Monoamine oxidase A (MAO-A) (MAO-A)

Monoamine oxidase A (MAO-A) is a flavin-containing enzyme localized to the outer mitochondrial membrane, where it catalyzes the oxidative deamination of biogenic amines such as serotonin, norepinephrine, and dopamine [1, 4]. In rats, MAO-A shares approximately 90% sequence identity with the human ortholog but functions as a dimer and exhibits significantly higher catalytic efficiency for amine neurotransmitter oxidation [4, 10]. It is a primary therapeutic target for the treatment of depression and anxiety, as its inhibition increases the availability of mood-regulating monoamines in the brain [14, 16]. Beyond its role in the central nervous system, rat MAO-A is also a significant source of oxidative stress in peripheral tissues, contributing to conditions like diabetic cardiomyopathy and pulmonary arterial hypertension [2]. Clinical use of MAO-A inhibitors is often limited by the 'cheese effect,' a potentially fatal hypertensive crisis caused by the failure to degrade dietary tyramine [17, 19]. The enzyme's activity is also linked to behavioral traits such as impulsivity and aggression, making it a focus of both pharmacological and genetic research [9, 12].

Other names

Amine oxidase [flavin-containing] AMAOAMonoamine oxidase type ArMAO-AAmine oxidase (flavin-containing) A

Inhibition of the oxidative deamination of monoamines, which prevents the degradation of neurotransmitters such as serotonin and norepinephrine, thereby increasing their concentration in the synaptic cleft [16, 18].