The Role of Monoamine Oxidase in Humans and Its Metabolism

PSYCHIATRIC ANNALS • Vol. 44, No. 11, 2014 495 ABSTRACT Monoamine oxidase (MAO) isoenzymes A and B are mitochondrial-bound proteins that catalyze the oxidative deamination of dietary amines and monoamine transmitters. Others include: serotonin, epinephrine, 2-phenylethylamine, and dopamine. MAOs can potentially modulate all the processes involving bioactive amines, including regulation of mood, emotional behavior, and other brain function. MAO enzymatic activity plays a role in the pathophysiology of a wide range of mental and neurodegenerative disorders, including personality disorders, depressive syndromes, and Parkinson’s disease. Similarly, the byproducts of MAO-mediated reactions include some chemical species that can cause mitochondrial damage leading to neurotoxicity, and can affect the function of other organs such as the heart. In this article, genetic variations, anatomical distribution, and physiological functions of MAO-A and MAO-B are described. [Psychiatr Ann. 2014;44(11):495-501.]