Deconstruction of the Abused Synthetic Cathinone Methylenedioxypyrovalerone (MDPV) and an Examination of Effects at the Human Dopamine Transporter

Synthetic cathinones, beta-keto analogues of amphetamine (or, more correctly, of phenylalkylamines), represent a new and growing class of abused substances. Several such analogues have been demonstrated to act as dopamine (DA) releasing agents. Methylenedioxypyrovalerone (MDPV) was the first synthetic cathinone shown to act as a cocaine-like DA reuptake inhibitor. MDPV and seven deconstructed analogues were examined to determine which of MDPV's structural features account(s) for uptake inhibition. In voltage-clamped (-60 mV) Xenopus oocytes transfected with the human DA transporter (hDAT), all analogues elicited inhibitor-like behavior shown as hDAT-mediated outward currents. Using hDAT-expressing mammalian cells we determined the affinities of MDPV and its analogues to inhibit uptake of [H-3]DA by hDAT that varied over a broad range (IC50 values ca. 135 to >25 000 nM). The methylenedioxy group of MDPV made a minimal contribution to affinity, the carbonyl group and a tertiary amine are more important, and the extended a-alkyl group seems most important. Either a tertiary amine, or the extended a-alkyl group (but not both), are required for the potent nature of MDPV as an hDAT inhibitor.