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.
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)
Clorgyline
An antidepressive agent and monoamine oxidase inhibitor related to PARGYLINE.
Selegiline
A selective, irreversible inhibitor of Type B monoamine oxidase. It is used in newly diagnosed patients with Parkinson's disease. It may slow progression of the clinical disease and delay the requirement for levodopa therapy. It also may be given with levodopa upon onset of disability. (From AMA Drug Evaluations Annual, 1994, p385) The compound without isomeric designation is Deprenyl.
Tranylcypromine
A propylamine formed from the cyclization of the side chain of amphetamine. This monoamine oxidase inhibitor is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in panic and phobic disorders. (From AMA Drug Evaluations Annual, 1994, p311)
Phenelzine
Vesicular Monoamine Transport Proteins
A family of vesicular amine transporter proteins that catalyze the transport and storage of CATECHOLAMINES and indolamines into SECRETORY VESICLES.
NADPH Oxidase
A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.
Tyramine
An indirect sympathomimetic. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine may be a neurotransmitter in some invertebrate nervous systems.
Biogenic Monoamines
Biogenic amines having only one amine moiety. Included in this group are all natural monoamines formed by the enzymatic decarboxylation of natural amino acids.
Iproniazid
Moclobemide
Serotonin
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
Vesicular Biogenic Amine Transport Proteins
Integral membrane proteins of the LIPID BILAYER of SECRETORY VESICLES that catalyze transport and storage of biogenic amine NEUROTRANSMITTERS such as ACETYLCHOLINE; SEROTONIN; MELATONIN; HISTAMINE; and CATECHOLAMINES. The transporters exchange vesicular protons for cytoplasmic neurotransmitters.
Phenethylamines
Xanthine Oxidase
An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.
Tetrabenazine
A drug formerly used as an antipsychotic and treatment of various movement disorders. Tetrabenazine blocks neurotransmitter uptake into adrenergic storage vesicles and has been used as a high affinity label for the vesicle transport system.
Kynuramine
Propylamines
Protein-Lysine 6-Oxidase
An enzyme oxidizing peptidyl-lysyl-peptide in the presence of water & molecular oxygen to yield peptidyl-allysyl-peptide plus ammonia & hydrogen peroxide. EC 1.4.3.13.
Hydroxyindoleacetic Acid
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.
Homovanillic Acid
Bufotenin
3,4-Dihydroxyphenylacetic Acid
A deaminated metabolite of LEVODOPA.
Reserpine
An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use.
Mitochondria, Liver
Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)
Aldehyde Oxidase
An aldehyde oxidoreductase expressed predominantly in the LIVER; LUNGS; and KIDNEY. It catalyzes the oxidation of a variety of organic aldehydes and N-heterocyclic compounds to CARBOXYLIC ACIDS, and also oxidizes quinoline and pyridine derivatives. The enzyme utilizes molybdenum cofactor and FAD as cofactors.
Amines
Glucose Oxidase
An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.
Isocarboxazid
Brain
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Methoxydimethyltryptamines
Compounds that contain the biogenic monoamine tryptamine and are substituted with one methoxy group and two methyl groups. Members of this group include several potent serotonergic hallucinogens found in several unrelated plants, skins of certain toads, and in mammalian brains. They are possibly involved in the etiology of schizophrenia.
Biogenic Amines
A group of naturally occurring amines derived by enzymatic decarboxylation of the natural amino acids. Many have powerful physiological effects (e.g., histamine, serotonin, epinephrine, tyramine). Those derived from aromatic amino acids, and also their synthetic analogs (e.g., amphetamine), are of use in pharmacology.
Benzylamines
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
Norepinephrine
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Semicarbazides
Amine Oxidase (Copper-Containing)
Methoxyhydroxyphenylglycol
Synthesized from endogenous epinephrine and norepinephrine in vivo. It is found in brain, blood, CSF, and urine, where its concentrations are used to measure catecholamine turnover.
