effects of tricyclic and tetracyclic antidepressants on the levels of norepinephrine, dopamine and serotonin in rat brain

ABSTRACT

After 3 weeks of daily intraperitoneal administration of either incyclic [amitriptyline, clomipramine] or tetracyclic [maprotiline] antidepressants in a dose of 20 mg/kg each to male rats, the whole brain levels of norepinephrine and dopamine were significantly increased as compared to control values. In contrast, the level of serotonin increased only with the tetracyclic antidepressant maprotiline and this increase was moderate. However, it is not yet certain, how far these effects contribute to the mechanism of antidepressant action. A study of the turn-over rate and the activities of the enzymes along the monoamine metabolic pathway are currently underway for adequate interpretation of the results: