New directions in monoamine oxidase A and B selective inhibitors and substrates.

Identification, cellular localization, and cDNA cloning of MAO subtypes A and B have increased the insight into the pharmacology of these enzymes, whose primary functions are intra- and extraneuronal inactivation of neurotransmitter (dopamine, noradrenaline and serotonin) and other biogenic amines. In addition, MAO oxidizes the inert uncharacteristic tertiary amine, MPTP, to the parkinson inducing dopaminergic neurotoxin, MPP+, and the novel secondary amine anticonvulsant milacemide to the inhibitory amino acid neurotransmitter, glycine. These recent developments have provided new therapeutic perspectives for the management of Parkinson's disease and seizure disorders via the use of selective inhibitors and amino acid amine prodrug substrates of MAO-B.