Definition of norepinephrine in US English:



  • A hormone that is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. It is also used as a drug to raise blood pressure.

    Chemical formula: (HO)₂C₆H₃CHOHCH₂NH₂

    Also called noradrenaline
    • ‘It inhibits serotonin, norepinephrine, and dopamine reuptake.’
    • ‘When you're under stress your adrenal glands produce the hormones cortisol, norepinephrine, and adrenaline.’
    • ‘Some scientists believe that the combination of the norepinephrine and endorphins help us to learn quickly and permanently.’
    • ‘Within the adrenal medulla dopamine is converted to norepinephrine and epinephrine.’
    • ‘As a natural response to a diseased heart, the body releases the hormone norepinephrine, causing the heart to beat up to five times faster than normal.’


1940s: from nor- + epinephrine.