). The above results suggested that the OFQ in the spinal dorsal horn may be involved in neurophathic pain.