Norepinephrine Plasma Membrane Transport Proteins
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of noradrenergic neurons. They remove NOREPINEPHRINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. It regulates signal amplitude and duration at noradrenergic synapses and is the target of ADRENERGIC UPTAKE INHIBITORS.
D-Amino-Acid Oxidase
D-Amino-Acid Oxidase is an enzyme that catalyzes the oxidative deamination of D-amino acids to their corresponding α-keto acids, ammonia, and hydrogen peroxide, playing a crucial role in the metabolism of non-proteinogenic D-amino acids.
Serotonin Plasma Membrane Transport Proteins
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.
Oxidoreductases
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
Nictitating Membrane
5-Hydroxytryptophan
The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.
Antidepressive Agents
Mood-stimulating drugs used primarily in the treatment of affective disorders and related conditions. Several MONOAMINE OXIDASE INHIBITORS are useful as antidepressants apparently as a long-term consequence of their modulation of catecholamine levels. The tricyclic compounds useful as antidepressive agents (ANTIDEPRESSIVE AGENTS, TRICYCLIC) also appear to act through brain catecholamine systems. A third group (ANTIDEPRESSIVE AGENTS, SECOND-GENERATION) is a diverse group of drugs including some that act specifically on serotonergic systems.
Catechol O-Methyltransferase
Butylamines
Dihydroxyphenylalanine
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Flavin-Adenine Dinucleotide
A condensation product of riboflavin and adenosine diphosphate. The coenzyme of various aerobic dehydrogenases, e.g., D-amino acid oxidase and L-amino acid oxidase. (Lehninger, Principles of Biochemistry, 1982, p972)
Imidazoline Receptors
Mitochondria
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Imipramine
Allylamine
Dopamine Plasma Membrane Transport Proteins
Fenclonine
A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.
Galactose Oxidase
Blood Platelets
Nomifensine
An isoquinoline derivative that prevents dopamine reuptake into synaptosomes. The maleate was formerly used in the treatment of depression. It was withdrawn worldwide in 1986 due to the risk of acute hemolytic anemia with intravascular hemolysis resulting from its use. In some cases, renal failure also developed. (From Martindale, The Extra Pharmacopoeia, 30th ed, p266)
Harmine
Alkaloid isolated from seeds of Peganum harmala L., Zygophyllaceae. It is identical to banisterine, or telepathine, from Banisteria caapi and is one of the active ingredients of hallucinogenic drinks made in the western Amazon region from related plants. It has no therapeutic use, but (as banisterine) was hailed as a cure for postencephalitic Parkinson disease in the 1920's.
Levodopa
The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.
Urate Oxidase
Flavins
Banisteriopsis
A plant genus of the family MALPIGHIACEAE which includes an Amazonian psychoactive plant that contains the beta-carboline harmine and N,N-dimethyltryptamine.
Desipramine
A tricyclic dibenzazepine compound that potentiates neurotransmission. Desipramine selectively blocks reuptake of norepinephrine from the neural synapse, and also appears to impair serotonin transport. This compound also possesses minor anticholinergic activity, through its affinity to muscarinic receptors.
Picolinic Acids
Picolinic acid is an organic compound that belongs to the class of pyridine derivatives, acting as a chelating agent in mammals, primarily found in the liver and kidneys, and playing a significant role in the metabolism of proteins, vitamins, and minerals.
Acyl-CoA Oxidase
An enzyme that catalyzes the first and rate-determining steps of peroxisomal beta-oxidation of fatty acids. It acts on COENZYME A derivatives of fatty acids with chain lengths from 8 to 18, using FLAVIN-ADENINE DINUCLEOTIDE as a cofactor.
Benzyl Compounds
Phenylhydrazines
Substrate Specificity
Hydrazines
Membrane Transport Proteins
Serotonin Syndrome
An adverse drug interaction characterized by altered mental status, autonomic dysfunction, and neuromuscular abnormalities. It is most frequently caused by use of both serotonin reuptake inhibitors and monoamine oxidase inhibitors, leading to excess serotonin availability in the CNS at the serotonin 1A receptor.
