Naunyn-Schmiedeberg's Archives of Pharmacology

, Volume 323, Issue 4, pp 315–320 | Cite as

The deamination of noradrenaline and 5-hydroxytryptamine by rat brain and heart monoamine oxidase and their inhibition by cimoxatone, toloxatone and MD 770222

  • Margherita Strolin Benedetti
  • Thierry Boucher
  • Christopher J. Fowler


In both rat brain and heart, noradrenaline and 5-hydroxytryptamine are metabolised predominantly by monoamine oxidase-A. The Km values for 14C-noradrenaline in the rat brain and heart are 290 μM and 300 μM, respectively, whereas for 14C-5-hydroxytryptamine the values are 180 μM and 140 μM, respectively. In the rat brain, mixed substrate experiments suggested that 14C-noradrenaline and 14C-5-hydroxytryptamine are metabolised at the same active centre. Both substrates are inhibited with similar Ki values by the reversible inhibitors cimoxatone, toloxatone and MD 770222.

Key words

Monoamine oxidase Noradrenaline 5-Hydroxytryptamine Rat brain and heart 


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Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • Margherita Strolin Benedetti
    • 1
  • Thierry Boucher
    • 1
  • Christopher J. Fowler
    • 1
  1. 1.Centre de Recherche DelalandeRueil-MalmaisonFrance

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