Thioether metabolites of 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine inhibit human serotonin transporter (hSERT) function and simultaneously stimulate dopamine uptake into hSERT-expressing SK-N-MC cells.

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Jones DC, Lau SS, Monks TJ

J Pharmacol Exp Ther. 2004 Oct;311(1):298-306. Epub 2004 May 28.

PubMed ID

15169827 [ View in PubMed

]

Abstract

3,4-Methylenedioxyamphetamine (MDA) and 3,4-methyl-enedioxymethamphetamine (MDMA, ecstasy) are widely abused amphetamine derivatives that target the serotonin system. The serotonergic neurotoxicity of MDA and MDMA seems dependent on their systemic metabolism. 5-(Glutathion-S-yl)-alpha-methyldopamine [5-(GSyl)-alpha-MeDA] and 2,5-bis(glutathion-S-yl)-alpha-methyldopamine [2,5-bis(GSyl)-alpha-MeDA], metabolites of MDA and MDMA, are also selective serotonergic neurotoxicants and produce behavioral and neurochemical changes similar to those seen with MDA and MDMA. We now show that 5-(GSyl)-alpha-MeDA and 2,5-bis(GSyl)-alpha-MeDA are more potent than MDA and MDMA (K(i) = 69, 50, 107, and 102 microM, respectively) at inhibiting 5-hy-droxytryptamine (serotonin) transport into SK-N-MC cells transiently transfected with the human serotonin transporter (hSERT). Moreover, 5-(GSyl)-alpha-MeDA and 2,5-bis(GSyl)-alpha-MeDA simultaneously stimulated dopamine (DA) transport into the hSERT-expressing cells, an effect attenuated by fluoxetine, indicating that stimulated DA transport was hSERT-dependent. Finally, 5-(GSyl)-alpha-MeDA and 2,5-bis(GSyl)-alpha-MeDA, and to a lesser extent MDA and MDMA, induced a concentration and time-dependent increase in reactive oxygen species (ROS) in both hSERT and human dopamine transporter-transfected cells. Fluoxetine attenuated the increase in ROS generation in hSERT-expressing cells. The results are consistent with the view that the serotonergic neurotoxicity of MDA and MDMA may be mediated by the metabolism-dependent stimulation of DA transport into hSERT-expressing cells and ROS generation by redox active catechol-thioether metabolites and DA.

DrugBank Data that Cites this Article

Binding Properties

Drug	Target	Property	Measurement	pH	Temperature (°C)
Midomafetamine	Sodium-dependent serotonin transporter	Ki (nM)	>10000	N/A	N/A	Details