Ozaki S, Kawamoto H, Itoh Y, Miyaji M, Azuma T, Ichikawa D, Nambu H, Iguchi T, Iwasawa Y, Ohta H
Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., 3 Okubo, Tsukuba, 300-2611, Ibaraki, Japan.
Eur J Pharmacol. 2000 Aug 18;402(1-2):45-53. doi: 10.1016/s0014-2999(00)00520-3.
1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl -1, 3-dihydro-2H-benzimidazol-2-one (J-113397) was found to be the first potent nonpeptidyl ORL1 receptor antagonist (K(i): cloned human ORL1=1.8 nM) with high selectivity over other opioid receptors (K(i): 1000 nM for human mu-opioid receptor, >10,000 nM for human delta-opioid receptor, and 640 nM for human kappa-opioid receptor). In vitro, J-113397 inhibited nociceptin/orphanin FQ-stimulated [35S]guanosine 5'-O-(gamma-thio)triphosphate (GTP gamma S) binding to Chinese Hamster Ovary (CHO) cells expressing ORL1 (CHO-ORL1) with an IC(50) value of 5.3 nM but had no effect on [35S]GTP gamma S binding by itself. Schild plot analysis of the [35S]GTP gamma S binding assay and cAMP assay using CHO-ORL1 indicated competitive antagonism of J-113397 on the ORL1 receptor. In CHO cells expressing mu-, delta- or kappa-opioid receptors, J-113397 had no effects on [35S]GTP gamma S binding up to a concentration of 100 nM, indicating selective antagonism of the compound on the ORL1 receptor. In vivo, J-113397, when administered subcutaneously (s.c.), dose-dependently inhibited hyperalgesia elicited by intracerebroventricular (i.c.v.) administration of nociceptin/orphanin FQ in a tail-flick test with mice. An in vitro binding study using mouse brains indicated that J-113397 possesses high affinity for the mouse ORL1 receptor (K(i): 1.1 nM) as well as the human receptor. In summary, J-113397 is the first potent, selective ORL1 receptor antagonist that may be useful in elucidating the physiological roles of nociceptin/orphanin FQ.
1-[(3R,4R)-1-环辛基甲基-3-羟甲基-4-哌啶基]-3-乙基-1,3-二氢-2H-苯并咪唑-2-酮（J-113397）被发现是首个强效非肽类孤啡肽受体拮抗剂（K(i)：克隆人孤啡肽受体=1.8 nM），对其他阿片受体具有高选择性（K(i)：人μ-阿片受体为1000 nM，人δ-阿片受体>10000 nM，人κ-阿片受体为640 nM）。在体外，J-113397抑制孤啡肽/孤啡肽FQ刺激的[35S]鸟苷5'-O-(γ-硫代)三磷酸（GTPγS）与表达孤啡肽受体的中国仓鼠卵巢（CHO）细胞（CHO-ORL1）的结合，IC(50)值为5.3 nM，但自身对[35S]GTPγS结合无影响。使用CHO-ORL1对[35S]GTPγS结合试验和cAMP试验进行的Schild图分析表明J-113397对孤啡肽受体具有竞争性拮抗作用。在表达μ-、δ-或κ-阿片受体的CHO细胞中，J-113397在浓度高达100 nM时对[35S]GTPγS结合无影响，表明该化合物对孤啡肽受体具有选择性拮抗作用。在体内，J-113397皮下注射时，在小鼠甩尾试验中剂量依赖性地抑制脑室内注射孤啡肽/孤啡肽FQ引起的痛觉过敏。使用小鼠脑进行的体外结合研究表明J-113397对小鼠孤啡肽受体（K(i)：1.1 nM）以及人受体具有高亲和力。总之，J-113397是首个强效、选择性孤啡肽受体拮抗剂，可能有助于阐明孤啡肽/孤啡肽FQ的生理作用。
