However, more recent in vivo studies that involved performing microdialysis on rats showed a different trend. These studies showed that 4-methylamphetamine is much more potent at elevating serotonin (~18 x baseline) relative to dopamine (~5 x baseline). The authors speculated that this is because 5-HT release dampens DA release through some mechanism. For example, it was suggested that a possible cause for this could be activation of 5HT2C receptors since this is known to inhibit DA release. In addition there are alternative explanations such as 5-HT release then going on to encourage GABA release, which has an inhibitory effect on DA neurons.[2]
4-MA was investigated as an appetite suppressant in 1952 and was even given a trade name, Aptrol, but development was apparently never completed.[20] More recently it has been reported as a novel designer drug.
In animal studies, 4-MA was shown to have the lowest rate of self-administration out of a range of similar drugs tested (the others being 3-methylamphetamine, 4-fluoroamphetamine, and 3-fluoroamphetamine), likely as a result of having the highest potency for releasing serotonin relative to dopamine.[1][21]
Society and culture
More than a dozen deaths were reported throughout Europe in 2012-2013 after consumption of amphetamine ('speed') contaminated with 4-methylamphetamine.[22][23][24]
^ abWee 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.
^ 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.
^Rothman RB, Baumann MH (October 2003). "Monoamine transporters and psychostimulant drugs". European Journal of Pharmacology. 479 (1–3): 23–40. doi:10.1016/j.ejphar.2003.08.054. PMID14612135.
^Rothman RB, Baumann MH (2006). "Therapeutic potential of monoamine transporter substrates". Current Topics in Medicinal Chemistry. 6 (17): 1845–1859. doi:10.2174/156802606778249766. PMID17017961.
^Gelvin EP, McGAVACK TH (January 1952). "2-Amino-1-(p-methylphenyl)-propane (aptrol) as an anorexigenic agent in weight reduction". New York State Journal of Medicine. 52 (2): 223–226. PMID14890975.
^Blanckaert P, van Amsterdam J, Brunt T, van den Berg J, Van Durme F, Maudens K, et al. (September 2013). "4-Methyl-amphetamine: a health threat for recreational amphetamine users". Journal of Psychopharmacology. 27 (9): 817–822. doi:10.1177/0269881113487950. PMID23784740. S2CID35436194.
^Coppola M, Mondola R (December 2013). "4-methylamphetamine (4-MA): chemistry, pharmacology and toxicology of a new potential recreational drug". Mini Reviews in Medicinal Chemistry. 13 (14): 2097–2101. doi:10.2174/13895575113136660106. PMID24195663.