Final answer:
MAO is responsible for the metabolism of neurotransmitters in the liver by oxidative deamination, forming metabolites like VMA. There are two subtypes, MAO-A and MAO-B, with different substrate specificities, which influences their roles in psychiatric treatments and side effects.
Step-by-step explanation:
Role of Monoamine Oxidase (MAO)
Monoamine Oxidase (MAO) plays a crucial role in the metabolism of neurotransmitters. In the liver, MAO is responsible for the oxidative deamination of monoamines which is a process where an amine group is removed from molecules. This deamination results in the formation of various metabolites, including deaminated products such as Vanillylmandelic acid (VMA), which is a major excretory product of catecholamines.
Differences Between MAO Subtypes
There are two subtypes of MAO: MAO-A and MAO-B. MAO-A primarily metabolizes neurotransmitters such as serotonin, norepinephrine, and dopamine, thereby influencing mood and emotional behaviors. It is targeted by MAO inhibitors (MAOIs) that were among the first antidepressants used in psychiatric treatment.
On the other hand, MAO-B is more involved in the metabolism of phenylethylamine and certain other neurotransmitters. The differences in substrate specificity between the two subtypes have important implications for the treatment of psychiatric conditions and the side effects of MAOIs.