Spagnolo Barbara, Carrà Giacomo, Fantin Martina, Fischetti Carmela, Hebbes Chris, McDonald John, Barnes Timothy A, Rizzi Anna, Trapella Claudio, Fanton Giulia, Morari Michele, Lambert Dave G, Regoli Domenico, Calò Girolamo
Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara, Ferrara, Italy.
J Pharmacol Exp Ther. 2007 Jun;321(3):961-7. doi: 10.1124/jpet.106.116764. Epub 2007 Feb 28.
The compound SB-612111 [(-)-cis-1-methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol] was recently identified as a selective antagonist for the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP). In the present study, the in vitro pharmacological profile of SB-612111 at human recombinant NOP receptors expressed in Chinese hamster ovary (CHO) cells [receptor binding, guanosine 5'-O-(3-[(35)S]thio)triphosphate (GTPgamma[(35)S]) binding, and cAMP level experiments] as well as at native NOP receptors expressed in peripheral (mouse and rat vas deferens, guinea pig ileum) and central (mouse cerebral cortex synaptosomes releasing [(3)H]5-HT) preparations was evaluated and compared with that of the standard nonpeptide antagonist (+/-)J-113397 [(+/-)-trans-1-[1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one]. SB-612111 produced a concentration-dependent displacement of [(3)H]N/OFQ binding to CHO(hNOP) cell membranes, showing higher affinity and NOP selectivity over classical opioid receptors than (+/-)J-113397. SB-612111 and (+/-)J-113397 competitively antagonized the effects of N/OFQ on GTPgamma[(35)S] binding in CHO(hNOP) cell membranes (pK(B), 9.70 and 8.71, respectively) and on cAMP accumulation in CHO(hNOP) cells (pK(B), 8.63 and 7.95, respectively), being per se inactive. In isolated peripheral tissues of mice, rats, and guinea pigs and in mouse cerebral cortex synaptosomes preloaded with [(3)H]5-HT, SB-612111 competitively antagonized the inhibitory effects of N/OFQ, with pA(2) values in the range of 8.20 to 8.50. In parallel experiments, (+/-)J-113397 was found to be 2- to 9-fold less potent than SB-612111. In the electrically stimulated tissues, 1 microM SB-612111 did not modify the effects of classical opioid receptor agonists. In conclusion, the results of the present study demonstrated that SB-612111 is among the most potent and NOP-selective nonpeptide antagonists identified to date.
化合物SB - 612111 [(-)-顺式-1-甲基-7-[[4-(2,6-二氯苯基)哌啶-1-基]甲基]-6,7,8,9-四氢-5H-苯并环庚烯-5-醇]最近被鉴定为孤啡肽/孤啡肽FQ (N/OFQ)肽受体(NOP)的选择性拮抗剂。在本研究中，评估了SB - 612111在中华仓鼠卵巢(CHO)细胞中表达的人重组NOP受体上的体外药理学特性[受体结合、鸟苷5'-O-(3-[(35)S]硫代)三磷酸(GTPγ[(35)S])结合及cAMP水平实验]，以及在周围组织(小鼠和大鼠输精管、豚鼠回肠)和中枢组织(释放[(3)H]5-羟色胺的小鼠大脑皮质突触体)中表达的天然NOP受体上的体外药理学特性，并与标准非肽拮抗剂(+/-)J - 113397 [(+/-)-反式-1-[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]进行了比较。SB - 612111引起[(3)H]N/OFQ与CHO(hNOP)细胞膜结合的浓度依赖性位移，与(+/-)J - 113397相比，对经典阿片受体显示出更高的亲和力和NOP选择性。SB - 612111和(+/-)J - 113397竞争性拮抗N/OFQ对CHO(hNOP)细胞膜中GTPγ[(35)S]结合的作用(pK(B)分别为9.70和8.71)以及对CHO(hNOP)细胞中cAMP积累的作用(pK(B)分别为8.63和7.95)，其本身无活性。在小鼠、大鼠和豚鼠的离体周围组织以及预先加载[(3)H]5-羟色胺的小鼠大脑皮质突触体中，SB - 612111竞争性拮抗N/OFQ的抑制作用，pA(2)值在8.20至8.50范围内。在平行实验中，发现(+/-)J - 113397的效力比SB - 612111低2至9倍。在电刺激组织中，1 μM SB - 612111不改变经典阿片受体激动剂的作用。总之，本研究结果表明，SB - 612111是迄今为止鉴定出的最有效且NOP选择性最强的非肽拮抗剂之一。
