Convergent lines of evidence support a dual deficit model of stimulant withdrawal, where reductions in synaptic dopamine (DA) and 5-hydroxytryptamine (serotonin) (5-HT) contribute to dysphoria, drug craving, and relapse. Thus, we predicted that a nonamphetamine compound with substrate activity at DA and 5-HT transporters (i.e., a dual DA/5-HT releaser) would be an effective medication for treating stimulant addictions. Ideally, this type of medication would alleviate withdrawal symptoms, suppress cocaine self-administration, and lack side effects commonly associated with central nervous system stimulants. In the present work, more than 350 compounds were screened in vitro for activity as substrate-type releasing agents at DA, 5-HT, and norepinephrine transporters. These efforts identified PAL-287 (1-napthyl-2-aminopropane) as a nonamphetamine compound with potent substrate activity at biogenic amine transporters. In vivo microdialysis in rats demonstrated that PAL-287 (1–3 mg/kg i.v.) increased extracellular DA and 5-HT in frontal cortex, but effects on 5-HT were somewhat greater. PAL-287 induced substantially less locomotor stimulation than (+)-amphetamine, a drug that increases only extracellular DA. Administration of high-dose (+)-methamphetamine or (±)-3,4-methylenedioxymethamphetamine to rats produced long-lasting depletion of cortical 5-HT, whereas PAL-287 (18 mg/kg i.p. × 3) did not. PAL-287 displayed little or no reinforcing properties in rhesus monkeys trained to self-administer cocaine, yet PAL-287 produced a dose-dependent decrease in responding for cocaine when infused at a dose of 1.0 mg/kg/h. Collectively, the findings reported here demonstrate that nonamphetamine monoamine releasing agents such as PAL-287 might be promising candidate medications for the treatment of stimulant dependence.
一系列证据支持兴奋剂戒断的双重缺陷模型,其中突触
多巴胺 (
DA) 和 5-羟
色胺(
血清素)(5-HT) 的减少会导致烦躁、药物渴望和复发。因此,我们预测对
DA 和 5-HT 转运蛋白具有底物活性的非苯
丙胺化合物(即双
DA/5-HT 释放剂)将是治疗兴奋剂成瘾的有效药物。理想情况下,这种药物可以缓解戒断症状,抑制
可卡因的自我给药,并且不会产生中枢神经系统兴奋剂常见的副作用。在目前的工作中,在体外筛选了 350 多种化合物作为
DA、5-HT 和
去甲肾上腺素转运蛋白底物型释放剂的活性。这些工作将 PA
L-287(1-
萘基-2-
氨基
丙烷)确定为一种非苯
丙胺化合物,对
生物胺转运蛋白具有有效的底物活性。大鼠体内微透析表明,PA
L-287(1-3 mg/kg 静脉注射)可增加额叶皮质中的细胞外
DA 和 5-HT,但对 5-HT 的影响稍大。 PA
L-287 诱导的运动刺激明显低于 (+)-
安非他明(一种仅增加细胞外
DA 的药物)。给大鼠施用高剂量 (+)-甲基苯
丙胺或 (±)-3,4-亚甲二氧基甲基苯
丙胺会导致皮质 5-HT 持久耗竭,而 PA
L-287(18 mg/kg 腹腔注射 × 3)则不会。 PA
L-287 在训练自我施用
可卡因的恒河猴中表现出很少或没有增强特性,但当以 1.0 mg/kg/h 的剂量输注时,PA
L-287 对
可卡因的反应产生剂量依赖性下降。总的来说,本文报告的研究结果表明,PA
L-287 等非苯
丙胺单胺释放剂可能是治疗兴奋剂依赖的有前途的候选药物。