Comparative actions of monomethoxy amphetamines on the release and uptake of biogenic amines in brain tissue

para Methoxyamphetamine (PMA), a known hallucinogen, is the most potent compound among methoxyamphetamines in disrupting behavior in rats. PMA, unlike d amphetamine (A), did not induce stereotyped behavior and was less effective than A in stimulation of locomotor d amphetamine like effects, but ortho methoxyamphetamine (OMA) was devoid of any locomotor stimulation. To investigate the reasons for the different behavioral effects caused by PMA, meta methoxyamphetamine (MMA), OMA and A, a comparison was made among these drugs on the release and uptake of ³H 5 hydroxytryptamine (³H 5 HT), ³H norepinephrine (³H NE) and ³H dopamine (³H DA) in tissue slices of cerebral cortex and corpus striatum of rat brain. The potencies for the increased release of ³H 5 HT were found to be PMA > MMA ≥ A > OMA in cerebral cortex, of ³H NE in cortex, A ≥ PMA = MMA > OMA, and of ³H DA in corpus striatum, A > MMA > PMA ≥ OMA. The potencies for inhibiting the uptake of ³H 5 HT in cerebral cortex and corpus striatum were found to be PMA > MMA > A > OMA and of ³H NE in cortex A > PMA ≥ MMA > OMA, and ³H DA in corpus striatum A > MMA > PMA > OMA. d PMA is equipotent to l PMA in increasing the release of ³H 5 HT but is more potent than l PMA in blocking the uptake of ³H 5 HT. The high potency of PMA on increasing the release and inhibiting the uptake of 5 HT suggests that 5 HT may be involved in the production of hallucinogenic effects of PMA.