Alkynes
NADH, NADPH Oxidoreductases
A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.
Dextroamphetamine
The d-form of AMPHETAMINE. It is a central nervous system stimulant and a sympathomimetic. It has also been used in the treatment of narcolepsy and of attention deficit disorders and hyperactivity in children. Dextroamphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulating release of monamines, and inhibiting monoamine oxidase. It is also a drug of abuse and a psychotomimetic.
Cholesterol Oxidase
An enzyme that catalyzes the oxidation of cholesterol in the presence of molecular oxygen to 4-cholesten-3-one and hydrogen peroxide. The enzyme is not specific for cholesterol, but will also oxidize other 3-hydroxysteroids. EC 1.1.3.6.
Tryptophan Hydroxylase
An enzyme that catalyzes the hydroxylation of TRYPTOPHAN to 5-HYDROXYTRYPTOPHAN in the presence of NADPH and molecular oxygen. It is important in the biosynthesis of SEROTONIN.
Oxidoreductases Acting on CH-NH Group Donors
Enzymes catalyzing the dehydrogenation of secondary amines, introducing a C=N double bond as the primary reaction. In some cases this is later hydrolyzed.
L-Amino Acid Oxidase
An enzyme that catalyzes the oxidative deamination of L-amino acids to KETO ACIDS with the generation of AMMONIA and HYDROGEN PEROXIDE. L-amino acid oxidase is widely distributed in and is thought to contribute to the toxicity of SNAKE VENOMS.
Cluster Headache
A primary headache disorder that is characterized by severe, strictly unilateral PAIN which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15-180 min. occurring 1 to 8 times a day. The attacks are associated with one or more of the following, all of which are ipsilateral: conjunctival injection, lacrimation, nasal congestion, rhinorrhea, facial SWEATING, eyelid EDEMA, and miosis. (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)
Isoenzymes
Pyruvate Oxidase
Glycols
Hydrogen Peroxide
Brain Chemistry
Rats, Sprague-Dawley
Isatin
Lobeline
Chlorphenamidine
Sympathomimetics
Octopamine
An alpha-adrenergic sympathomimetic amine, biosynthesized from tyramine in the CNS and platelets and also in invertebrate nervous systems. It is used to treat hypotension and as a cardiotonic. The natural D(-) form is more potent than the L(+) form in producing cardiovascular adrenergic responses. It is also a neurotransmitter in some invertebrates.
Dopamine beta-Hydroxylase
Dopamine beta-Hydroxylase is an enzyme that catalyzes the conversion of dopamine to norepinephrine, a crucial step in the synthesis of catecholamines within the adrenal glands and central nervous system.
Oxazoles
Neurotransmitter Uptake Inhibitors
Drugs that inhibit the transport of neurotransmitters into axon terminals or into storage vesicles within terminals. For many transmitters, uptake determines the time course of transmitter action so inhibiting uptake prolongs the activity of the transmitter. Blocking uptake may also deplete available transmitter stores. Many clinically important drugs are uptake inhibitors although the indirect reactions of the brain rather than the acute block of uptake itself is often responsible for the therapeutic effects.
Cattle
Zimeldine
One of the SEROTONIN UPTAKE INHIBITORS formerly used for depression but was withdrawn worldwide in September 1983 because of the risk of GUILLAIN-BARRE SYNDROME associated with its use. (From Martindale, The Extra Pharmacopoeia, 29th ed, p385)
Liver
Metaraminol
Sympathectomy
Phenylacetates
Derivatives of phenylacetic acid. Included under this heading are a variety of acid forms, salts, esters, and amides that contain the benzeneacetic acid structure. Note that this class of compounds should not be confused with derivatives of phenyl acetate, which contain the PHENOL ester of ACETIC ACID.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Antisocial Personality Disorder
A personality disorder whose essential feature is a pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood. The individual must be at least age 18 and must have a history of some symptoms of CONDUCT DISORDER before age 15. (From DSM-IV, 1994)