Wang J L, Zhu C B, Cao X D, Wu G C
State Key Laboratory of Medical Neurobiology, Department of Neurobiology, Shanghai Medical University, People's Republic of China.
Regul Pept. 1999 Feb 5;79(2-3):159-63. doi: 10.1016/s0167-0115(98)00161-x.
Nociceptin/orphanin FQ (nociceptin/OFQ), a newly discovered heptadecapeptide has been regarded as an endogenous ligand for orphan opioid receptor. The present study was designed to investigate the effect of nociceptin/OFQ on pain response and opioid analgesia in the rat formalin test. The results showed that intracerebroventricular injection of 1 microg nociceptin/OFQ enhanced the pain response, and 0.1 or 0.5 microg nociceptin/OFQ had no effect on formalin-induced pain. When 0.1 or 1 microg nociceptin/OFQ were used together with mu-, delta-, or kappa-opioid receptor agonists, endomorphin-1, DSLET or U50488H, respectively, it attenuated mu- and kappa- but not delta-receptor mediated analgesia. On the other hand, intrathecal injection of nociceptin/OFQ (0.1, 1 and 5 microg) reduced the pain response in the formalin test. In conclusion, nociceptin/OFQ potentiated formalin-induced pain response and antagonized opioid analgesia in the rat brain but inhibited pain response in the spinal cord.
孤啡肽（痛敏肽/孤啡肽FQ），一种新发现的十七肽，被认为是孤儿阿片受体的内源性配体。本研究旨在探讨孤啡肽/痛敏肽FQ对大鼠福尔马林试验中疼痛反应及阿片类镇痛作用的影响。结果显示，脑室内注射1微克孤啡肽/痛敏肽FQ可增强疼痛反应，而0.1或0.5微克孤啡肽/痛敏肽FQ对福尔马林诱导的疼痛无影响。当0.1或1微克孤啡肽/痛敏肽FQ分别与μ-、δ-或κ-阿片受体激动剂内吗啡肽-1、DSLET或U50488H联合使用时，它可减弱μ-和κ-受体介导的镇痛作用，但对δ-受体介导的镇痛作用无影响。另一方面，鞘内注射孤啡肽/痛敏肽FQ（0.1、1和5微克）可减轻福尔马林试验中的疼痛反应。总之，孤啡肽/痛敏肽FQ增强了福尔马林诱导的大鼠脑部疼痛反应并拮抗了阿片类镇痛作用，但抑制了脊髓中的疼痛反应。
