EFFECT OF LONG-TERM FLUVOXAMINE TREATMENT ON ENDOGENOUS SEROTONIN UPTAKE INHIBITOR-LIKE SUBSTANCE IN MONKEY CEREBROSPINAL-FLUID

We found that substances present in monkey cerebrospinal fluid (CSF) c ould inhibit [H-3]-paroxetine binding in monkey brain preparations. Th e molecular weight of one of these inhibitory substances was approxima tely 2000, which is in agreement with earlier studies using human CSF. We also found that the inhibitory effect of the substances present in monkey CSF on [3H]-paroxetine binding decreased after 8 weeks of chro nic fluvoxamine (5 mg/kg day, p.o.) treatment. These results suggest t hat the ability of a drug to decrease the activity of endogenous 5-HT uptake modulators may related to its antidepressive effects.