( super(3)H)Dihydrotetrabenazine binding to bovine striatal synaptic vesicles

(2- super(3)H)Dihydrotetrabenazine (2-hydroxy-3-isobutyl-9, 10-dimethoxy-1,2,3,4,6,7-hexahydro-11bH-benzo(a)quinolizine) bound to a single class of binding sites in synaptic vesicles isolated from bovine corpus striatum. Dopamine, serotonin, and other substrates for transport into synaptic vesicles inhibited binding. The results suggest that dihydrotetrabenazine interacts with the catecholamine/serotonin porter in synaptic vesicles, although the binding site is probably not identical to that involved in active transport of substrate.