norepinephrine

American

[nawr-ep-uh-nef-rin, -reen] / ˌnɔr ɛp əˈnɛf rɪn, -rin /

noun

Also called noradrenaline. Physiology. a neurotransmitter, released by adrenergic nerve terminals in the autonomic and possibly the central nervous system, that has such effects as constricting blood vessels, raising blood pressure, and dilating bronchi.
Pharmacology. a commercial form of this substance used for emergency treatment of lowered blood pressure.

norepinephrine British

/ ˌnɔːrɛpɪˈnɛfrɪn, -riːn /

noun

the US name for noradrenaline

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

norepinephrine Scientific

/ nôr′ĕp-ə-nĕf′rĭn /

A substance that acts both as a neurotransmitter and hormone, secreted in the central nervous system, at the nerve endings of the sympathetic nervous system, and by the adrenal gland. Norepinephrine is similar to epinephrine in its physiological effects but acts to regulate regular physiologic activity rather than being released in response to stress. Also called noradrenaline. Chemical formula: C ₈ H ₁₁ NO ₃ .

Etymology

Origin of norepinephrine

First recorded in 1940–45; nor- + epinephrine

Compare meaning

How does norepinephrine compare to similar and commonly confused words? Explore the most common comparisons:

epinephrine vs. norepinephrine

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Most current antidepressants work by targeting brain chemicals such as serotonin, dopamine, and norepinephrine.

From Science Daily • May 28, 2026

Shortly after administration, levels of dopamine and its precursor levodopa increased, along with norepinephrine and its metabolite normetanephrine in the locus coeruleus-noradrenaline network.

From Science Daily • Feb. 7, 2026

He began to explore the role of pharmacology in treating depression, and in 1965 published a seminal paper positing that depression arose due to low levels of certain neurochemicals, highlighting the role of one, norepinephrine.

From Salon • May 23, 2025

Beta-blockers work by blocking the action of norepinephrine, a neurotransmitter and hormone involved in the "fight or flight" response.

From Science Daily • Dec. 2, 2024

The pharmacological market is dominated by two classes of drugs known as selective serotonin reuptake inhibitors and serotonin and norepinephrine reuptake inhibitors.

From Slate • Aug. 20, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023