Biomaterial Database

The role of monoamine oxidase and catechol O-methyltransferase in dopaminergic neurotransmission. 1995

A Napolitano, and A M Cesura, and M Da Prada

Pharma Division, F. Hoffmann-La Roche Ltd., Basel, Switzerland.

The action of dopamine (DA) released in the synaptic cleft is mainly terminated by its reuptake and catabolism by the enzymes monoamine oxidase (MAO) and catechol O-methyltransferase (COMT). Preclinical data show that the reduction of the catabolism of DA elicited by MAO and COMT inhibitors leads to an enhancement of DA neurotransmission. Moreover, there is evidence suggesting that MAO-B inhibition might protect DA neurons from oxidative stress. Nevertheless, due to differences in enzyme localization and activity between man and rodents, results obtained in experimental animals might not reflect the actual situation in humans. Today the availability of potent and selective MAO and COMT inhibitors makes it feasible for the clinician to test whether the blockade of catabolic enzymes would result in a symptomatic improvement in Parkinsonian patients, and whether MAO-B inhibition might additionally exert a neuroprotective effect.

UI	MeSH Term	Description	Entries
D008995	Monoamine Oxidase	An enzyme that catalyzes the oxidative deamination of naturally occurring monoamines. It is a flavin-containing enzyme that is localized in mitochondrial membranes, whether in nerve terminals, the liver, or other organs. Monoamine oxidase is important in regulating the metabolic degradation of catecholamines and serotonin in neural or target tissues. Hepatic monoamine oxidase has a crucial defensive role in inactivating circulating monoamines or those, such as tyramine, that originate in the gut and are absorbed into the portal circulation. (From Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 8th ed, p415) EC 1.4.3.4.	Amine Oxidase (Flavin-Containing),MAO,MAO-A,MAO-B,Monoamine Oxidase A,Monoamine Oxidase B,Type A Monoamine Oxidase,Type B Monoamine Oxidase,Tyramine Oxidase,MAO A,MAO B,Oxidase, Monoamine,Oxidase, Tyramine
D008996	Monoamine Oxidase Inhibitors	A chemically heterogeneous group of drugs that have in common the ability to block oxidative deamination of naturally occurring monoamines. (From Gilman, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p414)	MAO Inhibitor,MAO Inhibitors,Reversible Inhibitors of Monoamine Oxidase,Monoamine Oxidase Inhibitor,RIMA (Reversible Inhibitor of Monoamine Oxidase A),Reversible Inhibitor of Monoamine Oxidase,Inhibitor, MAO,Inhibitor, Monoamine Oxidase,Inhibitors, MAO,Inhibitors, Monoamine Oxidase
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D010300	Parkinson Disease	A progressive, degenerative neurologic disease characterized by a TREMOR that is maximal at rest, retropulsion (i.e. a tendency to fall backwards), rigidity, stooped posture, slowness of voluntary movements, and a masklike facial expression. Pathologic features include loss of melanin containing neurons in the substantia nigra and other pigmented nuclei of the brainstem. LEWY BODIES are present in the substantia nigra and locus coeruleus but may also be found in a related condition (LEWY BODY DISEASE, DIFFUSE) characterized by dementia in combination with varying degrees of parkinsonism. (Adams et al., Principles of Neurology, 6th ed, p1059, pp1067-75)	Idiopathic Parkinson Disease,Lewy Body Parkinson Disease,Paralysis Agitans,Primary Parkinsonism,Idiopathic Parkinson's Disease,Lewy Body Parkinson's Disease,Parkinson Disease, Idiopathic,Parkinson's Disease,Parkinson's Disease, Idiopathic,Parkinson's Disease, Lewy Body,Parkinsonism, Primary
D002394	Catechol O-Methyltransferase	Enzyme that catalyzes the movement of a methyl group from S-adenosylmethionone to a catechol or a catecholamine.	Catechol Methyltransferase,Catechol-O-Methyltransferase,Catechol O Methyltransferase,Methyltransferase, Catechol,O-Methyltransferase, Catechol
D002490	Central Nervous System	The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.	Cerebrospinal Axis,Axi, Cerebrospinal,Axis, Cerebrospinal,Central Nervous Systems,Cerebrospinal Axi,Nervous System, Central,Nervous Systems, Central,Systems, Central Nervous
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D065098	Catechol O-Methyltransferase Inhibitors	Compounds and drugs that inhibit or block the activity of CATECHOL O-METHYLTRANSFERASE enzymes. Drugs in this class are used in management of central nervous system disorders such as PARKINSON DISEASE.	Catechol O Methyltransferase Inhibitors,O-Methyltransferase Inhibitors, Catechol