A catecholamine is a monoamine neurotransmitter, an organic compound that has a catechol and a side-chain amine.
A dopamine reuptake inhibitor (DRI) is a class of drug which acts as a reuptake inhibitor of the monoamine neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). Reuptake inhibition is achieved when extracellular dopamine not absorbed by the postsynaptic neuron is blocked from re-entering the presynaptic neuron. This results in increased extracellular concentrations of dopamine and increase in dopaminergic neurotransmission.
α-Methyl-p-tyrosine (AMPT), or simply α-methyltyrosine, also known in its chiral 2-(S) form as metirosine, is a tyrosine hydroxylase enzyme inhibitor and is therefore a drug involved in inhibiting the catecholamine biosynthetic pathway. AMPT inhibits tyrosine hydroxylase whose enzymatic activity is normally regulated through the phosphorylation of different serine residues in regulatory domain sites. Catecholamine biosynthesis starts with dietary tyrosine, which is hydroxylated by tyrosine hydroxylase and it is hypothesized that AMPT competes with tyrosine at the tyrosine-binding site, causing inhibition of tyrosine hydroxylase.
Dopaminergic means "related to dopamine", a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
Apomorphine, sold under the brand name Apokyn among others, is a type of aporphine having activity as a non-selective dopamine agonist which activates both D2-like and, to a much lesser extent, D1-like receptors. It also acts as an antagonist of 5-HT2 and α-adrenergic receptors with high affinity. The compound is an alkaloid belonging to nymphaea caerulea, or blue lotus, but is also historically known as a morphine decomposition product made by boiling morphine with concentrated acid, hence the -morphine suffix. Contrary to its name, apomorphine does not actually contain morphine or its skeleton, nor does it bind to opioid receptors. The apo- prefix relates to it being a morphine derivative ("[comes] from morphine").
A dopamine agonist is a compound that activates dopamine receptors. There are two families of dopamine receptors, D1-like and D2-like. They are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the D2-like family includes D2, D3 and D4 receptors. Dopamine agonists are primarily used in the treatment of the motor symptoms of Parkinson's disease, and to a lesser extent, in hyperprolactinemia and restless legs syndrome. They are also used off-label in the treatment of clinical depression. Impulse control disorders are associated with the use of dopamine agonists for whatever condition.
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). It does so using molecular oxygen (O2), as well as iron (Fe2+) and tetrahydrobiopterin as cofactors. L-DOPA is a precursor for dopamine, which, in turn, is a precursor for the important neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline). Tyrosine hydroxylase catalyzes the rate limiting step in this synthesis of catecholamines. In humans, tyrosine hydroxylase is encoded by the TH gene, and the enzyme is present in the central nervous system (CNS), peripheral sympathetic neurons and the adrenal medulla. Tyrosine hydroxylase, phenylalanine hydroxylase and tryptophan hydroxylase together make up the family of aromatic amino acid hydroxylases (AAAHs).
Aporphine is an alkaloid with the chemical formula C17H17N. It is the core chemical substructure of the aporphine alkaloids, a subclass of quinoline alkaloids. It can exist in either of two enantiomeric forms, (R)-aporphine and (S)-aporphine.
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone, neurotransmitter and neuromodulator. The name "noradrenaline" is more commonly used in the United Kingdom and the rest of the world, whereas "norepinephrine" is usually preferred in the United States. "Norepinephrine" is also the international nonproprietary name given to the drug. Regardless of which name is used for the substance itself, parts of the body that produce or are affected by it are referred to as noradrenergic.
Nuciferine is an alkaloid found within the plants Nymphaea caerulea and Nelumbo nucifera.
Monoamine oxidase B (MAO-B) is an enzyme that in humans is encoded by the MAOB gene.
Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters:
Higenamine (norcoclaurine) is a chemical compound found in a variety of plants including Nandina domestica (fruit), Aconitum carmichaelii (root), Asarum heterotropioides, Galium divaricatum, Annona squamosa, and Nelumbo nucifera.
Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and duration of action of acetylcholine in the central nervous system, autonomic ganglia and neuromuscular junctions, which are rich in acetylcholine receptors. Acetylcholinesterase inhibitors are one of two types of cholinesterase inhibitors; the other being butyryl-cholinesterase inhibitors. Acetylcholinesterase is the primary member of the cholinesterase enzyme family.
Sonepiprazole (U-101,387, PNU-101,387-G) is a drug of the phenylpiperazine class which acts as a highly selective D4 receptor antagonist. In animals, unlike D2 receptor antagonists like haloperidol, sonepiprazole does not block the behavioral effects of amphetamine or apomorphine, does not alter spontaneous locomotor activity on its own, and lacks extrapyramidal and neuroendocrine effects. However, it does reverse the prepulse inhibition deficits induced by apomorphine, and has also been shown to enhance cortical activity and inhibit stress-induced cognitive impairment. As a result, it was investigated as an antipsychotic for the treatment of schizophrenia in a placebo-controlled clinical trial, but in contrast to its comparator olanzapine no benefits were found and it was not researched further for this indication.
Corydaline is an acetylcholinesterase inhibitor isolated from Corydalis yanhusuo.
Blarcamesine is an experimental drug which is under development for the treatment of Alzheimer's disease and a variety of other indications.
2-Hydroxyestradiol (2-OHE2), also known as estra-1,3,5(10)-triene-2,3,17β-triol, is an endogenous steroid, catechol estrogen, and metabolite of estradiol, as well as a positional isomer of estriol.
Catecholamines up (Catsup) is a dopamine regulatory membrane protein that functions as a zinc ion transmembrane transporter (orthologous to ZIP7), and a negative regulator of rate-limiting enzymes involved in dopamine synthesis and transport: Tyrosine hydroxylase (TH), GTP Cyclohydrolase I (GTPCH), and Vesicular Monoamine Transporter (VMAT) in Drosophila melanogaster.
Phenserine is a synthetic drug which has been investigated as a medication to treat Alzheimer's disease (AD), as the drug exhibits neuroprotective and neurotrophic effects.
