Prevention of the serotonin syndrome in rats by repeated administration of monoamine oxidase inhibitors but not tricyclic antidepressants

I. Lucki, A. Frazer

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80 Scopus citations


The serotonin syndrome, a behavioral response produced by the activation of serotonin receptors, and 3H-serotonin binding were examined after repeated treatment of rats with different types of antidepressant drugs. The serotonin syndrome was produced by the direct-acting serotonin receptor agonists 5-methoxy-N,N-dimethyltryptamine (5-MeDMT) or d-lysergic acid diethylamide (LSD). Repeated, but not acute treatment of rats with monoamine oxidase inhibitors (nialamide, pargyline, and phenelzine) prevented the serotonin syndrome in response to either 5-MeDMT or LSD and also reduced 3H-serotonin binding in the brain stem and spinal cord. Pretreatment of rats with p-chlorophenylalanine blocked the ability of nialamide treatment to inhibit the serotonin syndrome caused by 5-MeDMT. By contrast, neither the serotonin syndrome or 3H-serotonin binding was affected significantly by the repeated administration of tricyclic antidepressants (amitriptyline, desmethyl-imipramine, and chlorimipramine) or iprindole. Repeated monoamine oxidase inhibitor treatments may prevent the serotonin syndrome by causing a reduction of 3H-serotonin receptor binding sites in the brain stem and/or spinal cord.

Original languageEnglish (US)
Pages (from-to)205-211
Number of pages7
Issue number3
Publication statusPublished - Jul 1 1982



  • Depression
  • H-serotonin binding
  • Monoamine oxidase inhibitors
  • Serotonin syndrome
  • Tricyclic antidepressants

ASJC Scopus subject areas

  • Pharmacology

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