norepinephrine


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Related to norepinephrine: dopamine, serotonin

norepinephrine

 [nor″ep-ĭ-nef´rin]
a catecholamine that is the neurotransmitter of most sympathetic postganglionic neurons and also of certain tracts in the central nervous system. It is also a neurohormone stored in the chromaffin granules of the adrenal medulla and released in response to sympathetic stimulation, primarily in response to hypotension. It produces vasoconstriction, an increase in heart rate, and elevation of blood pressure. It is administered intravenously in the form of the bitartrate salt as a vasopressor to restore blood pressure in certain cases of acute hypotension and to improve cardiac function during decompensation associated with congestive heart failure or cardiovascular surgery. Called also noradrenaline.

nor·ep·i·neph·rine (NE),

(nōr'ep-i-nef'rin),
A catecholamine hormone the natural form of which is d, although the l form has some activity; the base is considered to be the postganglionic adrenergic mediator, acting on α and β receptors; it is stored in chromaffin granules in the adrenal medulla in much smaller amounts than epinephrine and secreted in response to hypotension and physical stress; in contrast to epinephrine it has little effect on bronchial smooth muscle, metabolic processes, and cardiac output, but has strong vasoconstrictive effects and is used pharmacologically as a vasopressor, primarily as the bitartrate salt.

norepinephrine

/nor·epi·neph·rine/ (-ep-ĭ-nef´rin) a catecholamine, which is the principal neurotransmitter of postganglionic adrenergic neurons, having predominant α-adrenergic activity; also secreted by the adrenal medulla in response to splanchnic stimulation, being released predominantly in response to hypotension. It is a powerful vasopressor and is used, in the form of the bitartrate salt, to restore the blood pressure in certain cases of acute hypotension and to improve cardiac function during decompensation associated with congestive heart failure or cardiovascular surgery.

norepinephrine

(nôr′ĕp-ə-nĕf′rĭn)
n.
A substance, C8H11NO3, both a hormone and neurotransmitter, that is secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system and causes vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called noradrenaline.

norepinephrine (NE)

[nôr′epinef′rin]
an adrenergic hormone (catecholamine) that acts to increase blood pressure by vasoconstriction but does not affect cardiac output. It is synthesized by the adrenal medulla, the peripheral sympathetic nerves, and the central nervous system. It is available as a drug, levarterenol, which is used to maintain the blood pressure in acute hypotension secondary to trauma, heart disease, or vascular collapse.

nor·ep·i·neph·rine

(nōr'ep-i-nef'rin)
A catecholamine hormone, acting on α- and β-receptors; it is stored in chromaffin granules in the medulla of suprarenal gland in much smaller amounts than epinephrine and secreted in response to hypotension and physical stress; used pharmacologically as a vasopressor.
Synonym(s): noradrenaline.

Norepinephrine

Norepinephrine is a hormone secreted by certain nerve endings of the sympathetic nervous system, and by the medulla (center) of the adrenal glands. Its primary function is to help maintain a constant blood pressure by stimulating certain blood vessels to constrict when the blood pressure falls below normal.

norepinephrine

; noradrenaline postganglionic neurotransmitter (catecholamine hormone); has similar excitatory action to adrenaline but little/no inhibitory action (see Table 1)
Table 1: Effects of stimulation of alpha, beta and dopamine receptors
ReceptorActionStimulating drug
Alpha-1 (α1); postsynapticVasoconstriction; positive inotropism; antidiuresisAdrenaline +
Noradrenaline +++
Alpha-2 (α2); presynapticVasodilatation; inhibition of noradrenaline releaseAdrenaline +
Noradrenaline +++
Dopamine +
Alpha-2 (α2); postsynapticConstriction of coronary arteries; promotion of salt and water excretionAdrenaline +
Noradrenaline +++
Dopamine +
Beta-1 (β1); postsynapticPositive inotropism; chronotropism; renin releaseAdrenaline ++
Noradrenaline ++
Isoprenaline ++
Dopamine +
Beta-2 (β2); presynapticNoradrenaline release accelerated; positive inotropism; chronotropismAdrenaline +
Isoprenaline +++
Beta-2 (β2); postsynapticVasodilatation; relaxation of bronchial smooth muscleAdrenaline +
Isoprenaline +++
Dopamine1; postsynapticVasodilatation; diuresisDopamine ++
Dopamine1; presynapticInhibits noradrenaline releaseDopamine +

Plus signs indicate degree of effect.

norepinephrine (nōrˈ·ep·i·nefˑ·rin),

n a neurotransmitter released by the adrenal gland; part of the fight-or-flight response and also directly increases heart rate, blood pressure, energy release from fat, and muscle readiness.

noradrenaline (norepinephrine)

A neurohumoral transmitter for most postganglionic sympathetic fibres. It is produced with adrenaline (epinephrine) in the adrenal medulla. It is a powerful excitator of α-adrenergic receptors. See adrenaline (epinephrine); adrenergic receptors; mydriatic; neurotransmitter.

nor·ep·i·neph·rine

(nōr'ep-i-nef'rin)
Catecholamine hormone with strong vasoconstrictive effects; used pharmacologically as a vasopressor, primarily as the bitartrate salt.

norepinephrine (nôr´epinef´rin),

n the neurohormonal transmitter for neuroeffector junctions of adrenergic nerve fibers. Its official drug name in the United States is levarterenol. See also levarterenol.

norepinephrine

a catecholamine which is the neurotransmitter of most sympathetic postganglionic neurons and also of certain tracts in the central nervous system. It is also a neurohormone stored in the chromaffin granules of the adrenal medulla and released in response to sympathetic stimulation, primarily in response to hypotension. It produces vasoconstriction, an increase in heart rate, and elevation of blood pressure. It is used as a vasopressor, administered by intravenous infusion, to restore blood pressure in certain cases of acute hypotension and as an adjunct in the treatment of cardiac arrest. Called also norepinephrine.
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The fact that PKC-alpha is activated through the release of norepinephrine is an important discovery.
We do not have a precise explanation for the delayed increase in norepinephriner but the important point is that after long-term treatment with a non-selective MAO inhibitor, there is an increase in transmission, mainly as a result of increased availability of norepinephrine.
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The compounds identified to date encompass various combinations of amine-transporter inhibition profiles that act selectively or in combination to increase brain levels of serotonin, norepinephrine or dopamine.