孤啡肽、内吗啡肽-1和-2与无脊椎动物免疫和神经系统的μ_3阿片受体无相互作用(英文)

AIM: To determine if endomorphin-1,-2 and nociceptin (orphanin FQ) bind to the μ3 opiate receptor subtype or release nitric oxide as μ3 selective ligands do. METHODS: These opioid peptides were examined for their ability to displace [3H]dihydromorphine (DHM) binding from the invertebrate (immunocytes and pedal ganglia)μ3 opiate receptor in membrane homogenates. The ligands were also tested for their ability to release nitric oxide from the same intact tissues utilizing an amperometric probe that measures nitric oxide in real-time. RESULTS: Endomorphin-1,-2 and nociceptin do not displace [3H]DHM binding from immunocyte or pedal ganglia membrane homogenates nor do they release nitric oxide from these tissues. CONCLUSION: Since these newly discovered opioid peptides do not interact with the μ3 opiate receptor subtype, endogenous morphine' s significance is enhanced because it appears to be the only naturally occurring opiate ligand for the receptor. Furthermore, since this study involves invertebrate t     

内吗啡肽抑制苯肾上腺素和血管紧张素Ⅱ诱导的离体大鼠胸主动脉环收缩

目的:研究吗啡、内吗啡肽-1和内吗啡肽-2对由苯肾上腺素(PE)和血管紧张素(Ang)Ⅱ诱导离体大鼠胸主动脉环收缩的抑制作用.方法:离体血管环张力试验.结果:与对照组相比,吗啡、内吗啡肽-1和内吗啡肽-2的预处理(0.1-10μmol/L)能明显降低由PE(0.1μmol/L)和Aug Ⅱ(1μmol/L)(P<0.01)诱导离体大鼠胸主动脉环的张力,但是不能减少去内皮血管的张力.纳络酮(1μmol/L)能部分阻断内吗啡肽-1和内吗啡肽-2的抑制作用(P<0.01),N~(ω)-nitro-L-arginine(10μmol/L)或血管环去内皮能完全阻断这种作用(P<0.01).结论:内吗啡肽-1和内吗啡肽-2通过纳络酮敏感方式抑制由PE和AngⅡ诱导的离体大鼠胸主动脉环收缩,这种抑制作用可能与血管内皮NO的释放有关.