• Separate genes encode two isoforms of MAO (types A and B), which were distinguished by their specificity to particular catecholamines:
MAO-A
  • Involved in the metabolism of serotonin, noradrenaline, adrenaline and tyramine
  • High concentrations in brain, gut, liver, placenta and skin
MAO-B
  • Involved in the metabolism of dopamine and tyramine
  • High concentrations in brain, platelets and lymphocytes