Distribution and localization of p-hydroxy-d-amphetamine in rat brain

p-Hydroxy-d-amphetamine (p-OHdA) penetrates the blood--brain barrier poorly, when given acutely or by repeated systemic treatments, or when formed by biotransformation from administered d-amphetamine. However its distribution is relatively selective as it accumulates in the striatum more than in the brainstem. The rate of disappearance also differs in the two areas, being slower in the striatum than in the brainstem. These findings suggest that p-OHdA might be stored in different compartments. To check whether p-OHdA specificially accumulated in nerve terminals, catecholaminergic nerve endings were destroyed with 6-hydroxydopamine (6-OHDA). It has been shown that p-HOdA accumulates much less in the striatum of 6-OHDA-treated rats than of controls. This effect was not present in the brainstem. Accumulation of p-OHdA was similar after repeated d-amphetamine administration. The results are interpreted as showing that p-OHdA tends to accumulate in dopaminergic structures.