Hiranita Takato, Hong Weimin C, Kopajtic Theresa, Katz Jonathan L
Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health (T.H., T.K., J.L.K.), and Department of Pharmaceutical Sciences, Butler University (W.C.H.), Indianapolis, Indiana.
Psychobiology Section, Molecular Neuropsychiatry Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health (T.H., T.K., J.L.K.), and Department of Pharmaceutical Sciences, Butler University (W.C.H.), Indianapolis, Indiana
J Pharmacol Exp Ther. 2017 Jul;362(1):2-13. doi: 10.1124/jpet.117.241109. Epub 2017 Apr 25.
Several N-substituted benztropine (BZT) analogs are atypical dopamine transport inhibitors as they have affinity for the dopamine transporter (DAT) but have minimal cocaine-like pharmacologic effects and can block numerous effects of cocaine, including its self-administration. Among these compounds, -methyl (AHN1-055), -allyl (AHN2-005), and -butyl (JHW007) analogs of 3-[bis(4'-fluorophenyl)methoxy]-tropane were more potent in antagonizing self-administration of cocaine and -methamphetamine than in decreasing food-maintained responding. The antagonism of cocaine self-administration (0.03-1.0 mg/kg per injection) with the above BZT analogs was reproduced in the present study. Further, the stimulant-antagonist effects resembled previously reported effects of pretreatments with combinations of standard DAT inhibitors and -receptor (R) antagonists. Therefore, the present study examined binding of the BZT analogs to Rs, as well as their in vivo R antagonist effects. Each of the BZT analogs displaced radiolabeled R ligands with nanomolar affinity. Further, self-administration of the R agonist DTG (0.1-3.2 mg/kg/injection) was dose dependently blocked by AHN2-005 and JHW007 but potentiated by AHN1-055. In contrast, none of the BZT analogs that were active against DTG self-administration was active against the self-administration of agonists at dopamine D-like [(+)-SKF 81297, (±)-SKF 82958 (0.00032-0.01 mg/kg per injection each)], D-like [(-)-NPA (0.0001-0.0032 mg/kg per injection), (-)-quinpirole (0.0032-0.1 mg/kg per injection)], or -opioid (remifentanil, 0.0001-0.0032 mg/kg per injection) receptors. The present results indicate that behavioral antagonist effects of the -substituted BZT analogs are specific for abused drugs acting at the DAT and further suggest that R antagonism contributes to those actions.
几种N-取代苯托品(BZT)类似物是非典型多巴胺转运体抑制剂,因为它们对多巴胺转运体(DAT)具有亲和力,但可卡因样药理作用极小,并且可以阻断可卡因的多种作用,包括其自我给药行为。在这些化合物中,3-[双(4'-氟苯基)甲氧基]-托烷的α-甲基(AHN1-055)、α-烯丙基(AHN2-005)和α-丁基(JHW007)类似物在拮抗可卡因和甲基苯丙胺的自我给药方面比减少食物维持反应更有效。本研究重现了上述BZT类似物对可卡因自我给药(每次注射0.03 - 1.0 mg/kg)的拮抗作用。此外,这些兴奋剂拮抗作用类似于先前报道的标准DAT抑制剂和σ-受体(R)拮抗剂联合预处理的效果。因此,本研究检测了BZT类似物与σRs的结合以及它们在体内的σR拮抗作用。每种BZT类似物都以纳摩尔亲和力取代放射性标记的σR配体。此外,σR激动剂DTG(每次注射0.1 - 3.2 mg/kg)的自我给药行为被AHN2-005和JHW007剂量依赖性阻断,但被AHN1-055增强。相反,对DTG自我给药有活性的BZT类似物对多巴胺D1样[(+)-SKF 81297,(±)-SKF 82958(每次注射各0.00032 - 0.01 mg/kg)]、D2样[(-)-NPA(每次注射0.0001 - 0.0032 mg/kg),(-)-喹吡罗(每次注射0.0032 - 0.1 mg/kg)]或μ-阿片受体(瑞芬太尼,每次注射0.0001 - 0.0032 mg/kg)激动剂的自我给药均无活性。目前的结果表明,α-取代BZT类似物的行为拮抗作用对作用于DAT的滥用药物具有特异性,并且进一步表明σR拮抗作用有助于这些作用。