EFFECT OF LITHIUM ON THE PROLACTIN RESPONSE TO D-FENFLURAMINE IN HEALTHY-SUBJECTS

We assessed the effect of two regimes of lithium treatment (3 days and 2 weeks) on brain serotonin (5-HT) function in healthy subjects by me asuring the prolactin (PRL) responses to the 5-HT releasing agent, d-f enfluramine (30 mg) before and after lithium administration. Neither r egime of lithium treatment altered d-fenfluramine-induced PRL release. These results are in contrast to the facilitation produced by lithium of the PRL responses to the 5-HT precursor L-tryptophan. The data sug gest that the ability of lithium to increase brain 5-HT neurotransmiss ion in humans may depend on interactions with particular 5-HT receptor subtypes or specific mechanisms of 5-HT release.