Amphetamine- and phenylethylamine-induced alterations in dopamine synthesis regulation in rat brain striatal...

Amphetamine and phenylethylamine stimulate dopamine synthesis in rat brain striatal synaptosomes via a calcium- and tyrosine-dependent mechanism. The similarity of this stimulation to that produced by depolarizing concentrations of veratridine, along with the non-additivity of maximally stimulating concentrations of amphetamine and veratridine, suggests that these treatments may all share a common locus of action. Differences in exact modes of action can be seen, however, in the blockade only of the stimulation of veratridine by tetrodotoxin, and by the lack of effect of amphetamine or phenylethylamine on tyrosine uptake. At high concentrations, amphetamine and phenylethylamine lose their ability to stimulate dopamine synthesis and produce an antagonism of veratridine-induced synthesis stimulation.