Methylphenidate-like stimulants in vitro release [3H]tyramines but not [14C]dopamine

The effects of methylphenidate, cocaine, nomifensine and amfonelic acid on the simultaneous uptake and release of [14C]dopamine and [3H]p-tyramine or [3H]m-tyramine were examined in rat striatal slices. While the uptake of each amine was inhibited equally by each drug, only [3H]tyramines were released. The d-amphetamine-induced release of [14C]dopamine and [3H]p-tyramine was antagonized by these drugs. These findings suggest that the tyramines can be transported independently from dopamine.