PT - JOURNAL ARTICLE AU - Charles W. Schindler AU - Eric B. Thorndike AU - Kenner C. Rice AU - John S. Partilla AU - Michael H. Baumann TI - The Supplement Adulterant <em>β</em>-Methylphenethylamine Increases Blood Pressure by Acting at Peripheral Norepinephrine Transporters AID - 10.1124/jpet.118.255976 DP - 2019 Jun 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 328--336 VI - 369 IP - 3 4099 - http://jpet.aspetjournals.org/content/369/3/328.short 4100 - http://jpet.aspetjournals.org/content/369/3/328.full SO - J Pharmacol Exp Ther2019 Jun 01; 369 AB - β-Methylphenethylamine [(BMPEA), 2-phenylpropan-1-amine] is a structural isomer of amphetamine (1-phenylpropan-2-amine) that has been identified in preworkout and weight loss supplements, yet little information is available about its pharmacology. Here, the neurochemical and cardiovascular effects of BMPEA and its analogs, N-methyl-2-phenylpropan-1-amine (MPPA) and N,N-dimethyl-2-phenylpropan-1-amine (DMPPA), were compared with structurally related amphetamines. As expected, amphetamine and methamphetamine were potent substrate-type releasing agents at dopamine transporters (DATs) and norepinephrine transporters (NETs) in rat brain synaptosomes. BMPEA and MPPA were also substrates at DATs and NETs, but they were at least 10-fold less potent than amphetamine. DMPPA was a weak substrate only at NETs. Importantly, the releasing actions of BMPEA and MPPA were more potent at NETs than DATs. Amphetamine produced significant dose-related increases in blood pressure (BP), heart rate (HR), and locomotor activity in conscious rats fitted with surgically implanted biotelemetry transmitters. BMPEA, MPPA, and DMPPA produced increases in BP that were similar to the effects of amphetamine, but the compounds failed to substantially affect HR or activity. The hypertensive effect of BMPEA was reversed by the α-adrenergic antagonist prazosin but not the ganglionic blocker chlorisondamine. Radioligand binding at various G protein–coupled receptors did not identify nontransporter sites of action that could account for cardiovascular effects of BMPEA or its analogs. Our results show that BMPEA, MPPA, and DMPPA are biologically active. The compounds are unlikely to be abused due to weak effects at DATs, but they could produce adverse cardiovascular effects via substrate activity at peripheral NET sites.