Rialas C M, Weeks B, Cadet P, Goumon Y, Stefano G B
Neuroscience Research Institute, State University of New York at Old Westbury, Old Westbury, NY 11568-0210, USA.
Acta Pharmacol Sin. 2000 Jun;21(6):516-20.
To determine if endomorphin-1, -2 and nociceptin (orphanin FQ) bind to the mu 3 opiate receptor subtype or release nitric oxide as mu 3 selective ligands do.
These opioid peptides were examined for their ability to displace [3H]dihydromorphine (DHM) binding from the invertebrate (immunocytes and pedal ganglia) mu 3 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.
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.
Since these newly discovered opioid peptides do not interact with the mu 3 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 tissues, this signal system had to evolve early during evolution.
确定内吗啡肽-1、-2和孤啡肽（痛敏肽）是否像μ3选择性配体那样与μ3阿片受体亚型结合或释放一氧化氮。
检测这些阿片肽从膜匀浆中的无脊椎动物（免疫细胞和足神经节）μ3阿片受体置换[3H]二氢吗啡（DHM）结合的能力。还利用一种可实时测量一氧化氮的电流型探针，检测这些配体从相同完整组织释放一氧化氮的能力。
内吗啡肽-1、-2和孤啡肽既不能从免疫细胞或足神经节膜匀浆中置换[3H]DHM结合，也不能从这些组织中释放一氧化氮。
由于这些新发现的阿片肽不与μ3阿片受体亚型相互作用，内源性吗啡的重要性得到增强，因为它似乎是该受体唯一天然存在的阿片配体。此外，由于本研究涉及无脊椎动物组织，这一信号系统必定在进化早期就已形成。
