EFFECTS OF FLUVOXAMINE ON THE PROTEIN-PHOSPHORYLATION SYSTEM ASSOCIATED WITH RAT NEURONAL MICROTUBULES

We have studied the phosphorylation system associated with the rat cer ebrocortical microtubule fraction after short- and long-term administr ation (15 mg/kg) of fluvoxamine, a selective serotonin reuptake inhibi tor with antidepressant activity. Fluvoxamine administered for 5 days significantly enhanced the P-32 incorporation stimulated by cAMP into MAP2, while it failed to produce this effect after 12 and 21 days. Mor eover, in the same periods of treatment no changes were observed in ba sal phosphorylation and in the pattern of microtubule proteins. In con clusion, our results suggest that changes in the protein phosphorylati on system associated with the microtubule fraction could represent an early neurochemical modification involved in the action of fluvoxamine .