Catecholamine

catecholaminescatecholamine synthesiscatecholamine systemscatecholamine plasma membrane transport proteinsMethyltyrosineadrenergic fiberscatcholaminescatecholamine neurotransmitterscatecholaminergic signalingcatecolamine
A catecholamine (abbreviated CA) is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine.wikipedia
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Norepinephrine

noradrenalinenoradrenergicnoradrenalin
Included among catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. In neurons that use DA as the transmitter, the decarboxylation of L -DOPA to dopamine is the final step in formation of the transmitter; however, in those neurons using norepinephrine (noradrenaline) or epinephrine (adrenaline) as transmitters, the enzyme dopamine β-hydroxylase (DBH), which converts dopamine to yield norepinephrine, is also present.
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 and neurotransmitter.

Dopamine

dopaminergic systemDAdopaminergic
Included among catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. Dopamine, which acts as a neurotransmitter in the central nervous system, is largely produced in neuronal cell bodies in two areas of the brainstem: the ventral tegmental area and the substantia nigra, the latter of which contains neuromelanin-pigmented neurons.
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is an organic chemical of the catecholamine and phenethylamine families.

Fight-or-flight response

stress responsefight or flightfight-or-flight
Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response.
More specifically, the adrenal medulla produces a hormonal cascade that results in the secretion of catecholamines, especially norepinephrine and epinephrine.

Adrenal gland

adrenal glandsadrenalsuprarenal gland
Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response.
The medulla produces the catecholamine, adrenaline and noradrenaline, which function to produce a rapid response throughout the body in stress situations.

Adrenaline

epinephrineadrenaline junkieadrenalin
Included among catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. Epinephrine is produced in small groups of neurons in the human brain which express its synthesizing enzyme, phenylethanolamine N-methyltransferase; these neurons project from a nucleus that is adjacent (ventrolateral) to the area postrema and from a nucleus in the dorsal region of the solitary tract. In neurons that use DA as the transmitter, the decarboxylation of L -DOPA to dopamine is the final step in formation of the transmitter; however, in those neurons using norepinephrine (noradrenaline) or epinephrine (adrenaline) as transmitters, the enzyme dopamine β-hydroxylase (DBH), which converts dopamine to yield norepinephrine, is also present.
The adrenal medulla is a minor contributor to total circulating catecholamines ( L -DOPA is at a higher concentration in the plasma), though it contributes over 90% of circulating adrenaline.

L-DOPA

levodopa L -DOPADOPA
Catecholamine-secreting cells use several reactions to convert tyrosine serially to L -DOPA and then to dopamine.
-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), which are collectively known as catecholamines.

Chromaffin cell

chromaffin cellschromaffinchromaffin granules
Catecholamines are produced mainly by the chromaffin cells of the adrenal medulla and the postganglionic fibers of the sympathetic nervous system.
The chromaffin cells release catecholamines: ~80% of adrenaline (epinephrine) and ~20% of noradrenaline (norepinephrine) into systemic circulation for systemic effects on multiple organs (similarly to secretory neurones of the hypothalamus), and can also send paracrine signals.

Neurotransmitter

neurotransmittersexcitatory neurotransmitterneurotransmitter system
Dopamine, which acts as a neurotransmitter in the central nervous system, is largely produced in neuronal cell bodies in two areas of the brainstem: the ventral tegmental area and the substantia nigra, the latter of which contains neuromelanin-pigmented neurons.

Phenylalanine

PheL-phenylalaninephenylalanine metabolism
Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine.
The latter three are known as the catecholamines.

Tyrosine

Tyrtyrosine metabolismL-tyrosine
Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine.
Dopamine can then be converted into other catecholamines, such as norepinephrine (noradrenaline) and epinephrine (adrenaline).

Adrenal medulla

medullamedullary(medulla)
Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response. Catecholamines are produced mainly by the chromaffin cells of the adrenal medulla and the postganglionic fibers of the sympathetic nervous system. Extremely high levels of catecholamine can also be caused by neuroendocrine tumors in the adrenal medulla, a treatable condition known as pheochromocytoma.
The adrenal medulla is the principal site of the conversion of the amino acid tyrosine into the catecholamines; epinephrine, norepinephrine, and dopamine.

Amino acid

amino acidsresiduesresidue
Catecholamines are derived from the amino acid tyrosine, which is derived from dietary sources as well as synthesis from phenylalanine.

Tyrosine hydroxylase

THtyrosine 3-monooxygenasetyrosine
Catecholamine synthesis is inhibited by alpha-methyl-p-tyrosine (AMPT), which inhibits tyrosine hydroxylase.
Tyrosine hydroxylase catalyzes the rate limiting step in this synthesis of catecholamines.

