Localization of monoamine oxidases in human peripheral tissues

Life Sci. 1996;59(16):1341-9. doi: 10.1016/0024-3205(96)00459-6.


Localization of monoamine oxidases (MAO) A and B and beta-adrenoceptors, was studied in aged human peripheral tissues (age 68-80 years) by quantitative autoradiography. The tissues analyzed were heart, lung, liver, kidney, spleen and duodenum. [3H]Ro41-1049 and [3H]lazabemide, two recently characterized selective radioligands were used to map MAO-A and MAO-B respectively. The regional pattern of distribution of MAO-A and MAO-B did not differ markedly, except in kidney and especially in duodenum. Highest levels of MAOs were measured in liver, and lowest in spleen. MAO-A was more abundant than MAO-B in lung and duodenal mucosa, and the reverse was true in myocardium. These results show marked differences in the abundance and patterns of distribution of MAOs, particularly MAO-B, in human and rodent peripheral tissues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Autoradiography
  • Duodenum / enzymology
  • Humans
  • Isoenzymes / metabolism*
  • Kidney / enzymology
  • Liver / enzymology
  • Lung / enzymology
  • Monoamine Oxidase / metabolism*
  • Monoamine Oxidase Inhibitors / metabolism
  • Myocardium / enzymology
  • Picolinic Acids / metabolism
  • Receptors, Adrenergic, beta / metabolism
  • Spleen / enzymology
  • Thiazoles / metabolism


  • Isoenzymes
  • Monoamine Oxidase Inhibitors
  • Picolinic Acids
  • Receptors, Adrenergic, beta
  • Thiazoles
  • Ro 41-1049
  • lazabemide
  • Monoamine Oxidase