from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A substance, C8H11NO3, both a hormone and neurotransmitter, secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system to cause vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called noradrenaline.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A neurotransmitter found in the locus coeruleus which is synthesized from dopamine.
from the GNU version of the Collaborative International Dictionary of English
- n. A hormone (C8H11NO3) secreted by the adrenal medulla; it also serves as a neurotransmitter, released at synapses; called also noradrenaline. Chemically it is 2-amino-1-(3,4-dihydroxyphenyl)ethanol. It is a precursor of epinephrine in the body.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a catecholamine precursor of epinephrine that is secreted by the adrenal medulla and also released at synapses
From nor- + epinephrine. (Wiktionary)