p-Methoxyamphetamine, a potent reversible inhibitor of type-A monoamine oxidase in vitro and in vivo

J Pharm Pharmacol. 1980 Apr;32(4):262-6. doi: 10.1111/j.2042-7158.1980.tb12909.x.


p-Methoxyamphetamine is over 20 times as potent as (+)-amphetamine as an inhibitor of 5-HT oxidation by monoamine oxidase in mouse brain in vitro, with a Ki value of 0.22 microM. It is highly selective towards A-type monoamine oxidase and possesses only weak activity against the B-type enzyme (Ki value about 500 microM with benzylamine as substrate and solubilized rat liver mitochondria as enzyme source). It is 10 times more active than (+)-amphetamine in protecting mouse brain monoamine oxidase from inhibition by phenelzine in vivo. o-Methoxy- and m-methoxyamphetamines inhibit monoamine oxidase both in vitro and in vivo with potencies comparable with, or less than that of (+)-amphetamine.

Publication types

  • Comparative Study

MeSH terms

  • Amphetamine / pharmacology
  • Amphetamines / pharmacology*
  • Animals
  • Brain / enzymology
  • Clorgyline / pharmacology
  • Dose-Response Relationship, Drug
  • In Vitro Techniques
  • Kinetics
  • Male
  • Mice
  • Monoamine Oxidase Inhibitors*
  • Phenelzine / pharmacology
  • Rats
  • Serotonin / metabolism
  • Structure-Activity Relationship
  • Substrate Specificity


  • Amphetamines
  • Monoamine Oxidase Inhibitors
  • Serotonin
  • Amphetamine
  • Clorgyline
  • Phenelzine
  • 4-methoxyamphetamine