Michel M E, Bolger G, Weissman B A
Methods Find Exp Clin Pharmacol. 1985 Apr;7(4):175-7.
Nalmefene (6-methylene-naltrexone) is a potent, orally active, opiate antagonist. IC50's were obtained for nalmefene, naloxone and naltrexone using radiolabelled prototype ligands for mu, kappa and delta receptors in homogenates of rat brain minus cerebellum. Nalmefene antagonized the bindings of [3H]-dihydromorphine, [3H]-ethylketocyclazocine and [3H]-D-ala-D-leu enkephalin with IC50's in the low nanomolar range. At the central mu receptor, nalmefene bound with an IC50 of 1.0 nM, equal to that of naltrexone and approximately four times lower than that of naloxone. At central kappa and delta sites the IC50's for nalmefene were somewhat lower than those of naltrexone and considerably lower than those of naloxone. All three antagonists had sodium indices less than 1.0. These results indicate that nalmefene is a universal opiate antagonist, has no agonist character at the central mu site and binds more effectively to central opiate receptors than either naloxone or naltrexone.
纳美芬（6-亚甲基-纳曲酮）是一种强效的、口服活性阿片类拮抗剂。使用大鼠脑（不含小脑）匀浆中μ、κ和δ受体的放射性标记原型配体，获得了纳美芬、纳洛酮和纳曲酮的半数抑制浓度（IC50）。纳美芬拮抗[3H]-二氢吗啡、[3H]-乙基酮环唑辛和[3H]-D-丙氨酸-D-亮氨酸脑啡肽的结合，其IC50处于低纳摩尔范围。在中枢μ受体处，纳美芬的结合IC50为1.0 nM，与纳曲酮相当，约为纳洛酮的四分之一。在中枢κ和δ位点，纳美芬的IC50略低于纳曲酮，显著低于纳洛酮。这三种拮抗剂的钠指数均小于1.0。这些结果表明，纳美芬是一种通用的阿片类拮抗剂，在中枢μ位点无激动剂特性，且比纳洛酮或纳曲酮更有效地结合中枢阿片受体。
