title: Monoamine transporter and receptor interaction profiles of novel psychoactive substances: para-halogenated amphetamines and pyrovalerone cathinones.
abstract: The pharmacology of novel psychoactive substances is mostly unknown. We evaluated the transporter and receptor interaction profiles of a series of para-(4)-substituted amphetamines and pyrovalerone cathinones. We tested the potency of these compounds to inhibit the norepinephrine (NE), dopamine (DA), and serotonin (5-HT) transporters (NET, DAT, and SERT, respectively) using human embryonic kidney 293 cells that express the respective human transporters. We also tested the substance-induced efflux of NE, DA, and 5-HT from monoamine-loaded cells, binding affinities to monoamine receptors, and 5-HT2B receptor activation. Para-(4)-substituted amphetamines, including 4-methylmethcathinone (mephedrone), 4-ethylmethcathinone, 4-fluoroamphetamine, 4-fluoromethamphetamine, 4-fluoromethcatinone (flephedrone), and 4-bromomethcathinone, were relatively more serotonergic (lower DAT:SERT ratio) compared with their analogs amphetamine, methamphetamine, and methcathinone. The 4-methyl, 4-ethyl, and 4-bromo groups resulted in enhanced serotonergic properties compared with the 4-fluoro group. The para-substituted amphetamines released NE and DA. 4-Fluoramphetamine, 4-flouromethamphetamine, 4-methylmethcathinone, and 4-ethylmethcathinone also released 5-HT similarly to 3,4-methylenedioxymethamphetamine. The pyrovalerone cathinones 3,4-methylenedioxypyrovalerone, pyrovalerone, α-pyrrolidinovalerophenone, 3,4-methylenedioxy-α-pyrrolidinopropiophenone, and 3,4-methylenedioxy-α-pyrrolidinobutiophenone potently inhibited the NET and DAT but not the SERT. Naphyrone was the only pyrovalerone that also inhibited the SERT. The pyrovalerone cathinones did not release monoamines. Most of the para-substituted amphetamines exhibited affinity for the 5-HT2A receptor but no relevant activation of the 5-HT2B receptor. All the cathinones exhibited reduced trace amine-associated receptor 1 binding compared with the non-β-keto-amphetamines. In conclusion, para-substituted amphetamines exhibited enhanced direct and indirect serotonergic agonist properties and are likely associated with more MDMA-like effects. The pharmacological profile of the pyrovalerone cathinones predicts pronounced stimulant effects and high abuse liability.
authors.affiliation: Psychopharmacology Research, Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Rickli
authors.affiliation: Pharmaceuticals Division, F. Hoffmann-La Roche Ltd., Basel, CH-4070, Switzerland.
authors.forename: Marius C
authors.initials: MC
authors.lastname: Hoener
authors.affiliation: Psychopharmacology Research, Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland. Electronic address: matthias.liechti@usb.ch.
authors.forename: Matthias E
authors.initials: ME
authors.lastname: Liechti
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D015306:Biogenic Monoamines / Q000378:metabolism* / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D057809:HEK293 Cells; D006801:Humans; D026901:Membrane Transport Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011759:Pyrrolidines / Q000494:pharmacology*; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D014316:Tritium / Q000493:pharmacokinetics
chemical_list: D015306:Biogenic Monoamines; D000697:Central Nervous System Stimulants; D026901:Membrane Transport Proteins; D011759:Pyrrolidines; D017981:Receptors, Neurotransmitter; D014316:Tritium; D000661:Amphetamine; C005719:pyrovalerone
keywords: Amphetamine; Cathinone; Dopamine; Novel psychoactive substances; Serotonin; Transporter