One of two catecholamine hormones (epinephrine is the other) secreted by the adrenal glands, as well as at nerve endings, as a neurotransmitter. It resembles adrenaline chemically and in its actions on the body, which mimic sympathetic nervous system stimulation. It constricts most blood vessels and is given for certain types of shock. Norepinephrine is formed from tyrosine and converted to epinephrine. It was discovered by Ulf von Euler-Chelpin (1905–83) in the mid-1940s.


norepinephrine or noradrenaline

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