The effect of nomifensine on the depletion of brain serotonin and catecholamines induced respectively by fenfluramine and 6-hydroxydopamine in rats.

Nomifensine, at a dose of 10 mg/kg i.p., completely antagonized the decrease of brain dopamine induced by an intraventricular injection of 6-hydroxydopamine. The decrease of brain noradrenaline was also significantly antagonized by nomifensine. Desipramine antagonized the effect of 6-hydroxydopamine on noradrenaline but not on dopamine. The decrease of brain serotonin induced by fenfluramine was antagonized by chlorimipramine but not by nomifensine. The findings indicate that nomifensine specifically blocks the uptake mechanism for catecholamines in the brain without significant effects on serotonin.