Reticuline: A dopamine receptor blocker

Reticuline, a benzylisoquinoline alkaloid, inhibited specific ³H] dopamine binding to dopamine receptors in tissue homogenates from rat corpora striata. The alkaloid blocked amphetamine-induced circling behavior in mice with unilateral (chemically-induced) degeneration of dopaminergic neurons in the corpus striatum. Blockade of apomorphine-induced climbing behavior by reticuline was observed in mice. Reticuline did not produce catalepsy at doses which blocked circling behavior. These results show that reticuline is a dopamine receptor blocking agent in the central nervous system.