MAO-A and MAO-B activities in rat striatum, frontal cortex and liver are unaltered after long-term treatment with fluvoxamine and desipramine

In the course of investigating the mechanisms underlying the beneficial eff ect of fluvoxamine augmentation on negative symptoms of schizophrenia, the authors found a reduction in human platelet monoamine oxidase-B activity af ter 5 weeks of treatment. This unexpected finding raised the possibility th at MAO activity may be one of the factors altered by chronic tricyclic or S SRI antidepressant treatment. The current study examined the effect of long -term administration, up to 6 weeks, of fluvoxamine, desipramine or saline on MAO-A and MAO-B activities in rat striatum, frontal cortex and liver. No differences were noted between drug-treated groups and their saline-treate d controls. The hypothesis that long-term treatment with tricyclic and SSRI antidepressants alters MAO activity was not supported. MAO is not among pr oteins whose activity may be altered by chronic tricyclic or SSRI antidepre ssant treatment. (C) 2000 Elsevier Science B.V. All rights reserved.