Monoamine neurotransmitter

monoaminemonoaminesmonoamine neurotransmitters
A catecholamine (abbreviated CA) is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine.

Stimulant

stimulantspsychostimulantpsychostimulants
Various stimulant drugs (such as a number of substituted amphetamines) are catecholamine analogues.
Amphetamine, through activation of a trace amine receptor, increases biogenic amine and excitatory neurotransmitter activity in the brain, with its most pronounced effects targeting the catecholamine neurotransmitters norepinephrine and dopamine.

Catechol

pyrocatecholcatecholscatecholate
A catecholamine (abbreviated CA) is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine.
Catecholamines are biochemically significant phenethylamine hormones and neurotransmitters in which the phenyl group has a catechol skeleton structure.

Phenylethanolamine N-methyltransferase

phenylethanolamine ''N''-methyltransferasePNMTphenylethanolamine N-methyl transferase
Epinephrine is produced in small groups of neurons in the human brain which express its synthesizing enzyme, phenylethanolamine N-methyltransferase; these neurons project from a nucleus that is adjacent (ventrolateral) to the area postrema and from a nucleus in the dorsal region of the solitary tract.
It works by bringing the cofactor SAM and substrate together in close proximity, so that the reactive methyl group can be attacked by the primary amine of the norepinephrine molecule or another catecholamine substrate.

Homovanillic acid

HVAhomovanillic acid (HVA)
Dopamine catabolism leads to the production of homovanillic acid (HVA).
Homovanillic acid (HVA) is a major catecholamine metabolite that is produced by a consecutive action of monoamine oxidase and catechol-O-methyltransferase on dopamine.

Neuron

neuronsnerve cellsnerve cell
In neurons that use DA as the transmitter, the decarboxylation of L -DOPA to dopamine is the final step in formation of the transmitter; however, in those neurons using norepinephrine (noradrenaline) or epinephrine (adrenaline) as transmitters, the enzyme dopamine β-hydroxylase (DBH), which converts dopamine to yield norepinephrine, is also present.
Some neurons also contain pigment granules, such as neuromelanin (a brownish-black pigment that is byproduct of synthesis of catecholamines), and lipofuscin (a yellowish-brown pigment), both of which accumulate with age.

Vanillylmandelic acid

vanilmandelic acidvanillylmandelic acid (VMA)Vanillyl mandelic acid
The end product of epinephrine and norepinephrine is vanillylmandelic acid (VMA) which is excreted in the urine.
Vanillylmandelic acid (VMA) is a chemical intermediate in the synthesis of artificial vanilla flavorings and is an end-stage metabolite of the catecholamines (dopamine, epinephrine, and norepinephrine).

Pheochromocytoma

phaeochromocytomapheochromocytomasadrenal cancers
Extremely high levels of catecholamine can also be caused by neuroendocrine tumors in the adrenal medulla, a treatable condition known as pheochromocytoma.
They make, store, metabolize and usually but not always release catecholamines.

Sympathetic nervous system

sympatheticsympathetic nervesympathetic nerves
Catecholamines are produced mainly by the chromaffin cells of the adrenal medulla and the postganglionic fibers of the sympathetic nervous system.
Therefore, this response that acts primarily on the cardiovascular system is mediated directly via impulses transmitted through the sympathetic nervous system and indirectly via catecholamines secreted from the adrenal medulla.

Dopamine beta-hydroxylase

dopamine β-hydroxylaseDBHDopamine beta-monooxygenase
In neurons that use DA as the transmitter, the decarboxylation of L -DOPA to dopamine is the final step in formation of the transmitter; however, in those neurons using norepinephrine (noradrenaline) or epinephrine (adrenaline) as transmitters, the enzyme dopamine β-hydroxylase (DBH), which converts dopamine to yield norepinephrine, is also present.
DBH primarily contributes to catecholamine and trace amine biosynthesis.

Neuromelanin

Dopamine, which acts as a neurotransmitter in the central nervous system, is largely produced in neuronal cell bodies in two areas of the brainstem: the ventral tegmental area and the substantia nigra, the latter of which contains neuromelanin-pigmented neurons.
Neuromelanin biosynthesis is driven by excess cytosolic catecholamines not accumulated by synaptic vesicles.

Stress (biology)

stressenvironmental stressemotional stress
High catecholamine levels in blood are associated with stress, which can be induced from psychological reactions or environmental stressors such as elevated sound levels, intense light, or low blood sugar levels.
Stress, either severe, acute stress or chronic low-grade stress may induce abnormalities in three principal regulatory systems in the body: serotonin systems, catecholamine systems, and the hypothalamic-pituitary-adrenocortical axis.