Ha-117 and Ha-118 are potent dopamine receptor agonists

In-vitro studies evaluated the presynaptic dopamine receptor activities of trans-N-propyl-7,9-dihydroxyoctahydrobenzo[f]quinoline (Ha-117) and trans-N-ethyl-7,9-dihydroxyoctahydrobenzo[f]quinoline (Ha-118) using isolated field-stimulated cat right atria. Ha-117 and Ha-118 were found to be potent dopamine receptor agonists since their effects were antagonized by haloperidol. Compounds were inactive on presynaptic alpha 2-adrenoceptors using rat vas deferens and guinea-pig ileum. Results show that both resorcinol derivatives of octahydrobenzo[f]quinoline are potent dopamine receptor agonists without having presynaptic alpha 2-adrenoceptor stimulating activity.