In contrast to methamphetamine and methcathinone, 4-MMA appears to produce minimal dopaminergic neurotoxicity in mice.[5][6] Conversely, mephedrone shows no dopaminergic neurotoxicity at all in mice.[5][6] It was theorized that 4-methyl and β-keto substitutions on amphetamines may result in loss of activity at the vesicular monoamine transporter 2 (VMAT2), loss of elevations of cytosolic dopamine concentrations, and consequent loss of dopaminergic neurotoxic potential.[5][6] Accordingly, the dopaminergic neurotoxicity of 4-MMA was greatly enhanced by the dopamine precursorlevodopa (L-DOPA), the monoamine oxidase inhibitor (MAOI) pargyline, and methamphetamine (a VMAT2 inhibitor/reverser), all of which are known to increase the cytosolic pool of dopamine.[6] However, in contrast to 4-MMA, the dopaminergic neurotoxicity of methcathinone was enhanced only by levodopa and of mephedrone was enhanced only by methamphetamine.[6]
^Meyer MR, Wilhelm J, Peters FT, Maurer HH (March 2010). "Beta-keto amphetamines: studies on the metabolism of the designer drug mephedrone and toxicological detection of mephedrone, butylone, and methylone in urine using gas chromatography-mass spectrometry". Analytical and Bioanalytical Chemistry. 397 (3): 1225–33. doi:10.1007/s00216-010-3636-5. PMID20333362. S2CID21471611.
^Coppola M, Mondola R (December 2013). "4-methylamphetamine (4-MA): chemistry, pharmacology and toxicology of a new potential recreational drug". Mini Rev Med Chem. 13 (14): 2097–2101. doi:10.2174/13895575113136660106. PMID24195663.
^ abPartilla JS, Dersch CM, Baumann MH, Carroll FI, Rothman RB (1999). "Profiling CNS Stimulants with a High-Throughput Assay for Biogenic Amine Transporter Substractes". Problems of Drug Dependence 1999: Proceedings of the 61st Annual Scientific Meeting, The College on Problems of Drug Dependence, Inc(PDF). NIDA Res Monogr. Vol. 180. pp. 1–476 (252). PMID11680410. RESULTS. Methamphetamine and amphetamine potently released NE (IC50s = 14.3 and 7.0 nM) and DA (IC50s = 40.4 nM and 24.8 nM), and were much less potent releasers of 5-HT (IC50s = 740 nM and 1765 nM). Phentermine released all three biogenic amines with an order of potency NE (IC50 = 28.8 nM)> DA (IC50 = 262 nM)> 5-HT (IC50 = 2575 nM). Aminorex released NE (IC50 = 26.4 nM), DA (IC50 = 44.8 nM) and 5-HT (IC50 = 193 nM). Chlorphentermine was a very potent 5-HT releaser (IC50 = 18.2 nM), a weaker DA releaser (IC50 = 935 nM) and inactive in the NE release assay. Chlorphentermine was a moderate potency inhibitor of [3H]NE uptake (Ki = 451 nM). Diethylpropion, which is self-administered, was a weak DA uptake inhibitor (Ki = 15 µM) and NE uptake inhibitor (Ki = 18.1 µM) and essentially inactive in the other assays. Phendimetrazine, which is self-administered, was a weak DA uptake inhibitor (IC50 = 19 µM), a weak NE uptake inhibitor (8.3 µM) and essentially inactive in the other assays.
^Wee S, Anderson KG, Baumann MH, Rothman RB, Blough BE, Woolverton WL (May 2005). "Relationship between the serotonergic activity and reinforcing effects of a series of amphetamine analogs". The Journal of Pharmacology and Experimental Therapeutics. 313 (2): 848–854. doi:10.1124/jpet.104.080101. PMID15677348. S2CID12135483.