EFFECTS OF TIANEPTINE, SERTRALINE AND CLOMIPRAMINE ON BRAIN-SEROTONINMETABOLISM - A VOLTAMMETRIC APPROACH IN THE RAT

Tianeptine is a substance enhancing the serotonin uptake while sertral ine and clomipramine inhibit it. By means of 5-hydroxyindoleacetic aci d (5-HIAA) voltammetric measurements, this study investigated their in fluence on serotonin metabolism which depends mainly upon the activity of monoamine oxidase type A. After tianeptine injection the 5-HIAA si gnal increased by about 60%. This effect was maintained when the anima ls were pre-treated with MDL 72145 (an inhibitor of monoamine oxidase type B) but reduced when clorgyline (an inhibitor of monoamine oxidase type A) was administered after tianeptine. Administration of sertrali ne or clomipramine reduced the 5-HIAA signal by about 30-50%, whether the animals were pre-treated with MDL 72145 or not. It is to be conclu ded that tianeptine, sertraline and clomipramine can regulate the 5-HT fraction present in the synaptic cleft, not only by acting at the lev el of the serotoninergic neurons, but also by favoring or reducing the access of the amine to monoamine oxidase type A which is synthesized within non-serotoninergic neurons and glial cells.