[ nawr-ep-uh-nef-rin, -reen ]

  1. 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.

  2. Pharmacology. a commercial form of this substance used for emergency treatment of lowered blood pressure.

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Origin of norepinephrine

First recorded in 1940–45; nor- + epinephrine

Words Nearby norepinephrine Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use norepinephrine in a sentence

British Dictionary definitions for norepinephrine


/ (ˌnɔːrɛpɪˈnɛfrɪn, -riːn) /

  1. 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

Scientific definitions for norepinephrine


[ nôr′ĕp-ə-nĕfrĭn ]

  1. 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: C8H11NO3.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.