norepinephrine

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Related to noradrenergic: Noradrenergic system

norepinephrine

(nôr'ĕpīnĕf`rən), a neurotransmitterneurotransmitter,
chemical that transmits information across the junction (synapse) that separates one nerve cell (neuron) from another nerve cell or a muscle. Neurotransmitters are stored in the nerve cell's bulbous end (axon).
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 in the catecholaminecatecholamine
, any of several compounds occurring naturally in the body that serve as hormones or as neurotransmitters in the sympathetic nervous system. The catecholamines include such compounds as epinephrine, or adrenaline, norepinephrine, and dopamine.
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 family that mediates chemical communication in the sympathetic nervous system, a branch of the autonomic nervous system. Like other neurotransmitters, it is released at synaptic nerve endings to transmit the signal from a nerve cell to other cells. Norepinephrine is almost identical in structure to epinephrineepinephrine
, hormone important to the body's metabolism, also known as adrenaline. Epinephrine, a catecholamine, together with norepinephrine, is secreted principally by the medulla of the adrenal gland.
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, which is released into the bloodstream from the adrenal medulla under sympathetic activation. The sympathetic nervous system functions in response to short-term stress; hence norepinephrine and epinephrine increase the heart rate as well as blood pressure. Other actions of norepinephrine include increased glycogenolysis (the conversion of glycogenglycogen
, starchlike polysaccharide (see carbohydrate) that is found in the liver and muscles of humans and the higher animals and in the cells of the lower animals. Chemically it is a highly branched condensation polymer of glucose; it is readily hydrolyzed to glucose.
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 to glucoseglucose,
 dextrose,
or grape sugar,
monosaccharide sugar with the empirical formula C6H12O6 . This carbohydrate occurs in the sap of most plants and in the juice of grapes and other fruits.
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) in the liver, increased lipolysis (the conversion of fats to fatty acids; see fats and oilsfats and oils,
group of organic substances that form an important part of the diet and also are useful in many industries. The fats are usually solid, the oils generally liquid at ordinary room temperatures.
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) in adipose (fat) tissue, and relaxation of bronchial smooth muscle to open up the air passages to the lungs. All of these actions represent a mobilization of the body's resources in order to meet the stressful challenge—such a response is often termed the "flight or fight" syndrome.

Norepinephrine

 

(also noradrenaline, arterenol, 3,4-dihydroxyphenylethanolamine), a biologically active catecholamine. Norepinephrine has the following structure:

In animals and man, norepinephrine is in part produced by the chromaffin cells of the adrenal medulla, but it is mostly secreted by the adrenergic nerve elements of the sympathetic nervous system, where it serves as a chemical transmitter, or mediator substance, in nerve excitation. Judging by its action on the heart, blood vessels, smooth muscles, and carbohydrate metabolism, norepinephrine possesses the properties of hormones and is similar to its N-methyl derivative—adrenaline. The level of norepinephrine in the blood, organs, and excretions of the body is an indicator of the tone and reactivity of the sympathetic nervous system.

Norepinephrine can be produced synthetically. It is used in medicine to treat such conditions as low blood pressure, collapse, shock, and hemorrhage.

norepinephrine

[‚nȯr·ep·ə′ne·frən]
(biochemistry)
C8H11O3N A hormone produced by chromaffin cells of the adrenal medulla; acts as a vasoconstrictor and mediates transmission of sympathetic nerve impulses. Also known as noradrenaline.
References in periodicals archive ?
Gao, "New perspectives on catecholaminergic regulation of executive circuits: evidence for independent modulation of prefrontal functions by midbrain dopaminergic and noradrenergic neurons," Frontiers in Neural Circuits, vol.
Pertovaara, "Noradrenergic pain modulation," Progress in Neurobiology, vol.
The noradrenergic system has been identified as one of the important regulatory systems for the hypothalamicpituitary-adrenal axis, acting mainly on the release of corticotropin releasing factor in neurons in the paraventricular nucleus (PVN) of the hypothalamus (32).
It has been observed that MMC [1-20 mg/mL; equivalent to scopoletin (18.95-379 [micro]g/mL) and rutin (1.66-33.2 [micro]g/mL)] dose-dependently decrease the slope as well as maxima of the agonists (DA/NA) curves (Figures 5(a), 5(b), 6(a), and 6(b)) and suggested that the antagonistic effect of MMC (<40 mg/mL) on dopaminergic and noradrenergic system might be irreversible.
The mechanism of action of bupropion is not known but may possibly be related to relatively weak effects on noradrenergic, dopaminergic, and serotonergic systems., Bupropion is not associated with the anticholinergic, antihistaminergic, or cardiac effects of the TCAs or venlafaxine.
(6) The ability to impact pain modulation would, therefore, depend on the degree to which an antidepressant capitalizes on both noradrenergic and serotonergic neurotransmission.
"We should also be able to use indirect strategies to reduce noradrenergic overactivity: GABA agents like benzodiazepines, alcohol, and gabapentin oppose noradrenaline action in the amygdala.
Another target for antidepressant activity is noradrenergic system.[26] Depressed individuals were found to have increased levels of [[alpha].sub.1]-adrenoreceptor in the prefrontal cortex,[27] downregulation of [[alpha].sub.2] receptors,[28] and reduced levels of monoamines (NA, DA, and 5HT) in the cortical and limbic areas.
Noradrenergic and locus coeruleus modulation of the perforant path-evoked potential in rat dentate gyrus supports a role for the locus coeruleus in attentional and memorial processes.
In Pharmacotherapy for Co-Occurring Alcohol Use Disorder and Post-Traumatic Stress Disorder: Targeting the Opioidergic, Noradrenergic, Serotonergic, and GABAergic/Glutamatergic Systems, Verplaetse and colleagues report on pharmacotherapies for co-occurring AUD and PTSD.
Sympathetic neurons originate from trunk neural crest cells that arrest their migration upon arrival at the dorsal aorta and begin to express the catecholaminergic and noradrenergic biosynthetic enzymes tyrosine hydroxylase (TH) and dopamine betahydroxylase (DBH), respectively (Figures 1(a) and 1(b)).